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Aim: The study aims to improve glioblastoma multiforme (GBM) treatment by combining temozolomide (TMZ) and quercetin (Qct), using folic acid (FA)-conjugated exosomes to overcome TMZ resistance and enhance blood–brain barrier (BBB) penetration. Methods: Exosomes were isolated and after characterizing and modifying their surfaces with FA, drug loading of TMZ and Qct into exosomes was done. In vitro assays, including cell viability tests, RT-PCR, Western-blotting and flow-cytometry, were performed using U87MG and U251MG GBM cell lines. In vivo analysis included administering exosome-drug formulations to glioblastoma-bearing Wistar rats, monitored through optical imaging and PET scans, followed by post-mortem immunohistochemistry and histological examination. Results: The results showed successful exosome isolation and FA conjugation, with drug release studies indicating accelerated release of TMZ and Qct in acidic conditions, enhancing cytotoxicity. Immunofluorescence indicated greater exosome uptake in GBM cells due to FA conjugation. Cell viability assays demonstrated increased toxicity of the combination therapy, correlating with elevated apoptosis. In vivo studies revealed significant tumor size reduction, alongside increased apoptosis and reduced angiogenesis, particularly in the TMZ-Qct-Exo-FA group. Conclusion: FA-conjugated exosomes loaded with TMZ and Qct represent a promising strategy to enhance GBM treatment efficacy by improving drug delivery, apoptosis induction and inhibiting the PI3K/Akt/mTOR pathway. Graphical Abstract Schematic illustration of exosome isolation and conjugation followed by loading with temozolomide (TMZ) and Quercetin (Qct) for glioblastoma therapy. (A) Process of isolating exosomes and conjugating them with folic acid loaded with TMZ and Qct (B) Function of exosomes conjugated with folic acid in a rat model of glioblastoma (C) Mechanism of how exosomes bearing TMZ and Qct work inside the glioblastoma cell line. Article highlights The study emphasizes the successful use of exosome encapsulation to enhance the delivery of temozolomide (TMZ) and quercetin (Qct) across the blood–brain barrier (BBB), improving drug stability for glioblastoma multiforme (GBM) therapy. Encapsulating TMZ and Qct within exosomes (TMZ-Qct-Exo) showed significantly greater potential in reducing GBM cell viability compared with their unencapsulated counterparts, suggesting an effective approach against TMZ resistance. The introduction of folic acid-conjugated exosomes (TMZ-Qct-Exo-FA) enhanced the targeting of GBM cells, leading to better cellular uptake and improved therapeutic outcomes marked by greater apoptosis and increased caspase-3 levels. The combined treatment effectively inhibited the PI3K/Akt/mTOR signaling pathway, vital for tumor growth and survival, thereby boosting the anti-tumor effects of the TMZ-Qct-Exo-FA treatment. In vivo studies demonstrated that the TMZ-Qct-Exo-FA formulation resulted in superior tumor targeting, significantly reduced tumor size and higher levels of apoptotic markers compared with alternative treatment methods. The findings highlight that exosome-mediated drug delivery could serve as a promising strategy to circumvent resistance mechanisms commonly associated with TMZ in GBM treatment. The research indicates that combining exosome technology with conventional chemotherapy could pave the way for new therapeutic modalities in the treatment of aggressive brain tumors like GBM. The use of folic acid as a targeting moiety suggests an innovative approach to enhance specificity in drug delivery systems directed at tumor cells. These results underscore the need for further clinical studies to explore the full potential of exosome-mediated delivery systems in enhancing the effectiveness of existing cancer therapies. [ABSTRACT FROM AUTHOR]

This phase 1/2 study aimed to evaluate the safety and preliminary efficacy of combining disulfiram and copper (DSF/Cu) with radiation therapy (RT) and temozolomide (TMZ) in patients with newly diagnosed glioblastoma (GBM). Patients received standard RT and TMZ with DSF (250-375 mg/d) and Cu, followed by adjuvant TMZ plus DSF (500 mg/d) and Cu. Pharmacokinetic analyses determined drug concentrations in plasma and tumors using high-performance liquid chromatography-mass spectrometry. Thirty-three patients, with a median follow-up of 26.0 months, were treated, including 12 IDH -mutant, 9 NF1 -mutant, 3 BRAF -mutant, and 9 other IDH -wild-type cases. In the phase 1 arm, 18 patients were treated; dose-limiting toxicity probabilities were 10% (95% CI, 3%-29%) at 250 mg/d and 21% (95% CI, 7%-42%) at 375 mg/d. The phase 2 arm treated 15 additional patients at 250 mg/d. No significant difference in overall survival or progression-free survival was noted between IDH - and NF1 -mutant cohorts compared with institutional counterparts treated without DSF/Cu. However, extended remission occurred in 3 BRAF -mutant patients. Diethyl-dithiocarbamate-copper, the proposed active metabolite of DSF/Cu, was detected in plasma but not in tumors. The maximum tolerated dose of DSF with RT and TMZ is 375 mg/d. DSF/Cu showed limited clinical efficacy for most patients. However, promising efficacy was observed in BRAF -mutant GBM, warranting further investigation. [ABSTRACT FROM AUTHOR]

AbstractIntroductionMaterials and methodsResultsConclusionRadiotherapy-related damage of normal tissue inevitably influences the treatment outcomes in the context of high-grade gliomas (HGGs) treatment. We reported the survival outcomes and toxicities of patients with HGG treated with helical tomotherapy (HT) and the prognostic factors were analyzed.A total of 67 patients (29 had grade III and 38 had grade IV HGGs) who received HT between January 2016 and June 2020 were analyzed. Overall survival (OS) and progression-free survival (PFS) from the beginning of HT and OS from surgery were assessed, and toxicity and disease control were described briefly.For patients with grade III HGGs, median OS (mOS) and median PFS (mPFS) from the beginning of HT were 68.933 and 62.967 months, respectively. For patients with grade IV HGGs, mOS and mPFS from the beginning of HT were 19.667 and 7.23 months, respectively. No grade ≥3 acute or late nonhematologic toxicities were observed. Multivariable Cox regression analysis showed that methylguanine methyltransferase (MGMT) methylated status, age, number of lesions, WHO grade, and monocyte count for PFS were significant. Age, monocyte count, and isocitrate dehydrogenase (IDH) status for OS.Treatment of HGGs with HT appears to be potentially effective and safe. HT is promising for glioblastomas (GBM), especially complex cases with infratentorial involvement or multiple lesions. This study highlighted the potential clinical significance of systemic inflammation indicators in predicting survival and disease progression. [ABSTRACT FROM AUTHOR]

Hypermutation and malignant transformation are potential complications arising from temozolomide treatment of IDH‐mutant gliomas. However, the natural history of IDH‐mutant low‐grade gliomas without temozolomide treatment is actually under‐studied. We retrieved retrospectively from our hospitals paired tumors from 19 patients with IDH‐mutant, 1p19q non‐codeleted Grade 2 astrocytomas where no interim adjuvant treatment with either temozolomide or radiotherapy was given between primary resections and first recurrences. Tissues from multiple recurrences were available from two patients and radiotherapy but not temozolomide was given before the last specimens were resected. We studied the natural molecular history of these low‐grade IDH‐mutant astrocytomas without pressure of temozolomide with DNA methylation profiling and copy number variation (CNV) analyses, targeted DNA sequencing, TERTp sequencing, FISH for ALT and selected biomarkers. Recurrences were mostly higher grades (15/19 patients) and characterized by new CNVs not present in the primary tumors (17/19 cases). Few novel mutations were identified in recurrences. Tumors from 17/19 (89.5%) patients showed either CDKN2A homozygous deletion, MYC or PDGFRA focal and non‐focal gains at recurrences. There was no case of hypermutation. Phylogenetic trees constructed for tumors for the two patients with multiple recurrences suggested a lack of subclone development in their evolution when under no pressure from temozolomide. In summary, our studies demonstrated, in contrast to the phenomenon of temozolomide‐induced hypermutation, IDH‐mutant, 1p19q non‐codeleted Grade 2 astrocytomas which had not been treated by temozolomide, acquired new CNVs at tumor recurrences. These findings improve our understanding of the molecular life history of IDH‐mutant astrocytomas. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is an aggressive form of cancer affecting the Central Nervous System (CNS) of thousands of people every year. Redox alterations have been shown to play a key role in the development and progression of these tumors as Reactive Oxygen Species (ROS) formation is involved in the modulation of several signaling pathways, transcription factors, and cytokine formation. The second-generation oral alkylating agent temozolomide (TMZ) is the first-line chemotherapeutic drug used to treat of GBM, though patients often develop primary and secondary resistance, reducing its efficacy. Antioxidants represent promising and potential coadjutant agents as they can reduce excessive ROS formation derived from chemo- and radiotherapy, while decreasing pharmacological resistance. S-allyl-cysteine (SAC) has been shown to inhibit the proliferation of several types of cancer cells, though its precise antiproliferative mechanisms remain poorly investigated. To date, SAC effects have been poorly explored in GBM cells. Here, we investigated the effects of SAC in vitro, either alone or in combination with TMZ, on several toxic and modulatory endpoints—including oxidative stress markers and transcriptional regulation—in two glioblastoma cell lines from rats, RG2 and C6, to elucidate some of the biochemical and cellular mechanisms underlying its antiproliferative properties. SAC (1–750 µM) decreased cell viability in both cell lines in a concentration-dependent manner, although C6 cells were more resistant to SAC at several of the tested concentrations. TMZ also produced a concentration-dependent effect, decreasing cell viability of both cell lines. In combination, SAC (1 µM or 100 µM) and TMZ (500 µM) enhanced the effects of each other. SAC also augmented the lipoperoxidative effect of TMZ and reduced cell antioxidant resistance in both cell lines by decreasing the TMZ-induced increase in the GSH/GSSG ratio. In RG2 and C6 cells, SAC per se had no effect on Nrf2/ARE binding activity, while in RG2 cells TMZ and the combination of SAC + TMZ decreased this activity. Our results demonstrate that SAC, alone or in combination with TMZ, exerts antitumor effects mediated by regulatory mechanisms of redox activity responses. SAC is also a safe drug for testing in other models as it produces non-toxic effects in primary astrocytes. Combined, these effects suggest that SAC affords antioxidant properties and potential antitumor efficacy against GBM. [ABSTRACT FROM AUTHOR]

Glioblastoma is the most aggressive and fatal brain cancer, characterized by a high growth rate, invasiveness, and treatment resistance. The presence of the blood–brain barrier (BBB) and blood–brain tumor barrier (BBTB) poses a challenging task for chemotherapeutics, resulting in low efficacy, bioavailability, and increased dose-associated side effects. Despite the rigorous treatment strategies, including surgical resection, radiotherapy, and adjuvant chemotherapy with temozolomide, overall survival remains poor. The failure of current chemotherapeutics and other treatment regimens in glioblastoma necessitates the development of new drug delivery methodologies to precisely and efficiently target glioblastoma. Nanoparticle-based drug delivery systems offer a better therapeutic option in glioblastoma, considering their small size, ease of diffusion, and ability to cross the BBB. Liposomes are a specific category of nanoparticles made up of fatty acids. Furthermore, liposomes can be surface-modified to target a particular receptor and are nontoxic. This review discusses various methods of liposome modification for active/directed targeting and various liposome-based therapeutic approaches in the delivery of current chemotherapeutic drugs and nucleic acids in targeting the glioblastoma and tumor microenvironment. [ABSTRACT FROM AUTHOR]

α-Pinene (PEN) is a phyto compound present in terpene plants. In traditional medicine, PEN has been used for its anti-inflammatory, pain-relieving, and bronchodilator properties. The effect of PEN in combination with temozolomide (TMZ) in glioblastoma multiforme (GBM) cells has been evaluated. The action of the PEN + TMZ combination on cell migration, soft-agar, and cell death was determined in LN229 and U87MG human glioblastoma cells. In combination, PEN with TMZ showed a synergistic inhibitory effect in the GBM cells. The PEN + TMZ treatment showed a higher fluorescent intensity and reduced the percentage of wound area closure compared to the compound alone. The compounds in combination also resulted in a reduction in single-cell colony formation. To conclude, the study showed that plant-derived PEN enhanced the effectiveness of standard chemotherapeutic, TMZ, in LN229 and U87MG cells. [ABSTRACT FROM AUTHOR]

Pediatric low-grade gliomas (PLGG) are commonly treated with a combination of surgery, radiotherapy, and chemotherapy. Recent trends prioritize reducing long-term morbidities, particularly in younger patients. While historically chemotherapy was reserved for cases progressing after radiotherapy, evolving recommendations now advocate for its early use, particularly in younger age groups. The carboplatin and vincristine (CV) combination stands as a standard systemic therapy for PLGG, varying in dosage and administration between North America and Europe. Clinical trials have shown promising response rates, albeit with varying toxicity profiles. Vinblastine has emerged as another effective regimen with minimal toxicity. TPCV, a regimen combining thioguanine, procarbazine, lomustine, and vincristine, was compared to CV in a Children's Oncology Group trial, showing comparable outcomes, but more toxicity. Vinorelbine, temozolomide, and metronomic chemotherapy have also been explored, with varied success rates and toxicity profiles. Around 40–50% of PLGG patients require subsequent chemotherapy lines. Studies have shown varied efficacy in subsequent lines, with NF1 patients generally exhibiting better outcomes. The identification of molecular drivers like BRAF mutations has led to targeted therapies' development, showing promise in specific molecular subgroups. Trials comparing targeted therapy to conventional chemotherapy aim to delineate optimal treatment strategies based on molecular profiles. The landscape of chemotherapy in PLGG is evolving, with a growing focus on molecular subtyping and targeted therapies. Understanding the role of chemotherapy in conjunction with novel treatments is crucial for optimizing outcomes in pediatric patients with low-grade gliomas. [ABSTRACT FROM AUTHOR]

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 <2 years. The identification of natural molecules with strong anti-tumor activity led to the combination of these compounds with conventional chemotherapeutic agents, developing protocols for integrated anticancer therapies. Curcumin (CUR), resveratrol (RES), and its glucoside polydatin (PLD) are widely employed in the pharmaceutical and nutraceutical fields, and several studies have demonstrated that the combination of these natural products was more cytotoxic than the individual compounds alone against different cancers. Some of us recently demonstrated the synergistic efficacy of the sublingual administration of a new nutraceutical formulation of CUR+PLD in reducing tumor size and improving GBL patient survival. To provide some experimental evidence to reinforce these clinical results, we investigated if pretreatment with a combination of CUR+PLD can improve TMZ cytotoxicity on GBL cells by analyzing the effects on cell cycle, viability, morphology, expression of proteins related to cell proliferation, differentiation, apoptosis or autophagy, and the actin network. Cell viability was assessed using the MTT assay or a CytoSmart cell counter. CalcuSyn software was used to study the CUR+PLD synergism. The morphology was evaluated by optical and scanning electron microscopy, and protein expression was analyzed by Western blot. Flow cytometry was used for the cell cycle, autophagic flux, and apoptosis analyses. The results provide evidence that CUR and PLD, acting in synergy with each other, strongly improve the efficacy of alkylating anti-tumor agents such as TMZ on drug-resistant GBL cells through their ability to affect survival, differentiation, and tumor invasiveness. [ABSTRACT FROM AUTHOR]

AbstractVesicular nanocarriers like niosomes and liposomes are widely researched for controlled drug delivery systems, with niosomes emerging as promising alternatives due to their higher stability and ease of manufacturing. This study aimed to develop and characterize a niosomal formulation for the encapsulation and sustained release of temozolomide (TMZ), a model lipophilic drug, and to compare the stability of niosomes and liposomes, with a particular focus on the behavior of their lipid bilayers. Niosomes were prepared using the thin-film hydration method, composed of Span 60 (Sorbitan monostearate), cholesterol, and soy lecithin in varying molar ratios. The study investigated critical properties such as drug loading capacity, release kinetics, and resistance to enzymatic degradation. The optimized formulation was analyzed for drug entrapment efficiency and stability against phospholipase A2 (PLA2) degradation. The optimized niosomal formulation, with a 4:2:1 molar ratio of Span 60: cholesterol, achieved a high TMZ entrapment efficiency of 73.23 ± 1.02% and demonstrated sustained drug release over 24 hours. In comparison, liposomes released their TMZ payload within 4 hours upon exposure to PLA2, while the niosomes maintained their release profile, indicating superior stability. Spectroscopic and thermal analysis confirmed successful drug encapsulation with no component incompatibilities. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients diagnosed with glioblastoma multiforme (GBM) often undergo concurrent temozolomide and radiation therapy. Antineoplastic medication nonadherence continues to be an issue for patients with cancer. OBJECTIVES: This quality improvement project aimed to institute an evidence-based standardized educational tool for patients with GBM undergoing concurrent temozolomide and radiation therapy. METHODS: To assess medication adherence, patients completed the Brief Adherence Rating Scale at the end of the last radiation therapy visit. Patients and providers completed satisfaction surveys. FINDINGS: Data analysis from the administered Brief Adherence Rating Scale demonstrated a mean of 99.3% (N = 13) medication adherence among participants. Median medication adherence was demonstrated to be 100%, with scores ranging from 93% to 100%. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The mechanisms underlying breast cancer brain metastasis (BCBM) development are complex, and its clinical presentation varies depending on the number, location, and size of brain metastases. Common symptoms include headache, neurologic deficits, and seizures. Diagnosis of BCBM typically relies on neuroimaging techniques, such as magnetic resonance imaging and computed tomography scans. Local therapies, such as surgery and stereotactic radiosurgery, can be used to control tumor growth and relieve symptoms. Whole-brain radiotherapy has been a mainstay of treatment for BCBM, but its use has been associated with cognitive decline. Systemic therapy with chemotherapy and targeted agents plays an increasingly important role in the management of BCBM. Novel agents, such as human epidermal growth factor receptor 2 (HER2)–targeted therapies and tyrosine kinase inhibitors, have shown promising results in improving survival for patients with HER2-positive and triple-negative BCBM. This comprehensive review synthesizes current knowledge, clinical insights, and evolving paradigms to provide a robust understanding and roadmap for optimizing the diagnosis and management of BCBM. Improved Management of BCBM through Multi-Disciplinary Approaches, Leads to Enhanced Patient Outcomes [ABSTRACT FROM AUTHOR]

The prognosis of patients with osteosarcoma who experience recurrence or progression (R/P) is extremely poor, and more effective and less toxic therapies are needed. In the current study, the clinical data of osteosarcoma patients who experienced R/P were retrospectively analyzed to verify the reliability of O‐6‐methylguanine‐DNA methyltransferase (MGMT) protein expression or MGMT promoter methylation for predicting the response to off‐label temozolomide (TMZ)‐containing chemotherapy. Of the 30 evaluable patients, 9 (30%) showed no/low MGMT protein expression, whereas all 16 evaluable patients had unmethylated MGMT promoter irrespective of MGMT protein expression levels. Twenty‐three patients received TMZ‐containing chemotherapy for measurable lesions (n = 14) or as adjuvant therapy following resection of recurrent lesions (n = 9). Among 14 patients with radiologically measurable lesions, the objective response rate was higher in the MGMT no/low‐expression group (50.0%) than in the MGMT intermediate/high‐expression group with borderline significance (0%, p = 0.066). The 6‐month progression‐free survival (PFS) rate in patients with radiologically measurable lesions was significantly higher in the MGMT no/low‐expression group (50.0%) than in the MGMT intermediate/high‐expression group (0%, p = 0.036). In the multivariate analysis of the 23 patients receiving TMZ‐containing chemotherapy, MGMT expression and disease status before TMZ‐containing chemotherapy were significantly associated with PFS. No severe adverse effects were observed during TMZ‐containing chemotherapy. MGMT protein expression, but not MGMT promoter methylation, could predict a favorable outcome in patients receiving TMZ‐containing chemotherapy. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aims: This study aims to systematically analyze the global trends in glioma methylation research using bibliometricmethodologies. 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. Methods: We performed a comprehensive literature search of the Web of Science Core Collection (WoSCC) to identify articles related to glioma methylation published fromJanuary 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 Graph Pad Prism, CiteSpace, and VOSviewer software. Results: The 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. Conclusions: The 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. [ABSTRACT FROM AUTHOR]

This document discusses the role of LOXL2 in promoting the occurrence and progression of glioma, a type of brain tumor. LOXL2 activates autophagy, a cellular process that promotes tumor growth and resistance to chemotherapy. The specific mechanisms of LOXL2's relationship with histological grade and autophagy's regulation of epithelial-mesenchymal transition (EMT) are still unclear and require further study. The findings suggest that targeting LOXL2 in combination with chemotherapy may be an effective treatment strategy for glioma and potentially other tumors. [Extracted from the article]

Gliomas are highly malignant brain tumours that remain refractory to treatment. Treatment is typically surgical intervention followed by concomitant temozolomide and radiotherapy; however patient prognosis remains poor. Voltage gated ion channels have emerged as novel targets in cancer therapy and inhibition of a potassium selective subtype (hERG, Kv11.1) has demonstrated antitumour activity. Unfortunately blockade of hERG has been limited by cardiotoxicity, however hERG channel agonists have produced similar chemotherapeutic benefit without significant side effects. In this study, electrophysiological recordings suggest the presence of hERG channels in the anaplastic astrocytoma cell line SMA-560, and treatment with the hERG channel agonist NS1643, resulted in a significant reduction in the proliferation of SMA-560 cells. In addition, NS1643 treatment also resulted in a reduction of the secretion of matrix metalloproteinase-9 and SMA-560 cell migration. When combined with temozolomide, an additive impact was observed, suggesting that NS1643 may be a suitable adjuvant to temozolomide and limit the invasiveness of glioma. [ABSTRACT FROM AUTHOR]

Background: Temozolomide, 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. Methods: We 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. Results: In 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. Conclusion: The 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. [ABSTRACT FROM AUTHOR]

As the most common and aggressive primary malignant brain tumor, glioblastoma is still lacking a satisfactory curative approach. The standard management consisting of gross total resection followed by radiotherapy and chemotherapy with temozolomide only prolongs patients' life moderately. In recent years, many therapeutics have failed to give a breakthrough in GBM treatment. In the search for new treatment solutions, we became interested in the repurposing of existing medicines, which have established safety profiles. We focused on the possible implementation of well-known drugs, metformin, and arginine. Metformin is widely used in diabetes treatment, but arginine is mainly a cardiovascular protective drug. We evaluated the effects of metformin and arginine on total DNA methylation, as well as the oxidative stress evoked by treatment with those agents. In glioblastoma cell lines, a decrease in 5-methylcytosine contents was observed with increasing drug concentration. When combined with temozolomide, both guanidines parallelly increased DNA methylation and decreased 8-oxo-deoxyguanosine contents. These effects can be explained by specific interactions of the guanidine group with m5CpG dinucleotide. We showed that metformin and arginine act on the epigenetic level, influencing the foreground and potent DNA regulatory mechanisms. Therefore, they can be used separately or in combination with temozolomide, in various stages of disease, depending on desired treatment effects. [ABSTRACT FROM AUTHOR]

Simple Summary: Immune checkpoint inhibitors (ICIs) have been experimentally used in refractory pituitary neuroendocrine tumours (PitNETs). We reviewed the published data on PitNETs treated with PD-1/PD-L1 inhibitors. Demographics, clinical–pathological features, treatment details, radiological and biochemical responses, and survival were evaluated. Among twenty-nine ICI-treated PitNETs, eighteen secreted adrenocorticotropic hormone (ACTH) (62.1%), seven were prolactinomas (24.1%), and four were non-functioning PitNETs. All patients underwent various therapies prior to ICI treatment. A positive radiological response (i.e., partial/complete radiological response and stable disease) was observed in eighteen cases (62.1%), of which ten and four were ACTH- and prolactin-secreting PitNETs, respectively. Hormonal levels reduced or stabilised after using ICIs in 11 cases (64.7%). The median survival after using ICIs was 13 months. These data suggest a promising role of ICIs in patients with PitNETs refractory to other treatment modalities. Therapeutic options for pituitary neuroendocrine tumours (PitNETs) refractory to temozolomide are scarce. Immune checkpoint inhibitors (ICIs), particularly inhibitors of the programmed cell death-1 (PD-1) pathway and its ligand (PD-L1), have been experimentally used in aggressive or metastatic PitNETs. We aimed to study the therapeutic usefulness of anti-PD-1 drugs in patients with aggressive or metastatic PitNETs. Published cases and case series involving patients with PitNETs treated with PD-1/PD-L1 inhibitors were reviewed. Demographic data, clinical–pathological features, previous therapies, drug dosage and posology, and the best radiological and biochemical responses, as well as survival data, were evaluated. We identified 29 cases of aggressive (n = 13) or metastatic (n = 16) PitNETs treated with PD-1/PD-L1 inhibitors. The hypersecretion of adrenocorticotropic hormone (ACTH) was documented in eighteen cases (62.1%), seven were prolactinomas (24.1%), and four were non-functioning PitNETs. All patients underwent various therapies prior to using ICIs. Overall, a positive radiological response (i.e., partial/complete radiological response and stable disease) was observed in eighteen of twenty-nine cases (62.1%), of which ten and four were ACTH- and prolactin-secreting PitNETs, respectively. Hormonal levels reduced or stabilised after using ICIs in 11 of the 17 functioning PitNET cases with available data (64.7%). The median survival of patients treated with ICIs was 13 months, with a maximum of 42 months in two ACTH-secreting tumours. Among 29 patients with PitNETs treated with PD-1/PD-L1 inhibitors, the positive radiological and biochemical response rates were 62.1% and 64.7%, respectively. Altogether, these data suggest a promising role of ICIs in patients with aggressive or metastatic PitNETs refractory to other treatment modalities. [ABSTRACT FROM AUTHOR]

Simple Summary: Peptide Receptor Radionuclide Therapy (PRRT) and Capecitabine/Temozolomide (CAPTEM) are cornerstones of systemic therapy for metastatic pancreatic neuroendocrine tumors (PNETs). In clinical practice, most patients receive more than one regimen, and the optimal sequence of treatments for these patients remains poorly understood. We present a real-world comparison of progression-free survival (PFS) between PRRT and CAPTEM in PNETs. Our analysis found that clinical outcomes were comparable to previously reported data in the real-world setting and were similar for both regimens. PFS for patients without extrahepatic metastases and those with MEN1, DAXX, and/or ATRX mutations might be prolonged with PRRT. Patients with grade 3 disease might fare better with CAPTEM initially. Candidates for surgical debulking or those with tumor-induced symptoms may benefit from initial treatment with CAPTEM due to the shorter time to response. Background: Peptide Receptor Radionuclide Therapy (PRRT), a form of Radioligand Therapy (RLT), and Capecitabine/Temozolomide (CAPTEM) are cornerstones of systemic therapy for metastatic pancreatic neuroendocrine tumors (PNETs). Data regarding comparative efficacy are lacking. Herein, we compare the efficacy of PRRT vs. CAPTEM as second-line/beyond regimens and treatment sequencing. Methods: Clinicopathologic, radiographic, and genomic data were captured for metastatic PNETs seen in our multi-disciplinary NET clinic between 2013 and 2023. The primary outcome was progression-free survival (PFS) after progression on a previous line of systemic therapy. The secondary outcomes were objective response rate (ORR), time to response (TTR), and overall survival (OS). Results: Fifty-nine cases were included. PFS was similar in the PRRT (n = 29) and CAPTEM (n = 30) groups (PRRT = 21.90 months vs. CAPTEM = 20.03 months; HR 0.99; p = 0.97). On subgroup analysis, PRRT had longer PFS in cases without extrahepatic metastases (26.47 months vs. 17.67 months; p = 0.03) and cases with a mutation in the MEN1, DAXX, and/or ATRX genes (28.43 months vs. 18.67 months; p = 0.03). PRRT had reduced PFS in patients with grade 3 disease (7.83 months vs. 16.33 months; p = 0.02). ORR did not vary significantly (34.78% vs. 40.91%; p = 0.67). CAPTEM responders showed shorter TTR (6.03 months vs. 11.15 months; p = 0.03). In patients who received both, OS did not vary based on the sequence (HR 1.20; p = 0.75). Conclusions: PFS, ORR, and OS are similar when using PRRT vs. CAPTEM as second-line-and-beyond therapy for patients with metastatic PNETs. However, patients with MEN1, DAXX, and/or ATRX mutations or without extrahepatic metastases might better benefit from PRRT and patients with grade 3 disease from CAPTEM. Candidates for surgical debulking or with tumor-induced symptoms may benefit from initial treatment with CAPTEM due to shorter TTR. [ABSTRACT FROM AUTHOR]

Overcoming temozolomide (TMZ)-resistance is a major challenge in glioblastoma therapy. Therefore, identifying the key molecular player in chemo-resistance becomes urgent. We previously reported the downregulation of PDCD10 in primary glioblastoma patients and its tumor suppressor-like function in glioblastoma cells. Here, we demonstrate that the loss of PDCD10 causes a significant TMZ-resistance during treatment and promotes a rapid regrowth of tumor cells after treatment. PDCD10 knockdown upregulated MGMT, a key enzyme mediating chemo-resistance in glioblastoma, accompanied by increased expression of DNA mismatch repair genes, and enabled tumor cells to evade TMZ-induced cell-cycle arrest. These findings were confirmed in independent models of PDCD10 overexpressing cells. Furthermore, PDCD10 downregulation led to the dedifferentiation of glioblastoma cells, as evidenced by increased clonogenic growth, the upregulation of glioblastoma stem cell (GSC) markers, and enhanced neurosphere formation capacity. GSCs derived from PDCD10 knockdown cells displayed stronger TMZ-resistance and regrowth potency, compared to their parental counterparts, indicating that PDCD10-induced stemness may independently contribute to tumor malignancy. These data provide evidence for a dual role of PDCD10 in tumor suppression by controlling both chemo-resistance and dedifferentiation, and highlight PDCD10 as a potential prognostic marker and target for combination therapy with TMZ in glioblastoma. [ABSTRACT FROM AUTHOR]

Glioma cancer is the primary cause of cancer-related fatalities globally for both men and women. Traditional chemotherapy treatments for this condition frequently result in reduced efficacy and significant adverse effects. This investigation developed a new drug delivery system for the chemotherapeutic drug temozolomide (TMZ) using pH-sensitive drug delivery zeolitic imidazolate frameworks (ZIF-8). These nanoplatforms demonstrate excellent biocompatibility and hold potential for cancer therapy. Utilizing the favorable reaction milieu offered by ZIFs, a 'one-pot method' was employed for the fabrication and loading of drugs, leading to a good capacity for loading. TMZ@TA@ZIF-8 NPs exhibit a notable response to an acidic milieu, resulting in an enhanced drug release pattern characterized by a controlled release outcome. The effectiveness of TMZ@TA@ZIF-8 NPs in inhibiting the migration and invasion of U251 glioma cancer cells, as well as promoting apoptosis, was confirmed through various tests, including MTT (3-(4,5)-dimethylthiahiazo(-z-y1)) assay, DAPI/PI dual staining, and cell scratch assay. The biochemical fluorescent staining assays showed that TMZ@TA@ZIF-8 NPs potentially improved ROS, reduced MMP, and triggered apoptosis in U251 cells. In U251 cells treated with NPs, the p53, Bax, Cyt-C, caspase-3, −8, and −9 expressions were significantly enhanced, while Bcl-2 expression was diminished. These outcomes show the potential of TMZ@TA@ZIF-8 NPs as a therapeutic agent with anti-glioma properties. Overall, the pH-responsive drug delivery systems we fabricated using TMZ@TA@ZIF-8 NPs show great potential for cancer treatment. This approach has the potential to make significant contributions to the improvement of cancer therapy by overcoming the problems associated with TMZ-based treatments. [ABSTRACT FROM AUTHOR]

Glioblastoma tumors are the most aggressive primary brain tumors that develop resistance to temozolomide (TMZ). Eribulin (ERB) exhibits a unique mechanism of action by inhibiting microtubule dynamics during the G2/M cell cycle phase. We utilized the T98G human glioma cell line to investigate the effects of ERB and TMZ, both individually and in combination. The experimental groups were established as follows: control, E5 (5 nM ERB), T0.75 (0.75 mM TMZ), T1 (1.0 mM TMZ), and combination groups (E5+T0.75 and E5+T1). All groups showed a significant decrease in cell proliferation. Apoptotic markers revealed a time-dependent increase in annexin-V expression, across all treatment groups at the 48-hour time point. Caspase-3, exhibited an increase in the combination treatment groups at the 48-hour mark. Transmission electron microscopy (TEM) revealed normal ultrastructural features in the glioma cells of the control group. However, treatments induced ultrastructural changes within the spheroid glioblastoma model, particularly in the combination groups. These changes included a dose-dependent increase in autophagic vacuoles and apoptotic morphology of the cells. In conclusion, the similarity in the mechanism of action between ERB and TMZ suggests the potential for synergistic effects when combined. Our results highlight that this combination induced severe damage and autophagy in glioma spheroids after 48 hours. [ABSTRACT FROM AUTHOR]

Local failure remains the major concern in grade 4 glioma or glioblastoma (GBM). Pilot studies have shown a radiotherapy (RT) dose–response relationship in GBM. Here we present our preliminary data of RT dose escalation using 68Ga-Pentixafor PET scan. High 68Ga-pentixafor uptake in glioma cells helps in sharp demarcation between tumour and normal brain. This phase II prospective study was conducted from 2018 to 2020. Thirty, biopsy-proven cases of grade 4 glioma were included. All patients underwent post-operative MRI of the brain and 68Ga-Pentixafor PET scan. RT was planned in 2-phases. Phase-1 GTV (GTV1) comprised of T2/flair abnormality, PET-avid disease and post-op cavity. A margin of 2cm was given to GTV-1 to create phase-1 CTV (CTV1), which was further expanded to 0.5cm to generate phase-1 PTV (PTV1). A radiation dose of 46Gy/23fr was prescribed to PTV-1. Phase-2 GTV (GTV2) consisted of CT/MRI contrast-enhancing lesion, PET avid disease and post-op cavity. A margin of 0.5 cm was given to GTV2 to create phase-2 CTV (CTV2) which was expanded to 0.5 cm to create phase-2 PTV (PTV2). RT dose of 14 Gy/7 fr was prescribed to PTV2. PET avid disease was delineated as GTV PET and a margin of 3mm was given to generate PTV-PET which received escalated RT dose of 21 Gy/7fr by simultaneous integrated boost (SIB) in phase 2 (Total dose to PTV PET = 67 Gy/30 fr). All patients received concurrent and adjuvant temozolomide. The data was prospectively maintained in Microsoft Excel sheet. SPSS v 23 was used for statistical analysis. The primary endpoints were estimation of the overall survival (OS) and progression-free survival (PFS), and secondary endpoint was to measure the incidence of radiation necrosis. Categorical variables were reported as frequency and percentage and quantitative variables were reported as median and range. Data from thirty patients were analysed. A median OS of 23 months was observed with estimated 1, 2 and 3 years OS of 90%, 40% and 17.8% respectively. A significant association of OS was seen with the extent of surgery (p = 0.04) and kernofsky performance status (p = 0.007). No patient developed significant radiation necrosis. The index study did not show any survival benefit from dose escalation RT. However, all of the patients tolerated the treatment well and none of them developed radiation necrosis. Considering the small sample size as a limitation of the index study, the role of 68Ga-pentixafor PET scan for radiation dose escalation should be further explored. CTRI/2019/05/019146. • Radiotherapy dose escalation in grade 4 glioma using 68Ga-Pentixafor PET scan. • Increased RT dose (67Gy/30#/6 weeks) was used for PET avid lesion. • None of the patients developed radiation necrosis. • No survival benefit from RT dose escalation. • Limitation – Small sample size. [ABSTRACT FROM AUTHOR]

) Objective To explore effective treatments and prognostic factors for diffuse intrinsic pontine glioma (DIPG). Methods Clinical and imaging information and survival data of 14 DIPG patients, treated with radiotherapy combined with temozolomide and nitolizumab or radiotherapy combined with ACT001, were retrospectively analysed at Beijing Tiantan Hospital, Capital Medical University from April 2021 to January 2024. The median progression free survival (PFS) and overall survival (OS) were calculated using Kaplan - Meier survival curves, and multifactorial Cox regression analysis was used to investigate the effects of different factors on PFS and OS. Results The objective response rate (ORR) was 10/14, and the median PFS and OS were 7.83 and 8.30 months, respectively. Multfactorial Cox regression analysis identified the absence of enhancement on baseline imaging as a good prognostic variable for both PFS (RR = 0.052, 95%CI: 0.006-0.416; P = 0.005) and OS (RR = 0.046, 95%CI: 0.005-0.413; P = 0.006), while male (RR = 0.085, 95%CI: 0.009-0.764; P = 0.028), older age (RR = 0.631, 95%CI: 0.423-0.942; P = 0.024), and the absence of symptoms of cranial nerve involvement at the onset (RR = 0.116, 95%CI: 0.017- 0.781; P = 0.027) were also good prognostic variables for OS. Conclusions Female, younger age at diagnosis, cranial nerve involvement at the onset, and enhancement on baseline imaging are risk factors for the survival of children with DIPG. Key words: Diffuse intrinsic pontine glioma; Radiotherapy; Antineoplastic combined chemotherapy protocols; Molecular targeted therapy; Child [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the prognostic performance of amino-acid PET in high-grade gliomas (HGG) patients at the time of temozolomide (TMZ) treatment discontinuation, after the Stupp protocol. Methods: The analysis included consecutive HGG patients with dynamic [18F]FDOPA PET imaging within 3 months of the end of TMZ therapy, post-Stupp protocol. Static and dynamic PET parameters, responses to RANO criteria for MRI and clinical and histo-molecular factors were correlated to progression-free (PFS). Results: Thirty-two patients (59.4 [54.0;67.6] years old, 13 (41%) women) were included. Static PET parameters peak tumor-to-background ratio and metabolic tumor volume (respective thresholds of 1.9 and 1.5 mL) showed the best 84% accuracies for predicting PFS at 6 months (p = 0.02). These static PET parameters were also independent predictor of PFS in multivariate analysis (p ≤ 0.05). Conclusion: In HGG patients having undergone a Stupp protocol, the absence of significant PET uptake after TMZ constitutes a favorable prognostic factor. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is the most common malignant brain tumor and has the poorest prognosis attributed to its chemoresistance to temozolomide (TMZ), the first-line drug for treating GBM. TMZ resistance represents a significant obstacle to successful GBM treatment, necessitating the development of new strategies to overcome this resistance and augment the chemosensitivity of GBM cells to TMZ. This study established a TMZ-resistant U251 (U251-TMZ) cell line by exposing it to increasing doses of TMZ in vitro. We focused on the DNA methyltransferase 3B (DNMT3B) gene, phosphorylated Akt (p-Akt), total Akt (t-Akt), phosphorylated PI3K (p-PI3K), and total PI3K (t-PI3K) protein expression. Results showed that the DNMT3B gene was significantly upregulated in the U251-TMZ cell line. The p-Akt and p-PI3K protein expression in U251-TMZ cells was also significantly elevated. Moreover, we found that DNMT3B downregulation was correlated with the increased chemosensitivity of GBM cells to TMZ. LY294002 suppressed the PI3K/Akt signaling pathway, leading to a notable inhibition of PI3K phosphorylation and a significant decrease in DNMT3B expression in U251-TMZ cells. Given that DNMT3B expression is mediated by the PI3K/Akt signaling pathway, its downregulation further increased the chemosensitivity of GBM cells to TMZ and therefore is a promising therapeutic for GBM treatment. Our results suggested that DNMT3B downregulation can inhibit the proliferation of GBM cells and induce GBM cell apoptosis in vitro. In addition, the PI3K/Akt signaling pathway plays an important role in the chemosensitivity of GBM cells to TMZ by regulating DNMT3B expression. [ABSTRACT FROM AUTHOR]

Humans are unavoidably exposed to numerous different mutagenic DNA alkylating agents (AAs), but their role in the initiation of cancers is uncertain, in part due to difficulties in assessing human exposure. To address this, we have developed a screening method that measures promutagenic O6-alkylguanines (O6-AlkGs) in DNA and applied it to human DNA samples. The method exploits the ability of the Schizosaccharomyces pombe alkyltransferase-like protein (Atl1) to recognise and bind to a wide range of O6-AlkGs in DNA. We established an Atl1-based slot-blot (ASB) assay and validated it using calf thymus DNA alkylated in vitro with a range of alkylating agents and both calf thymus and human placental DNA methylated in vitro with temozolomide (TMZ). ASB signals were directly proportional to the levels of O6-meG in these controls. Pre-treatment of DNA with the DNA repair protein O6-methylguanine–DNA methyltransferase (MGMT) reduced binding of Atl1, confirming its specificity. In addition, MCF 10A cells were treated with 500 μM TMZ and the extracted DNA, analysed using the ASB, was found to contain 1.34 fmoles O6 -meG/μg DNA. Of six human breast tumour DNA samples assessed, five had detectable O6-AlkG levels (mean ± SD 1.24 ± 0.25 O6-meG equivalents/μg DNA. This study shows the potential usefulness of the ASB assay to detect and quantify total O6-AlkGs in human DNA samples. [ABSTRACT FROM AUTHOR]

Angiogenesis is critical for tumor growth and metastasis. Bevacizumab is an antiangiogenic drug used to treat various adult and childhood solid tumors. Its potential efficacy in Wilms tumor (WT) with poor prognosis is not established. The response to bevacizumab-containing regimens in relapsed or refractory WT was reviewed in available literature. Searches were conducted using PubMed, Scopus, and ClinicalTrials.gov databases. Eight papers were identified, published between 2007 and 2020, including six treatment regimens, predominantly vincristine, irinotecan, and bevacizumab (VIB) ± temozolomide (VITB). Among 16 evaluable patients, there were two complete responses, seven partial responses, five patients achieved stable disease (SD), and two patients had progressive disease. Objective responses (OR) were observed in 56% of all cases. OR or SD was observed in 89% (8/9) patients who received VIB/VITB. Bevacizumab was generally well tolerated. Related toxicities included hypertension, proteinuria, and delayed wound healing. This review suggests potential effectiveness and good tolerability of bevacizumab in the setting of relapsed/refractory WT when used in combination with other drugs. Such combination therapies may serve as a bridging treatment option to other interventions and more personalized treatment options in the future; however, focused trials are needed to obtain additional evidence. [ABSTRACT FROM AUTHOR]

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.

Glioblastoma (GBM) is the most common lethal primary brain cancer in adults. Despite treatment regimens including surgical resection, radiotherapy, and temozolomide (TMZ) chemotherapy, growth of residual tumor leads to therapy resistance and death. At recurrence, a quarter to a third of all gliomas have hypermutated genomes, with mutational burdens orders of magnitude greater than in normal tissue. Here, we quantified the mutational landscape progression in a patients primary and recurrent GBM, and we uncovered Cas9-targetable repeat elements. We show that CRISPR-mediated targeting of highly repetitive loci enables rapid elimination of GBM cells, an approach we term genome shredding. Importantly, in the patients recurrent GBM, we identified unique repeat sequences with TMZ mutational signature and demonstrated that their CRISPR targeting enables cancer-specific cell ablation. Cancer shredding leverages the non-coding genome and therapy-induced mutational signatures for targeted GBM cell depletion and provides an innovative paradigm to develop treatments for hypermutated glioma.