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Abstract HOX transcript antisense RNA (HOTAIR) is upregulated in glioblastoma (GBM) and associated with temozolomide (TMZ) resistance. However, the mechanisms underlying HOTAIR-mediated TMZ resistance remains poorly understood. HOTAIR expression in glioma-related public datasets and drug response estimation were analyzed using bioinformatics. These findings were verified by overexpressing HOTAIR in TMZ-sensitive U251 cells and/or silencing HOTAIR in resistant U251 cells (U251R). The cytotoxic effects were evaluated using cell viability assay and flow cytometry analysis of cell cycle and apoptosis. In this study, we found that HOTAIR was upregulated in TMZ-resistant GBM cell lines and patients with high HOTAIR expression responded poorly to TMZ therapy. HOTAIR knockdown restored TMZ sensitivity in U251R cells, while HOTAIR overexpression conferred TMZ resistance in U251 cells. Wnt/β-catenin signaling was enriched in patients with high HOTAIR expression; consistently, HOTAIR positively regulated β-catenin expression in U251 cells. Moreover, HOTAIR-mediated TMZ resistance was associated with increased MGMT protein level, which resulted from the HOTAIR/miR-214-3p/β-catenin network. Besides, GBM with high HOTAIR expression exhibited sensitivity to methotrexate. Methotrexate enhanced TMZ sensitivity in U251R cells, accompanied by reduced expression of HOTAIR and β-catenin. Thus, we conlcude that HOTAIR is a risk factor for TMZ resistance and methotrexate may represent a potential therapeutic drug for patients with high HOTAIR expression level.

Abstract Interleukin-18, a member of the interleukin − 1 family of cytokines, is upregulated in glioma. However, its effects on glioma remain unclear. This study aimed to explore the role and underlying mechanisms of interleukin-18 expression in glioma. Here, we demonstrated that interleukin-18 enhanced resistance to temozolomide by increasing proliferation and inhibiting apoptosis in cultured glioma cells. Further in vivo studies revealed that interleukin-18 promoted temozolomide resistance in BALB/c nude mice bearing tumor. Mechanical exploration indicated that interleukin-18 stimulation could activate the PI3K/AKT signaling pathway in glioma cells, and PI3K inhibition could reduce the temozolomide resistance promoted by interleukin-18. We found that interleukin-18 upregulated CD274 expression in glioma, revealing its potential effects on the microenvironment. Furthermore, we established a tumor xenograft model and explored the therapeutic efficacy of anti-interleukin-18 monoclonal antibody. Targeting interleukin-18 prolonged survival and attenuated CD274 expression in the mice bearing tumor. Combined treatment with anti-interleukin-18 and anti-PD-1 monoclonal antibody showed better efficacy in suppressing tumor growth than either treatment alone in mice bearing tumor. Collectively, these data present that interleukin-18 promotes temozolomide chemoresistance in glioma cells via PI3K/Akt activation and establishes an immunosuppressive milieu by modulating CD274. This study highlights the therapeutic value of interleukin-18 in glioma.

Objective To explore the clinical features, treatment and prognosis of glioblastomas (GBM) in adults. Methods A retrospective cohort study was performed on 176 adult GBM patients admitted to our department from January 2015 to December 2021. Chi-square test was used to investigate the clinical differences between isocitrate dehydrogenase (IDH) mutant and wild-type GBM. Kaplan-Meier and Log-Rank tests were employed to plot survival curve and compute the survival analysis. Multivariate Cox regression model was applied to identify the independent prognostic factors. Results IDH wild-type GBM account for 89.2% and had significantly differences from the IDH-mutant GBM in terms of age of onset, Karnofsky (KPS) score at admission, symptoms of neurological deficit, and methylation status of O6-methylguanine-DNA-methyltransferase (MGMT) promoter (P < 0.05). For the IDH wild-type GBM patients receiving conventional therapy, univariate Cox hazard analysis showed gross total resection, methylation of MGMT promoter, initiation of radiation within the 5th to 6th week after surgery, and adjuvant temozolomide (TMZ) chemotherapy ≥6 cycles were favorable prognostic factors for overall survival (OS); GBMs in the left hemisphere, involvement of single lobe, methylation of MGMT promoter, and initiation of radiation within the 5th to 6th week after surgery were favorable prognostic factors for progression free survival (PFS) (all P < 0.05). Moreover, multivariate Cox hazard regression analysis indicated that methylation of MGMT promoter, and initiation of radiation within the 5th to 6th week after surgery, and adjuvant TMZ chemotherapy ≥6 cycles were independent protective factors for OS, and GBMs in the left hemisphere, involvement of single lobe and methylation of MGMT promoter were independent protective factors for PFS in the GBM patients (all P < 0.05). Conclusion The clinical and prognostic features are totally different between IDH mutant and wild-type GBM, and molecular detections are needed for the further pathological classification. Methylation of MGMT promoter is a primary marker of favorite prognosis for IDH wild-type GBM, and slightly delay in radiotherapy (the 5th to 6th week after surgery) can effectively improve the survival prognosis of IDH wild-type GBM.

Abstract Temozolomide (TMZ) resistance is a major challenge in the treatment of glioblastoma (GBM). Tumour reproductive cells (TRCs) have been implicated in the development of chemotherapy resistance. By culturing DBTRG cells in three-dimensional soft fibrin gels to enrich GBM TRCs and performing RNA-seq analysis, the expression of stanniocalcin-1 (STC), a gene encoding a secreted glycoprotein, was found to be upregulated in TRCs. Meanwhile, the viability of TMZ-treated TRC cells was significantly higher than that of TMZ-treated 2D cells. Analysis of clinical data from CGGA (Chinese Glioma Genome Atlas) database showed that high expression of STC1 was closely associated with poor prognosis, glioma grade and resistance to TMZ treatment, suggesting that STC1 may be involved in TMZ drug resistance. The expression of STC1 in tissues and cells was examined, as well as the effect of STC1 on GBM cell proliferation and TMZ-induced DNA damage. The results showed that overexpression of STC1 promoted and knockdown of STC1 inhibited TMZ-induced DNA damage. These results were validated in an intracranial tumour model. These data revealed that STC1 exerts regulatory functions on MGMT expression in GBM, and provides a rationale for targeting STC1 to overcome TMZ resistance.

Abstract Background Glioblastoma is an aggressive brain cancer, usually of unknown etiology, and with a very poor prognosis. Survival from diagnosis averages only 3 months if left untreated and this only increases to 12–15 months upon treatment. Treatment options are currently limited and typically comprise radiotherapy plus a course of the DNA-alkylating chemotherapeutic temozolomide. Unfortunately, the disease invariably relapses after several months of treatment with temozolomide, due to the development of resistance to the drug. Increased local tryptophan metabolism is a feature of many solid malignant tumours through increased expression of tryptophan metabolising enzymes. Glioblastomas are notable for featuring increased expression of the tryptophan catabolizing enzymes indole-2,3-dioxygenase-1 (IDO1), and especially tryptophan-2,3-dioxygenase-2 (TDO2). Increased IDO1 and TDO2 activity is known to suppress the cytotoxic T cell response to tumour cells, and this has led to the proposal that the IDO1 and TDO2 enzymes represent promising immuno-oncology targets. In addition to immune modulation, however, recent studies have also identified the activity of these enzymes is important in the development of resistance to chemotherapeutic agents. Methods In the current study, the efficacy of a novel dual inhibitor of IDO1 and TDO2, AT-0174, was assessed in an orthotopic mouse model of glioblastoma. C57BL/6J mice were stereotaxically implanted with GL261(luc2) cells into the striatum and then administered either vehicle control, temozolomide (8 mg/kg IP; five 8-day cycles of treatment every 2 days), AT-0174 (120 mg/kg/day PO) or both temozolomide + AT-0174, all given from day 7 after implantation. Results Temozolomide decreased tumour growth and improved median survival but increased the infiltration of CD4+ Tregs. AT-0174 had no significant effect on tumour growth or survival when given alone, but provided clear synergy in combination with temozolomide, further decreasing tumour growth and significantly improving survival, as well as elevating CD8+ T cell expression and decreasing CD4+ Treg infiltration. Conclusion AT-0174 exhibited an ideal profile for adjunct treatment of glioblastomas with the first-line chemotherapeutic drug temozolomide to prevent development of CD4+ Treg-mediated chemoresistance.

Abstract Background In the fight against GBM, drug repurposing emerges as a viable and time-saving approach to explore new treatment options. Chlorpromazine, an old antipsychotic medication, has recently arisen as a promising candidate for repositioning in GBM therapy in addition to temozolomide, the first-line standard of care. We previously demonstrated the antitumor efficacy of chlorpromazine and its synergistic effects with temozolomide in suppressing GBM cell malignant features in vitro. This prompted us to accomplish a Phase II clinical trial to evaluate the efficacy and safety of adding chlorpromazine to temozolomide in GBM patients with unmethylated MGMT gene promoter. In this in vitro study, we investigate the potential role of chlorpromazine in overcoming temozolomide resistance. Methods In our experimental set, we analyzed Connexin-43 expression at both the transcriptional and protein levels in control- and chlorpromazine-treated GBM cells. DNA damage and subsequent repair were assessed by immunofluorescence of γ-H2AX and Reverse-Phase Protein microArrays in chlorpromazine treated GBM cell lines. To elucidate the relationship between DNA repair systems and chemoresistance, we analyzed a signature of DNA repair genes in GBM cells after treatment with chlorpromazine, temozolomide and Connexin-43 downregulation. Results Chlorpromazine treatment significantly downregulated connexin-43 expression in GBM cells, consequently compromising connexin-dependent cellular resilience, and ultimately contributing to cell death. In line with this, we observed concordant post-translational modifications of molecular determinants involved in DNA damage and repair pathways. Our evaluation of DNA repair genes revealed that temozolomide elicited an increase, while chlorpromazine, as well as connexin-43 silencing, a decrease in DNA repair gene expression in GBM cells. Conclusions Chlorpromazine potentiates the cytotoxic effects of the alkylating agent temozolomide through a mechanism involving downregulation of Cx43 expression and disruption of the cell cycle arrest essential for DNA repair processes. This finding suggests that chlorpromazine may be a potential therapeutic strategy to overcome TMZ resistance in GBM cells by inhibiting their DNA repair mechanisms.

Abstract Glioblastoma (GBM) is an aggressive nervous system tumor with a poor prognosis. Although, surgery, radiation therapy, and chemotherapy are the current standard protocol for GBM patients, there is still a poor prognosis in these patients. Temozolomide (TMZ) as a first-line therapeutic agent in GBM can easily cross from the blood-brain barrier to inhibit tumor cell proliferation. However, there is a high rate of TMZ resistance in GBM patients. Since, there are limited therapeutic choices for GBM patients who develop TMZ resistance; it is required to clarify the molecular mechanisms of chemo resistance to introduce the novel therapeutic targets. MicroRNAs (miRNAs) regulate chemo resistance through regulation of drug metabolism, absorption, DNA repair, apoptosis, and cell cycle. In the present review we discussed the role of miRNAs in TMZ response of GBM cells. It has been reported that miRNAs mainly induced TMZ sensitivity by regulation of signaling pathways and autophagy in GBM cells. Therefore, miRNAs can be used as the reliable diagnostic/prognostic markers in GBM patients. They can also be used as the therapeutic targets to improve the TMZ response in GBM cells.

Abstract Purpose Diffuse midline glioma (DMG), H3 K27M-mutant is a type of diffuse high-grade glioma that occurs in the brain midline carrying an extremely poor prognosis under the best efforts of surgery, radiation, and other therapies. For better therapy, we explored the efficacy and toxicity of a novel therapy that combines apatinib and temozolomide in DMG. Methods A retrospective analysis of 32 patients with DMG who underwent apatinib plus temozolomide treatment was performed. Apatinib was given 500 mg in adults, 250 mg in pediatric patients once daily. Temozolomide was administered at 200 mg/m2/d according to the standard 5/28 days regimen. The main clinical data included basic information of patients, radiological and pathological characteristics of tumors, treatment, adverse reactions, prognosis. Results The objective response rate was 24.1%, and the disease control rate was 79.3%. The median PFS of all patients was 5.8 months, and median OS was 10.3 months. A total of 236 cycles of treatment were available for safety assessment and the toxicity of the combination therapy was relatively well tolerated. The most common grade 3 toxicities were myelosuppression including leukopenia (5.08%), neutropenia (4.24%), lymphopenia (2.12%), thrombocytopenia (1.69%) and anemia (1.27%). Grade 4 toxicities included neutropenia (2.12%), thrombocytopenia (2.12%) and proteinuria (1.69%). All the adverse events were relieved after symptomatic treatment or dose reduction. Conclusions Apatinib plus temozolomide could be an effective regimen with manageable toxicities and favorable efficacy and may outperform temozolomide monotherapy, particularly in newly diagnosed adults with tumors located outside the pons. The novel therapy deserves further investigation in adult DMG patients.

IntroductionPituitary carcinoma (PC) is an extremely rare tumor of the adenohypophysis, which manifests as craniospinal dissemination and/or systemic metastasis. The diagnosis of PC is particularly difficult, as the clinical diagnosis only can be made after the metastasis is found. Owing to the complex diagnostic process and less effective treatments, the clinical prognosis of PC is usually very poor. Hence, it is of great significance to illustrate the diagnosis and treatment course of PC.MethodsIn this case report, we described a 48-year-old male patient who was diagnosed with pituitary adenoma (PA) initially and then was diagnosed with PC eventually after spinal cord metastasis was found, and we illustrated the treatment course as well. Furthermore, we summarized all the published case reports until now and provided a comprehensive review of the diagnosis, treatment, prediction, and clinical outcome of PC.Results and ConclusionsWe found that most PC patients had adrenocorticotropic hormone/prolactin (ACTH/PRL)-secreting tumors, Ki-67 ≥ 10%, and P53 positivity, which may have the potential to predict the transformation from PA to PC; surgery excision combined with temozolomide (TMZ) and radiotherapy is helpful to prolong the survival of PC patients.

ABSTRACT Objectives Glioblastoma multiforme (GBM) is considered the most assailant subtype of gliomas, presenting a formidable obstacle because of its inherent resistance to temozolomide (TMZ). This study aimed to characterize the function of lncRNA NEAT1 in facilitating the advancement of gliomas. Methods The expression level of NEAT1 in glioma tissues and cells was detected by qRT‐PCR. RNA interference experiment, cell proliferation assay, FITC/PI detection assay, immunoblotting, bioinformatics prediction, a double luciferase reporter gene assay, RNA immunoprecipitation (RIP) assay, SLDT assay and correlation analysis of clinical samples were performed to explore the regulatory effects of NEAT1, miR‐454‐3p and Cx43 and their role in malignant progression of GBM. The role of NEAT1 in vivo was investigated by an intracranial tumor formation experiment in mice. Results The results showed that recurring gliomas displayed elevated levels of NEAT1 compared to primary gliomas. The suppression of NEAT1 led to a restoration of sensitivity in GBM cells to TMZ. NEAT1 functioned as a competitive endogenous RNA against miR‐454‐3p. Connexin 43 was identified as a miR‐454‐3p target. NEAT1 was found to regulate gap junctional intercellular communication by modulating Connexin 43, thereby impacting the response of GBM cells to TMZ chemotherapy. Downregulation of NEAT1 resulted in enhanced chemosensitivity to TMZ and extended the survival of mice. Conclusions Overall, these results indicated that the NEAT1/miR‐454‐3p/Connexin 43 pathway influences GBM cell response to TMZ and could offer a potential new strategy for treating GBM.

Targeted drug delivery for primary brain tumors, particularly gliomas, is currently a promising approach to reduce patient relapse rates. The use of substitutable scaffolds, which enable the sustained release of clinically relevant doses of anticancer medications, offers the potential to decrease the toxic burden on the patient’s organism while also enhancing their quality of life and overall survival. Upconversion nanoparticles (UCNPs) are being actively explored as promising agents for detection and monitoring of tumor growth, and as therapeutic agents that can provide isolated therapeutic effects and enhance standard chemotherapy. Our study is focused on the feasibility of constructing scaffolds using methacrylated hyaluronic acid with additional impregnation of UCNPs and the chemotherapeutic drug temozolomide (TMZ) for glioma treatment. The designed scaffolds have been demonstrated their efficacy as a drug and UCNPs delivery system for gliomas. Using the aggressive orthotopic glioma model in vivo, it was found that the scaffolds possess the capacity to ameliorate neurological disorders in mice. Moreover, upon intracranial co-implantation of the scaffolds and glioma cells, the constructs disintegrate into distinct segments, augmenting the release of UCNPs into the surrounding tissue and concurrently reducing postoperative damage to brain tissue. The use of TMZ in the scaffold composition contributed to restraining glioma development and the reduction of tumor invasiveness. Our findings unveil promising prospects for the application of photopolymerizable biocompatible scaffolds in the realm of neuro-oncology.

Abstract O6‐methylguanine DNA methyltransferase (MGMT) removes alkyl adducts from the guanine O6 position (O6‐MG) and repairs DNA damage. High MGMT expression results in poor response to temozolomide (TMZ). However, the biological importance of MGMT and the mechanism underlying its high expression in pancreatic neuroendocrine tumors (PanNETs) remain elusive. Here, it is found that MGMT expression is highly elevated in PanNET tissues compared with paired normal tissues and negatively associated with progression‐free survival (PFS) time in patients with PanNETs. Knocking out MGMT inhibits cancer cell growth in vitro and in vivo. Ectopic MEN1 expression suppresses MGMT transcription in a manner that depends on β‐Catenin nuclear export and degradation. The Leucine 267 residue of MEN1 is crucial for regulating β‐Catenin‐MGMT axis activation and chemosensitivity to TMZ. Interference with β‐Catenin re‐sensitizes tumor cells to TMZ and significantly reduces the cytotoxic effects of high‐dose TMZ treatment, and MGMT overexpression counteracts the effects of β‐Catenin deficiency. This study reveals the biological importance of MGMT and a new mechanism by which MEN1 deficiency regulates its expression, thus providing a potential combinational strategy for treating patients with TMZ‐resistant PanNETs.

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor among adults. Despite advancements in multimodality therapy for GBM, the overall prognosis remains poor, with an extremely high risk of recurrence. Currently, there is no established consensus on the optimal treatment option for recurrent GBM, which may include reoperation, reirradiation, chemotherapy, or a combination of the above. Bevacizumab is considered a first-line treatment option for recurrent GBM, as is temozolomide. However, in recurrent GBM, it is necessary to balance the risks and benefits of reirradiation in combination with bevacizumab and temozolomide. Herein, we report the case of a patient with recurrent GBM after standard treatment who benefited from stereotactic radiotherapy followed by bevacizumab and temozolomide maintenance therapy. Following 16 months of concurrent chemoradiotherapy (CCRT), the patient was diagnosed with recurrent GBM by a 3-T contrast-enhanced magnetic resonance imaging (MRI). The addition of localized radiotherapy to the ongoing treatment regimen of bevacizumab, in combination with temozolomide therapy, prolonged the patient’s disease-free survival to over 2 years, achieving a significant long-term outcome, with no notable adverse effects observed. This clinical case may provide a promising new option for patients with recurrent GBM.

AimsThis study aims to systematically analyze the global trends in glioma methylation research using bibliometric methodologies. We focus on identifying the scholarly trajectory and key research interests, and we utilize these insights to predict future research directions within the epigenetic context of glioma.MethodsWe performed a comprehensive literature search of the Web of Science Core Collection (WoSCC) to identify articles related to glioma methylation published from January 1, 2004, to December 31, 2023. The analysis included full-text publications in the English language and excluded non-research publications. Analysis and visualization were performed using GraphPad Prism, CiteSpace, and VOSviewer software.ResultsThe search identified 3,744 publications within the WoSCC database, including 3,124 original research articles and 620 review articles. The research output gradually increased from 2004 to 2007, followed by a significant increase after 2008, which peaked in 2022. A minor decline in publication output was noted during 2020–2021, potentially linked to the coronavirus disease 2019 pandemic. The United States and China were the leading contributors, collectively accounting for 57.85% of the total research output. The Helmholtz Association of Germany, the German Cancer Research Center (DKFZ), and the Ruprecht Karls University of Heidelberg were the most productive institutions. The Journal of Neuro-Oncology led in terms of publication volume, while Neuro-Oncology had the highest Impact Factor. The analysis of publishing authors revealed Michael Weller as the most prolific contributor. The co-citation network analysis identified David N. Louis's article as the most frequently cited. The keyword analysis revealed “temozolomide,” “expression,” “survival,” and “DNA methylation” as the most prominent keywords, while “heterogeneity,” “overall survival,” and “tumor microenvironment” showed the strongest citation bursts.ConclusionsThe findings of this study illustrate the increasing scholarly interest in glioma methylation, with a notable increase in research output over the past two decades. This study provides a comprehensive overview of the research landscape, highlighting the importance of temozolomide, DNA methylation, and the tumor microenvironment in glioma research. Despite its limitations, this study offers valuable insights into the current research trends and potential future directions, particularly in the realm of immunotherapy and epigenetic editing techniques.

In recent years, the application of engineered NMts has significantly contributed to various biomedical fields. ZnO NMts (ZnO NMts) are widely utilized due to their biocompatibility, unique physical and chemical properties, stability, and cost-effectiveness for large-scale production. They have emerged as potential materials for anti-cancer applications. This study aims to study the impact of ZnO Nanorod flowers (ZnO NRfs) and their combination with temozolomide (TMZ) on glioma cells. Normal mouse microglia (BV2) will be used as a control to assess the effects on mouse glioma cells (G422) and human glioma cells (LN229). The effects of these substances were evaluated on G422 and LN229 cells through various parameters such as IC50 value, Zn2+ accumulation, ROS production, apoptosis, mitochondrial membrane potential (MMP) depolarization, and examination of organelles like mitochondria and lysosomes. Additionally, hypoxia-inducible factor-1α (HIF-1α), endothelial cell PAS domain protein 1 (EPAS1), autophagy markers (LC3), mitophagy and phagocytosis marker (BNIP3) were assessed. The results demonstrated that the combination of ZnO NRfs and TMZ could influence the expression of HIF-1α, EPAS1, LC3, and BNIP3 proteins, leading to mitophagy in glioma cells. This combination treatment has the potential to effectively eliminate glioma cells by activating the mitophagy pathway, which provides a good prospect for the clinical treatment of glioma.

Objective: Glioblastomas are highly vascularized malignant tumors. We determined the efficacy and safety of the anti-angiogenic multi-kinase inhibitor, anlotinib, for a newly diagnosed glioblastoma. Methods: This multicenter, single-arm trial (NCT04119674) enrolled 33 treatment-naïve patients with histologically proven glioblastomas between March 2019 and November 2020. Patients underwent treatment with the standard STUPP regimen [fractionated focal irradiation in daily fractions of 1.8-2 Gy given 5 d/w × 6 w (total = 54-60 Gy)] or radiotherapy plus continuous daily temozolomide (TMZ) (75 mg/m2 of body surface area/d, 7 d/w from the first to the last day of radiotherapy), followed by 6 cycles of adjuvant TMZ (150–200 mg/m2 × 5 d during each 28-d cycle) plus anlotinib (8 mg/d on d 1–14 of each 3-w cycle for 2 cycles during concomitant chemoradiotherapy, 8 maximal cycles as adjuvant therapy, followed by maintenance at 8 mg/d. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and adverse events (AEs). Results: Thirty-three patients received the planned treatment. The median PFS was 10.9 months (95% CI, 9.9–18.7 months) and the 12-month PFS rate was 48.5%. The median OS was 17.4 months (95% CI, 14.5–21.1 months) and the 12-month OS rate was 81.8%. The most common AEs included hypertriglyceridemia [58% (n = 19)], hypoalbuminemia [46% (n = 15)], and hypercholesterolemia [46% (n = 15)] during concurrent chemoradiotherapy and leukopenia [73% (n = 24)], hypertriglyceridemia [67% (n = 22)], and neutropenia [52% (n = 17)] during adjuvant therapy. Five patients discontinued treatment due to AEs. HEG1 (HR, 5.6; 95% CI, 1.3–23.7; P = 0.021) and RP1L1 alterations (HR, 11.1; 95% CI, 2.2–57.2; P = 0.004) were associated with a significantly shorter PFS. Conclusions: Anlotinib plus the STUPP regimen has promising anti-tumor activity against glioblastoma and manageable toxicity. HEG1 and RP1L1 alterations might be novel predictive biomarkers of the response to anlotinib.

Abstract Glioblastoma (GBM) is the most aggressive primary brain tumor with low survival rate. Currently, temozolomide (TMZ) is the first-line drug for GBM treatment of which efficacy is unfortunately hindered by short circulation time and drug resistance associated to hypoxia and redox tumor microenvironment. Herein, a dual-targeted and multi-responsive nanoplatform is developed by loading TMZ in hollow manganese dioxide nanoparticles functionalized by polydopamine and targeting ligands RAP12 for photothermal and receptor-mediated dual-targeted delivery, respectively. After accumulated in GBM tumor site, the nanoplatform could respond to tumor microenvironment and simultaneously release manganese ion (Mn2+), oxygen (O2) and TMZ. The hypoxia alleviation via O2 production, the redox balance disruption via glutathione consumption and the reactive oxygen species generation, together would down-regulate the expression of O6-methylguanine-DNA methyltransferase under TMZ medication, which is considered as the key to drug resistance. These strategies could synergistically alleviate hypoxia microenvironment and overcome TMZ resistance, further enhancing the anti-tumor effect of chemotherapy/chemodynamic therapy against GBM. Additionally, the released Mn2+ could also be utilized as a magnetic resonance imaging contrast agent for monitoring treatment efficiency. Our study demonstrated that this nanoplatform provides an alternative approach to the challenges including low delivery efficiency and drug resistance of chemotherapeutics, which eventually appears to be a potential avenue in GBM treatment.

Abstract A direct strategy to achieve specific treatments and reduce side effects is through cell type‐specific drug delivery. Exosomes (Exos) can be modified with folic acid (FA) to prepare drug delivery systems targeting tumor cells that highly express FA receptors. This study aimed to produce an exo drug delivery system with FA decoration and temozolomide (TMZ) loading to improve the sustained TMZ release and targeting. We used DSPE‐PEG2000‐FA to modify exos derived from astrocyte U‐87 to prepare FA‐modified exos (Astro‐exo‐FA). TMZ was encapsulated into Astro‐exo‐FA or Astro‐exo through electroporation to produce TMZ@Astro‐exo and TMZ@Astro‐exo‐FA. In vitro drug release was examined using the dialysis bag method. Through cell experiments in vitro and mouse glioma models in vivo, the effect of TMZ@Astro‐exo‐FA on U‐87 cells was determined. Exo properties were not affected by FA modification and TMZ loading. The drug release rate of TMZ@Astro‐exo‐FA was slower. TMZ@Astro‐exo‐FA uptake by U‐87 cells was higher compared to TMZ@Astro‐exo, indicating that TMZ@Astro‐exo‐FA has a stronger targeting toward U‐87 cells. TMZ@Astro‐exo‐FA remarkably reduced U‐87 cell proliferation, migration, and invasion compared with TMZ@Astro‐exo and free TMZ. Treatment with TMZ@Astro‐exo‐FA reduced the side effects of TMZ (minimal change in body weight), prolonged survival, and inhibited tumor growth in mouse glioma models, and its efficacy was stronger than that of TMZ@Astro‐exo and free TMZ. TMZ@Astro‐exo‐FA could enhance the effect of TMZ against glioma, providing novel ideas for drug targeting delivery and exploring exos as drug carriers against glioma.

Abstract Background Glioblastoma is a malignant and aggressive type of central nevous system malignancy characterized by many distinct biological features including extensive hypoxia. Hypoxia in glioblatoma associates with complex signaling patterns including activation of several pathways such as MAPK, PI3K-AKT/mTOR and IL-6/JAK/STAT3 with the master regulator HIF-1, which in turn drive particular tumor behaviors determining, in the end, treatment outcomes and patients fate. Thus, the present study was designed to investigate the expression of selected hypoxia related factors including STAT3 in a small set of long-term surviving glioma patients. Methods The expression of selected hypoxia related factors including STAT3 was evaluated in a time series of formalin fixed paraffin embedded and cryopreserved glioma samples from repeatedly resected patients. In addition, comparative studies were also conducted on primary glioma cells derived from original patient samples, stabilized glioma cell lines and tumor-xenograft mice model. Obtained data were correlated with clinical findings too. Results Glioblastoma samples of the analyzed patients displayed heterogeneity in the expression of hypoxia- related and EMT markers with most interesting trend being observed in pSTAT3. This heterogeneity was subsequently confirmed in other employed models (primocultures derived from glioblastoma tissue resections, cryopreserved tumor specimens, stabilized glioblastoma cell line in vitro and in vivo) and concerned, in particular, STAT3 expression which remained stable. In addition, subsequent studies on the role of STAT3 in the context of glioblastoma hypoxia demonstrated opposing effects of its deletion on cell viability as well as the expression of hypoxia and EMT markers. Conclusions Our results suport the importance of STAT3 expression and activity in the context of hypoxia in malignant glioblastoma long-term surviving glioma patients while emphasizing heterogeneity of biological outcomes in varying employed tumor models.

Abstract Background Temozolomide (TMZ) is an effective oral alkylating agent used in treating glioblastoma multiforme (GBM) and high-grade gliomas. It works by introducing methyl groups into DNA, inhibiting cell division. A case of blepharoconjunctivitis linked to the administration of TMZ is detailed in this report. Case presentation We present a case of a 58-year-old African-American man diagnosed with GBM. Following adjuvant TMZ treatment, he developed blepharoconjunctivitis, characterized by eyelid and conjunctival inflammation. Symptoms included eyelid swelling, crusting, and conjunctival discharge, which were promptly resolved with topical steroid cream and eye drops. Conclusions Reports specifically linking TMZ to blepharoconjunctivitis are limited. The exact mechanism remains unclear but may involve inflammation extending from blepharitis to the conjunctiva. Healthcare providers must recognize and manage ophthalmic complications promptly. This case report highlights blepharoconjunctivitis associated with TMZ use in a GBM patient. While TMZ is an effective treatment, ophthalmic side effects can occur.

Abstract Objective Glioma, a malignant primary brain tumor, is notorious for its high incidence rate. However, the clinical application of temozolomide (TMZ) as a treatment option for glioma is often limited due to resistance, which has been linked to hypoxic glioma cell-released exosomes. In light of this, the present study aimed to investigate the role of exosomal pyruvate kinase M2 (PKM2) in glioma cells that exhibit resistance to TMZ. Methods Sensitive and TMZ-resistant glioma cells were subjected to either a normoxic or hypoxic environment, and the growth patterns and enzymatic activity of glycolysis enzymes were subsequently measured. From these cells, exosomal PKM2 was isolated and the subsequent effect on TMZ resistance was examined and characterized, with a particular focus on understanding the relevant mechanisms. Furthermore, the intercellular communication between hypoxic resistant cells and tumor-associated macrophages (TAMs) via exosomal PKM2 was also assessed. Results The adverse impact of hypoxic microenvironments on TMZ resistance in glioma cells was identified and characterized. Among the three glycolysis enzymes that were examined, PKM2 was found to be a critical mediator in hypoxia-triggered TMZ resistance. Upregulation of PKM2 was found to exacerbate the hypoxia-mediated TMZ resistance. Exosomal PKM2 were identified and isolated from hypoxic TMZ-resistant glioma cells, and were found to be responsible for transmitting TMZ resistance to sensitive glioma cells. The exosomal PKM2 also contributed towards mitigating TMZ-induced apoptosis in sensitive glioma cells, while also causing intracellular ROS accumulation. Additionally, hypoxic resistant cells also released exosomal PKM2, which facilitated TMZ resistance in tumor-associated macrophages. Conclusion In the hypoxic microenvironment, glioma cells become resistant to TMZ due to the delivery of PKM2 by exosomes. Targeted modulation of exosomal PKM2 may be a promising strategy for overcoming TMZ resistance in glioma.

Glioblastoma multiform (GBM) is a commonly diagnosed brain neoplasm with a poor prognosis. Accumulating evidence has highlighted the significance of microRNA (miR) dysregulation in tumor development and progression. This study investigated the effect of hsa-miR-34a-5p and its combination with temozolomide on GBM, the related molecular mechanisms, and the signaling pathway using in-silico and in-vitro approaches. The in-silico tumor bulk and single-cell RNA sequencing analyses were done on TCGA-GTEx, CGGA, GSE13276, GSE90603, and GSE182109 datasets. After selecting the A172 cell line, hsa-miR-34a-5p mimics were transfected, and the cell viability, migration, cell cycle, clonogenicity, and apoptosis of studied groups were studied using MTT, scratch, flow cytometry, colony formation, and Annexin V/PI assays. The mRNA expression of CASP9, CASP3, CASP8, MMP2, CD44, CDK6, CDK4, CCND1, RAF1, MAP2K1, MET, SRC, and CD274 was studied using qRT-PCR method. hsa-miR-34a-5p downregulated RAF1 expression, as the signaling factor of the MAPK pathway. The combined treatment significantly downregulated the expression of MET, SRC, and MAP2K1, leading to the inhibition of the MET/MAPK pathway compared to temozolomide. Besides exerting anti-tumoral effects on the cell viability, migration, cell cycle, apoptosis, and clonogenicity of A172 cells, its combination with temozolomide enhanced temozolomide anti-tumoral effect. Compared to temozolomide, the combined treatment significantly decreased CDK4, CDK6, CCND1, and MMP2 expression. hsa-miR-34a-5p targets RAF1, as the signaling factor of the MAPK pathway, and potentiates the temozolomide anti-tumoral effect on A172 cells.

Abstract Background Impact of Isocitrate dehydrogenase1 (IDH1) and O6-methylguanine-DNA methyltransferase (MGMT) in glioblastoma (GBM) have been of great interest due to their implications in prediction of prognosis of several types of cancer. It was aimed to investigate the clinical role of IDH1 mutation and MGMT methylation pattern among GBM patients versus non-neuro-oncological diseases (NND) patients and their impact on survival criteria. Methods Formalin-fixed paraffin-embedded (FFPE) tissue sections of 58 GBM and 20 non-neuro-oncological diseases patients were recruited and IDH1 mutation and MGMT methylation was detected using Cast-PCR technology and Methyl II quantitative PCR approach, respectively. Results were assessed with other clinicopathological criteria and survival patterns. Results IDH1 mutation was detected among 15 GBM cases (15/58) and it was not reported among NND (P = 0.011). Receiver operating characteristic (ROC) curve was plotted to discriminate between MGMT methylation among studied groups. Patients with MGMT methylation ≥ 66% were reported as high methylation, which was recorded significantly in 51.7% and 100% of GBM cases and NND, respectively. Both showed significant difference with performance status, while MGMT methylation was significantly related with tumor size and tumor location. IDH1 mutation and MGMT methylation reported significant increase with GB patients revealed complete response to treatment. Survival pattern was better for IDH1 mutation and MGMT high methylation as compared to IDH1 wild type or MGMT low–moderate methylation, respectively, and favorable survival was detected when both were combined than using either of them alone. Conclusion Detection of IDH1 mutation and MGMT methylation among GB patients could aid in prediction of their response to treatment and their survival patterns, and their combination is better than using any of them alone.

Abstract Background Glioblastoma multiform (GBM) is among the commonly diagnosed brain malignancies with poor prognosis. CD133 has been introduced as an oncogene in various cancers, like GBM. This study aimed to investigate the significance of CD133 in GBM development using in silico and in vitro techniques. Method The TCGA-GBM database was analyzed for the correlational and comparative studies. After selecting the U87MG cell line, CD133-siRNA was transfected into U87MG cells and treated with temozolomide. The cell viability, cell cycle, migration, clonogenicity, and apoptosis of groups were investigated using MTT, flow cytometry, wound-healing, colony formation, and annexin V/PI assays. Using qRT-PCR method, the mRNA expression levels of MMP16, SOX2, RAF1, MAP2K1, MAPK3, PIK3CA, AKT3, mTOR, CDK4, and BCL2 were studied. Results CD133 silencing improves apoptosis rate, arrests the cell cycle at the sub-G1 phase, suppresses the clonogenicity of U87MG cells, and inhibits the PI3K/Akt and MAPK pathways via downregulating the RAF1, MAP2K1, MAPK3, PIK3CA, AKT3, and mTOR expression. Besides, combining CD133 silencing with temozolomide treatment considerably inhibits the migration of U87MG cells compared to temozolomide monotherapy. Conclusion CD133 can regulate the PI3K/Akt and MAPK pathways and modulate the clonogenicity, apoptosis, and cell cycle of GBM. Combining CD133 silencing with temozolomide treatment considerably increases apoptosis, arrests the cell cycle at the sub-G1, and suppresses migration of U87MG cells compared to temozolomide monotherapy. Graphical Abstract

Abstract Background Glioblastoma multiforme (GBM) is the most aggressive form of brain cancer, and chemoresistance poses a significant challenge to the survival and prognosis of GBM. Although numerous regulatory mechanisms that contribute to chemoresistance have been identified, many questions remain unanswered. This study aims to identify the mechanism of temozolomide (TMZ) resistance in GBM. Methods Bioinformatics and antibody-based protein detection were used to examine the expression of E2F7 in gliomas and its correlation with prognosis. Additionally, IC50, cell viability, colony formation, apoptosis, doxorubicin (Dox) uptake, and intracranial transplantation were used to confirm the role of E2F7 in TMZ resistance, using our established TMZ-resistance (TMZ-R) model. Western blot and ChIP experiments provided confirmation of p53-driven regulation of E2F7. Results Elevated levels of E2F7 were detected in GBM tissue and were correlated with a poor prognosis for patients. E2F7 was found to be upregulated in TMZ-R tumors, and its high levels were linked to increased chemotherapy resistance by limiting drug uptake and decreasing DNA damage. The expression of E2F7 was also found to be regulated by the activation of p53. Conclusions The high expression of E2F7, regulated by activated p53, confers chemoresistance to GBM cells by inhibiting drug uptake and DNA damage. These findings highlight the significant connection between sustained p53 activation and GBM chemoresistance, offering the potential for new strategies to overcome this resistance.

ABSTRACTGBM is one of the most malignant tumor in central nervous system. The resistance to temozolomide (TMZ) is inevitable in GBM and the characterization of TMZ resistance seriously hinders clinical treatment. It is worthwhile exploring the underlying mechanism of aggressive invasion and TMZ resistance in GBM treatment. Bioinformatic analysis was used to analyze the association between RND1 and a series of EMT-related genes. Colony formation assay and cell viability assay were used to assess the growth of U87 and U251 cells. The cell invasion status was evaluated based on transwell and wound-healing assays. Western blot was used to detect the protein expression in GBM cells. Treatment targeted RND1 combined with TMZ therapy was conducted in nude mice to evaluate the potential application of RND1 as a clinical target for GBM. The overexpression of RND1 suppressed the progression and migration of U87 and U251 cells. RND1 knockdown facilitated the growth and invasion of GBM cells. RND1 regulated the EMT of GBM cells via inhibiting the phosphorylation of AKT and GSK3-β. The promoted effects of RND1 on TMZ sensitivity was identified both in vitro and in vivo. This research demonstrated that the overexpression of RND1 suppressed the migration and EMT status by downregulating AKT/GSK3-β pathway in GBM. RND1 enhanced the TMZ sensitivity of GBM cells both in vitro and in vivo. Our findings may contribute to the targeted therapy for GBM and the understanding of mechanisms of TMZ resistance in GBM.

BackgroundTemozolomide, which is the standard drug for glioma treatment, has several Adverse events (AEs) in the treatment of gliomas and other tumors that are not yet fully understood. This is due to the pharmacological nature of the alkylating agent. A significant proportion of these effects have not been systematically documented or reported.MethodsWe selected data from the United States FDA Adverse Event Reporting System (FAERS) database from the first quarter of 2004 to the fourth quarter of 2023. Four algorithms were used for disproportionate analysis, with the objective of assessing the association between temozolomide and related adverse events.ResultsIn this study, 20,079,906 case reports were collected from the FAERS database, of which 15,152 adverse events related to temozolomide were reported. A total of 352 preferred terms (PTs) and 24 system organ classes (SOCs) that were significantly disproportionally related to the four algorithms were included. The SOCs included blood and lymphatic system disorders (χ2 = 18,220.09, n = 4,325); skin and subcutaneous tissue disorders (χ2 = 408.06, n = 1,347); investigations (χ2 = 639.44, n = 3,925); musculoskeletal and connective tissue disorders (χ2 = 1,317.29, n = 588); and psychiatric disorders (χ2 = 1,098.47, n = 877). PT levels were screened for adverse drug reaction signals consistent with drug inserts, such as anemia, thrombocytopenia, liver function abnormalities, nausea and vomiting, as well as rarely reported adverse drug reactions, such as aplastic anemia, myelodysplastic syndromes, electrolyte disorders, cerebral edema, and high-frequency mutations.ConclusionThe results of our investigation demonstrated both adverse effects that had been reported and a multitude of unreported adverse effects that were serious in nature and lacked a clear cause. These novel findings suggest that more attention should be given to the clinical conditions of patients after treatment to provide a more comprehensive perspective and understanding for further clarifying the safety of temozolomide.

ObjectiveThe objective of this study is to assess the viability of utilizing radiomics for predicting the treatment response of lung cancer brain metastases (LCBM) to whole-brain radiotherapy (WBRT) combined with temozolomide (TMZ).MethodsFifty-three patients diagnosed with LCBM and undergoing WBRT combined with TMZ were enrolled. Patients were divided into responsive and non-responsive groups based on the RANO-BM criteria. Radiomic features were extracted from contrast-enhanced the whole brain tissue CT images. Feature selection was performed using t-tests, Pearson correlation coefficients, and Least Absolute Shrinkage And Selection (LASSO) regression. Logistic regression was employed to construct the radiomics model, which was then integrated with clinical data to develop the nomogram model. Model performance was evaluated using receiver operating characteristic (ROC) curves, and clinical utility was assessed using decision curve analysis (DCA).ResultsA total of 1834 radiomic features were extracted from each patient's images, and 3 features with predictive value were selected. Both the radiomics and nomogram models exhibited satisfactory predictive performance and clinical utility, with the nomogram model demonstrating superior predictive value. The ROC analysis revealed that the AUC of the radiomics model in the training and testing sets were 0.776 and 0.767, respectively, while the AUC of the nomogram model were 0.799 and 0.833, respectively. DCA curves demonstrated that both models provided benefits to patients across various thresholds.ConclusionRadiomic-defined image biomarkers can effectively predict the treatment response of WBRT combined with TMZ in patients with LCBM, offering potential to optimize treatment decisions for this condition.

ABSTRACT: Prolactinoma is a benign tumor of the pituitary gland that leads to the overproduction of prolactin. It is the most common type of pituitary adenoma, accounting for approximately 50% of all pituitary tumors. The clinical presentation of prolactinoma varies depending on the level of prolactin elevation and the size of the tumor. In women, common symptoms include galactorrhea, amenorrhea, and infertility. Men may present with hypogonadism, decreased libido, erectile dysfunction, and gynecomastia. Large prolactinomas, known as macroadenomas, can cause mass effects such as headaches, visual disturbances due to compression of the optic chiasm, and hypopituitarism due to pressure on surrounding pituitary tissue. Understanding the pathogenesis of prolactinoma is crucial for developing effective treatments and improving patient outcomes. The development of prolactinomas involves a complex interplay of genetic, hormonal, and cellular factors. Treatment of prolactinoma aims to normalize prolactin levels, reduce tumor size, and alleviate symptoms. The first-line therapy is dopamine agonists, such as cabergoline and bromocriptine, with surgery and radiotherapy reserved for refractory cases. Furthermore, chemotherapeutic agent - temozolomide may be a treatment of choice in aggressive or malignant prolactinomas. By understanding the underlying mechanisms and different treatment methods, healthcare providers can optimize the management and outcomes for patients with prolactinoma.

Chromobox (CBX) 2, a member of the CBX protein family and a crucial component of the polycomb repressive complex (PRC), exerts significant influence on the epigenetic regulation of tumorigenesis, including glioma. However, the precise role of CBX2 in glioma has remained elusive. In our study, we observed a substantial upregulation of CBX2 expression in glioma, which displayed a strong correlation with pathological grade, chemoresistance, and unfavorable prognosis. Through a series of in vivo and in vitro experiments, we established that heightened CBX2 expression facilitated glioma cell proliferation and bolstered resistance to chemotherapy. Conversely, CBX2 knockdown led to a significant inhibition of glioma cell growth and a reduction in chemoresistance. Notably, our investigation uncovered the underlying mechanism by which CBX2 operates, primarily by inhibiting PTEN transcription and activating the AKT/mTOR signalling pathway. Conversely, silencing CBX2 curtailed cell proliferation and attenuated chemoresistance by impeding the activation of the PTEN/AKT/mTOR signalling pathway. Delving deeper into the molecular intricacies, we discovered that CBX2 can recruit EZH2 and modulate the trimethylation of histone H3 lysine 27 (H3K27me3) levels on the PTEN promoter, effectively suppressing PTEN transcription. Our research unveils a comprehensive understanding of how CBX2 impacts the tumorigenesis, progression, chemoresistance, and prognosis of glioma. Furthermore, it presents CBX2 as a promising therapeutic target for drug development and clinical management of glioma.

IntroductionGlioblastoma, despite advancements in molecular evolution, remains incurable and has low survival rates. Currently, two of the most commonly used chemotherapy regimens are temozolomide and CCNU. This review aims to provide a comprehensive analysis of the current status of chemotherapy strategies for GBM.MethodsWe reviewed the published literature describing the chemotherapy regimen differences in system treatment of GBM reported in the last ten years and summarised the available information that may reveal the latest changes in chemotherapy.ResultsIn patients with adequate functioning, temozolomide and radiation are the primary treatments for newly diagnosed GBM. We recommend postoperative radiation therapy with concurrent and adjuvant temozolomide for patients with MGMT-methylated GBM who are less than 70 years old. Combining temozolomide and lomustine with radiation therapy may be an option for younger, fit patients, but efficacy data is inconclusive. For patients with unknown MGMT methylation status, radiation therapy combined with temozolomide remains the standard of care. We recommend hypofractionated radiation and concurrent temozolomide treatment for elderly patients over 70 years old who have satisfactory performance and no significant underlying health conditions. We should tailor treatment choices to each patient’s personal preferences, previous treatments, function, quality of life, and overall care objectives.ConclusionRadiation therapy, along with temozolomide, is still the standard of care for most people with MGMT-unmethylated GBMs because there aren’t any better options, and it’s generally safe and well-tolerated. These patients have a lower overall survival rate and less benefit from temozolomide, but there are no better alternatives. Clinical trial participation is encouraged.

ObjectivesTo assess the efficacy and adverse events of bevacizumab (BEV) combined with temozolomide (TMZ) in the treatment of glioma.Materials and methodsRandomized controlled trials (RCT) involving BEV combined with TMZ in the treatment of glioma were searched using PubMed, Embase and Cochrane library, and a comprehensive meta-analysis was conducted. The primary outcomes were overall survival time (OS) and progression-free survival time (PFS), and the secondary outcome was adverse events. Researchers conducted literature screening, data extraction and quality assessment according to inclusion and exclusion criteria. RevMan 5.3 software was used for meta-analysis.ResultsA total of 8 prospective RCTs of 3,039 cases were included in the meta-analysis. Meta-analysis showed that compared with TMZ alone, BEV combined with TMZ could significantly improve PFS, OS and complete remission rate (CR). A total of 6 studies reported related adverse events, mainly including thrombocytopenia, neutropenia, leukopenia, anemia and fatigue. Combination therapy may have more adverse events but no serious consequences.ConclusionThe combination of BEV and TMZ had a better therapeutic effect on glioblastoma, significantly prolonged the survival time of patients and improved the quality of life. However, some patients are afflicted with the adverse events of combination therapy, and subsequent studies should continue to conduct larger, multi-center RCTs to confirm the findings and explore in depth how to minimize and manage adverse events effectively.

Temozolomide (TMZ) is a methylating agent used as the first-line drug in the chemotherapy of glioblastomas. However, cancer cells eventually acquire resistance, necessitating the development of TMZ-potentiating therapy agents. TMZ induces several DNA base adducts, including O6-meG, 3-meA, and 7-meG. TMZ cytotoxicity stems from the ability of these adducts to directly (3-meA) or indirectly (O6-meG) impair DNA replication. Although TMZ toxicity is generally attributed to O6-meG, other alkylated bases can be similarly important depending on the status of various DNA repair pathways of the treated cells. In this mini-review we emphasize the necessity to distinguish TMZ-sensitive glioblastomas, which do not express methylguanine-DNA methyltransferase (MGMT) and are killed by the futile cycle of mismatch repair (MMR) of the O6-meG/T pairs, vs. TMZ-resistant MGMT-positive or MMR-negative glioblastomas, which are selected in the course of the treatment and are killed only at higher TMZ doses by the replication-blocking 3-meA. These two types of cells can be TMZ-sensitized by inhibiting different DNA repair pathways. However, in both cases, the toxic intermediates appear to be ssDNA gaps, a vulnerability also seen in BRCA-deficient cancers. PARP inhibitors (PARPi), which were initially developed to treat BRCA1/2-deficient cancers by synthetic lethality, were re-purposed in clinical trials to potentiate the effects of TMZ. We discuss how the recent advances in our understanding of the genetic determinants of TMZ toxicity might lead to new approaches for the treatment of glioblastomas by inhibiting PARP1 and other enzymes involved in the repair of alkylation damage (e.g., APE1).

The blood-brain Barrier (BBB), combined with immune clearance, contributes to the low efficacy of drug delivery and suboptimal treatment outcomes in glioma. Here, we propose a novel approach that combines the self-assembly of mouse bone marrow-derived macrophage membrane with a targeted positive charge polymer (An-PEI), along with low-frequency ultrasound (LFU) irradiation, to achieve efficient and safe therapy for glioma. Our findings demonstrate the efficacy of a charge-induced self-assembly strategy, resulting in a stable co-delivery nanosystem with a high drug loading efficiency of 44.2 %. Moreover, this structure triggers a significant release of temozolomide in the acidic environment of the tumor microenvironment. Additionally, the macrophage membrane coating expresses Spyproteins, which increase the amount of An-BMP-TMZ that can evade the immune system by 40 %, while LFU irradiation treatment facilitates the opening of the BBB, allowing for enormously increased entry of An-BMP-TMZ (approximately 400 %) into the brain. Furthermore, after crossing the BBB, the Angiopep-2 peptide-modified An-BMP-TMZ exhibits the ability to selectively target glioma cells. These advantages result in an obvious tumor inhibition effect in animal experiments and significantly improve the survival of glioma-bearing mice. These results suggest that combining the macrophage membrane-coated drug delivery system with LFU irradiation offers a feasible approach for the accurate, efficient and safe treatment of brain disease.

Abstract Adjuvant Temozolomide is considered the front-line Glioblastoma chemotherapeutic treatment; yet not all patients respond. Latest trends in clinical trials usually refer to Doxorubicin; yet it can lead to severe side-effects if administered in high doses. While Glioblastoma prognosis remains poor, little is known about the combination of the two chemotherapeutics. Patient-derived spheroids were generated and treated with a range of Temozolomide/Doxorubicin concentrations either as monotherapy or in combination. Optical microscopy was used to monitor the growth pattern and cell death. Based on the monotherapy experiments, we developed a probabilistic mathematical framework in order to describe the drug-induced effect at the single-cell level and simulate drug doses in combination assuming probabilistic independence. Doxorubicin was found to be effective in doses even four orders of magnitude less than Temozolomide in monotherapy. The combination therapy doses tested in vitro were able to lead to irreversible growth inhibition at doses where monotherapy resulted in relapse. In our simulations, we assumed both drugs are anti-mitotic; Temozolomide has a growth-arrest effect, while Doxorubicin is able to cumulatively cause necrosis. Interestingly, under no mechanistic synergy assumption, the in silico predictions underestimate the in vitro results. In silico models allow the exploration of a variety of potential underlying hypotheses. The simulated-biological discrepancy at certain doses indicates a supra-additive response when both drugs are combined. Our results suggest a Temozolomide–Doxorubicin dual chemotherapeutic scheme to both disable proliferation and increase cytotoxicity against Glioblastoma.

Abstract Background Recent advances in the management of pancreatic neuroendocrine tumors (pNETs) highlight the potential benefits of temozolomide, an alkylating agent, for these patients. In this meta-analysis, we aimed to assess the outcome of temozolomide, alone or in combination with other anticancer medications in patients with advanced pNET. Methods Online databases of PubMed, Web of Science, Embase, the Cochrane Library, and ClinicalTrials.gov were searched systematically for clinical trials that reported the efficacy and safety of temozolomide in patients with advanced pNET. Random-effect model was utilized to estimate pooled rates of outcomes based on Response Evaluation Criteria in Solid Tumors criteria, biochemical response, and adverse events (AEs). Results A total of 14 studies, providing details of 441 individuals with advanced pNET, were included. The quantitative analyses showed a pooled objective response rate (ORR) of 41.2% (95% confidence interval, CI, of 32.4%-50.6%), disease control rate (DCR) of 85.3% (95% CI of 74.9%-91.9%), and a more than 50% decrease from baseline chromogranin A levels of 44.9% (95% CI of 31.6%-49.0%). Regarding safety, the results showed that the pooled rates of nonserious AEs and serious AEs were 93.8% (95% CI of 88.3%-96.8%) and 23.7% (95% CI of 12.0%-41.5%), respectively. The main severe AEs encompassed hematological toxicities. Conclusions In conclusion, our meta-analysis suggests that treatment with temozolomide, either as a monotherapy or in combination with other anticancer treatments might be an effective and relatively safe option for patients with advanced locally unresectable and metastatic pNET. However, additional clinical trials are required to further strengthen these findings. This study has been registered in PROSPERO (CRD42023409280). Graphical Abstract

Abstract Temozolomide (TMZ) resistance presents a significant challenge in the treatment of gliomas. Although lysine demethylase 4A (KDM4A) has been implicated in various cancer‐related processes, its role in TMZ resistance remains unclear. This study aims to elucidate the contribution of KDM4A to TMZ resistance in glioma cells and its potential implications for glioma prognosis. We assessed the expression of KDM4A in glioma cells (T98G and U251MG) using qRT‐PCR and Western blot assays. To explore the role of KDM4A in TMZ resistance, we transfected siRNA targeting KDM4A into drug‐resistant glioma cells. Cell viability was assessed using the CCK‐8 assay and the TMZ IC50 value was determined. ChIP assays were conducted to investigate KDM4A, H3K9me3, and H3K36me3 enrichment on the promoters of ROCK2 and HUWE1. Co‐immunoprecipitation confirmed the interaction between HUWE1 and ROCK2, and we examined the levels of ROCK2 ubiquitination following MG132 treatment. Notably, T98G cells exhibited greater resistance to TMZ than U251MG cells, and KDM4A displayed high expression in T98G cells. Inhibiting KDM4A resulted in decreased cell viability and a reduction in the TMZ IC50 value. Mechanistically, KDM4A promoted ROCK2 transcription by modulating H3K9me3 levels. Moreover, disruption of the interaction between HUWE1 and ROCK2 led to reduced ROCK2 ubiquitination. Inhibition of HUWE1 or overexpression of ROCK2 counteracted the sensitization effect of si‐KDM4A on TMZ responsiveness in T98G cells. Our findings highlight KDM4A's role in enhancing TMZ resistance in glioma cells by modulating ROCK2 and HUWE1 transcription and expression through H3K9me3 and H3K36me3 removal.

In this study, temozolomide (TMZ), a drug used in the treatment of anaplastic astrocytoma and glioblastoma multiforme, was incorporated in multiwalled carbon nanotubes (MWCNTs) and hybrid carbon nanotubes with graphene (MWCNTs-G) functionalized by polyethylene glycol (PEG). The aim was to evaluate the potential of these nanocarriers for targeted delivery and sustained release of TMZ in brain tumor cells. Oxidized MWCNTs and MWCNTs-G were noncovalently functionalized with PEGs of different molecular weights and subsequently loaded with TMZ following standard procedures. Thorough physicochemical and biopharmaceutical characterization of the TMZ-loaded carbon nanocarriers pointed to high encapsulation efficacy (up to 67%) and drug loading (up to 18% out of 25% theoretical value) and homogeneous particle size distribution, with z-average (160 to 300 nm) and zeta potential (–31 to –21 mV) of the particles adequate for crossing the blood-brain-tumor-barrier (BBTB) and entering into the tumor cells. Successful functionalization and TMZ loading were confirmed by SEM and TEM images, UV-Vis absorption, infrared and Raman spectroscopy, and TGA analyses. Sustained release of TMZ from the carbon nanocarriers was observed in vitro. The presented findings form a fundamental platform for further investigation of these formulations against different types of glioma cells and in adequate animal models.

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular neoplasm with an intermediate pattern of malignancy between benign neoplasms and angiosarcomas. Only 46 cases of intracranial localization of primary EHE in adults have been published.Case report: A 47-year-old male patient developed pronounced speech disorder of sensory and amnestic aphasia type, right-sided pyramidal hemiparesis within 3–4 days. Magnetic resonance imaging revealed a delimited left sided brain islet neoplasm with signs of hemorrhage and small perifocal edema. Intraoperatively, the neoplasm was represented by a conglomerate of pathologic vessels, with involvement of the terminal branches of the M2 segment of the middle cerebral artery, which prevented radical resection of the neoplasm. Based on histopathological and immunohistochemistry analysis of the neoplasm (positive expression of CD31, CD34, proliferative activity index Ki-67 10%) the morphologic diagnosis of EHE was established. 3 months after surgery, continued growth of the residual part of the neoplasm was noted. Temozolomide chemotherapy was clinically ineffective. The patient died due to the development of dislocation syndrome after 9 months.Discussion. The malignant characteristics of EHE include invasive growth, recurrence, and metastasis, which is more common in intracranial localization of the neoplasm. If EHE is suspected, radical surgical removal of the neoplasm should be sought.

Background: Malignant gliomas represent a heterogenous group of brain cancers that are characterized by infiltrative growth that lacks a clearly identifiable tumor border. The lack of the possibility of radical surgical resection and targeted therapy results in a poor prognosis. Although Temozolomide (TMZ) is still the leading chemotherapeutic agent in glioma treatment, its efficacy is limited due to the development of tumor resistance. Therefore, there an urgent need to improve the diagnosis and treatment of these tumors. Finding and developing biomarkers that are specific to glioma could be useful for both identifying therapy targets and monitoring treatment as well as for constructing a personalized therapy. However, there are still no reliable markers that would change the quality of glioma treatment. Methods: In this study, differences in the expression of 84 cancer-related proteins in three glioma cell lines were analyzed using the dot-blot method: commercial T98G cells and two patient-derived cell lines. The influence of TMZ on changes in protein expression, cell morphology, and migration was also investigated (Proteome Profiler Human XL Oncology Array, LeviCell System, Microscopic imaging). The lines that were analyzed were characterized by a remarkably different plasticity of protein expression and the proteomic alterations that were induced by TMZ. Results: A dot-blot analysis revealed ten proteins that were common to all of the lines and five (Cathepsin b, FGF, Survivin, AXL, Osteopontin) that were modulated by the TMZ. As a result of the exposure of TMZ, the proteins that are involved in chemoresistance and invasion (TIE-2, Thrombospondin) were detected in both the HROG02 and T98G cell lines. In the control culture (not exposed to TMZ) of HROG17 cells, the proteins that are involved in metabolism were strongly suppressed. Conclusions: The presented data sheds new light on the modulatory effect of Temozolomide on the expression of a protein panel: Cathepsin b, fibroblast growth factor (FGF), Survivin, AXL, and Osteopontin that may suggest their potential as therapeutic targets or biomarkers to monitoring therapy effects. However, further high-throughput analysis and detection of the proteins in the body fluids are necessary.

Glioblastoma (GBM) is the most aggressive cancer originating in the brain, but unfortunately combination treatments with resection, radiation, and chemotherapy are relatively ineffective. Therefore, novel methods of adjuvant therapy are critically needed. Cyclotides are plant-derived circular peptides that chemosensitize drug-resistant breast cancer to doxorubicin. We analyzed naturally occurring and synthetic cyclotides (Cycloviolacin O3, Cycloviolacin O19, natural Kalata B1, synthetic Kalata B1, and Vitri E) alone and in co-exposure treatments with the drug temozolomide (TMZ) in human glioblastoma cells. The cyclotides were identified by UPLC-PDA and HPLC-UV. The synthetic Kalata B1 sequence was verified with orbitrap LC-MS, and structural confirmation was provided by NMR spectroscopy. The cyclotides displayed dose-dependent cytotoxicity (IC50 values 2.4–21.1 µM) both alone and as chemosensitizers of U-87 MG and T 98 cells to TMZ. In fact, a 16-fold lower concentration of TMZ (100 µM) was needed for significant cytotoxicity in U-87 MG cells co-exposed to synthetic Kalata B (0.5 µM). Similarly, a 15-fold lower concentration of TMZ (75 µM) was required for a significant reduction in cell viability in T 98 cells co-exposed to synthetic Kalata B1 (0.25 µM). Kalata B1 remained stable in human serum stability assays. The data support the assertion that cyclotides may chemosensitize glioblastoma cells to TMZ.

Glioblastoma (GBL) is one of the more malignant primary brain tumors; it is currently treated by a multimodality strategy including surgery, and radio- and chemotherapy, mainly consisting of temozolomide (TMZ)-based chemotherapy. Tumor relapse often occurs due to the establishment of TMZ resistance, with a patient median survival time of

One of the main causes of poor prognoses in patient with glioblastoma (GBM) is drug resistance to current standard treatment, which includes chemoradiation and adjuvant temozolomide (TMZ). In addition, the concept of cancer stem cells provides new insights into therapy resistance and management also in GBM and glioblastoma stem cell-like cells (GSCs), which might contribute to therapy resistance. Bone morphogenetic protein-4 (BMP4) stimulates astroglial differentiation of GSCs and thereby reduces their self-renewal capacity. Exposure of GSCs to BMP4 may also sensitize these cells to TMZ. A recent phase I trial has shown that local delivery of BMP4 is safe, but a large variation in survival is seen in these treated patients and in features of their cultured tumors. We wanted to combine TMZ and BMP4 (TMZ + BMP4) therapy and assess the inter-tumoral variability in response to TMZ + BMP4 in patient-derived GBM cultures. A phase II trial could then benefit a larger group of patients than those treated with BMP4 only. We first show that simultaneous treatment with TMZ + BMP4 is more effective than sequential treatment. Second, when applying our optimized treatment protocol, 70% of a total of 20 GBM cultures displayed TMZ + BMP4 synergy. This combination induces cellular apoptosis and does not inhibit cell proliferation. Comparative bulk RNA-sequencing indicates that treatment with TMZ + BMP4 eventually results in decreased MAPK signaling, in line with previous evidence that increased MAPK signaling is associated with resistance to TMZ. Based on these results, we advocate further clinical trial research to test patient benefit and validate pathophysiological hypothesis.

Purpose: To evaluate the chemotherapeutic activity of temozolomide counter to mammary carcinoma. Methods: In-vitro anticancer activity has been conducted on MCF7 cells, and mammary carcinoma has been induced in Wistar rats by introduction of 7, 12-Dimethylbenz(a)anthracene (DMBA), which was sustained for 24 weeks. Histopathology, immunohistochemistry, cell proliferation study and apoptosis assay via TUNEL method was conducted to evaluate an antineoplastic activity of temozolomide in rat breast tissue. Results: IC50 value of temozolomide in MCF7 cell has been obtained as 103 μM, which demonstrated an initiation of apoptosis. The temozolomide treatment facilitated cell cycle arrest in G2/M and S phase dose dependently. The treatment with temozolomide suggested decrease of the hyperplastic abrasions and renovation of the typical histological features of mammary tissue. Moreover, temozolomide therapy caused the downregulation of epidermal growth factor receptor, extracellular signal-regulated kinase, and metalloproteinase-1 expression and upstream of p53 and caspase-3 proliferation to indicate an initiation of apoptotic events. Conclusions: The occurrence of mammary carcinoma has been significantly decreased by activation of apoptotic pathway and abrogation of cellular propagation that allowable for developing a suitable mechanistic pathway of temozolomide in order to facilitate chemotherapeutic approach.

Glioma is a common tumor originating in the brain that has a high mortality rate. Temozolomide (TMZ) is the first-line treatment for high-grade gliomas. However, a large proportion of gliomas are resistant to TMZ, posing a great challenge to their treatment. In the study, the specific functions and mechanism(s) by which cortistatin (CORT) regulates TMZ resistance and glioma progression were evaluated. The decreased expression of CORT was detected in glioma tissues, and highly expressed CORT was associated with a better survival rate in patients with glioma. CORT overexpression notably decreased the capacity of glioma cells to proliferate and migrate in vitro and to form tumors in vivo. CORT overexpression also markedly suppressed the viability and enhanced the apoptosis of TMZ-resistant U251 cells by regulating MGMT, p21, and Puma expression. Importantly, CORT overexpression reduced the resistance of gliomas to TMZ in vivo. CORT expression was negatively correlated with MGMT expression in both glioma tissues and cells, and it was found that CORT inhibited NF-κB pathway activation in glioma cells, thereby inhibiting MGMT expression. In conclusion, CORT regulates glioma cell growth, migration, apoptosis, and TMZ resistance by weakening the activity of NF-κB/p65 and thereby regulating MGMT expression. The CORT/NF-κB/MGMT axis might be regarded as a molecular mechanism contributing to the resistance of glioma to TMZ. Our data also suggest that CORT regulates the viability and metastatic potential of glioma cells, independent of its effects on TMZ resistance, providing evidence of novel therapeutic targets for glioma that should be evaluated in further studies.

Key Clinical Message We report a rare clinical case of a malignant prolactinoma in which the exponential increase of prolactin levels with minimal tumor growth and no response to treatment led to diagnosis of abdominal, thoracic, and vertebral metastases.

BackgroundTemozolomide (TMZ) is a key component in the treatment of gliomas. Hypermutation induced by TMZ can be encountered in routine clinical practice, and its significance is progressively gaining recognition. However, the relationship between TMZ-induced hypermutation and the immunologic response remains controversial.Case presentationWe present the case of a 38-year-old male patient who underwent five surgeries for glioma. Initially diagnosed with IDH-mutant astrocytoma (WHO grade 2) during the first two surgeries, the disease progressed to grade 4 in subsequent interventions. Prior to the fourth surgery, the patient received 3 cycles of standard TMZ chemotherapy and 9 cycles of dose-dense TMZ regimens. Genomic and immunologic analyses of the tumor tissue obtained during the fourth surgery revealed a relatively favorable immune microenvironment, as indicated by an immunophenoscore of 5, suggesting potential benefits from immunotherapy. Consequently, the patient underwent low-dose irradiation combined with immunoadjuvant treatment. After completing 4 cycles of immunotherapy, the tumor significantly shrank, resulting in a partial response. However, after a 6-month duration of response, the patient experienced disease progression. Subsequent analysis of the tumor tissue obtained during the fifth surgery revealed the occurrence of hypermutation, with mutation signature analysis attributing TMZ treatment as the primary cause. Unfortunately, the patient succumbed shortly thereafter, with a survival period of 126 months.ConclusionPatients subjected to a prolonged regimen of TMZ treatment may exhibit heightened vulnerability to hypermutation. This hypermutation induced by TMZ holds the potential to function as an indicator associated with unfavorable response to immunotherapy in gliomas.

Glioma is the leading cancer of the central nervous system (CNS). The efficacy of glioma treatment is significantly hindered by the presence of the blood-brain barrier (BBB) and blood-brain tumour barrier (BBTB), which prevent most drugs from entering the brain and tumours. Hence, we established a novel drug delivery nanosystem of brain tumour-targeting that could self-assemble the method using an amphiphilic Zein protein isolated from corn. Zein's amphiphilicity prompted it to self-assembled into NPs, efficiently containing TMZ. This allowed us to investigate temozolomide (TMZ) for glioblastoma (GBM) treatment. To construct TMZ-encapsulated NPs (TMZ@RVG-Zein NPs), the NPs' Zein was clocked to rabies virus glycoprotein 29 (RVG29). To verify that the NPs could penetrate the BBB and precisely target and kill the GBM cancer cell line, in vitro studies were performed. The process of NPs penetrating cancer cell membranes was investigated using enzyme-linked immunosorbent assays (ELISAs) to measure the expressions of nicotinic acetylcholine receptors (nAChRs) on the U87 cell line. Therefore, effective targeted brain cancer treatment is possible by forming NP clocks, a cell-penetrating natural Zein protein with an RVG29. These NPs can penetrate the blood-brain barrier (BBB) and enter the glioblastoma (U87) cell line to release TMZ. These NPs have a distinct cocktail of biocompatibility and brain-targeting abilities, making them ideal for involving brain diseases.

Key Clinical Message Optimized treatments for relapsed isolated CNS lymphoma (RI‐SCNSL) remains under investigation. Temozolomide combination‐based therapy, which is often used in glioblastoma may be used as potential treatment in RI‐SCNSL. Abstract One of the most common types of non‐Hodgkin lymphoma (NHL) is diffuse large B‐cell lymphoma (DLBCL). Despite advances in treatment, relapsed isolated CNS lymphoma (RI‐SCNSL) from DLBCL remains an issue. The optimal approach in RI‐SCNSL remains an area of active investigation as currently there is no high level of evidence for the treatments due to lack of randomized studies. In this case report, we present a DLBCL patient with CNS recurrence treated radiotherapy and intrathecal methotrexate (MTX) followed by intravenous high‐dose MTX, rituximab, and temozolomide. To the best of our knowledge, this is the first case report describing RI‐SCNSL treated with the regiments above which also include temozolomide which is used for glioblastoma.