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Simple Summary: This paper discusses the challenges in treating high-grade gliomas, particularly glioblastomas, which are aggressive brain tumors with high recurrence rates. It highlights the limitations of current diagnostic imaging modalities, such as gadolinium-based MRI, in accurately detecting tumor recurrence versus treatment-related changes. The paper explores the emerging role of positron emission tomography (PET) in glioma imaging, especially with the use of radiotracers like PSMA, which can help differentiate between tumor recurrence and treatment effects. Furthermore, the paper reviews the concept of theranostics, which integrates diagnostics and therapy, offering a targeted approach to glioma treatment. It discusses various radioligands, including PSMA, 213Bi-DOTA-substance P, 90Y-DOTATOC, 18F-FDOPA, p-[131I]-iodo-L-phenylalanine, and 18F-GE-180, which have shown promise in diagnosing and treating recurrent gliomas. The potential of theranostics to minimize systemic toxicity and improve treatment outcomes is emphasized. Moreover, the paper highlights the importance of considering quality-of-life (QOL) outcomes in glioma patients, as conventional treatments often have significant impacts on patients' well-being. While theranostics offers a personalized approach to treatment, its potential promise for functional outcomes and QOL needs further investigation. The paper suggests that future research should focus on understanding the broader implications of theranostics on patient well-being, incorporating factors such as demographics, tumor characteristics, and treatment-related effects into QOL assessments. Overall, the paper underscores the potential of theranostics to revolutionize glioma management and improve patient outcomes in the future. Gliomas represent the most commonly occurring tumors in the central nervous system and account for approximately 80% of all malignant primary brain tumors. With a high malignancy and recurrence risk, the prognosis of high-grade gliomas is poor, with a mean survival time of 12–18 months. While contrast-enhanced MRI serves as the standard diagnostic imaging modality for gliomas, it faces limitations in the evaluation of recurrent gliomas, failing to distinguish between treatment-related changes and tumor progression, and offers no direct therapeutic options. Recent advances in imaging modalities have attempted to address some of these limitations, including positron emission tomography (PET), which has demonstrated success in delineating tumor margins and guiding the treatment of recurrent gliomas. Additionally, with the advent of theranostics in nuclear medicine, PET tracers, when combined with therapeutic agents, have also evolved beyond a purely diagnostic modality, serving both diagnostic and therapeutic roles. This review will discuss the growing involvement of theranostics in diagnosing and treating recurrent gliomas and address the associated impact on quality of life and functional recovery. [ABSTRACT FROM AUTHOR]

Simple Summary: This review explores the emerging area of the therapeutic use of chimeric antigen receptor (CAR)-T cells in nervous tissue tumors. Through a detailed analysis of the existing literature, this paper highlights the most recent applications of CAR-T cells to the therapy of pediatric and adult nervous system neoplasia. Furthermore, it discusses the potential mechanisms underlying sensitivity or resistance to CAR-T cell-based therapies. Overall, this review underscores the importance of CAR-T cell therapies to the treatment of some nervous system tumors. Chimeric antigen receptor T cells (CAR-Ts) have shown a remarkable efficacy in hematological malignancies but limited responses in solid tumors. Among solid tumors, CAR-T cell therapy has been particularly explored in brain tumors. CAR-T cells have shown a limited clinical efficacy in various types of brain tumors due to several factors that have hampered their activity, including tumor antigen heterogeneity, the limited access of CAR-T cells to brain tumor cells, limited CAR-T cell trafficking and in vivo persistence and the presence of a highly immunosuppressive tumor microenvironment. Despite these considerations, some recent studies have shown promising antitumor activity of GD2-CAR-T cells on diffuse midline gliomas and neuroblastomas and of CARv3-TEAM-E cells in glioblastomas. However, strategies are required to improve the effect of CAR-T cells in brain tumors, including advanced CAR-T cell design with multiple antigenic targeting and incorporation of combination therapies. [ABSTRACT FROM AUTHOR]

Simple Summary: Currently, contrast-enhancing gliomas FLAIRectomies or supramarginal gliresections are gaining momentum. This paper presents a semiquantitative analysis of FET uptake in biopsy targets inside and outside glioma masses based on PET/MR images. An exact threshold to differentiate glioma and astrogliosis within FLAIR using dual-timepoint PET acquisition and referring to various anatomical structures is a major strength of this study. Doing so paves the way for an optimized PET protocol to enable precise and reproducible FET-PET quantification for glioma mapping in clinical trials and practice. Accurately defining glioma infiltration is crucial for optimizing radiotherapy and surgery, but glioma infiltration is heterogeneous and MRI imperfectly defines the tumor extent. Currently, it is impossible to determine the tumor infiltration gradient within a FLAIR signal. O-(2-[18F]fluoroethyl)-L-tyrosine (FET)-PET often reveals high-grade glioma infiltration beyond contrast-enhancing areas on MRI. Here, we studied FET uptake dynamics in tumor and normal brain structures by dual-timepoint (10 min and 40–60 min post-injection) acquisition to optimize analysis protocols for defining glioma infiltration. Over 300 serial stereotactic biopsies from 23 patients (mean age 47, 12 female/11 male) of diffuse contrast-enhancing gliomas were taken from areas inside and outside contrast enhancement or outside the FET hotspot but inside FLAIR. The final diagnosis was G4 in 11, grade 3 in 10, and grade 2 in 2 patients. The target-to-background (TBRs) ratios and standardized uptake values (SUVs) were calculated in areas used for biopsy planning and in background structures. The optimal method and threshold values were determined to find a preferred strategy for defining glioma infiltration. Standard thresholding (1.6× uptake in the contralateral brain) in standard acquisition PET images differentiated a tumor of any grade from astrogliosis, although the uptake in astrogliosis and grade 2 glioma was similar. Analyzing an optimal strategy for infiltration volume definition astrogliosis could be accurately differentiated from tumor samples using a choroid plexus as a background. Early acquisition improved the AUC in many cases, especially within FLAIR, from 56% to 90% sensitivity and 41% to 61% specificity (standard TBR 1.6 vs. early TBR plexus). The current FET-PET evaluation protocols for contrast-enhancing gliomas are limited, especially at the tumor border where grade 2 tumor and astrogliosis have similar uptake, but using choroid plexus uptake in early acquisitions as a background, we can precisely define a tumor within FLAIR that was outside of the scope of current FET-PET protocols. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is an aggressive brain cancer. Despite progress made in cancer research, patients diagnosed with glioblastomas continue to have a poor rate of survival. Lipidomics is a field of study that seeks to comprehend the structure and function of lipids, otherwise known as fats. Glioblastomas have demonstrated imbalance in lipids, and, therefore, lipidomics shows promise as an avenue to better understand glioblastomas. This paper reviews the literature on lipidomics in glioblastomas and suggests future directions for lipidomic research into the diagnosis, prognosis, and treatment of glioblastomas. Glioblastoma is the most aggressive primary brain malignancy in adults, and has a survival duration of approximately 15 months. First line treatment involves surgical resection, chemotherapy, and radiation, but despite the multi-pronged approach and advances in cancer research, glioblastoma remains devastating with a high mortality rate. Lipidomics is an emerging discipline that studies lipid pathways and characteristics, and is a promising field to understand biochemical mechanisms. In glioblastoma, disrupted lipid homeostasis has been reported in the literature. A thorough understanding of serum lipidomics may offer ways to better understand glioblastoma biomarkers, prognosis, and treatment options. Here, we review the literature, offering future directions for lipidomics research in glioblastomas. [ABSTRACT FROM AUTHOR]

Simple Summary: The new trends in the research on glioblastomas (GBMs) are focusing on understanding the crosstalk between proper neoplastic tissue and its microenvironment. Against this background, the extracellular matrix (ECM) has been classically linked to a purely structural role. However, it has recently become clear that it actively shapes the functional responses of cells to their environment as well. While many components of the ECM have been isolated and characterized, its modifications in the specific setting of GBMs have only been recently explored in the literature. The aim of this paper is to provide a systematic review on the topic and to assess the ECM's role in shaping tumoral development. Background and aim: While many components of the ECM have been isolated and characterized, its modifications in the specific setting of GBMs have only been recently explored in the literature. The aim of this paper is to provide a systematic review on the topic and to assess the ECM's role in shaping tumoral development. Methods: An online literature search was launched on PubMed/Medline and Scopus using the research string "((Extracellular matrix OR ECM OR matrix receptor OR matrix proteome) AND (glioblastoma OR GBM) AND (tumor invasion OR tumor infiltration))", and a systematic review was conducted in accordance with the PRISMA-P guidelines. Results: The search of the literature yielded a total of 693 results. The duplicate records were then removed (n = 13), and the records were excluded via a title and abstract screening; 137 studies were found to be relevant to our research question and were assessed for eligibility. Upon a full-text review, 59 articles were finally included and were summarized as follows based on their focus: (1) proteoglycans; (2) fibrillary proteins, which were further subdivided into the three subcategories of collagen, fibronectin, and laminins; (3) glycoproteins; (4) degradative enzymes; (5) physical forces; (6) and glioma cell and microglia migratory and infiltrative patterns. Conclusions: Our systematic review demonstrates that the ECM should not be regarded anymore as a passive scaffold statically contributing to mechanical support in normal and pathological brain tissue but as an active player in tumor-related activity. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma (GBM) generally recurs locally with a dismal median survival of <18 months. Combining thermal therapy with radiation therapy enhances radiation response and improves clinical outcomes. This study evaluates a thermobrachytherapy balloon implant intended for the simultaneous heat and radiation treatment of tumor resection cavities. The data demonstrate that our prototype implant produces spherically symmetric heat and radiation dose distributions around the balloon, while the in vivo experiments confirm our ability to heat ≥40 °C at a 5 mm distance from the balloon surface in highly perfused pig brain tissue. The device is now ready for the finalization of regulatory approvals in anticipation of early-stage clinical investigation. Previous work has reported the design of a novel thermobrachytherapy (TBT) balloon implant to deliver magnetic nanoparticle (MNP) hyperthermia and high-dose-rate (HDR) brachytherapy simultaneously after brain tumor resection, thereby maximizing their synergistic effect. This paper presents an evaluation of the robustness of the balloon device, compatibility of its heat and radiation delivery components, as well as thermal and radiation dosimetry of the TBT balloon. TBT balloon devices with 1 and 3 cm diameter were evaluated when placed in an external magnetic field with a maximal strength of 8.1 kA/m at 133 kHz. The MNP solution (nanofluid) in the balloon absorbs energy, thereby generating heat, while an HDR source travels to the center of the balloon via a catheter to deliver the radiation dose. A 3D-printed human skull model was filled with brain-tissue-equivalent gel for in-phantom heating and radiation measurements around four 3 cm balloons. For the in vivo experiments, a 1 cm diameter balloon was surgically implanted in the brains of three living pigs (40–50 kg). The durability and robustness of TBT balloon implants, as well as the compatibility of their heat and radiation delivery components, were demonstrated in laboratory studies. The presence of the nanofluid, magnetic field, and heating up to 77 °C did not affect the radiation dose significantly. Thermal mapping and 2D infrared images demonstrated spherically symmetric heating in phantom as well as in brain tissue. In vivo pig experiments showed the ability to heat well-perfused brain tissue to hyperthermic levels (≥40 °C) at a 5 mm distance from the 60 °C balloon surface. [ABSTRACT FROM AUTHOR]

Simple Summary: This paper describes a new MR imaging technique known as downfield MR spectroscopic imaging (DF-MRSI) that has only recently been shown to be possible in the human brain on commonly available 3 Tesla MRI scanners. This is the first application of this methodology to human brain tumors. Purpose: To investigate the use of 3D downfield proton magnetic resonance spectroscopic imaging (DF-MRSI) for evaluation of tumor recurrence in patients with glioblastoma (GBM). Methods: Seven patients (4F, age range 44–65 and mean ± standard deviation 59.3 ± 7.5 years) with previously treated GBM were scanned using a recently developed 3D DF-MRSI sequence at 3T. Short TE 3D DF-MRSI and water reference 3D-MRSI scans were collected with a nominal spatial resolution of 0.7 cm3. DF volume data in eight slices covered 12 cm of brain in the cranio-caudal axis. Data were analyzed using the 'LCModel' program and a basis set containing nine peaks ranging in frequency between 6.83 to 8.49 ppm. The DF8.18 (assigned to amides) and DF7.90 peaks were selected for the creation of metabolic images and statistical analysis. Longitudinal MR images and clinical history were used to classify brain lesions as either recurrent tumor or treatment effect, which may include necrosis. DF-MRSI data were compared between lesion groups (recurrent tumor, treatment effect) and normal-appearing brain. Results: Of the seven brain tumor patients, two were classified as having recurrent tumor and the rest were classified as treatment effect. Amide metabolite levels from recurrent tumor regions were significantly (p < 0.05) higher compared to both normal-appearing brain and treatment effect regions. Amide levels in lesion voxels classified as treatment effect were significantly lower than normal brain. Conclusions: 3D DF-MRSI in human brain tumors at 3T is feasible and was well tolerated by all patients enrolled in this preliminary study. Amide levels measured by 3D DF-MRSI were significantly different between treatment effect and tumor regrowth. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is the most common malignant brain tumor associated with a poor prognosis, with a median survival of 14 months. Despite initial treatment with surgery, radiotherapy, and chemotherapy, recurrence is the usual situation. Controversy remains over the best treatment strategy for recurrent disease, and there is no standard of treatment in this situation. Different forms of treatment have been addressed, including a surgical procedure or radiotherapy, systemic treatment with chemotherapy or targeted drugs, and different immunotherapy strategies. Knowledge of the data from these studies allows for improved decision-making in this clinical situation. Glioblastoma is a disease with a poor prognosis. Multiple efforts have been made to improve the long-term outcome, but the 5-year survival rate is still 5–10%. Recurrence of the disease is the usual way of progression. In this situation, there is no standard treatment. Different treatment options can be considered. Among them would be reoperation or reirradiation. There are different studies that have assessed the impact on survival and the selection of patients who may benefit most from these strategies. Chemotherapy treatments have also been considered in several studies, mainly with alkylating agents, with data mostly from phase II studies. On the other hand, multiple studies have been carried out with target-directed treatments. Bevacizumab, a monoclonal antibody with anti-angiogenic activity, has demonstrated activity in several studies, and the FDA has approved it for this indication. Several other TKI drugs have been evaluated in this setting, but no clear benefit has been demonstrated. Immunotherapy treatments have been shown to be effective in other types of tumors, and several studies have evaluated their efficacy in this disease, both immune checkpoint inhibitors, oncolytic viruses, and vaccines. This paper reviews data from different studies that have evaluated the efficacy of different forms of relapsed glioblastoma. [ABSTRACT FROM AUTHOR]

Simple Summary: In this paper, we report on the inhibition of glioblastoma (GBM) cell growth and migration by the putative S1PR1 modulator ACT-2009905, using appropriate in vitro models. This work is based on our previously published finding that S1PR1 expression is strongly up-regulated in human glioblastoma samples and the fact that there is an association between S1PR1 with patients' survival times. We now show that pharmacological modulation by the putative S1PR1 modulator ACT-209905 inhibits GBM cell growth and migration. Furthermore, we investigated the influence of co-culture of GBM cells with THP-1 cells as a model for human monocytes, showing pro-tumoral effects and arguing for a complex interplay between GBM cells, immune cells and underlying signaling pathways. We believe that this manuscript fits the interests of the readership of the journal Cancers as it addresses the impact of alternative therapeutic options using ACT-209905 for improving GBM therapy. Glioblastoma (GBM) is still a deadly tumor due to its highly infiltrative growth behavior and its resistance to therapy. Evidence is accumulating that sphingosine-1-phosphate (S1P) acts as an important tumor-promoting molecule that is involved in the activation of the S1P receptor subtype 1 (S1PR1). Therefore, we investigated the effect of ACT-209905 (a putative S1PR1 modulator) on the growth of human (primary cells, LN-18) and murine (GL261) GBM cells. The viability and migration of GBM cells were both reduced by ACT-209905. Furthermore, co-culture with monocytic THP-1 cells or conditioned medium enhanced the viability and migration of GBM cells, suggesting that THP-1 cells secrete factors which stimulate GBM cell growth. ACT-209905 inhibited the THP-1-induced enhancement of GBM cell growth and migration. Immunoblot analyses showed that ACT-209905 reduced the activation of growth-promoting kinases (p38, AKT1 and ERK1/2), whereas THP-1 cells and conditioned medium caused an activation of these kinases. In addition, ACT-209905 diminished the surface expression of pro-migratory molecules and reduced CD62P-positive GBM cells. In contrast, THP-1 cells increased the ICAM-1 and P-Selectin content of GBM cells which was reversed by ACT-209905. In conclusion, our study suggests the role of S1PR1 signaling in the growth of GBM cells and gives a partial explanation for the pro-tumorigenic effects that macrophages might have on GBM cells. [ABSTRACT FROM AUTHOR]

Simple Summary: We present eight core attributes of cancer growth that we must address for a more effective treatment than we currently have. To do this we outline why a regimen simultaneously using many different drugs will be needed. At our current state of knowledge, even adding two or three drugs will not counter all the growth attributes of a currently incurable cancer. We show in this paper, the details of how an example six drug regimen, when added alongside of current traditional treatments, might inhibit enough of the eight core growth driving elements to allow those standard treatments to be more effective. We further show how medicines from general medical practice used to treat pain, fungal infections, psychosis, leprosy and other non-cancer related illnesses can be repurposed to block cancer cells' survival pathways and growth drives. In part one of this two-part paper, we present eight principles that we believe must be considered for more effective treatment of the currently incurable cancers. These are addressed by multidrug adjunctive cancer treatment (MDACT), which uses multiple repurposed non-oncology drugs, not primarily to kill malignant cells, but rather to reduce the malignant cells' growth drives. Previous multidrug regimens have used MDACT principles, e.g., the CUSP9v3 glioblastoma treatment. MDACT is an amalgam of (1) the principle that to be effective in stopping a chain of events leading to an undesired outcome, one must break more than one link; (2) the principle of Palmer et al. of achieving fractional cancer cell killing via multiple drugs with independent mechanisms of action; (3) the principle of shaping versus decisive operations, both being required for successful cancer treatment; (4) an idea adapted from Chow et al., of using multiple cytotoxic medicines at low doses; (5) the idea behind CUSP9v3, using many non-oncology CNS-penetrant drugs from general medical practice, repurposed to block tumor survival paths; (6) the concept from chess that every move creates weaknesses and strengths; (7) the principle of mass—by adding force to a given effort, the chances of achieving the goal increase; and (8) the principle of blocking parallel signaling pathways. Part two gives an example MDACT regimen, gMDACT, which uses six repurposed drugs—celecoxib, dapsone, disulfiram, itraconazole, pyrimethamine, and telmisartan—to interfere with growth-driving elements common to cholangiocarcinoma, colon adenocarcinoma, glioblastoma, and non-small-cell lung cancer. gMDACT is another example of—not a replacement for—previous multidrug regimens already in clinical use, such as CUSP9v3. MDACT regimens are designed as adjuvants to be used with cytotoxic drugs. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is the most prevalent cerebral cancer in adults without proven therapy. Chimeric antigen receptor T cell treatment has demonstrated good clinical success in hematologic cancers. The application of chimeric antigen receptor T cell therapy to solid tumors, such as glioblastoma, is currently the subject of scientific investigation. The creation of chimeric antigen receptor T cells and its iterations are briefly described in this article. Specifically, this study addresses the obstacles and hurdles faced and glioblastoma targets studied in recent years. This review provides the reader with a comprehensive understanding of the current state of chimeric antigen receptor T cell therapy for glioblastoma and a clear understanding of each therapeutic target. Glioblastoma (GBM) is an aggressive primary brain tumor with a poor prognosis following conventional therapeutic interventions. Moreover, the blood–brain barrier (BBB) severely impedes the permeation of chemotherapy drugs, thereby reducing their efficacy. Consequently, it is essential to develop novel GBM treatment methods. A novel kind of pericyte immunotherapy known as chimeric antigen receptor T (CAR-T) cell treatment uses CAR-T cells to target and destroy tumor cells without the aid of the antigen with great specificity and in a manner that is not major histocompatibility complex (MHC)-restricted. It has emerged as one of the most promising therapy techniques with positive clinical outcomes in hematological cancers, particularly leukemia. Due to its efficacy in hematologic cancers, CAR-T cell therapy could potentially treat solid tumors, including GBM. On the other hand, CAR-T cell treatment has not been as therapeutically effective in treating GBM as it has in treating other hematologic malignancies. CAR-T cell treatments for GBM have several challenges. This paper reviewed the use of CAR-T cell therapy in hematologic tumors and the selection of targets, difficulties, and challenges in GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: The prognostic expectancies of patients affected by glioblastoma have remained almost unchanged during the last thirty years. Along with specific oncological research and surgical technical alternatives, corollary disciplines are requested to provide their contributions to improve patient management and outcomes. Technological improvements in radiology have led to the development of radiomics, a new discipline able to detect tumoral phenotypical features through the extraction and analysis of a large amount of data. Intuitively, the early foreseeing of glioma features may constitute a tremendous contribution to the management of patients. The present manuscript analyzes the pertinent literature regarding the current role of radiomics and its potentialities. Background: The fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), published in 2021, marks a step forward the future diagnostic approach to these neoplasms. Alongside this, radiomics has experienced rapid evolution over the last several years, allowing us to correlate tumor imaging heterogeneity with a wide range of tumor molecular and subcellular features. Radiomics is a translational field focused on decoding conventional imaging data to extrapolate the molecular and prognostic features of tumors such as gliomas. We herein analyze the state-of-the-art of radiomics applied to glioblastoma, with the goal to estimate its current clinical impact and potential perspectives in relation to well-rounded patient management, including the end-of-life stage. Methods: A literature review was performed on the PubMed, MEDLINE and Scopus databases using the following search items: "radiomics and glioma", "radiomics and glioblastoma", "radiomics and glioma and IDH", "radiomics and glioma and TERT promoter", "radiomics and glioma and EGFR", "radiomics and glioma and chromosome". Results: A total of 719 articles were screened. Further quantitative and qualitative analysis allowed us to finally include 11 papers. This analysis shows that radiomics is rapidly evolving towards a reliable tool. Conclusions: Further studies are necessary to adjust radiomics' potential to the newest molecular requirements pointed out by the 2021 WHO classification of CNS tumors. At a glance, its application in the clinical routine could be beneficial to achieve a timely diagnosis, especially for those patients not eligible for surgery and/or adjuvant therapies but still deserving palliative and supportive care. [ABSTRACT FROM AUTHOR]

Simple Summary: Despite the continuous development of treatment technology, glioblastoma remains a challenge for modern medicine. The standard of care remains a radical surgical resection combined with adjuvant radiotherapy and chemotherapy with temozolomide. However, the usage of these procedures is not associated with satisfactory treatment responses. Therefore, it is important to develop systemic therapies that support treatment and sometimes represent the only therapeutic option. Molecular targeted therapy and immunotherapy appear to be encouraging approaches. In recent years, a number of key metabolic points for the progression of glioblastoma have been identified. In this review, we presented the therapeutic targets that are currently under study for new clinical trials. The aim of our study was to present and analyze the up-to date literature describing the epidemiology, genetics, and histopathology of glioblastoma, as well as to compare treatment efficacy in patients treated with selected potential antitumor drugs. Glioblastoma is the most common histologic type of all gliomas and contributes to 57.3% of all cases. Despite the standard management based on surgical resection and radiotherapy, it is related to poor outcome, with a 5-year relative survival rate below 6.9%. In order to improve the overall outcome for patients, the new therapeutic strategies are needed. Herein, we describe the current state of knowledge on novel targeted therapies in glioblastoma. Based on recent studies, we compared treatment efficacy measured by overall survival and progression-free survival in patients treated with selected potential antitumor drugs. The results of the application of the analyzed inhibitors are highly variable despite the encouraging conclusions of previous preclinical studies. This paper focused on drugs that target major glioblastoma kinases. As far, the results of some BRAF inhibitors are favorable. Vemurafenib demonstrated a long-term efficacy in clinical trials while the combination of dabrafenib and trametinib improves PFS compared with both vemurafenib and dabrafenib alone. There is no evidence that any MEK inhibitor is effective in monotherapy. According to the current state of knowledge, BRAF and MEK inhibition are more advantageous than BRAF inhibitor monotherapy. Moreover, mTOR inhibitors (especially paxalisib) may be considered a particularly important group. Everolimus demonstrated a partial response in a significant proportion of patients when combined with bevacizumab, however its actual role in the treatment is unclear. Neither nintedanib nor pemigatinib were efficient in treatment of GBM. Among the anti-VEGF drugs, bevacizumab monotherapy was a well-tolerated option, significantly associated with anti-GBM activity in patients with recurrent GBM. The efficacy of aflibercept and pazopanib in monotherapy has not been demonstrated. Apatinib has been proven to be effective and tolerable by a single clinical trial, but more research is needed. Lenvatinib is under trial. Finally, promising results from a study with regorafenib may be confirmed by the ongoing randomized AGILE trial. The studies conducted so far have provided a relatively wide range of drugs, which are at least well tolerated and demonstrated some efficacy in the randomized clinical trials. The comprehensive understanding of the molecular biology of gliomas promises to further improve the treatment outcomes of patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma (GBM), a serious brain cancer, has poor treatment outcomes despite surgery, radiation, and chemotherapy. The blood–brain barrier (BBB) makes GBM-targeted drug delivery difficult. Recent studies have shown that nanomedicine delivery systems (NDDSs) can target GBM safely and effectively. In this review, we look at ways to overcome the BBB with NDDSs in preclinical studies, summarize the clinical progress, and discuss strategies to improve NDDSs and speed up their use in GBM treatment through clinical trials. Glioblastoma (GBM) is a prevalent type of malignancy within the central nervous system (CNS) that is associated with a poor prognosis. The standard treatment for GBM includes the surgical resection of the tumor, followed by radiotherapy and chemotherapy; yet, despite these interventions, overall treatment outcomes remain suboptimal. The blood–brain barrier (BBB), which plays a crucial role in maintaining the stability of brain tissue under normal physiological conditions of the CNS, also poses a significant obstacle to the effective delivery of therapeutic agents to GBMs. Recent preclinical studies have demonstrated that nanomedicine delivery systems (NDDSs) offer promising results, demonstrating both effective GBM targeting and safety, thereby presenting a potential solution for targeted drug delivery. In this review, we first explore the various strategies employed in preclinical studies to overcome the BBB for drug delivery. Subsequently, the results of the clinical translation of NDDSs are summarized, highlighting the progress made. Finally, we discuss potential strategies for advancing the development of NDDSs and accelerating their translational research through well-designed clinical trials in GBM therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: This study identified the risk factors of non-local recurrence of isocitrate dehydrogenase (IDH) wild-type glioblastoma, a highly aggressive brain tumor. We found that subventricular zone involvement significantly increased the risk of non-local recurrence, with the tumor contacting the trigone of the lateral ventricle and tending to develop subependymal dissemination. A meta-analysis of previous studies confirmed subventricular zone involvement and O-6-methylguanine DNA methyltransferase promoter methylation as risk factors for non-local recurrence. In contrast, ventricular opening via surgery did not increase the risk of non-local recurrence. These findings emphasize the need for tailored therapeutic strategies based on tumor location and molecular characteristics and provide valuable guidance for clinical decision-making in managing recurrent glioblastoma. Isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM) is a highly aggressive brain tumor with a high recurrence rate despite adjuvant treatment. This study aimed to evaluate the risk factors for non-local recurrence of GBM. In the present study, we analyzed 104 GBMs with a single lesion (non-multifocal or multicentric). Univariate analysis revealed that subventricular zone (SVZ) involvement was significantly associated with non-local recurrence (hazard ratio [HR]: 2.09 [1.08–4.05]). Tumors in contact with the trigone of the lateral ventricle tended to develop subependymal dissemination (p = 0.008). Ventricular opening via surgery did not increase the risk of non-local recurrence in patients with SVZ involvement (p = 0.190). A systematic review was performed to investigate the risk of non-local recurrence, and 21 studies were identified. A meta-analysis of previous studies confirmed SVZ involvement (odds ratio [OR]: 1.30 [1.01–1.67]) and O-6-methylguanine DNA methyltransferase promoter methylation (OR: 1.55 [1.09–2.20]) as significant risk factors for local recurrence. A time-dependent meta-analysis revealed a significant association between SVZ involvement and dissemination (HR: 1.69 [1.09–2.63]), while no significant association was found for distant recurrence (HR: 1.29 [0.74–2.27]). Understanding SVZ involvement and specific tumor locations associated with non-local recurrence provides critical insights for the management of GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is the most common and aggressive brain tumor in adults. Despite surgery, radiation, and chemotherapy, survival rates remain low, which emphasizes the urgent need for improved therapies. Current preclinical models use untreated tumors, which do not reflect the clinical scenario where patients already receive initial treatments. This review examines the effects of current treatments on the properties of recurrent tumors and evaluates preclinical models that incorporate these standard treatments to better mimic real patient conditions. Improving these models could help to identify more effective treatments, potentially leading to better outcomes for glioblastoma patients. Glioblastoma (GBM) presents a significant public health challenge as the deadliest and most common malignant brain tumor in adults. Despite standard-of-care treatment, which includes surgery, radiation, and chemotherapy, mortality rates are high, underscoring the critical need for advancing GBM therapy. Over the past two decades, numerous clinical trials have been performed, yet only a small fraction demonstrated a benefit, raising concerns about the predictability of current preclinical models. Traditionally, preclinical studies utilize treatment-naïve tumors, failing to model the clinical scenario where patients undergo standard-of-care treatment prior to recurrence. Recurrent GBM generally exhibits distinct molecular alterations influenced by treatment selection pressures. In this review, we discuss the impact of treatment—surgery, radiation, and chemotherapy—on GBM. We also provide a summary of treatments used in preclinical models, advocating for their integration to enhance the translation of novel strategies to improve therapeutic outcomes in GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: Aldehyde dehydrogenases of the subfamily 1A (ALDH1A) are enzymes involved in the synthesis of retinoic acid, which is necessary for the normal development and maintenance of epithelia, reproduction, memory, and immune function in adults. ALDH1A3, one of the enzymes that belong to the ALD1A subfamily, is also expressed at high levels in many human cancers like glioblastoma and mesothelioma. Herein, we review the role of ALDH1A3 in cancer, showing its relation with excessive proliferation, chemoresistance, and invasiveness. We also illustrate the current attempts to develop ALDH1A3-selective inhibitors and specific fluorescent probes that are potentially useful for cancer therapy and fluorescence-guided tumor resection. Aldehyde dehydrogenases of the subfamily 1A (ALDH1A) are enzymes necessary for the oxidation of all-trans or 9-cis retinal to retinoic acid (RA). Retinoic acid and its derivatives are important for normal development and maintenance of epithelia, reproduction, memory, and immune function in adults. Moreover, in recent years, it has been demonstrated that ALDH1A members are also expressed and functional in several human cancers where their role is not limited to the synthesis of RA. Here, we review the current knowledge about ALDH1A3, one of the 1A isoforms, in cancers with an emphasis on two of the deadliest tumors that affect humans: glioblastoma multiforme and mesothelioma. In both tumors, ALDH1A3 is considered a negative prognostic factor, and its level correlates with excessive proliferation, chemoresistance, and invasiveness. We also review the recent attempts to develop both ALDH1A3-selective inhibitors for cancer therapy and ALDH1A3-specific fluorescent substrates for fluorescence-guided tumor resection. [ABSTRACT FROM AUTHOR]

Simple Summary: Epithelial to mesenchymal transition (EMT) programme is central to various cancers, however how this programme applies to glioblastoma, an aggressive primary brain tumor, remains unknown. In particular, the cadherin switch which involves E-cadherin down-regulation and N-cadherin upregulation, is considered a marker of the EMT in epithelial cancers. Given the knowledge gap in the EMT and cadherins expression in GBM, we studied these proteins (E-, P- and N-cadherin) expression in a large cohort of GBM, extensively characterized with clinical, imaging, neuropathological, treatment and survival data. Our results propose that cadherin expression subgroups reflect an EMT-like programme in GBM and predict patient prognosis. Cadherins are cell–cell adhesion proteins which have been strongly implicated in cancer invasion, dissemination and metastasis capacity; thus, they are key players in the epithelial-to-mesenchymal transition (EMT) program. However, their role in glioblastoma (GBM), a primary central nervous system aggressive tumor, remains to be clarified. N-, E- and P-cadherin expression was analyzed on a large series of GBMs, characterized with clinical, imaging and neuropathological parameters, as well as with patients' survival data. In addition, cadherins' expression was studied in match-recurrent cases. Using TCGA data, cadherin expression profiles were also evaluated according to GBM transcription subtypes. N-cadherin expression was observed in 81.5% of GBM, followed by E-cadherin in 31% and P-cadherin in 20.8%. Upon tumor recurrence, P-cadherin was the only significantly upregulated cadherin compared with the primary tumor, being positive in 65.8% of the cases. Actually, P-cadherin gain was observed in 51.4% of matched primary-recurrent cases. Cadherins' co-expression was also explored. Interestingly, E- and N-cadherin co-expression identified a GBM subgroup with frequent epithelial differentiation and a significant survival benefit. On the other hand, subgroups with P-cadherin expression carried the worse prognosis. P- and N-cadherin co-expression correlated with the presence of a mesenchymal phenotype. Expressions of isolated P-cadherin or E- and P-cadherin co-expression were associated with imaging characteristics of aggressiveness, to highly heterogeneous tumors, an d to worse patient survival. Classical cadherins co-expression subgroups present consistent clinical, imaging, neuropathological and survival differences, which probably reflect different states of an EMT-like program in GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: Laser interstitial thermal therapy (LITT) is a minimally invasive, MRI-guided procedure that causes localized tissue hyperthermia. This results in the ablation of targeted cells and disruption of the blood–brain barrier. LITT offers an alternative treatment option to standard-of-care resection for glioma in addition to potentially enhancing drug delivery of adjuvant therapy. Here, we present the first meta-analysis since the fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5) to assess the current literature on the safety and efficacy of LITT in the upfront treatment of primary brain tumors. This study summarizes the current relevant literature on LITT and supports its viability as a treatment option for glioblastoma and IDH-mutant astrocytoma. Although primary studies have reported the safety and efficacy of LITT as a primary treatment in glioma, they are limited by sample sizes and institutional variation in stereotactic parameters such as temperature and laser power. The current literature has yet to provide pooled statistics on outcomes solely for primary brain tumors according to the 2021 WHO Classification of Tumors of the Central Nervous System (WHO CNS5). In the present study, we identify recent articles on primary CNS neoplasms treated with LITT without prior intervention, focusing on relationships with molecular profile, PFS, and OS. This meta-analysis includes the extraction of data from primary sources across four databases using the Covidence systematic review manager. The pooled data suggest LITT may be a safe primary management option with tumor ablation rates of 94.8% and 84.6% in IDH-wildtype glioblastoma multiforme (GBM) and IDH-mutant astrocytoma, respectively. For IDH-wildtype GBM, the pooled PFS and OS were 5.0 and 9.0 months, respectively. Similar to rates reported in the prior literature, the neurologic and non-neurologic complication rates for IDH-wildtype GBM were 10.3% and 4.8%, respectively. The neurologic and non-neurologic complication rates were somewhat higher in the IDH-mutant astrocytoma cohort at 33% and 8.3%, likely due to a smaller cohort size. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma (GBM) is the most aggressive primary brain tumor. Despite intensive management with surgery, radio-, and chemotherapy, prognosis remains bleak, with a median survival of 15 months. Recently, microglia, the resident immune cells of the brain, have emerged as a potential therapeutic target for treatment of GBM. However, precisely how microglia interact with GBM cells and may be exploited for novel immunotherapies is not well understood. Here, we discuss the role of microglia in the GBM tumor microenvironment (TME), focusing particularly on the pro- and anti-tumorigenic pathways involved. We first introduce microglia and their role in the normal brain environment. Next, we discuss the microglia-GBM crosstalk, delving into specific factors that mediate these interactions. Finally, we present a comprehensive discussion of suitable microglial pathways that can be targeted to modulate the immune response in the TME to halt tumor progression. We discuss this in the context of current and past clinical trials targeting microglia, summarizing both successes and failures, and highlight promising pathways that are yet to be explored, suggesting future directions for study. Glioblastoma (GBM) is one of the most aggressive and devastating primary brain tumors, with a median survival of 15 months following diagnosis. Despite the intense treatment regimen which routinely includes maximal safe neurosurgical resection followed by adjuvant radio- and chemotherapy, the disease remains uniformly fatal. The poor prognosis associated with GBM is multifactorial owing to factors such as increased proliferation, angiogenesis, and metabolic switching to glycolytic pathways. Critically, GBM-mediated local and systemic immunosuppression result in inadequate immune surveillance and ultimately, tumor-immune escape. Microglia—the resident macrophages of the central nervous system (CNS)—play crucial roles in mediating the local immune response in the brain. Depending on the specific pathological cues, microglia are activated into either a pro-inflammatory, neurotoxic phenotype, known as M1, or an anti-inflammatory, regenerative phenotype, known as M2. In either case, microglia secrete corresponding pro- or anti-inflammatory cytokines and chemokines that either promote or hinder tumor growth. Herein, we review the interplay between GBM cells and resident microglia with a focus on contemporary studies highlighting the effect of GBM on the subtypes of microglia expressed, the associated cytokines/chemokines secreted, and ultimately, their impact on tumor pathogenesis. Finally, we explore how understanding the intricacies of the tumor-immune landscape can inform novel immunotherapeutic strategies against this devastating disease. [ABSTRACT FROM AUTHOR]

Simple Summary: The exact cellular origin of glioblastoma (GBM) remains uncertain, with prevalent theories suggesting emergence from transformed endogenous stem cells. These cells likely play pivotal roles in tumor initiation and progression. The impact of proximity of GBM to the brain's neurogenic zones on patient survival remains a lingering question. Our study investigated tumor infiltration into the subventricular zone (SVZ), the subgranular zone (SGZ) and the cortex alongside clinical variables, such as KPS score, multifocality and selected molecular markers. Utilizing a fully automated processing and segmentation pipeline, we objectively quantified these relationships in 177 IDH wild-type glioblastomas. Our findings support prior research indicating SVZ proximity as a predictor for poor survival, while SGZ proximity showed no significant impact. We also established new survival thresholds based on tumor mass fractions and minimal distances. Contrary to previous studies, we found no significant correlations between SVZ contact and multifocal growth pattern or MGMT promoter methylation. So far, the cellular origin of glioblastoma (GBM) needs to be determined, with prevalent theories suggesting emergence from transformed endogenous stem cells. Adult neurogenesis primarily occurs in two brain regions: the subventricular zone (SVZ) and the subgranular zone (SGZ) of the hippocampal dentate gyrus. Whether the proximity of GBM to these neurogenic niches affects patient outcome remains uncertain. Previous studies often rely on subjective assessments, limiting the reliability of those results. In this study, we assessed the impact of GBM's relationship with the cortex, SVZ and SGZ on clinical variables using fully automated segmentation methods. In 177 glioblastoma patients, we calculated optimal cutpoints of minimal distances to the SVZ and SGZ to distinguish poor from favorable survival. The impact of tumor contact with neurogenic zones on clinical parameters, such as overall survival, multifocality, MGMT promotor methylation, Ki-67 and KPS score was also examined by multivariable regression analysis, chi-square test and Mann–Whitney-U. The analysis confirmed shorter survival in tumors contacting the SVZ with an optimal cutpoint of 14 mm distance to the SVZ, separating poor from more favorable survival. In contrast, tumor contact with the SGZ did not negatively affect survival. We did not find significant correlations with multifocality or MGMT promotor methylation in tumors contacting the SVZ, as previous studies discussed. These findings suggest that the spatial relationship between GBM and neurogenic niches needs to be assessed differently. Objective measurements disprove prior assumptions, warranting further research on this topic. [ABSTRACT FROM AUTHOR]

Simple Summary: The use of antiretroviral therapy has shown promising antineoplastic effects in multiple cancers; however, its efficacy in glioblastoma is unknown. We conducted an unbiased screen of 16 antiretroviral medications in 40 glioma cell lines and validated their efficacy in patient-derived glioma neurospheres and established cell lines. Our study provides the first mechanistic and functional insight into the utility of drug repurposing for malignant gliomas, which supports the current literature. Given their safety profile, preclinical efficacy, and neuropenetrance, antiretroviral therapy may be a promising adjuvant treatment for glioblastoma. Outcomes for glioblastoma (GBM) remain poor despite standard-of-care treatments including surgical resection, radiation, and chemotherapy. Intratumoral heterogeneity contributes to treatment resistance and poor prognosis, thus demanding novel therapeutic approaches. Drug repositioning studies on antiretroviral therapy (ART) have shown promising potent antineoplastic effects in multiple cancers; however, its efficacy in GBM remains unclear. To better understand the pleiotropic anticancer effects of ART on GBM, we conducted a comprehensive drug repurposing analysis of ART in GBM to highlight its utility in translational neuro-oncology. To uncover the anticancer role of ART in GBM, we conducted a comprehensive bioinformatic and in vitro screen of antiretrovirals against glioblastoma. Using the DepMap repository and reversal of gene expression score, we conducted an unbiased screen of 16 antiretrovirals in 40 glioma cell lines to identify promising candidates for GBM drug repositioning. We utilized patient-derived neurospheres and glioma cell lines to assess neurosphere viability, proliferation, and stemness. Our in silico screen revealed that several ART drugs including reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs) demonstrated marked anti-glioma activity with the capability of reversing the GBM disease signature. RTIs effectively decreased cell viability, GBM stem cell markers, and proliferation. Our study provides mechanistic and functional insight into the utility of ART repurposing for malignant gliomas, which supports the current literature. Given their safety profile, preclinical efficacy, and neuropenetrance, ARTs may be a promising adjuvant treatment for GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: Brain tumors, including glioblastoma (GB), pose a significant health concern globally, with high mortality rates despite current therapies. Pentraxin 3 (PTX3) is a multifunctional regulatory protein implicated from the early stages of inflammatory processes. Recent studies suggest PTX3's involvement in tumor progression, including metastasis and invasion, in multiple cancer types. However, the role of PTX3 in GB remains poorly understood. This review aims to discuss PTX3's function in GB pathology, considering its diverse biological activities and its potential as a promising molecular target. Understanding PTX3's role in GB could provide insights into novel therapeutic approaches to improve patient outcomes and survival rates. Brain tumors are a heterogeneous group of brain neoplasms that are highly prevalent in individuals of all ages worldwide. Within this pathological framework, the most prevalent and aggressive type of primary brain tumor is glioblastoma (GB), a subtype of glioma that falls within the IV-grade astrocytoma group. The death rate for patients with GB remains high, occurring within a few months after diagnosis, even with the gold-standard therapies now available, such as surgery, radiation, or a pharmaceutical approach with Temozolomide. For this reason, it is crucial to continue looking for cutting-edge therapeutic options to raise patients' survival chances. Pentraxin 3 (PTX3) is a multifunctional protein that has a variety of regulatory roles in inflammatory processes related to extracellular matrix (ECM). An increase in PTX3 blood levels is considered a trustworthy factor associated with the beginning of inflammation. Moreover, scientific evidence suggested that PTX3 is a sensitive and earlier inflammation-related marker compared to the short pentraxin C-reactive protein (CRP). In several tumoral subtypes, via regulating complement-dependent and macrophage-associated tumor-promoting inflammation, it has been demonstrated that PTX3 may function as a promoter of cancer metastasis, invasion, and stemness. Our review aims to deeply evaluate the function of PTX3 in the pathological context of GB, considering its pivotal biological activities and its possible role as a molecular target for future therapies. [ABSTRACT FROM AUTHOR]

Simple Summary: This retrospective study investigates the validity of lateral ventricle opening during high-grade glioma (HGG) surgery, contributing to the literature by addressing its relationship with postoperative complications in a large cohort of newly diagnosed patients with HGG. The approach of dividing patients into groups with and without lateral ventricle opening enhances the study's internal validity, allowing for a direct comparison between the two conditions. The analysis of complications, including subependymal dissemination and multifocal progression, contributes to understanding associated side effects. Furthermore, the conclusion that lateral ventricle opening does not significantly increase the risks of dissemination, hydrocephalus or cerebrospinal fluid leakage suggests practical implications for surgery. Given the importance of maximizing resection for prognosis in patients with HGG and the potential risks associated with ventricle opening, this study aimed to assess the actual increase in post-surgical complications related to lateral ventricle opening and its influence on OS and PFS. A retrospective study was conducted on newly diagnosed HGG, dividing the patients into two groups according to whether the lateral ventricle was opened (69 patients) or not opened (311 patients). PFS, OS, subependymal dissemination, distant parenchymal recurrences, the development of hydrocephalus and CSF leak were considered outcome measures. A cohort of 380 patients (154 females (40.5%) and 226 males (59.5%)) was involved in the study (median age 61 years). The PFS averaged 10.9 months (±13.3 SD), and OS averaged 16.6 months (± 16.3 SD). Among complications, subependymal dissemination was registered in 15 cases (3.9%), multifocal and multicentric progression in 56 cases (14.7%), leptomeningeal dissemination in 12 (3.2%) and hydrocephalus in 8 (2.1%). These occurrences could not be clearly justified by ventricular opening. The act of opening the lateral ventricles itself does not carry an elevated risk of dissemination, hydrocephalus or cerebrospinal fluid (CSF) leak. Therefore, if necessary, it should be pursued to achieve radical removal of the disease. [ABSTRACT FROM AUTHOR]

Simple Summary: (CAR)-T cell-based therapies have achieved substantial success against different haematological malignancies. However, results for solid tumours have been limited up to now, in part due to the fact that the immunosuppressive tumour microenvironment inactivates CAR-T cell clones. In this paper we study mathematically the competition of CAR-T and tumour cells, taking into account their immunosuppressive capacity. Using computer simulations, we show that the use of large numbers of CAR-T cells targetting the solid tumour antigens could overcome the immunosuppressive potential of cancer. To achieve such high levels of CAR-T cells we propose, and study in silico, the manufacture and injection of CAR-T cells targetting two antigens: CD19 and a tumour-associated antigen. This strategy lead in our simulations to the expansion of the CAR-T cells injected and the production of a massive army of CAR-T cells targetting the solid tumour, and potentially overcoming its immune suppression capabilities. Thus, our proposed strategy could provide a way to develop successful CAR-T cell therapies against solid tumours. Chimeric antigen receptor (CAR)-T cell-based therapies have achieved substantial success against B-cell malignancies, which has led to a growing scientific and clinical interest in extending their use to solid cancers. However, results for solid tumours have been limited up to now, in part due to the immunosuppressive tumour microenvironment, which is able to inactivate CAR-T cell clones. In this paper we put forward a mathematical model describing the competition of CAR-T and tumour cells, taking into account their immunosuppressive capacity. Using the mathematical model, we show that the use of large numbers of CAR-T cells targetting the solid tumour antigens could overcome the immunosuppressive potential of cancer. To achieve such high levels of CAR-T cells we propose, and study computationally, the manufacture and injection of CAR-T cells targetting two antigens: CD19 and a tumour-associated antigen. We study in silico the resulting dynamics of the disease after the injection of this product and find that the expansion of the CAR-T cell population in the blood and lymphopoietic organs could lead to the massive production of an army of CAR-T cells targetting the solid tumour, and potentially overcoming its immune suppression capabilities. This strategy could benefit from the combination with PD-1 inhibitors and low tumour loads. Our computational results provide theoretical support for the treatment of different types of solid tumours using T cells engineered with combination treatments of dual CARs with on- and off-tumour activity and anti-PD-1 drugs after completion of classical cytoreductive treatments. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastomas are very malignant and essentially incurable brain tumors. One problem is the extensive penetration of tumor cells into the adjacent normal brain tissue. Thus, the testing of novel drugs requires appropriate tumor models, preferentially avoiding animal studies. This paper describes so-called brain tissue slice tandem-culture systems. They consist of a slice of normal brain tissue and a second layer of tumor tissue. The microscopic analysis of these slice tandem-cultures allows for the simultaneous assessment of single cells invading into the normal brain tissue and the space occupying growth of the total tumor mass. It is shown that the direct application of test drugs onto the slices exerts inhibitory effects on both mechanisms. We thus describe a system mimicking the situation in glioblastoma patients. It reduces animal studies, allows for the direct application of test drugs and the precise quantitation of their inhibitory effects on tumor growth and invasion. Glioblastomas (GBMs) are the most malignant brain tumors and are essentially incurable even after extensive surgery, radiotherapy, and chemotherapy, mainly because of extensive infiltration of tumor cells into the adjacent normal tissue. Thus, the evaluation of novel drugs in malignant glioma treatment requires sophisticated ex vivo models that approach the authentic interplay between tumor and host environment while avoiding extensive in vivo studies in animals. This paper describes the standardized setup of an organotypic brain tissue slice tandem-culture system, comprising of normal brain tissue from adult mice and tumor tissue from human glioblastoma xenografts, and explore its utility for assessing inhibitory effects of test drugs. The microscopic analysis of vertical sections of the slice tandem-cultures allows for the simultaneous assessment of (i) the invasive potential of single cells or cell aggregates and (ii) the space occupying growth of the bulk tumor mass, both contributing to malignant tumor progression. The comparison of tissue slice co-cultures with spheroids vs. tissue slice tandem-cultures using tumor xenograft slices demonstrates advantages of the xenograft tandem approach. The direct and facile application of test drugs is shown to exert inhibitory effects on bulk tumor growth and/or tumor cell invasion, and allows their precise quantitation. In conclusion, we describe a straightforward ex vivo system mimicking the in vivo situation of the tumor mass and the normal brain in GBM patients. It reduces animal studies and allows for the direct and reproducible application of test drugs and the precise quantitation of their effects on the bulk tumor mass and on the tumor's invasive properties. [ABSTRACT FROM AUTHOR]

Simple Summary: The mesenchymal (MES) phenotype of glioblastoma (GBM) confers resistance to various therapeutic strategies and results from both tumor-intrinsic genetic alterations and tumor-extrinsic microenvironmental factors. In this study, we sought to identify and validate the key genes that regulate the MES phenotype of glioma via both mechanisms. By integrating bulk tumor data (using the TCGA and CGGA databases) and single-cell sequencing data of GBM, we revealed that the plasminogen activator, urokinase receptor (PLAUR) is the hub gene of the protumor microenvironment, encompassing hypoxia and immunosuppression, and we elucidated its role in driving the MES transition through both tumor-intrinsic function and cell-to-cell interaction. Our findings indicate that PLAUR may be a potential target for GBM treatment, as our research elucidated its functions through a comprehensive study. The mesenchymal (MES) phenotype of glioblastoma (GBM) is the most aggressive and therapy-resistant subtype of GBM. The MES phenotype transition during tumor progression results from both tumor-intrinsic genetic alterations and tumor-extrinsic microenvironmental factors. In this study, we sought to identify genes that can modulate the MES phenotype via both mechanisms. By integrating weighted gene co-expression network analysis (WGCNA) and the differential expression analysis of hypoxia-immunosuppression-related genes, we identified the plasminogen activator, urokinase receptor (PLAUR) as the hub gene. Functional enrichment analysis and GSVA analysis demonstrated that PLAUR was associated with the MES phenotype of glioma and the hypoxia-immunosuppression-related microenvironmental components. Single-cell sequencing analysis revealed that PLAUR mediated the ligand–receptor interaction between tumor-associated macrophages (TAMs) and glioma cells. Functional experiments in vitro with cell lines or primary glioma cells and xenograft models using BALB/c nude mice confirmed the role of PLAUR in promoting the MES phenotype of GBM. Our findings indicate that PLAUR regulates both glioma cells and tumor cell-extrinsic factors that favor the MES phenotype and suggest that PLAUR might be a potential target for GBM therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is a lethal primary brain tumor, and so far, immunotherapeutic strategies have not significantly improved patients' prognosis, both in newly diagnosed and recurrent settings. Understanding the features of the immune environment of the central nervous system is crucial to designing new treatment strategies able to counteract site-specific immunosuppressive and pro-tumorigenic factors. Here, we review next-generation immunomodulating therapeutic strategies such as immune check-point blockade, vaccinations, and adoptive cell therapies, aiming to re-shape the tumor microenvironment and restore active anti-tumor immunity. The door for immunotherapeutic strategies in glioblastoma treatment is not completely closed; researchers should test combinatorial treatments and design trials with solid translational analyses to gain more close and deep insight into on-treatment modifications of the tumor microenvironment. Glioblastoma (GBM) is the most aggressive and lethal primary brain tumor, bearing a survival estimate below 10% at five years, despite standard chemoradiation treatment. At recurrence, systemic treatment options are limited and the standard of care is not well defined, with inclusion in clinical trials being highly encouraged. So far, the use of immunotherapeutic strategies in GBM has not proved to significantly improve patients' prognosis in the treatment of newly diagnosed GBM, nor in the recurrent setting. Probably this has to do with the unique immune environment of the central nervous system, which harbors several immunosuppressive/pro-tumorigenic factors, both soluble (e.g., TGF-β, IL-10, STAT3, prostaglandin E2, and VEGF) and cellular (e.g., Tregs, M2 phenotype TAMs, and MDSC). Here we review the immune composition of the GBMs microenvironment, specifically focusing on the phenotype and function of the T cell compartment. Moreover, we give hints on the therapeutic strategies, such as immune checkpoint blockade, vaccinations, and adoptive cell therapy, that, interacting with tumor-infiltrating lymphocytes, might both target in different ways the tumor microenvironment and potentiate the activity of standard therapies. The path to be followed in advancing clinical research on immunotherapy for GBM treatment relies on a twofold strategy: testing combinatorial treatments, aiming to restore active immune anti-tumor responses, tackling immunosuppression, and additionally, designing more phase 0 and window opportunity trials with solid translational analyses to gain deeper insight into the on-treatment shaping of the GBM microenvironment. [ABSTRACT FROM AUTHOR]

Simple Summary: Protein Tyrosine Phosphatase Receptor Type D (PTPRD) plays a role in cell proliferation, differentiation, oncogenic transformation, and brain development and serves as an orexigenic asprosin receptor. This study investigates the expression of PTPRD in endometrial cancer (EC) and the placenta, as well as in glioblastoma (GBM). PTPRD is significantly upregulated at the mRNA and protein levels in patients with EC and GBM compared to healthy controls. In patients with EC, PTPRD is significantly downregulated by obesity. Using a tissue microarray, abundant PTPRD expression in low- and high-grade EC tumours is noted. Using liquid biopsies from EC patients, we show the expression of PTPRD in peripheral leukocytes. Moreover, asprosin treatment upregulates the expression of PTPRD in syncytialised placental cells in vitro, but not in EC cell lines. Collectively, our data suggest that PTPRD may have potential as a biomarker for malignancies such as EC and GBM, further implicating asprosin as a potential metabolic regulator in these cancers. Background: Protein Tyrosine Phosphatase Receptor Type D (PTPRD) is involved in the regulation of cell growth, differentiation, and oncogenic transformation, as well as in brain development. PTPRD also mediates the effects of asprosin, which is a glucogenic hormone/adipokine derived following the cleavage of the C-terminal of fibrillin 1. Since the asprosin circulating levels are elevated in certain cancers, research is now focused on the potential role of this adipokine and its receptors in cancer. As such, in this study, we investigated the expression of PTPRD in endometrial cancer (EC) and the placenta, as well as in glioblastoma (GBM). Methods: An array of in silico tools, in vitro models, tissue microarrays (TMAs), and liquid biopsies were employed to determine the gene and protein expression of PTPRD in healthy tissues/organs and in patients with EC and GBM. Results: PTPRD exhibits high expression in the occipital lobe, parietal lobe, globus pallidus, ventral thalamus, and white matter, whereas in the human placenta, it is primarily localised around the tertiary villi. PTPRD is significantly upregulated at the mRNA and protein levels in patients with EC and GBM compared to healthy controls. In patients with EC, PTPRD is significantly downregulated with obesity, whilst it is also expressed in the peripheral leukocytes. The EC TMAs revealed abundant PTPRD expression in both low- and high-grade tumours. Asprosin treatment upregulated the expression of PTPRD only in syncytialised placental cells. Conclusions: Our data indicate that PTPRD may have potential as a biomarker for malignancies such as EC and GBM, further implicating asprosin as a potential metabolic regulator in these cancers. Future studies are needed to explore the potential molecular mechanisms/signalling pathways that link PTPRD and asprosin in cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: Proline metabolism has been found to play an important role in neoplasms, but little is known about proline in gliomas or in the normal brain. This work investigates how the metabolism of proline in the brain and in gliomas of WHO grade 4 (GG4) may differ. A total of 20 pairs of samples were studied, consisting of both tumor and unaffected brain tissue, partially removed to make a surgical corridor. The levels of proline oxidase/proline dehydrogenase (POX/PRODH), Δ1-pyrroline-5-carboxylate reductases (PYCR1/2/3), prolidase (PEPD), and metalloproteinase-2 and -9 (MMP-2 and MMP-9) were measured. Proline concentration was evaluated. GG4 levels of POX/PRODH were found to be lower, while PYCR1, PEPD, and MMPs were significantly higher than in brain tissue. In GG4, proline concentration was 358% higher. The results confirm changes in proline metabolism in GG4, with a low-POX/PRODH/high-PYCR pattern like that in other neoplasms. High levels of PEPD and MMPs are in keeping with GG4 aggressiveness. Proline metabolism has been identified as a significant player in several neoplasms, but knowledge of its role in gliomas is limited despite it providing a promising line of pursuit. Data on proline metabolism in the brain are somewhat historical. This study aims to investigate alterations of proline metabolism in gliomas of WHO grade 4 (GG4) in the context of the brain. A total of 20 pairs of samples were studied, consisting of excised tumor and unaffected brain tissue, obtained when partial brain resection was required to reach deep-seated lesions. Levels of proline oxidase/proline dehydrogenase (POX/PRODH), Δ1-pyrroline-5-carboxylate reductases (PYCR1/2/3), prolidase (PEPD), and metalloproteinases (MMP-2, MMP-9) were assessed, along with the concentration of proline and proline-related metabolites. In comparison to normal brain tissue, POX/PRODH expression in GG4 was found to be suppressed, while PYCR1 expression and activity of PEPD, MMP-2, and -9 were upregulated. The GG4 proline concentration was 358% higher. Hence, rewiring of the proline metabolism in GG4 was confirmed for the first time, with a low-POX/PRODH/high-PYCR profile. High PEPD and MMPs activity is in keeping with GG4-increased collagen turnover and local aggressiveness. Further studies on the mechanisms of the interplay between altered proline metabolism and the GG4 microenvironment are warranted. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is the most frequent and malignant primary tumor of the brain. Patient survival is dismal and personalized therapies are missing. In the diagnostic arena, the lack of an all-inclusive molecular subgroup classification for this tumor has delayed its personalized therapy. This study presents the validation of the first molecular subgroup classification of glioblastoma in a large patient cohort, and opens the avenue to rationalized therapeutic approaches. Preliminary comparative demographic studies between Caucasian/White and African American/Black patients offer the first comparative overview of the molecular diversity of glioblastoma. One molecular subgroup, G6/Multi-RTK, assembling several targetable gene fusions, is expanded and includes novel or rare examples of such events with associated tumorigenic mechanisms and cellular phenotypes. The bioinformatic analysis of the principal oncogenic pathways reveals important genetic associations and the extent of genomic heterogeneity at the populational level, offering the first organized molecular profiling of glioblastoma to be used as a foundation for therapy design, clinical practice and scientific research. Glioblastoma is the most frequent and malignant primary neoplasm of the central nervous system. In a recent breakthrough study on a prospective Discovery cohort, I proposed the first all-inclusive molecular classification of glioblastoma into seven subgroups, G1-G7, based on MAPK pathway activation. New data from a WHO-grade-4 diffuse glioma prospective Validation cohort offers, in this study, an integrated demographic–molecular analysis of a 213-patient Combined cohort. Despite cohort differences in the median age and molecular subgroup distribution, all the prospectively-acquired cases from the Validation cohort mapped into one of the G1-G7 subgroups defined in the Discovery cohort. A younger age of onset, higher tumor mutation burden and expanded G1/EGFR-mutant and G3/NF1 glioblastoma subgroups characterized the glioblastomas from African American/Black relative to Caucasian/White patients. The three largest molecular subgroups were G1/EGFR, G3/NF1 and G7/Other. The fourth largest subgroup, G6/Multi-RTK, was detailed by describing a novel gene fusion ST7–MET, rare PTPRZ1–MET, LMNA–NTRK1 and GOPC–ROS1 fusions and their overexpression mechanisms in glioblastoma. The correlations between the MAPK pathway G1-G7 subgroups and the PI3-kinase/PTEN, TERT, cell cycle G1 phase and p53 pathways defined characteristic subgroup pathway profiles amenable to personalized targeted therapy. This analysis validated the first all-inclusive molecular classification of glioblastoma, showed significant demographic and molecular differences between subgroups, and provided the first ethnic molecular comparison of glioblastoma. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma, the most deadly type of brain tumor in adults, poses a significant treatment challenge and often leads to poor outcomes. A recent study delved into the role of a protein called zonulin, known for its impact on the body's barrier functions, in glioblastoma. The research involved examining zonulin levels in both the bloodstream and tumor tissues of 34 newly diagnosed glioblastoma patients. The study discovered that higher levels of zonulin in tumors were linked to increased aggressiveness, which in turn correlated with a poorer prognosis. Elevated serum levels of zonulin in the blood also indicated a connection with a less favorable prognosis. In laboratory experiments, glioblastoma cells expressed higher levels of zonulin, particularly under conditions resembling glioma stem cells, which are associated with treatment resistance. This research suggests that heightened zonulin levels in both tumors and the blood may signal a more challenging prognosis for glioblastoma patients, underscoring the potential importance of this protein in the disease. Glioblastoma, the deadliest adult brain tumor, poses a significant therapeutic challenge with a dismal prognosis despite current treatments. Zonulin, a protein influencing tight junctions and barrier functions, has gained attention for its diverse roles in various diseases. This study aimed to preliminarily analyze the circulating and tumor zonulin levels, evaluating their impact on disease prognosis and clinical–radiological factors. Additionally, we investigated in vitro zonulin expression in different glioblastoma cell lines under two different conditions. The study comprised 34 newly diagnosed glioblastoma patients, with blood samples collected before treatment for zonulin and haptoglobin analysis. Tumor tissue samples from 21 patients were obtained for zonulin expression. Clinical, molecular, and radiological data were collected, and zonulin protein levels were assessed using ELISA and Western blot techniques. Furthermore, zonulin expression was analyzed in vitro in three glioblastoma cell lines cultured under standard and glioma-stem-cell (GSC)-specific conditions. High zonulin expression in glioblastoma tumors correlated with larger preoperative contrast enhancement and edema volumes. Patients with high zonulin levels showed a poorer prognosis (progression-free survival [PFS]). Similarly, elevated serum levels of zonulin were associated with a trend of shorter PFS. Higher haptoglobin levels correlated with MGMT methylation and longer PFS. In vitro, glioblastoma cell lines expressed zonulin under standard cell culture conditions, with increased expression in tumorsphere-specific conditions. Elevated zonulin levels in both the tumor and serum of glioblastoma patients were linked to a poorer prognosis and radiological signs of increased disruption of the blood–brain barrier. In vitro, zonulin expression exhibited a significant increase in tumorspheres. [ABSTRACT FROM AUTHOR]

Simple Summary: The major histocompatibility complex type II is downregulated in glioblastoma (GB) due to the silencing of the major transcriptional regulator class II transactivator (CIITA). Recent studies have posed CIITA as a possible target in treating patients with GB. However, our results show that in mice, vaccination experiments with wildtype (-WT) and CIITA-expressing cells (-CIITA) equivalently protect against subsequent intracerebral challenges with GL261 cells. Adoptive cell transfer experiments likewise showed a similar antitumor potential of lymphocytes harvested from mice implanted intracerebrally with GL261-WT or -CIITA. Human GB-infiltrating myeloid cells, lymphocytes and NK cells remained mostly inactivated and/or tumor-supportive when in co-culture with GB cells, regardless of CIITA. Altogether, these results question the therapeutic potential of CIITA-mediated immunotherapy in glioblastoma. Background: The major histocompatibility complex type II is downregulated in glioblastoma (GB) due to the silencing of the major transcriptional regulator class II transactivator (CIITA). We investigated the pro-immunogenic potential of CIITA overexpression in mouse and human GB. Methods: The intracerebral growth of wildtype GL261-WT cells was assessed following contralateral injection of GL261-CIITA cells or flank injections with GL261-WT or GL261-CIITA cells. Splenocytes obtained from mice implanted intracerebrally with GL261-WT, GL261-CIITA cells or phosphate buffered saline (PBS) were transferred to other mice and subsequently implanted intracerebrally with GL261-WT. Human GB cells and (syngeneic) GB-infiltrating immune cells were isolated from surgical samples and co-cultured with GB cells expressing CIITA or not, followed by RT-qPCR assessment of the expression of key immune regulators. Results: Intracerebral vaccination of GL261-CIITA significantly reduced the subsequent growth of GL261-WT cells implanted contralaterally. Vaccination with GL261-WT or -CIITA subcutaneously, however, equivalently retarded the intracerebral growth of GL261 cells. Adoptive cell transfer experiments showed a similar antitumor potential of lymphocytes harvested from mice implanted intracerebrally with GL261-WT or -CIITA. Human GB-infiltrating myeloid cells and lymphocytes were not activated when cultured with CIITA-expressing GB cells. Tumor-infiltrating NK cells remained mostly inactivated when in co-culture with GB cells, regardless of CIITA. Conclusion: these results question the therapeutic potential of CIITA-mediated immunotherapy in glioblastoma. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma stands as the most aggressive form of adult brain cancer, often resulting in a median survival of 14.6 months even following surgical intervention coupled with chemotherapy and radiotherapy. This review places emphasis on elucidating the current understanding of glioblastoma stem cell (GSC) biology, the intricacies of GSCs' molecular mechanisms, and their correlations with diverse signaling pathways. Notably, this includes exploration of pivotal pathways such as epidermal growth factor receptor, PI3K/AKT/mTOR, HGFR/c-MET, NF-αB, Wnt, Notch, and STAT3. Moreover, this review investigates the phenomenon of metabolic reprogramming observed within GSCs. Additionally, it delves into potential therapeutic avenues targeting GSCs, presenting current inhibitors along with their respective modes of action on GSC targets. Glioblastoma multiforme (GBM) represents a diverse spectrum of primary tumors notorious for their resistance to established therapeutic modalities. Despite aggressive interventions like surgery, radiation, and chemotherapy, these tumors, due to factors such as the blood–brain barrier, tumor heterogeneity, glioma stem cells (GSCs), drug efflux pumps, and DNA damage repair mechanisms, persist beyond complete isolation, resulting in dismal outcomes for glioma patients. Presently, the standard initial approach comprises surgical excision followed by concurrent chemotherapy, where temozolomide (TMZ) serves as the foremost option in managing GBM patients. Subsequent adjuvant chemotherapy follows this regimen. Emerging therapeutic approaches encompass immunotherapy, including checkpoint inhibitors, and targeted treatments, such as bevacizumab, aiming to exploit vulnerabilities within GBM cells. Nevertheless, there exists a pressing imperative to devise innovative strategies for both diagnosing and treating GBM. This review emphasizes the current knowledge of GSC biology, molecular mechanisms, and associations with various signals and/or pathways, such as the epidermal growth factor receptor, PI3K/AKT/mTOR, HGFR/c-MET, NF-κB, Wnt, Notch, and STAT3 pathways. Metabolic reprogramming in GSCs has also been reported with the prominent activation of the glycolytic pathway, comprising aldehyde dehydrogenase family genes. We also discuss potential therapeutic approaches to GSC targets and currently used inhibitors, as well as their mode of action on GSC targets. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is the most common and most aggressive brain tumor in adults. The chemotherapeutic substance temozolomide plays an important role in glioblastoma therapy. However, the response of glioblastoma patients to temozolomide depends on the expression level of the repair protein O6-methylguanine-DNA methyltransferase (MGMT) in the tumor. Since the DNA methylation status of the MGMT promoter has an impact on MGMT expression, it serves as biomarker for predicting the response to temozolomide and prognosis of glioblastoma. We investigated if the DNA methylation status of enhancers, other important regulatory elements, is also associated with MGMT expression. We found the methylation status of several regions of enhancers to be associated with MGMT expression. In addition, we found associations with common genetic variants and clinical parameters, including overall survival. The response of glioblastoma (GBM) patients to the alkylating agent temozolomide (TMZ) vitally depends on the expression level of the repair protein O6-methylguanine-DNA methyltransferase (MGMT). Since MGMT is strongly regulated by promoter methylation, the methylation status of the MGMT promoter has emerged as a prognostic and predictive biomarker for GBM patients. By determining the methylation levels of the four enhancers located within or close to the MGMT gene, we recently found that enhancer methylation contributes to MGMT regulation. In this study, we investigated if methylation of the four enhancers is associated with SNP rs16906252, TERT promoter mutations C228T and C250T, TERT SNP rs2853669, proliferation index Ki-67, overall survival (OS), age, and sex of the patients. In general, associations with genetic variants, clinical parameters, and demographic characteristics were caused by a complex interplay of multiple CpGs in the MGMT promoter and of multiple CpGs in enhancer regions. The observed associations for intragenic enhancer 4, located in intron 2 of MGMT, differed from associations observed for the three intergenic enhancers. Some findings were restricted to subgroups of samples with either methylated or unmethylated MGMT promoters, underpinning the relevance of the MGMT promoter status in GBMs. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the effectiveness of different modern radiotherapy strategies in the treatment of patients with newly diagnosed glioblastoma using a comprehensive review of the literature from sources such as MEDLINE, Embase and the Cochrane Central Registry. It included randomized and nonrandomized trials on treatments such as three-dimensional conformal radiotherapy, intensity-modulated radiotherapy and proton therapy, assessing their impact on overall survival and progression-free survival. A Bayesian network meta-analysis was utilized to provide a nuanced comparison of the varied therapies. The analysis of 816 patients from six studies indicated the significant benefit of proton therapy in terms of the survival outcomes, suggesting that proton therapy might be most effective for primary glioblastoma. Background: This study aimed to assess the relative efficacy of modern radiotherapy strategies in patients with newly diagnosed glioblastoma. Method: A comprehensive literature review was conducted through MEDLINE, Embase and the Cochrane Central Registry of Controlled Trials of studies focused on newly diagnosed glioblastoma published up to and counting 15 September 2022. We included randomized controlled trials (RCTs) and comparative nonrandomized studies (NRSs) of radiotherapy for newly diagnosed glioblastoma. Eligible studies included patients treated with three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, volumetric modulated arc therapy or proton therapy reporting either overall survival, progression-free survival or both. The impact of different radiotherapy modalities on survival was evaluated by direct comparisons of indirect evidence and estimated hazard ratios in terms of a Bayesian network meta-analysis. Results: A total of six RCTs or NRSs comprising 816 glioblastoma patients with modern radiotherapy strategies were reviewed, yielding improved overall survival by proton therapy over all other regimens. The network meta-analysis also indicated a significant advantage of proton therapy compared with other radiotherapy strategies in regard to progression-free survival. Conclusion: Our findings suggested PT as a standard RT regime with possibly superior survival outcomes for selected patients with GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: Patients with gliomas experience worsened quality of life due to epileptic attacks. Over 80% of patients are susceptible to seizures, significantly hindering their treatment and well-being. No cause of epilepsy associated with glioma has been identified; however, some mutations are known to contribute to seizures in various situations. The development of a tumour creates advantageous conditions for abnormal neuronal activity to occur. Identifying a therapeutic target is a significant undertaking that numerous studies are endeavouring to undertake. We investigate the potential correlation of pathophysiological processes in the development of both gliomas and epilepsy, aiming to identify any shared factors. Furthermore, we propose that the mutational profile of different types of gliomas may have an impact on the occurrence or absence of seizures. We conclude that spontaneous neuronal activity arises from both the tumour microenvironment and blood ingress into neuronal networks resulting from the breakdown of the blood–brain barrier. Approximately 30% of glioma patients are able to survive beyond one year postdiagnosis. And this short time is often overshadowed by glioma-associated epilepsy. This condition severely impairs the patient's quality of life and causes great suffering. The genetic, molecular and cellular mechanisms underlying tumour development and epileptogenesis remain incompletely understood, leading to numerous unanswered questions. The various types of gliomas, namely glioblastoma, astrocytoma and oligodendroglioma, demonstrate distinct seizure susceptibility and disease progression patterns. Patterns have been identified in the presence of IDH mutations and epilepsy, with tumour location in cortical regions, particularly the frontal lobe, showing a more frequent association with seizures. Altered expression of TP53, MGMT and VIM is frequently detected in tumour cells from individuals with epilepsy associated with glioma. However, understanding the pathogenesis of these modifications poses a challenge. Moreover, hypoxic effects induced by glioma and associated with the HIF-1a factor may have a significant impact on epileptogenesis, potentially resulting in epileptiform activity within neuronal networks. We additionally hypothesise about how the tumour may affect the functioning of neuronal ion channels and contribute to disruptions in the blood–brain barrier resulting in spontaneous depolarisations. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastomas are the most common primary brain tumors in adults. They harbor a dismal prognosis and intrinsic resistance to treatment. Nonetheless, around 5% of glioblastomas present a unique genetic alteration, the FGFR3-TACC3 gene fusion, that drives tumor transformation and could represent a therapeutic opportunity. In this review, we discuss the state-of-the-art knowledge regarding glioblastomas with FGFR3-TACC3 gene fusions. We present their unique features and the methods for their identification. Targeted therapies aimed at inhibiting the protein resulting from the gene fusion have been developed with moderate clinical efficacy. An integrated effort is ongoing to improve the treatment results for these patients. In 2012, whole-transcriptome sequencing analysis led to the discovery of recurrent fusions involving the FGFR3 and TACC3 genes as the main oncological driver in a subset of human glioblastomas. Since then, FGFR3-TACC3 fusions have been identified in several other solid cancers. Further studies dissected the oncogenic mechanisms of the fusion protein and its complex interplay with cancer cell metabolism. FGFR3-TACC3 fusion-driven gliomas emerged as a defined subgroup with specific clinical, histological, and molecular features. Several FGFR inhibitors were tested in FGFR3-TACC3 fusion-positive gliomas and proved some efficacy, although inferior to the results seen in other FGFR3-TACC3 fusion-driven cancers. In this review, we summarize and discuss the state-of-the-art knowledge resulting from a 10-year research effort in the field, its clinical implications for glioma patients, the potential reasons for targeted therapy failures, and the perspective of emerging treatments. [ABSTRACT FROM AUTHOR]

Simple Summary: This paper summarizes the crosstalk between tumor/non-tumor cells and other elements of the glioblastoma (GB) microenvironment. In tumor pathology, glial cells result in the highest number of cancers, and GB is considered the most lethal tumor of the central nervous system (CNS). The tumor microenvironment (TME) is a complex peritumoral hallo composed of tumor cells and several non-tumor cells (e.g., nervous cells, stem cells, fibroblasts, vascular and immune cells), which might be a key factor for the ineffective treatment since the microenvironment modulates the biologic status of the tumor with the increase in its evasion capacity. A deeper understanding of cell–cell interactions in the TME and with the tumor cells could be the basis for a more efficient therapy. The central nervous system (CNS) represents a complex network of different cells, such as neurons, glial cells, and blood vessels. In tumor pathology, glial cells result in the highest number of cancers, and glioblastoma (GB) is considered the most lethal tumor in this region. The development of GB leads to the infiltration of healthy tissue through the interaction between all the elements of the brain network. This results in a GB microenvironment, a complex peritumoral hallo composed of tumor cells and several non-tumor cells (e.g., nervous cells, stem cells, fibroblasts, vascular and immune cells), which might be the principal factor for the ineffective treatment due to the fact that the microenvironment modulates the biologic status of the tumor with the increase in its evasion capacity. Crosstalk between glioma cells and the brain microenvironment finally inhibits the beneficial action of molecular pathways, favoring the development and invasion of the tumor and its increasing resistance to treatment. A deeper understanding of cell–cell interactions in the tumor microenvironment (TME) and with the tumor cells could be the basis for a more efficient therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma is one of the worst cancer types and the most common cancer originating within the brain. Patients afflicted by glioblastoma suffer from poor prognosis, a lack of specific therapies and frequent tumor recurrences. Many researchers are confident that glioblastoma cells can display traits of stem cells and that these attributes lead to an aggressive growth and high rate of recurrence. Based on our previous work that demonstrates that the "sun hormone" vitamin D3 can block these stem cell traits, we have now gained additional insights into the effects of the active form of vitamin D3, calcitriol. We can show that specific gene variants of the vitamin D3 receptor might be responsible for the sensitivity towards calcitriol and that sensitive cells are blocked in their stemness attributes as well as migratory potential. Glioblastoma is the most common primary brain cancer in adults and represents one of the worst cancer diagnoses for patients. Suffering from a poor prognosis and limited treatment options, tumor recurrences are virtually inevitable. Additionally, treatment resistance is very common for this disease and worsens the prognosis. These and other factors are hypothesized to be largely due to the fact that glioblastoma cells are known to be able to obtain stem-like traits, thereby driving these phenotypes. Recently, we have shown that the in vitro and ex vivo treatment of glioblastoma stem-like cells with the hormonally active form of vitamin D3, calcitriol (1α,25(OH)2-vitamin D3) can block stemness in a subset of cell lines and reduce tumor growth. Here, we expanded our cell panel to over 40 different cultures and can show that, while half of the tested cell lines are sensitive, a quarter can be classified as high responders. Using genetic and proteomic analysis, we further determined that treatment success can be partially explained by specific polymorphism of the vitamin D3 receptor and that high responders display a proteome suggestive of blockade of stemness, as well as migratory potential. [ABSTRACT FROM AUTHOR]

Simple Summary: Current auto-segmentation methods for glioblastoma utilize mainly pre-operative 1.5T and 3T MRI. The first commercial MRI-linear accelerator (linac) radiation treatment platform acquires low-field (0.35T) post-operative MRI at the delivery of each treatment. This study presents the first automatic brain lesion segmentation network developed for MRI-linac to track tumor changes during radiotherapy. The tumors and resection cavities are automatically segmented using a deep learning network, allowing for daily monitoring of tumor volume changes, creation of tools necessary for adaptive radiotherapy of glioblastoma, and providing MRI regions of interest for further analyses that may discover prognostic markers. Glioblastoma changes during chemoradiotherapy are inferred from high-field MRI before and after treatment but are rarely investigated during radiotherapy. The purpose of this study was to develop a deep learning network to automatically segment glioblastoma tumors on daily treatment set-up scans from the first glioblastoma patients treated on MRI-linac. Glioblastoma patients were prospectively imaged daily during chemoradiotherapy on 0.35T MRI-linac. Tumor and edema (tumor lesion) and resection cavity kinetics throughout the treatment were manually segmented on these daily MRI. Utilizing a convolutional neural network, an automatic segmentation deep learning network was built. A nine-fold cross-validation schema was used to train the network using 80:10:10 for training, validation, and testing. Thirty-six glioblastoma patients were imaged pre-treatment and 30 times during radiotherapy (n = 31 volumes, total of 930 MRIs). The average tumor lesion and resection cavity volumes were 94.56 ± 64.68 cc and 72.44 ± 35.08 cc, respectively. The average Dice similarity coefficient between manual and auto-segmentation for tumor lesion and resection cavity across all patients was 0.67 and 0.84, respectively. This is the first brain lesion segmentation network developed for MRI-linac. The network performed comparably to the only other published network for auto-segmentation of post-operative glioblastoma lesions. Segmented volumes can be utilized for adaptive radiotherapy and propagated across multiple MRI contrasts to create a prognostic model for glioblastoma based on multiparametric MRI. [ABSTRACT FROM AUTHOR]

Simple Summary: Patients suffering from glioblastoma receive treatment according to the Stupp protocol. After chemoradiotherapy, the glioblastoma either continue to develop, or treatment-related vascular damage comes into play, both causing new, seemingly identical contrast-enhancing lesions in follow-up MRI, where clinicians and radiologists alike can only differentiate between tumor progression (TP) and treatment-related abnormalities (TRA) by seeing the temporal evolution of the lesion and the patients clinical status. We investigate the use of diffusion MRI and the quantitative apparent diffusion coefficient (ADC) in a retrospective patient cohort and we sought to validate a previously reported ADC cutoff value for its distinctive properties between TP and TRA. In the end, ADC values were shown not to be highly discriminative and, compared to the mean ADC values between TP and TRA previously reported in the literature, are more overlapping than expected. Distinguishing treatment-related abnormalities (TRA) from tumor progression (TP) in glioblastoma patients is a diagnostic imaging challenge due to the identical morphology of conventional MR imaging sequences. Diffusion-weighted imaging (DWI) and its derived images of the apparent diffusion coefficient (ADC) have been suggested as diagnostic tools for this problem. The aim of this study is to determine the diagnostic accuracy of different cut-off values of the ADC to differentiate between TP and TRA. In total, 76 post-treatment glioblastoma patients with new contrast-enhancing lesions were selected. Lesions were segmented using a T1-weighted, contrast-enhanced scan. The mean ADC values of the segmentations were compared between TRA and TP groups. Diagnostic accuracy was compared by use of the area under the curve (AUC) and the derived sensitivity and specificity values from cutoff points. Although ADC values in TP (mean = 1.32 × 10−3 mm2/s; SD = 0.31 × 10−3 mm2/s) were significantly different compared to TRA (mean = 1.53 × 10−3 mm2/s; SD = 0.28 × 10−3 mm2/s) (p = 0.003), considerable overlap in their distributions exists. The AUC of ADC values to distinguish TP from TRA was 0.71, with a sensitivity and specificity of 65% and 70%, respectively, at an ADC value of 1.47 × 10−3 mm2/s. These findings therefore indicate that ADC maps should not be used in discerning between TP and TRA at a certain timepoint without information on temporal evolution. [ABSTRACT FROM AUTHOR]

Simple Summary: As recurrence in glioblastoma is locally generated around the resection cavity, surviving glioma stem-like cells may cause recurrence. Glioma stem-like cells expressing high levels of CD44 are highly invasive and are required to change to less invasive, more proliferative types to generate a recurrent tumor. CD44 promotes both the invasion and proliferation of tumor cells via various signaling pathways. Among these, paired pathways show reciprocal activation of invasion and proliferation under different conditions of oxygenation. Severe hypoxia activates genes related to cell invasion, whereas moderate hypoxia activates genes related to cell proliferation. CD44 is associated with both pathways and plays a critical role in regulating the balance between the promotion of cell invasion and cell proliferation. These results may indicate that CD44 is a key molecule for executing tumor recurrence in glioblastoma. High invasiveness is a characteristic of glioblastoma (GBM), making radical resection almost impossible, and thus, resulting in a tumor with inevitable recurrence. GBM recurrence may be caused by glioma stem-like cells (GSCs) that survive many kinds of therapy. GSCs with high expression levels of CD44 are highly invasive and resistant to radio-chemotherapy. CD44 is a multifunctional molecule that promotes the invasion and proliferation of tumor cells via various signaling pathways. Among these, paired pathways reciprocally activate invasion and proliferation under different hypoxic conditions. Severe hypoxia (0.5–2.5% O2) upregulates hypoxia-inducible factor (HIF)-1α, which then activates target genes, including CD44, TGF-β, and cMET, all of which are related to tumor migration and invasion. In contrast, moderate hypoxia (2.5–5% O2) upregulates HIF-2α, which activates target genes, such as vascular endothelial growth factor (VEGF)/VEGFR2, cMYC, and cyclin D1. All these genes are related to tumor proliferation. Oxygen environments around GBM can change before and after tumor resection. Before resection, the oxygen concentration at the tumor periphery is severely hypoxic. In the reparative stage after resection, the resection cavity shows moderate hypoxia. These observations suggest that upregulated CD44 under severe hypoxia may promote the migration and invasion of tumor cells. Conversely, when tumor resection leads to moderate hypoxia, upregulated HIF-2α activates HIF-2α target genes. The phenotypic transition regulated by CD44, leading to a dichotomy between invasion and proliferation according to hypoxic conditions, may play a crucial role in GBM recurrence. [ABSTRACT FROM AUTHOR]

Simple Summary: New forms of cancer treatment are needed to target resistant cancers or reduce severe side effects associated with some treatments. Cold Atmospheric Plasma (CAP) has demonstrated promising anti-cancer effects in several types of cancer, not only by direct application onto cancer cells, but also by indirect treatment using activation of liquids, such as water. Although the exact mechanism of action and underlying signaling pathways are yet to be discovered, CAP has the potential to be combined with traditional therapies, such as chemotherapy. This study investigates a new approach for treating brain cancer by combining a conventional cancer drug with plasma-activated water, which is produced by exposing water to plasma. The reactive chemical species in these solutions may help to kill the cancer cells and reduce the amount of drug that is needed. Not only were the combined treatments able to interfere with cell metabolism and increase cell death, but they also reduced the long-term cell proliferation. This study provides evidence that indirect CAP-derived approaches could be used in combination with chemotherapeutics for prospective treatment of brain cancer. The increase in cancer diagnoses and cancer deaths, severe side effects of existing treatments and resistance to traditional treatments have generated a need for new anticancer treatments. Glioblastoma multiforme (GBM) is the most common, malignant and aggressive brain cancer. Despite many innovations regarding GBM treatment, the final outcome is still very poor, making it necessary to develop new therapeutic approaches. Cold atmospheric plasma (CAP) as well as plasma-activated liquids (PAL) are being studied as new possible approaches against cancer. The anticancer activity of PAL such as "plasma-activated water" (PAW) is dependent on the reactive chemical compounds present in the solution. Possible combinatory effects with conventional therapies, such as chemotherapeutics, may expand the potential of PAL for cancer treatment. We aim to explore the therapeutic properties of a combination of PAW and topotecan (TPT), an antineoplastic agent with major cytotoxic effects during the S phase of the cell cycle, on a GBM cancer cell line (U-251mg). Combined treatments with PAW and TPT showed a reduction in the metabolic activity and cell mass, an increase in apoptotic cell death and a reduction in the long-term survival. Single applications of PAW+TPT treatments showed a cytotoxic effect in the short term and an antiproliferative effect in the long term, warranting future exploration of combining PAW with chemotherapeutic agents as new therapeutic approaches. [ABSTRACT FROM AUTHOR]

Simple Summary: Integrins play an important role in the development and spread of cancers, including glioblastoma (GBM); therefore, blocking them should be an effective cancer treatment. Our research aims to use the RGD homodimeric disintegrin VLO4, isolated from Vipera lebetina obtusa venom, to target the α5β1 integrin, which is a key regulator of GBM cell migration and invasion. This study shows its effect on the adhesion, spreading, migration, and survival of the LBC3, LN18, and LN229 cell lines. The presented results suggest that VLO4 may be a structural platform to design therapeutics for gliomas, which may be used alone or in combination with other integrin blockers such as inhibitors of α9β1 integrin (e.g., structures based on MLD disintegrin, VLO5). Integrins play a fundamental role in the migration and invasiveness of glioblastoma (GBM) cells, making them suitable targets for innovative cancer therapy. The aim of this study was to evaluate the effect of the RGD homodimeric disintegrin VLO4, isolated from Vipera lebetina obtusa venom, on the adhesion, spreading, migration, and survival of LBC3, LN18, and LN229 cell lines. This disintegrin, as a potent antagonist for α5β1 integrin, showed pro-adhesive properties for these cell lines, the highest for LN229 and the lowest for LBC3. Glioblastoma cells displayed significant differences in the spreading on the immobilized VLO4 and the natural α5β1 integrin ligand, fibronectin. Solubilized VLO4 showed different cytotoxicity and pro-apoptotic properties among tested cell lines, with the highest against LN18 and none against LN229. Moreover, VLO4 revealed an inhibitory effect on the migration of LBC3 and LN18 cell lines, in contrast to LN229 cells, which were not sensitive to this disintegrin. However, LN229 migration was impaired by VLO5, a disintegrin antagonistic to integrin α9β1, used in combination with VLO4. A possible mechanism of action of VLO4 may be related to the downregulation of α5β1 integrin subunit expression, as revealed by Western blot. VLO4 also inhibited cell proliferation and induced caspase-dependent apoptosis in LBC3 and LN18 cell lines. These results indicate that targeting α5β1 integrin by related VLO4 compounds may be useful in the development of integrin-targeted therapy for glioblastoma. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma multiforme is the most lethal form of brain cancer. To improve patient outcomes, more effective treatments should be designed. Therefore, it is important to understand how this cancer continues to survive via interactions with its environment. Here, we evaluate this environment and several treatments that target it. Moreover, the brain is protected with a barrier that limits the entrance of drugs. Therefore, we review a novel class of treatments, known as aptamers, that can cross this barrier and can carry another drug with them. Our ultimate goal is to encourage the development of more aptamers for the treatment of this deadly cancer. The key challenges to treating glioblastoma multiforme (GBM) are the heterogeneous and complex nature of the GBM tumour microenvironment (TME) and difficulty of drug delivery across the blood–brain barrier (BBB). The TME is composed of various neuronal and immune cells, as well as non-cellular components, including metabolic products, cellular interactions, and chemical compositions, all of which play a critical role in GBM development and therapeutic resistance. In this review, we aim to unravel the complexity of the GBM TME, evaluate current therapeutics targeting this microenvironment, and lastly identify potential targets and therapeutic delivery vehicles for the treatment of GBM. Specifically, we explore the potential of aptamer-targeted delivery as a successful approach to treating brain cancers. Aptamers have emerged as promising therapeutic drug delivery vehicles with the potential to cross the BBB and deliver payloads to GBM and brain metastases. By targeting specific ligands within the TME, aptamers could potentially improve treatment outcomes and overcome the challenges associated with larger therapies such as antibodies. [ABSTRACT FROM AUTHOR]

Simple Summary: For accurate radiotherapy, a clear definition of the geometric extent of organs and tumor volumes is important. Due to the laborious task of manually drawing contours to define these, automatic segmentation models are becoming increasingly available. These models, however, need to be visually evaluated by radiation oncology experts. This evaluation itself takes up valuable time, therefore making an efficient and clinically relevant validation of auto-segmented results desirable. An accurate 3D dose prediction model can help create dose awareness prior to the actual dose-planning step. It can provide useful information for the quality assurance of the contouring step. In this study, we trained a 3D dose predictor for volumetric modulated arc therapy (VMAT) treatment of glioblastoma patients based on an existing architecture called a cascaded 3D U-Net. We further tested this model's sensitivity and robustness for the purpose of estimating dose changes due to contour variations. External beam radiation therapy requires a sophisticated and laborious planning procedure. To improve the efficiency and quality of this procedure, machine-learning models that predict these dose distributions were introduced. The most recent dose prediction models are based on deep-learning architectures called 3D U-Nets that give good approximations of the dose in 3D almost instantly. Our purpose was to train such a 3D dose prediction model for glioblastoma VMAT treatment and test its robustness and sensitivity for the purpose of quality assurance of automatic contouring. From a cohort of 125 glioblastoma (GBM) patients, VMAT plans were created according to a clinical protocol. The initial model was trained on a cascaded 3D U-Net. A total of 60 cases were used for training, 15 for validation and 20 for testing. The prediction model was tested for sensitivity to dose changes when subject to realistic contour variations. Additionally, the model was tested for robustness by exposing it to a worst-case test set containing out-of-distribution cases. The initially trained prediction model had a dose score of 0.94 Gy and a mean DVH (dose volume histograms) score for all structures of 1.95 Gy. In terms of sensitivity, the model was able to predict the dose changes that occurred due to the contour variations with a mean error of 1.38 Gy. We obtained a 3D VMAT dose prediction model for GBM with limited data, providing good sensitivity to realistic contour variations. We tested and improved the model's robustness by targeted updates to the training set, making it a useful technique for introducing dose awareness in the contouring evaluation and quality assurance process. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma (GB) is a malignant brain tumour with no cure, even after the best treatment. The evaluation of a therapy response is usually based on magnetic resonance imaging (MRI), but it lacks precision in early stages, and doctors must wait several weeks until they are confident information is produced, facing an uncertain time window. Magnetic resonance spectroscopy (MRS/MRSI) can provide additional information about tumours and their environment but is not widely used in clinical settings since the spectroscopy format is not standardised as MRI is, and doctors are not familiarised with outputs/interpretation. This study aims to improve the assessment of the treatment response in GB using MRSI data and machine learning, including state-of-the-art one-dimensional convolutional neural networks. Preclinical (murine) GB data were used for developing models that successfully identified tumour regions regarding their response to treatment (or the lack thereof). These models were accurate and outperformed previous methods, potentially providing new opportunities for GB patient management. Background: Glioblastoma (GB) is a malignant brain tumour that is challenging to treat, often relapsing even after aggressive therapy. Evaluating therapy response relies on magnetic resonance imaging (MRI) following the Response Assessment in Neuro-Oncology (RANO) criteria. However, early assessment is hindered by phenomena such as pseudoprogression and pseudoresponse. Magnetic resonance spectroscopy (MRS/MRSI) provides metabolomics information but is underutilised due to a lack of familiarity and standardisation. Methods: This study explores the potential of spectroscopic imaging (MRSI) in combination with several machine learning approaches, including one-dimensional convolutional neural networks (1D-CNNs), to improve therapy response assessment. Preclinical GB (GL261-bearing mice) were studied for method optimisation and validation. Results: The proposed 1D-CNN models successfully identify different regions of tumours sampled by MRSI, i.e., normal brain (N), control/unresponsive tumour (T), and tumour responding to treatment (R). Class activation maps using Grad-CAM enabled the study of the key areas relevant to the models, providing model explainability. The generated colour-coded maps showing the N, T and R regions were highly accurate (according to Dice scores) when compared against ground truth and outperformed our previous method. Conclusions: The proposed methodology may provide new and better opportunities for therapy response assessment, potentially providing earlier hints of tumour relapsing stages. [ABSTRACT FROM AUTHOR]

Simple Summary: People with glioblastoma (GBM) universally have poor survival despite undergoing aggressive treatments. In this study, we aimed to determine genetic biomarkers of GBM that exhibit prognostic implications and examine their role in the tumor microenvironment. To this end, we performed differential gene expression analysis in three independent GBM datasets, followed by establishing a risk model for disease progression. Containing eight genes, this model demonstrated robustness in identifying patient subgroups with poor survival outcome in independent datasets. Glioblastoma (GBM) is one of the most progressive and prevalent cancers of the central nervous system. Identifying genetic markers is therefore crucial to predict prognosis and enhance treatment effectiveness in GBM. To this end, we obtained gene expression data of GBM from TCGA and GEO datasets and identified differentially expressed genes (DEGs), which were overlapped and used for survival analysis with univariate Cox regression. Next, the genes' biological significance and potential as immunotherapy candidates were examined using functional enrichment and immune infiltration analysis. Eight prognostic-related DEGs in GBM were identified, namely CRNDE, NRXN3, POPDC3, PTPRN, PTPRN2, SLC46A2, TIMP1, and TNFSF9. The derived risk model showed robustness in identifying patient subgroups with significantly poorer overall survival, as well as those with distinct GBM molecular subtypes and MGMT status. Furthermore, several correlations between the expression of the prognostic genes and immune infiltration cells were discovered. Overall, we propose a survival-derived risk score that can provide prognostic significance and guide therapeutic strategies for patients with GBM. [ABSTRACT FROM AUTHOR]

Simple Summary: Differentiating between glioma and primary central nervous system lymphoma (PCNSL) is difficult, and current diagnostic methods are of limited efficacy. Liquid biopsies that detect circulating biomarkers, such as microRNAs (miRs), may provide valuable insights into diagnostic biomarkers. In this review, a systematic search was conducted, and 16 dysregulated miRs were identified, including miR-21, which was the most prominent miR with higher levels in PCNSL, followed by the glioma and control groups. The lowest levels of miR-16 and miR-205 were observed in glioma, followed by PCNSL and control groups, whereas miR-15b and miR-301 were higher in both tumor groups, with the highest levels observed in glioma patients. The levels of miR-711 were higher in glioma (including GBM patients) and downregulated in PCNSL compared to the control group. Using these six circulating microRNAs as liquid biomarkers with unique changing patterns could aid in better discrimination between glioma and PCNSL. Differentiating glioma from primary central nervous system lymphoma (PCNSL) can be challenging, and current diagnostic measures such as MRI and biopsy are of limited efficacy. Liquid biopsies, which detect circulating biomarkers such as microRNAs (miRs), may provide valuable insights into diagnostic biomarkers for improved discrimination. This review aimed to investigate the role of specific miRs in diagnosing and differentiating glioma from PCNSL. A systematic search was conducted of PubMed, Scopus, Web of Science, and Embase for articles on liquid biopsies as a diagnostic method for glioma and PCNSL. Sixteen dysregulated miRs were identified with significantly different levels in glioma and PCNSL, including miR-21, which was the most prominent miR with higher levels in PCNSL, followed by glioma, including glioblastoma (GBM), and control groups. The lowest levels of miR-16 and miR-205 were observed in glioma, followed by PCNSL and control groups, whereas miR-15b and miR-301 were higher in both tumor groups, with the highest levels observed in glioma patients. The levels of miR-711 were higher in glioma (including GBM) and downregulated in PCNSL compared to the control group. This review suggests that using these six circulating microRNAs as liquid biomarkers with unique changing patterns could aid in better discrimination between glioma, especially GBM, and PCNSL. [ABSTRACT FROM AUTHOR]