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Glioblastoma (GBM) presents a daunting challenge due to its resistance to temozolomide (TMZ), a hurdle exacerbated by the proneural-to-mesenchymal transition (PMT) from a proneural (PN) to a mesenchymal (MES) phenotype. TAGLN2 is prominently expressed in GBM, particularly in the MES subtype compared to low-grade glioma (LGG) and the PN subtype. Our research reveals TAGLN2's involvement in PMT and TMZ resistance through a series of in vitro and in vivo experiments. TAGLN2 knockdown can restrain proliferation and invasion, trigger DNA damage and apoptosis, and heighten TMZ sensitivity in GBM cells. Conversely, elevating TAGLN2 levels amplifies resistance to TMZ in cellular and intracranial xenograft mouse models. We demonstrate the interaction relationship between TAGLN2 and ERK1/2 through co-immunoprecipitation (Co-IP) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) spectrometry analysis. Knockdown of TAGLN2 results in a decrease in the expression of p-ERK1/2, whereas overexpression of TAGLN2 leads to an increase in p-ERK1/2 expression within the nucleus. Subsequently, the regulatory role of TAGLN2 in the expression and control of MGMT has been demonstrated. Finally, the regulation of TAGLN2 by NF-κB has been validated through chromatin immunoprecipitation and ChIP-PCR assays. In conclusion, our results confirm that TAGLN2 exerts its biological functions by interacting with the ERK/MGMT axis and being regulated by NF-κB, thereby facilitating the acquisition of promoting PMT and increased resistance to TMZ therapy in glioblastoma. These results provide valuable insights for the advancement of targeted therapeutic approaches to overcome TMZ resistance in clinical treatments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor. Standard therapy includes maximal surgical resection, radiotherapy, and adjuvant temozolomide (TMZ) administration. However, the rapid development of TMZ resistance and the impermeability of the blood-brain barrier (BBB) significantly hinder the therapeutic efficacy. Herein, we developed spatiotemporally controlled microneedle patches (BMNs) loaded with TMZ and niclosamide (NIC) to overcome GBM resistance. We found that hyaluronic acid (HA) increased the viscosity of bovine serum albumin (BSA) and evidenced that concentrations of BSA/HA exert an impact degradation rates exposure to high-temperature treatment, showing that the higher BSA/HA concentrations result in slower drug release. To optimize drug release rates and ensure synergistic antitumor effects, a 15% BSA/HA solution constituting the bottoms of BMNs was chosen to load TMZ, showing sustained drug release for over 28 days, guaranteeing long-term DNA damage in TMZ-resistant cells (U251-TR). Needle tips made from 10% BSA/HA solution loaded with NIC released the drug within 14 days, enhancing TMZ's efficacy by inhibiting the activity of O6-methylguanine-DNA methyltransferase (MGMT). BMNs exhibit superior mechanical properties, bypass the BBB, and gradually release the drug into the tumor periphery, thus significantly inhibiting tumor proliferation and expanding median survival in mice. The on-demand delivery of BMNs patches shows a strong translational potential for clinical applications, particularly in synergistic GBM treatment.

The currently available immune checkpoint therapy shows a disappointing therapeutic efficacy for glioblastoma multiforme (GBM), and it is of great importance to discover better immune checkpoints and develop innovative targeting strategies. The discovered metabolic immune checkpoint ecto-5-nucleotidase (CD73) in a tumor contributes to its immune evasion due to the dysregulation of extracellular adenosine (ADO), which significantly inhibits the function of antitumor T cells and increases the activity of immunosuppressive cells. Herein, we drastically inhibit the expression of CD73 to reduce the production of ADO by using versatile Au@Cu 2- x Se nanoparticles (ACS NPs). ACS NPs can decrease the expression of CD73 by alleviating the tumor hypoxia through their Fenton-like reaction to weaken the ADO-driven immunosuppression for enhancing antitumor T cell infiltration and activity of GBM. The copper ions (Cu 2+ ) released from ACS NPs can chelate with disulfide, leading to the formation of cytotoxic bis( N , N -diethyldithiocarbamate)-copper complex (CuET), which can be combined with radiotherapy to recruit more antitumor T cells to infiltrate into the tumor site. Based on the inhibition of CD73 to promote the infiltration and activity of antitumor T cells, a cascade of enhancing GBM immunotherapy effects can be achieved. The significant increase in CD8 + T and CD4 + T cells within the tumor and the memory T cells in the spleen effectively reduces tumor size by 92%, which demonstrates the excellent efficacy of immunotherapy achieved by a combination of metabolic immune checkpoint CD73 inhibition with chemoradiotherapy. This work demonstrates that modulation of CD73-mediated tumor immunosuppression is an important strategy of improving the outcome of GBM immunotherapy.

Glioblastoma (GBM) represents a primary malignant brain tumor. Temozolomide resistance is a major hurdle in GBM treatment. Proteins encoded by circular RNAs (circRNAs) can modulate the sensitivity of multiple tumor chemotherapies. However, the impact of circRNA-encoded proteins on GBM sensitivity to temozolomide remains unknown. Herein, we discover a circRNA (circCOPA) through the circRNA microarray profile in GBM samples, which can encode a novel 99 amino acid protein (COPA-99aa) through its internal ribosome entry site. Functionally, circCOPA overexpression in GBM cells inhibits cell proliferation, migration, and invasion in vitro and growth in vivo. Rather than itself, circCOPA mainly functions as a suppressive effector by encoding COPA-99aa. Moreover, we reveal that circCOPA is downregulated in GBM tissues and high expression of circCOPA is related to a better prognosis in GBM patients. Mechanistically, a heteromer of SFPQ and NONO is required for double-strand DNA break repair. COPA-99aa disrupts the dimerization of NONO and SFPQ by separately binding with the NONO and SFPQ proteins, thus resulting in the inhibition of proliferation or invasion and the increase of temozolomide-induced DNA damage in GBM cells. Collectively, our data suggest that circCOPA mainly contributes to inhibiting the GBM malignant phenotype through its encoded COPA-99aa and that COPA-99aa increases temozolomide-induced DNA damage by interfering with the dimerization of NONO and SFPQ. Restoring circCOPA or COPA-99aa may increase the sensitivity of patients to temozolomide., (© 2024. The Author(s).)

DNA repair proteins became the popular targets in research on cancer treatment. In our studies we hypothesized that inhibition of DNA polymerase theta (Polθ) and its combination with Poly (ADP-ribose) polymerase 1 (PARP1) or RAD52 inhibition and the alkylating drug temozolomide (TMZ) has an anticancer effect on glioblastoma cells (GBM21), whereas it has a low impact on normal human astrocytes (NHA). The effect of the compounds was assessed by analysis of cell viability, apoptosis, proliferation, DNA damage and cell cycle distribution, as well as gene expression. The main results show that Polθ inhibition causes a significant decrease in glioblastoma cell viability. It induces apoptosis, which is accompanied by a reduction in cell proliferation and DNA damage. Moreover, the effect was stronger when dual inhibition of Polθ with PARP1 or RAD52 was applied, and it is further enhanced by addition of TMZ. The impact on normal cells is much lower, especially when considering cell viability and DNA damage. In conclusion, we would like to highlight that Polθ inhibition used in combination with PARP1 or RAD52 inhibition has great potential to kill glioblastoma cells, and shows a synthetic lethal effect, while sparing normal astrocytes.

Objective: Inhibition and knockdown of GPR68 negatively affects glioblastoma cell survival in vitro by inducing ferroptosis. Herein, we aimed to demonstrate that inhibition of GPR68 reduces the survival of glioblastoma cells in vivo using two orthotopic larval xenograft models in Danio rerio, using GBM cell lines U87-MG and U138-MG. In vivo survival of the cancer cells was assessed in the setting of GPR68 inhibition or knockdown., Results: In vitro, shRNA-mediated knockdown of GPR68 inhibition demonstrated potent cytotoxic effects against U87 and U138 glioblastoma cell lines. This effect was associated with increased intracellular lipid peroxidation, suggesting ferroptosis as the underlying mechanism of cell death. Translating these findings in vivo, we established a novel xenograft model in zebrafish by successfully grafting fluorescently labeled human glioblastoma cells, which were previously shown to overexpress GPR68. shRNA knockdown of GPR68 significantly reduced the viability of grafted GBM cells within this model. Additionally, treatment with ogremorphin (OGM), a highly specific small molecule inhibitor of GPR68, also reduced the viability of grafted GBM cells with limited toxicity to the developing zebrafish embryos. This study suggests that therapeutic targeting of GPR68 with small molecules like OGM represents a promising approach for the treatment of GBM., (© 2024. The Author(s).)

The development of drug resistance is a nearly universal phenomenon in patients with glioblastoma multiforme (GBM) brain tumors. Upon treatment, GBM cancer cells may initially undergo a drug-induced cell-state change to a drug-tolerant, slow-cycling state. The kinetics of that process are not well understood, in part due to the heterogeneity of GBM tumors and tumor models, which can confound the interpretation of kinetic data. Here, we resolve drug-adaptation kinetics in a patient-derived in vitro GBM tumor model characterized by the epithelial growth factor receptor (EGFR) variant(v)III oncogene treated with an EGFR inhibitor. We use radiolabeled 18 F-fluorodeoxyglucose (FDG) to monitor the glucose uptake trajectories of single GBM cancer cells over a 12 h period of drug treatment. Autocorrelation analysis of the single-cell glucose uptake trajectories reveals evidence of a drug-induced cell-state change from a high- to low-glycolytic phenotype after 5-7 h of drug treatment. Information theoretic analysis of a bulk transcriptome kinetic series of the GBM tumor model delineated the underlying molecular mechanisms driving the cellular state change, including a shift from a stem-like mesenchymal state to a more differentiated, slow-cycling astrocyte-like state. Our results demonstrate that complex drug-induced cancer cell-state changes of cancer cells can be captured via measurements of single cell metabolic trajectories and reveal the extremely facile nature of drug adaptation.

The effect of chemotherapy for anti-glioblastoma is limited due to insufficient drug delivery across the blood-brain-barrier. Poloxamer 188-coated nanoparticles can enhance the delivery of nanoparticles across the blood-brain-barrier. This study presents the design, preparation, and evaluation of a combination of PLGA nanoparticles (PLGA NPs) loaded with methotrexate (P-MTX NPs) and PLGA nanoparticles loaded with paclitaxel (P-PTX NPs), both of which were surface-modified with poloxamer188. Cranial tumors were induced by implanting C6 cells in a rat model and MRI demonstrated that the tumors were indistinguishable in the two rats with P-MTX NPs + P-PTX NPs treated groups. Brain PET scans exhibited a decreased brain-to-background ratio which could be attributed to the diminished metabolic tumor volume. The expression of Ki-67 as a poor prognosis factor, was significantly lower in P-MTX NPs + P-PTX NPs compared to the control. Furthermore, the biodistribution of PLGA NPs was determined by carbon quantum dots loaded into PLGA NPs (P-CQD NPs), and quantitative analysis of ex-vivo imaging of the dissected organs demonstrated that 17.2 ± 0.6% of the NPs were concentrated in the brain after 48 h. The findings highlight the efficacy of combination nanochemotherapy in glioblastoma treatment, indicating the need for further preclinical studies., (© 2024. The Author(s).)

The use of TiO 2 as a photosensitizer in photodynamic therapy is limited due to TiO 2 generates reactive oxygen species only under UV irradiation. The TiO 2 surface has been modified with different functional groups to achieve activation at longer wavelengths (visible light). This work reports the synthesis, characterization, and biological toxicity assay of TiO 2 nanoparticles functionalized with folic acid and combined with a zinc phthalocyanine to obtain a nano-photosensitizer for its application in photodynamic therapy for glioblastoma cancer treatment. The nano-photosensitizer was prepared using the sol-gel method. Folic acid and zinc phthalocyanine were added during the hydrolysis and condensation of titanium butoxide, which was the TiO 2 precursor. The samples obtained were characterized by several microscopy and spectroscopy techniques. An in vitro toxicity test was performed using the MTT assay and the C6 cellular line. The results of the characterization showed that the structure of the nanoparticles corresponds mainly to the anatase phase. Successful functionalization with folic acid and an excellent combination with phthalocyanine was also achieved. Both folic acid-functionalized TiO 2 and phthalocyanine-functionalized TiO 2 had no cytotoxic effect on C6 cells (even at high concentrations) in comparison to Cis-Pt, which was very toxic to C6 cells. The materials behaved similarly to the control (untreated cells). The cell viability and light microscopy images suggest that both materials could be considered biocompatible and mildly phototoxic in these cells when activated by light., (© 2024. The Author(s).)

The main reasons for the difficulty in curing and high recurrence rate of glioblastoma multiforme (GBM) include: 1. The difficulty of chemotherapy drugs in penetrating the blood-brain barrier (BBB) to target tumor cells; 2. The presence of glioma stem cells (GSCs) leading to chemotherapy resistance. Therefore, breaking through the limitations of the BBB and overcoming the drug resistance caused by GSCs are the main strategies to address this problem. This study presents our results on the development of lactoferrin (Lf)/CD133 antibody conjugated nanostructured lipid carriers (Lf/CD133-NLCS) for simultaneously targeting BBB and GSCs. Temozolomide (TMZ) loaded Lf/CD133-NLCS (Lf/CD133-NLCS-TMZ) exhibited high-efficiency in vitro anti-tumor effects toward malignant glioma cells (U87-MG) and GSCs, while demonstrating no significant toxicity to normal cells at concentrations lower than 200 μg ml -1 . The results of the in vitro targeting GBM study revealed a notably higher cellular uptake of Lf/CD133-NLCS-TMZ in U87-MG cells and GSCs in comparison to Lf/CD133 unconjugated counterpart (NLCS-TMZ). In addition, increased BBB permeability were confirmed for Lf/CD133-NLCS-TMZ compared to NLCS-TMZ both in vitro and in vivo . Taking together, Lf/CD133-NLCS-TMZ show great potential for dual targeting of BBB and GSCs, as well as GBM therapy based on this strategy., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Glioblastoma multiforme (GBM) is a highly aggressive and fatal primary brain tumor. The resistance of GBM to conventional treatments is attributed to factors such as the blood-brain barrier, tumor heterogeneity, and treatment-resistant stem cells. Current therapeutic efforts show limited survival benefits, emphasizing the urgent need for novel treatments. In this context, natural anti-cancer extracts and especially animal venoms have garnered attention for their potential therapeutic benefits. Bee venom in general and that of the Middle Eastern bee, Apis mellifera syriaca in particular, has been shown to have cytotoxic effects on various cancer cell types, but not glioblastoma. Therefore, this study aimed to explore the potential of A. mellifera syriaca venom as a selective anti-cancer agent for glioblastoma through in vitro and in vivo studies. Our results revealed a strong cytotoxic effect of A. mellifera syriaca venom on U87 glioblastoma cells, with an IC50 of 14.32 µg/mL using the MTT test and an IC50 of 7.49 µg/mL using the LDH test. Cells treated with the bee venom became permeable to propidium iodide without showing any signs of early apoptosis, suggesting compromised membrane integrity but not early apoptosis. In these cells, poly (ADP-ribose) polymerase (PARP) underwent proteolytic cleavage similar to that seen in necrosis. Subsequent in vivo investigations demonstrated a significant reduction in the number of U87 cells in mice following bee venom injection, accompanied by a significant increase in cells expressing caspase-3, suggesting the occurrence of cellular apoptosis. These findings highlight the potential of A. mellifera syriaca venom as a therapeutically useful tool in the search for new drug candidates against glioblastoma and give insights into the molecular mechanism through which the venom acts on cancer cells.

The DNA damage response (DDR) and the blood-tumor barrier (BTB) restrict chemotherapeutic success for primary brain tumors like glioblastomas (GBMs). Coherently, GBMs almost invariably relapse with fatal outcomes. Here, we show that the interaction of GBM and myeloid cells simultaneously induces chemoresistance on the genetic and vascular levels by activating GP130 receptor signaling, which can be addressed therapeutically. We provide data from transcriptomic and immunohistochemical screens with human brain material and pharmacological experiments with a humanized organotypic GBM model, proteomics, transcriptomics, and cell-based assays and report that nanomolar concentrations of the signaling peptide humanin promote temozolomide (TMZ) resistance through DDR activation. GBM mouse models recapitulating intratumoral humanin release show accelerated BTB formation. GP130 blockade attenuates both DDR activity and BTB formation, resulting in improved preclinical chemotherapeutic efficacy. Altogether, we describe an overarching mechanism for TMZ resistance and outline a translatable strategy with predictive markers to improve chemotherapy for GBMs., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: The Hippo pathway is a conserved tumour suppressor signalling pathway, and its dysregulation is often associated with abnormal cell growth and tumorigenesis. We previously revealed that the transcriptional coactivator Yes-associated protein (YAP), the key effector of the Hippo pathway, is a molecular target for glioblastoma (GBM), the most common malignant brain tumour. Inhibiting YAP with small interfering RNA (siYAP) or the specific inhibitor verteporfin (VP) can diminish GBM growth to a certain degree., Results: In this study, to enhance the anti-GBM effect of siYAP and VP, we designed stepwise-targeting and hypoxia-responsive liposomes (AMVY@NPs), which encapsulate hypoxia-responsive polymetronidazole-coated VP and DOTAP adsorbed siYAP, with angiopep-2 (A2) modification on the surface. AMVY@NPs exhibited excellent blood‒brain barrier crossing, GBM targeting, and hypoxia-responsive and efficient siYAP and VP release properties. By inhibiting the expression and function of YAP, AMVY@NPs synergistically inhibited both the growth and stemness of GBM in vitro. Moreover, AMVY@NPs strongly inhibited the growth of orthotopic U87 xenografts and improved the survival of tumour-bearing mice without adverse effects., Conclusion: Specific targeting of YAP with stepwise-targeting and hypoxia-responsive liposome AMVY@NPs carrying siYAP and VP efficiently inhibited GBM progression. This study provides a valuable drug delivery platform and creative insights for molecular targeted treatment of GBM in the future., (© 2024. The Author(s).)

Bevacizumab, temozolomide (TMZ), and radiotherapy are three therapeutic methods, but the combination of them as a new approach for the treatment of newly diagnosed high-grade gliomas (HGGs) is still under investigation. Therefore, this study aims to evaluate the safety, efficacy, and clinical utility of this treatment approach for patients with glioblastoma (GBM). PubMed/Medline, Scopus, Embase, and Web of Science were systematically reviewed from inception to 24 August 2023. Relevant studies evaluating the therapeutic effect of adding Bevacizumab to TMZ-based chemotherapy and radiation therapy were enrolled. All statistical analysis was performed using the "meta" package of R. A total of 21 studies were included in this study. Our meta-analysis found that adding bevacizumab to standard therapy improved progression-free survival (PFS) in patients with newly diagnosed GBM. The pooled 6-month PFS rate was significantly higher with bevacizumab (79% vs. 56%, odds ratio 3.17). Overall survival (OS) showed modest improvements, with 2-year OS rates of 39% vs. 20% favoring bevacizumab. Radiological response rates varied, with a pooled overall response rate of 44% for bevacizumab-treated patients. The complete response rate was 16%, partial response 32%, and progressive disease 25%. Adverse events occurred in 62% of bevacizumab-treated patients. Common complications included fatigue, thrombocytopenia, and thromboembolic events. When added to standard therapy, bevacizumab demonstrates modest improvements in PFS and OS for newly diagnosedGBM. While it shows promise in short-term outcomes and radiological responses, long-term survival benefits remain limited. The risk of adverse events, particularly CNS hemorrhage, necessitates careful patient selection. These findings suggest that bevacizumab may have a role in treating high-grade gliomas, but its use should be individualized based on patient characteristics and risk-benefit assessment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Boron has been suggested to enhance the biological effectiveness of proton beams in the Bragg peak region via the p +  11 B → 3α nuclear capture reaction. However, a number of groups have observed no such enhancement in vitro or questioned its proposed mechanism recently. To help elucidate this phenomenon, we irradiated DU145 prostate cancer or U-87 MG glioblastoma cells by clinical 190 MeV proton beams in plateau or Bragg peak regions with or without 10 B or 11 B isotopes added as sodium mercaptododecaborate (BSH). The results demonstrate that 11 B but not 10 B or other components of the BSH molecule enhance cell killing by proton beams. The enhancement occurs selectively in the Bragg peak region, is present for boron concentrations as low as 40 ppm, and is not due to secondary neutrons. The enhancement is likely initiated by proton-boron capture reactions producing three alpha particles, which are rare events occurring in a few cells only, and their effects are amplified by intercellular communication to a population-level response. The observed up to 2-3-fold reductions in survival levels upon the presence of boron for the studied prostate cancer or glioblastoma cells suggest promising clinical applications for these tumour types., (© 2024. The Author(s).)

Glioblastoma (GBM) is a highly prevalent and deadly brain tumor with high mortality rates, especially among adults. Despite extensive research, the underlying mechanisms driving its progression remain poorly understood. Computational analysis offers a powerful approach to explore potential prognostic biomarkers, drug targets, and therapeutic agents for GBM. In this study, we utilized three gene expression datasets from the Gene Expression Omnibus (GEO) database to identify differentially expressed genes (DEGs) associated with GBM progression. Our goal was to uncover key molecular players implicated in GBM pathogenesis and potential avenues for targeted therapy. Analysis of the gene expression datasets revealed a total of 78 common DEGs that are potentially involved in GBM progression. Through further investigation, we identified nine hub DEGs that are highly interconnected in protein-protein interaction (PPI) networks, indicating their central role in GBM biology. Gene Ontology (GO) and pathway enrichment analyses provided insights into the biological processes and immunological pathways influenced by these DEGs. Among the nine identified DEGs, survival analysis demonstrated that increased expression of GMFG correlated with decreased patient survival rates in GBM, suggesting its potential as a prognostic biomarker and preventive target for GBM. Furthermore, molecular docking and ADMET analysis identified two compounds from the NIH clinical collection that showed promising interactions with the GMFG protein. Besides, a 100 nanosecond molecular dynamics (MD) simulation evaluated the conformational changes and the binding strength. Our study highlights the potential of GMFG as both a prognostic biomarker and a therapeutic target for GBM. The identification of GMFG and its associated pathways provides valuable insights into the molecular mechanisms driving GBM progression. Moreover, the identification of candidate compounds with potential interactions with GMFG offers exciting possibilities for targeted therapy development. However, further laboratory experiments are required to validate the role of GMFG in GBM pathogenesis and to assess the efficacy of potential therapeutic agents targeting this molecule., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Md. Wasim Alom et al.)

Glioblastoma (GBM) poses a formidable challenge in oncology due to its aggressive nature and dismal prognosis, with average survival rates around 15 months despite conventional treatments. This review proposes a novel therapeutic strategy for GBM by integrating microRNA (miRNA) therapy with 4-amino cyanine molecules possessing near-infrared (NIR) properties. miRNA holds promise in regulating gene expression, particularly in GBM, making it an attractive therapeutic target. 4-amino cyanine molecules, especially those with NIR properties, have shown efficacy in targeted tumor cell degradation. The combined approach addresses gene expression regulation and precise tumor cell degradation, offering a breakthrough in GBM treatment. Additionally, the review explores noncoding RNAs classification and characteristics, highlighting their role in GBM pathogenesis. Advanced technologies such as antisense oligonucleotides (ASOs), locked nucleic acids (LNAs), and peptide nucleic acids (PNAs) show potential in targeting noncoding RNAs therapeutically, paving the way for precision medicine in GBM. This synergistic combination presents an innovative approach with the potential to advance cancer therapy in the challenging landscape of GBM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 IBRO. Published by Elsevier Inc. All rights reserved.)

Smac mimetic compounds (SMCs) are small molecule drugs that sensitize cancer cells to TNF-α-induced cell death and have multiple immunostimulatory effects through alterations in NF-κB signaling. The combination of SMCs with immunotherapies has been reported to result in durable cures of up to 40% in syngeneic, orthotopic murine glioblastoma (GBM) models. Herein, we find that SMC resistance is not due to a cell-intrinsic mechanism of resistance. We thus evaluated the contribution of GBM and brain stromal components to identify parameters leading to SMC efficacy and resistance. The common physiological features of GBM tumors, such as hypoxia, hyaluronic acid, and glucose deprivation were found not to play a significant role in SMC efficacy. SMCs induced the death of microglia and macrophages, which are the major immune infiltrates in the tumor microenvironment. This death of microglia and macrophages then enhances the ability of SMCs to induce GBM cell death. Conversely, astrocytes promoted GBM cell growth and abrogated the ability of SMCs to induce death of GBM cells. The astrocyte-mediated resistance can be overcome in the presence of exogenous TNF-α. Overall, our results highlight that SMCs can induce death of microglia and macrophages, which then provides a source of death ligands for GBM cells, and that the targeting of astrocytes is a potential mechanism for overcoming SMC resistance for the treatment of GBM., (© 2024. The Author(s).)

Protein tyrosine phosphatase receptor zeta 1 (PTPRZ1) is a transmembrane tyrosine phosphatase (TP) that serves as a receptor for pleiotrophin (PTN) and vascular endothelial growth factor A 165 (VEGFA 165 ) to regulate endothelial cell migration. In the present work, we identify a PTN peptide fragment (PTN 97-110 ) that inhibits the interaction of PTN and VEGFA 165 with PTPRZ1 but not VEGF receptor 2. This peptide abolishes the stimulatory effect of PTN and VEGFA 165 on endothelial cell migration, tube formation on Matrigel, and Akt activation in vitro. It also partially inhibits VEGFA 165 -induced VEGF receptor 2 activation but does not affect ERK1/2 activation and cell proliferation. In vivo, PTN 97-110 inhibits or dysregulates angiogenesis in the chick embryo chorioallantoic membrane and the zebrafish assays, respectively. In glioblastoma cells in vitro, PTN 97-110 abolishes the stimulatory effect of VEGFA 165 on cell migration and inhibits their anchorage-independent growth, suggesting that this peptide might also be exploited in glioblastoma therapy. Finally, in silico and experimental evidence indicates that PTN and VEGFA 165 bind to the extracellular fibronectin type-III (FNIII) domain to stimulate cell migration. Collectively, our data highlight novel aspects of the interaction of PTN and VEGFA 165 with PTPRZ1, strengthen the notion that PTPRZ1 is required for VEGFA 165 -induced signaling, and identify a peptide that targets this interaction and can be exploited for the design of novel anti-angiogenic and anti-glioblastoma therapeutic approaches., Competing Interests: Declaration of competing interest All authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background and Purpose: The poor delivery of drugs to infiltrating tumor cells contributes to therapeutic failure in glioblastoma. During the early phase of an anti-angiogenic treatment, a remodeling of the tumor vasculature could occur, leading to a more functional vessel network that could enhance drug delivery. However, the restructuration of blood vessels could increase the proportion of normal endothelial cells that could be a barrier for the free diffusion of drugs. The net balance, in favor or not, of a better delivery of compounds during the course of an antiangiogenic treatment remains to be established. This study explored whether cediranib and thalidomide could modulate perfusion and vessel permeability in the brain U87 tumor mouse model., Methods: The dynamic evolution of the diffusion of agents outside the tumor core using the fluorescent dye Evans Blue in histology and Gd-DOTA using dynamic contrast-enhanced (DCE)-MRI. CD31 labelling of endothelial cells was used to measure the vascular density., Results and Interpretation: Cediranib and thalidomide effectively reduced tumor size over time. The accessibility of Evans Blue outside the tumor core continuously decreased over time. The vascular density was significantly decreased after treatment while the proportion of normal vessels remained unchanged over time. In contrast to histological studies, DCE-MRI did not tackle any significant change in hemodynamic parameters, in the core or margins of the tumor, whatever the parameter used or the pharmacokinetic model used. While cediranib and thalidomide were effective in decreasing the tumor size, they were ineffective in transiently increasing the delivery of agents in the core and the margins of the tumor.

Glioblastoma is a common brain tumor that poses considerable challenges in drug delivery. In this study, we investigated the potential of cell-based nanoparticles for targeted drug delivery to the glioblastoma sites. The anticancer drug of temozolomide (TMZ)-loaded T7-cholesterol nanoparticle micelles efficiently delivered nanoparticles to neutrophils and, subsequently, to the tumors. T7 is a cell-penetrating peptide that enhances the delivery of T7/TMZ to the target cells. T7 also serves as a transferrin target peptide, enabling targeted delivery to tumors. T7-conjugated cholesterol can self-assemble into micelles in aqueous solution and attach to the membrane of neutrophils. We confirmed that T7/TMZ nanoparticle micelles were efficiently located inside the neutrophils. Thereafter, T7/TMZ-conveyed neutrophils were administered to a glioblastoma mouse model, enabling neutrophils to penetrate the blood-brain barrier and deliver drugs directly to the tumor site. We evaluated the drug delivery efficiency and therapeutic effects of intravenous injection of T7/TMZ-conveyed neutrophils to a glioblastoma mouse model. These results demonstrate the promising role of neutrophil-based nanoparticle delivery systems in the targeted therapy of glioblastoma.

Glioblastoma (GBM) is the most aggressive and common malignant and CNS tumor, accounting for 47.7% of total cases. Glioblastoma has an incidence rate of 3.21 cases per 100,000 people. The regulation of autophagy, a conserved cellular process involved in the degradation and recycling of cellular components, has been found to play an important role in GBM pathogenesis and response to therapy. Autophagy plays a dual role in promoting tumor survival and apoptosis, and here we discuss the complex interplay between autophagy and GBM. We summarize the mechanisms underlying autophagy dysregulation in GBM, including PI3K/AKT/mTOR signaling, which is most active in brain tumors, and EGFR and mutant EGFRvIII. We also review potential therapeutic strategies that target autophagy for the treatment of GBM, such as autophagy inhibitors used in combination with the standard of care, TMZ. We discuss our current understanding of how autophagy is involved in TMZ resistance and its role in glioblastoma development and survival.

Glioblastoma (GBM) is a primary CNS tumor that is highly lethal in adults and has limited treatment options. Despite advancements in understanding the GBM biology, the standard treatment for GBM has remained unchanged for more than a decade. Only 6.8% of patients survive beyond five years. Telomerase, particularly the hTERT promoter mutations present in up to 80% of GBM cases, represents a promising therapeutic target due to its role in sustaining telomere length and cancer cell proliferation. This review examines the biology of telomerase in GBM and explores potential telomerase-targeted therapies. We conducted a systematic review following the PRISMA-P guidelines in the MEDLINE/PubMed and Scopus databases, from January 1995 to April 2024. We searched for suitable articles by utilizing the terms "GBM", "high-grade gliomas", "hTERT" and "telomerase". We incorporated studies addressing telomerase-targeted therapies into GBM studies, excluding non-English articles, reviews, and meta-analyses. We evaluated a total of 777 records and 46 full texts, including 36 studies in the final review. Several compounds aimed at inhibiting hTERT transcription demonstrated promising preclinical outcomes; however, they were unsuccessful in clinical trials owing to intricate regulatory pathways and inadequate pharmacokinetics. Direct hTERT inhibitors encountered numerous obstacles, including a prolonged latency for telomere shortening and the activation of the alternative lengthening of telomeres (ALT). The G-quadruplex DNA stabilizers appeared to be potential indirect inhibitors, but further clinical studies are required. Imetelstat, the only telomerase inhibitor that has undergone clinical trials, has demonstrated efficacy in various cancers, but its efficacy in GBM has been limited. Telomerase-targeted therapies in GBM is challenging due to complex hTERT regulation and inadequate inhibitor pharmacokinetics. Our study demonstrates that, despite promising preclinical results, no Telomerase inhibitors have been approved for GBM, and clinical trials have been largely unsuccessful. Future strategies may include Telomerase-based vaccines and multi-target inhibitors, which may provide more effective treatments when combined with a better understanding of telomere dynamics and tumor biology. These treatments have the potential to be integrated with existing ones and to improve the outcomes for patients with GBM.

Glioblastoma (GBM) is the most common brain tumor and remains incurable. Primary GBM cultures are widely used tools for drug screening, but there is a lack of genomic and pharmacological characterization for these primary GBM cultures. Here, we collect 50 patient-derived glioma cell (PDGC) lines and characterize them by whole genome sequencing, RNA sequencing, and drug response screening. We identify three molecular subtypes among PDGCs: mesenchymal (MES), proneural (PN), and oxidative phosphorylation (OXPHOS). Drug response profiling reveals that PN subtype PDGCs are sensitive to tyrosine kinase inhibitors, whereas OXPHOS subtype PDGCs are sensitive to histone deacetylase inhibitors, oxidative phosphorylation inhibitors, and HMG-CoA reductase inhibitors. PN and OXPHOS subtype PDGCs stably form tumors in vivo upon intracranial transplantation into immunodeficient mice, whereas most MES subtype PDGCs fail to form tumors in vivo. In addition, PDGCs cultured by serum-free medium, especially long-passage PDGCs, carry MYC/MYCN amplification, which is rare in GBM patients. Our study provides a valuable resource for understanding primary glioma cell cultures and clinical translation and highlights the problems of serum-free PDGC culture systems that cannot be ignored., (© 2024. The Author(s).)

Glioblastoma (GBM) is associated with a median survival rate of less than 15 months, necessitating innovative treatment approaches. This study investigates the safety and efficacy of the low-frequency magnetic field (LFMF) OM-100 instrument in GBM therapy. In vitro experiments utilized normal astrocyte and GBM cell lines, determining that OM-100 at 100 kHz for 72 h selectively targeted GBM cells without harming normal cells. Subsequent analyses revealed OM-100's impact on cell viability, apoptosis, migration, invasion, reactive oxide species levels, and PD-L1 expression. In vivo studies on mice with U87-induced GBM demonstrated OM-100's synergy with anti-PD-1 therapy, leading to significant tumor volume reduction and increased apoptosis. Notably, OM-100 exhibited safety in healthy mice. Overall, OM-100 could enhance anti-PD-1 immunotherapy effectiveness probably by directly inhibiting tumor proliferation and migration as well as promoting PD-L1 expression, offering a promising therapeutic strategy for GBM treatment., (© 2024. The Author(s).)

Glioblastoma (GBM) is the most common malignant primary brain tumor, characterized by limited treatment options and a poor prognosis. Its aggressiveness is attributed not only to the uncontrolled proliferation and invasion of tumor cells but also to the complex interplay between these cells and the surrounding microenvironment. Within the tumor microenvironment, an intricate network of immune cells, stromal cells, and various signaling molecules creates a pro-inflammatory milieu that supports tumor growth and progression. Docosahexaenoic acid (DHA), an essential ω3 polyunsaturated fatty acid for brain function, is associated with anti-inflammatory and anticarcinogenic properties. Therefore, in this work, DHA liposomes were synthesized using a microfluidic platform to target and reduce the inflammatory environment of GBM. The liposomes were rapidly taken up by macrophages in a time-dependent manner without causing cytotoxicity. Moreover, DHA liposomes successfully downregulated the expression of inflammatory-associated genes ( IL-6 ; IL-1β ; TNFα ; NF-κB , and STAT-1 ) and the secretion of key cytokines (IL-6 and TNFα) in stimulated macrophages and GBM cells. Conversely, no significant differences were observed in the expression of IL-10 , an anti-inflammatory gene expressed in alternatively activated macrophages. Additionally, DHA liposomes were found to be more efficient in regulating the inflammatory profile of these cells compared with a free formulation of DHA. The nanomedicine platform established in this work opens new opportunities for developing liposomes incorporating DHA to target GBM and its inflammatory milieu.

Sacituzumab Govitecan (SG) is an antibody-drug conjugate that has demonstrated efficacy in patients with TROP-2 expressing epithelial cancers. In a xenograft model of intracranial breast cancer, SG inhibited tumor growth and increased mouse survival. We conducted a prospective window-of-opportunity trial (NCT03995706) at the University of Texas Health Science Center at San Antonio to examine the intra-tumoral concentrations and intracranial activity of SG in patients undergoing craniotomy for breast cancer with brain metastases (BCBM) or recurrent glioblastoma (rGBM). We enrolled 25 patients aged ≥18 years diagnosed with BCBM and rGBM to receive a single intravenous dose of SG at 10 mg/kg given one day before resection and continued on days 1 and 8 of 21-day cycles following recovery. The PFS was 8 months and 2 months for BCBM and rGBM cohorts, respectively. The OS was 35.2 months and 9.5 months, respectively. Grade≥3 AE included neutropenia (28%), hypokalemia (8%), seizure (8%), thromboembolic event (8%), urinary tract infection (8%) and muscle weakness of the lower limb (8%). In post-surgical tissue, the median total SN-38 was 249.8 ng/g for BCBM and 104.5 ng/g for rGBM, thus fulfilling the primary endpoint. Biomarker analysis suggests delivery of payload by direct release at target site and that hypoxic changes do not drive indirect release. Secondary endpoint of OS was 35.2 months for the BCBM cohort and 9.5 months for rGBM. Non-planned exploratory endpoint of ORR was 38% for BCBM and 29%, respectively. Exploratory endpoint of Trop-2 expression was observed in 100% of BCBM and 78% of rGBM tumors. In conclusion, SG was found to be well tolerated with adequate penetration into intracranial tumors and promising preliminary activity within the CNS. Trial Registration: Trial (NCT03995706) enrolled at Clinical Trials.gov as Neuro/Sacituzumab Govitecan/Breast Brain Metastasis/Glioblastoma/Ph 0: https://clinicaltrials.gov/study/NCT03995706?cond=NCT03995706 ., (© 2024. The Author(s).)

Patients with high ALDH1A3-expressing glioblastoma (ALDH1A3 hi GBM) show limited benefit from postoperative chemoradiotherapy. Understanding the mechanisms underlying such resistance in these patients is crucial for the development of new treatments. Here, we show that the interaction between ALDH1A3 and PKM2 enhances the latter's tetramerization and promotes lactate accumulation in glioblastoma stem cells (GSCs). By scanning the lactylated proteome in lactate-accumulating GSCs, we show that XRCC1 undergoes lactylation at lysine 247 (K247). Lactylated XRCC1 shows a stronger affinity for importin α, allowing for greater nuclear transposition of XRCC1 and enhanced DNA repair. Through high-throughput screening of a small-molecule library, we show that D34-919 potently disrupts the ALDH1A3-PKM2 interaction, preventing the ALDH1A3-mediated enhancement of PKM2 tetramerization. In vitro and in vivo treatment with D34-919 enhanced chemoradiotherapy-induced apoptosis of GBM cells. Together, our findings show that ALDH1A3-mediated PKM2 tetramerization is a potential therapeutic target to improve the response to chemoradiotherapy in ALDH1A3 hi GBM., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Epithelioid glioblastoma (eGB), a very aggressive and rare brain tumour, is associated with a dismal median overall survival. Effective therapies for patients with eGB, particularly with leptomeningeal dissemination, are still lacking. Here, we describe a case of a 25-year-old male diagnosed with an intramedullary cervical tumour with subsequent leptomeningeal disease. Histopathology identified a highly necrotising, epithelioid-type tumour with high cell density, most compatible with the diagnosis of an eGB. DNA analysis revealed an unprecedented B-Raf protooncogene, serine/threonine kinase (BRAF) gene variant in exon 15 (ENST00000288602.6, c.1799_1810delinsATG, p.(V600_W604delinsDG)), triggering activation of the mitogen-activated protein kinase (MAPK) pathway. Consequently, we initiated MAPK inhibitor (MAPKi) therapy, utilizing a combination of BRAF and mitogen-activated protein kinase kinase (MEK) inhibitors. Liquid chromatography-tandem mass spectrometry analysis confirmed the drugs' presence in the patient's cerebrospinal fluid, indicating their capacity to cross the blood-brain barrier. Remarkably, the patient responded very well to therapy and transitioned from a near-comatose state to significantly improved health, sustained for over three months. This study highlights that MAPKi, particularly targeted towards novel BRAFV600 mutations, might offer promising advancements in eGB treatment strategies., (© 2024. The Author(s).)

Objective: Most recurrent glioblastoma (rGBM) patients do not benefit from immune checkpoint inhibition, emphasizing the necessity for response biomarkers. This study evaluates whether tumor in situ fluid (TISF) circulating tumor DNA (ctDNA) could serve as a biomarker for response to low-dose bevacizumab (Bev) plus anti-PD-1 therapy in rGBM patients, aiming to enhance systemic responses to immunotherapy., Methods: In this phase II trial, 32 GBM patients with first recurrence after standard therapy were enrolled and then received tislelizumab plus low-dose Bev each cycle. TISF samples were analyzed for ctDNA using a 551-gene panel before each treatment., Results: The median progression-free survival (mPFS) and overall survival (mOS) were 8.2 months (95% CI, 5.2-11.1) and 14.3 months (95% CI, 6.5-22.1), respectively. The 12-month OS was 43.8%, and the objective response rate was 56.3%. Patients with more than 20% reduction in the mutant allele fraction and tumor mutational burden after treatment were significantly associated with better prognosis compared to baseline TISF-ctDNA. Among detectable gene mutations, patients with MUC16 mutation, EGFR mutation & amplification, SRSF2 amplification, and H3F3B amplification were significantly associated with worse prognosis., Conclusions: Low-dose Bev plus anti-PD-1 therapy significantly improves OS in rGBM patients, offering guiding significance for future individualized treatment strategies. TISF-ctDNA can monitor rGBM patients' response to combination therapy and guide treatment., Clinical Trial Registration: This trial is registered with ClinicalTrials.gov, NCT05540275., (© 2024. The Author(s).)

With the increasing research and deepening understanding of the glioblastoma (GBM) tumour microenvironment (TME), novel and more effective therapeutic strategies have been proposed. The GBM TME involves intricate interactions between tumour and non-tumour cells, promoting tumour progression. Key therapeutic goals for GBM treatment include improving the immunosuppressive microenvironment, enhancing the cytotoxicity of immune cells against tumours, and inhibiting tumour growth and proliferation. Consequently, remodeling the GBM TME using nanotechnology has emerged as a promising approach. Nanoparticle-based drug delivery enables targeted delivery, thereby improving treatment specificity, facilitating combination therapies, and optimizing drug metabolism. This review provides an overview of the GBM TME and discusses the methods of remodeling the GBM TME using nanotechnology. Specifically, it explores the application of nanotechnology in ameliorating immune cell immunosuppression, inducing immunogenic cell death, stimulating, and recruiting immune cells, regulating tumour metabolism, and modulating the crosstalk between tumours and other cells.

Introduction: Glioblastoma (GBM) poses a significant challenge in oncology, with median survival times barely extending beyond a year due to resistance to standard therapies like temozolomide (TMZ). This study introduces a novel therapeutic strategy combining progesterone (Prog) and abiraterone (Abi) aimed at enhancing GBM treatment efficacy by modulating the tumor microenvironment and augmenting NK cell-mediated immunity., Methods: We employed in vitro and in vivo GBM models to assess the effects of Prog and Abi on cell viability, proliferation, apoptosis, and the immune microenvironment. Techniques included cell viability assays, Glo-caspase 3/7 apoptosis assays, RNA-seq and qPCR for gene expression, Seahorse analysis for mitochondrial function, HPLC-MS for metabolomics analysis, and immune analysis by flow cytometry to quantify NK cell infiltration., Results: Prog significantly reduced the IC50 of Abi in TMZ-resistant GBM cell, suggesting the enhanced cytotoxicity. Treatment induced greater apoptosis than either agent alone, suppressed tumor growth, and prolonged survival in mouse models. Notably, there was an increase in CD3 - /CD19 - /CD56 + /NK1.1 + NK cell infiltration in treated tumors, indicating a shift towards an anti-tumor immune microenvironment. The combination therapy also resulted in a reduction of MGMT expression and a suppression of mitochondrial respiration and glycolysis in GBM cells., Conclusion: The combination of Prog and Abi represents a promising therapeutic approach for GBM, showing potential in suppressing tumor growth, extending survival, and modulating the immune microenvironment. These findings warrant further exploration into the clinical applicability of this strategy to improve outcomes for GBM patients., (© 2024. The Author(s).)

Background: Glioblastoma is a highly aggressive type of brain tumor for which there is no curative treatment available. Immunotherapies have shown limited responses in unselected patients, and there is an urgent need to identify mechanisms of treatment resistance to design novel therapy strategies., Methods: Here we investigated the phenotypic and transcriptional dynamics at single-cell resolution during nivolumab immune checkpoint treatment of glioblastoma patients., Results: We present the integrative paired single-cell RNA-seq analysis of 76 tumor samples from patients in a clinical trial of the PD-1 inhibitor nivolumab and untreated patients. We identify a distinct aggressive phenotypic signature in both tumor cells and the tumor microenvironment in response to nivolumab. Moreover, nivolumab-treatment was associated with an increased transition to mesenchymal stem-like tumor cells, and an increase in TAMs and exhausted and proliferative T cells. We verify and extend our findings in large external glioblastoma dataset (n = 298), develop a latent immune signature and find 18% of primary glioblastoma samples to be latent immune, associated with mesenchymal tumor cell state and TME immune response. Finally, we show that latent immune glioblastoma patients are associated with shorter overall survival following immune checkpoint treatment (P = .0041)., Conclusions: We find a resistance mechanism signature in one fifth of glioblastoma patients associated with a tumor-cell transition to a more aggressive mesenchymal-like state, increase in TAMs and proliferative and exhausted T cells in response to immunotherapy. These patients may instead benefit from neuro-oncology therapies targeting mesenchymal tumor cells., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Cellular functions hinge on the meticulous orchestration of protein transport, both spatially and temporally. Central to this process is retrograde trafficking, responsible for targeting proteins to the nucleus. Despite its link to many diseases, the implications of retrograde trafficking in glioblastoma (GBM) are still unclear., Methods: To identify genetic drivers of TMZ resistance, we conducted comprehensive CRISPR-knockout screening, revealing ADP-ribosylation factor 4 (ARF4), a regulator of retrograde trafficking, as a major contributor., Results: Suppressing ARF4 significantly enhanced TMZ sensitivity in GBM patient-derived xenograft (PDX) models, leading to improved survival rates (P < .01) in both primary and recurrent lines. We also observed that TMZ exposure stimulates ARF4-mediated retrograde trafficking. Proteomics analysis of GBM cells with varying levels of ARF4 unveiled the influence of this pathway on EGFR signaling, with increased nuclear trafficking of EGFR observed in cells with ARF4 overexpression and TMZ treatment. Additionally, spatially resolved RNA-sequencing of GBM patient tissues revealed substantial correlations between ARF4 and crucial nuclear EGFR (nEGFR) downstream targets, such as MYC, STAT1, and DNA-PK. Decreased activity of DNA-PK, a DNA repair protein downstream of nEGFR signaling that contributes to TMZ resistance, was observed in cells with suppressed ARF4 levels. Notably, treatment with DNA-PK inhibitor, KU-57788, in mice with a recurrent PDX line resulted in prolonged survival (P < .01), highlighting the promising therapeutic implications of targeting proteins reliant on ARF4-mediated retrograde trafficking., Conclusions: Our findings demonstrate that ARF4-mediated retrograde trafficking contributes to the development of TMZ resistance, cementing this pathway as a viable strategy to overcome chemoresistance in GBM., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Glioblastoma (GBM) exhibits profound metabolic plasticity for survival and therapeutic resistance, while the underlying mechanisms remain unclear. Here, we show that GBM stem cells reprogram the epigenetic landscape by producing substantial amounts of phosphocreatine (PCr). This production is attributed to the elevated transcription of brain-type creatine kinase, mediated by Zinc finger E-box binding homeobox 1. PCr inhibits the poly-ubiquitination of the chromatin regulator bromodomain containing protein 2 (BRD2) by outcompeting the E3 ubiquitin ligase SPOP for BRD2 binding. Pharmacological disruption of PCr biosynthesis by cyclocreatine (cCr) leads to BRD2 degradation and a decrease in its targets' transcription, which inhibits chromosome segregation and cell proliferation. Notably, cyclocreatine treatment significantly impedes tumor growth and sensitizes tumors to a BRD2 inhibitor in mouse GBM models without detectable side effects. These findings highlight that high production of PCr is a druggable metabolic feature of GBM and a promising therapeutic target for GBM treatment. Significance: Glioblastoma (GBM) exhibits an adaptable metabolism crucial for survival and therapy resistance. We demonstrate that GBM stem cells modify their epigenetics by producing phosphocreatine (PCr), which prevents bromodomain containing protein 2 (BRD2) degradation and promotes accurate chromosome segregation. Disrupting PCr biosynthesis impedes tumor growth and improves the efficacy of BRD2 inhibitors in mouse GBM models., (©2024 American Association for Cancer Research.)

Given the infiltrative nature of human glioblastoma (GBM), cocktail drug therapy will remain a vital tool for the treatment of the disease. We investigated fluspirilene, perphenazine, and sulpiride, three classic anti-schizophrenic drugs, as possible anti-GBM agents. The CCK-8 assay demonstrated that fluspirilene possesses the most outstanding anti-GBM effect. We performed molecular mechanisms studies in vitro and an orthotopic xenograft model in mice. Fluspirilene inhibited proliferation and migration in vitro in U87MG and U251 GBM cell lines. Flow cytometry demonstrated that treatment increased apoptosis and cells accumulated in the G2/M phase. Our analysis of publicly available expression data for several cell lines treated with the drug led to the identification of several genes, including KIF20A, that are downregulated by fluspirilene and lead to growth inhibition/apoptosis. We also demonstrated that siRNA knockdown of KIF20A, a member of the kinesin family, attenuated cell proliferation in GBM cells and an orthotopic xenograft model in mice. A regulator of KIF20A, the oncogenic transcription factor FOXM1, was identified using the String database, which harbors protein interaction networks. In fluspirilene-treated cells, FOXM1 protein was decreased, indicating that KIF20A was downregulated in the presence of the drug due to decreased FOXM1 protein. These results demonstrate that fluspirilene is an effective anti-GBM agent that works by suppressing the FOXM1-KIF20A oncogenic axis.

Natural compounds such as thymoquinone (TQ) have recently gained increasing attention in treating glioblastoma (GBM). However, the effects of TQ in reversing drug resistance are not completely understood. Therefore, we aimed to examine TQ impacts on GBM cells with doxorubicin (DOX) resistance and the involvement of the PI3K/Akt/mTOR pathway. GBM cancer U87 and U87/DOX (resistant cells) cells were exposed to DOX and TQ, and cell proliferation was assessed by the MTT assay. ELISA was applied to evaluate cell apoptosis. The expression of apoptotic mediators such as Caspase-3, Bax, Bcl-2 and PI3K, Akt, mTOR, P-gp, and PTEN was assessed via qRT-PCR and western blot. We found that a combination of TQ and DOX suppressed dose-dependent cell growth capacity in cells and increased the cytotoxic effects of DOX in resistant cells. In addition, TQ treatment increased DOX-mediated apoptosis in U87/DOX cell lines via modulating the pro- and anti-apoptotic markers. A combination of TQ and DOX upregulated PTEN and downregulated PI3K, Akt, and mTOR, suppressing this signal transduction in resistant cells. In conclusion, we showed TQ potentiated doxorubicin-mediated antiproliferative and pro apoptotic function DOX-resistant glioblastoma cells, which is mediated by targeting and suppressing PI3K/Akt/mTOR signal transduction., (© 2024 John Wiley & Sons A/S.)

Silver nanoparticles (AgNPs) hold promise for cancer therapy. This study aimed to evaluate their impact on tumor and non-tumor cell number, viability, and morphology. Antitumor activity was tested on U-87MG (glioblastoma) and DU-145 (prostate cancer) cell lines. Treatment with AgNPs notably reached a reduction of U-87MG and DU-145 cell growth by 89.30% and 79.74%, respectively, resulting in slower growth rates. AgNPs induced DNA damage, evidenced by reduced nuclear area and DNA content via fluorescent image-based analyses. Conversely, HFF-1 non-tumor cells displayed no significant changes post-AgNPs exposure. Viability assays revealed substantial reductions in U-87MG and DU-145 cells (79% and 63% in MTT assays, 30% and 52.2% in high-content analyses), while HFF-1 cells exhibited lower sensitivity. Tumor cells had notably lower IC 50 values than non-tumor cells, indicating selective susceptibility. Transmission electron microscopy (TEM) showed morphological changes post-AgNPs administration, including increased vacuoles, myelin figures, membrane ghosts, cellular extravasation, and membrane projections. The findings suggest the potential of AgNPs against glioblastoma and prostate cancer, necessitating further exploration across other cancer cell lines., Competing Interests: Declaration of competing interest The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Studies have reported that cannabinoids, in particular Δ 9 -tetrahydrocannabinol (Δ 9 -THC) and cannabidiol (CBD), significantly reduce cancer cell viability in vitro . Unfortunately, treatment conditions vary significantly across reports. In particular, a majority of reports utilize conditions with reduced serum concentrations (0-3%) that may compromise the growth of the cells themselves, as well as the observed results. Objectives: This study was designed to test the hypothesis that, based on their known protein binding characteristics, cannabinoids would be less effective in the presence of fetal bovine serum (FBS). Moreover, we wished to determine if the treatments served to be cytotoxic or cytostatic under these conditions. Methods: Six cancer cell lines, representing two independent lines of three different types of cancer (glioblastoma, melanoma, and colorectal cancer [CRC]), were treated with 10 μM pure Δ 9 -THC, CBD, KM-233, and HU-331 for 48 h (in the presence or absence of FBS). Cell viability was measured with the MTT assay. Dose-response curves were then generated comparing the potencies of the four cannabinoids under the same conditions. Results: We found that serum-free medium alone produces cell cycle arrest for CRC cells and slows cell growth for the other cancer types. The antineoplastic effects of three of the four cannabinoids (Δ 9 -THC, CBD, and KM-233) increase when serum is omitted from the media. In addition, dose-response curves for these drugs demonstrated lower IC 50 values for serum-free media compared with the media with 10% serum in all cell lines. The fourth compound, HU-331, was equally effective under both conditions. A further confound we observed is that omission of serum produces dramatic binding of Δ 9 -THC and CBD to plastic. Conclusions: Treatment of cancer cells in the absence of FBS appears to enhance the potency of cannabinoids. However, omission of FBS itself compromises cell growth and represents a less physiological condition. Given the knowledge that cannabinoids are 90-95% protein bound and have well-known affinities for plastic, it may be ill-advised to treat cells under conditions where the cells are not growing optimally and where known concentrations cannot be assumed (i.e., FBS-free conditions).

Glioblastoma (GBM) is the most prevalent primary intracranial tumor. Temozolomide (TMZ) is the first-line chemotherapy for GBM. Nonetheless, the development of TMZ resistance has become a main cause of treatment failure in GBM patients. Evidence suggests that neuropilin-1 (NRP-1) silencing can attenuate GBM cell resistance to TMZ. This study aims to determine potential mechanisms by which NRP-1 affects TMZ resistance in GBM. The parental U251 and LN229 GBM cells were exposed to increasing concentrations of TMZ to construct TMZ-resistant GBM cells (U251/TMZ, LN229/TMZ). BALB/c nude mice were injected with U251/TMZ cells to establish the xenograft mouse model. Functional experiments were carried out to examine NRP-1 functions. Western blotting and real-time quantitative polymerase chain reaction were used to evaluate molecular protein and mRNA expression, respectively. Immunohistochemical staining showed NRP-1 and STAT1 expression in mouse tumors. The results showed that NRP-1 was highly expressed in TMZ-resistant cells. Moreover, knocking down NRP-1 attenuated the TMZ resistance of U251/TMZ cells, while upregulating NRP-1 enhanced TMZ resistance of the parental cells. NRP-1 silencing elevated GBM cell sensitivity to TMZ in tumor-bearing mice. Depleting NRP-1 reduced STAT1, p53, and p21 expression in U251/TMZ cells. STAT1 depletion offset NRP-1 silencing evoked attenuation of GBM cell resistance to TMZ. Collectively, our study reveals that NRP-1 enhances TMZ resistance in GBM possibly by regulating the STAT1/p53/p21 axis., (© 2024 Japanese Society of Neuropathology.)

Drug resistance has been a major problem for cancer chemotherapy, especially for glioblastoma multiforme that is aggressive, heterogeneous and recurrent with <3% of a five-year survival and limited methods of clinical treatment. To overcome the problem, great efforts have recently been put in searching for agents inducing death of tumor cells via various non-apoptotic pathways. In the present work, we report for the first time that vanadyl complexes, i.e. bis(acetylacetonato)oxidovanadium (IV) (VO(acac) 2 ), can cause mitotic catastrophe and methuotic death featured by catastrophic macropinocytic vacuole accumulation particularly in glioblastoma cells (GCs). Hence, VO(acac) 2 strongly suppressed growth of GCs with both in vitro (IC 50  = 4-6 μM) and in vivo models, and is much more potent than the current standard-of-care drug Temozolomide. The selective index is as high as ∼10 or more on GCs over normal neural cells. Importantly, GCs respond well to vanadium treatment regardless whether they are carrying IDH1 wild type gene that causes drug resistance. VO(acac) 2 may induce methuosis via the Rac-Mitogen-activated protein kinase kinase 4 (MKK4)-c-Jun N-terminal kinase (JNK) signaling pathway. Furthermore, VO(acac) 2 -induced methuosis is not through a immunogenicity mechanism, making vanadyl complexes safe for interventional therapy. Overall, our results may encourage development of novel vanadium complexes promising for treatment of neural malignant tumor cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Despite advances in therapies, glioblastoma (GBM) recurrence is almost inevitable due to the aggressive growth behavior of GBM cells and drug resistance. Temozolomide (TMZ) is the preferred drug for GBM chemotherapy, however, development of TMZ resistance is over 50% cases in GBM patients. To investigate the mechanism of TMZ resistance and invasive characteristics of GBM, analysis of combined RNA-seq and ChIP-seq was performed in GBM cells in response to TMZ treatment. We found that the PERK/eIF2α/ATF4 signaling was significantly upregulated in the GBM cells with TMZ treatment, while blockage of ATF4 effectively inhibited cell migration and invasion. SPHK1 expression was transcriptionally upregulated by ATF4 in GBM cells in response to TMZ treatment. Blockage of ATF4-SPHK1 signaling attenuated the cellular and molecular events in terms of invasive characteristics and TMZ resistance. In conclusion, GBM cells acquired chemoresistance in response to TMZ treatment via constant ER stress. ATF4 transcriptionally upregulated SPHK1 expression to promote GBM cell aggression and TMZ resistance. The ATF4-SPHK1 signaling in the regulation of the transcription factors of EMT-related genes could be the underlying mechanism contributing to the invasion ability of GBM cells and TMZ resistance. ATF4-SPHK1-targeted therapy could be a potential strategy against TMZ resistance in GBM patients., (© 2024. The Author(s).)

PARP inhibitors (PARPi) hold substantial promise in treating glioblastoma (GBM). However, the adverse effects have restricted their broad application. Through unbiased transcriptomic and proteomic sequencing, it is discovered that the BET inhibitor (BETi) Birabresib profoundly alters the processes of DNA replication and cell cycle progression in GBM cells, beyond the previously reported impact of BET inhibition on homologous recombination repair. Through in vitro experiments using established GBM cell lines and patient-derived primary GBM cells, as well as in vivo orthotopic transplantation tumor experiments in zebrafish and nude mice, it is demonstrated that the concurrent administration of PARPi and BETi can synergistically inhibit GBM. Intriguingly, it is observed that DNA damage lingers after discontinuation of PARPi monotherapy, implying that sequential administration of PARPi followed by BETi can maintain antitumor efficacy while reducing toxicity. In GBM cells with elevated baseline replication stress, the sequential regimen exhibits comparable efficacy to concurrent treatment, protecting normal glial cells with lower baseline replication stress from DNA toxicity and subsequent death. This study provides compelling preclinical evidence supporting the development of innovative drug administration strategies focusing on PARPi for GBM therapy., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

The CUSP9 protocol is a polypharmaceutical strategy aiming at addressing the complexity of glioblastoma by targeting multiple pathways. Although the rationale for this 9-drug cocktail is well-supported by theoretical and in vitro data, its effectiveness compared to its 511 possible subsets has not been comprehensively evaluated. Such an analysis could reveal if fewer drugs could achieve similar or better outcomes. We conducted an exhaustive in vitro evaluation of the CUSP9 protocol using COMBImageDL, our specialized framework for testing higher-order drug combinations. This study assessed all 511 subsets of the CUSP9v3 protocol, in combination with temozolomide, on two clonal cultures of glioma-initiating cells derived from patient samples. The drugs were used at fixed, clinically relevant concentrations, and the experiment was performed in quadruplicate with endpoint cell viability and live-cell imaging readouts. Our results showed that several lower-order drug combinations produced effects equivalent to the full CUSP9 cocktail, indicating potential for simplified regimens in personalized therapy. Further validation through in vivo and precision medicine testing is required. Notably, a subset of four drugs (auranofin, disulfiram, itraconazole, sertraline) was particularly effective, reducing cell growth, altering cell morphology, increasing apoptotic-like cells within 4-28 h, and significantly decreasing cell viability after 68 h compared to untreated cells. This study underscores the importance and feasibility of comprehensive in vitro evaluations of complex drug combinations on patient-derived tumor cells, serving as a critical step toward (pre-)clinical development., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest to disclose., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Intrinsic resistance to targeted therapeutics in PTEN-deficient glioblastoma (GBM) is mediated by redundant signaling networks that sustain critical metabolic functions. Here, we demonstrate that coordinated inhibition of the ribosomal protein S6 kinase 1 (S6K1) and the receptor tyrosine kinase AXL using LY-2584702 and BMS-777607 can overcome network redundancy to reduce GBM tumor growth. This combination of S6K1 and AXL inhibition suppressed glucose flux to pyrimidine biosynthesis. Genetic inactivation studies to map the signaling network indicated that both S6K1 and S6K2 transmit growth signals in PTEN-deficient GBM. Kinome-wide ATP binding analysis in inhibitor-treated cells revealed that LY-2584702 directly inhibited S6K1, and substrate phosphorylation studies showed that BMS-777607 inactivation of upstream AXL collaborated to reduce S6K2-mediated signal transduction. Thus, combination targeting of S6K1 and AXL provides a kinase-directed therapeutic approach that circumvents signal transduction redundancy to interrupt metabolic function and reduce growth of PTEN-deficient GBM., Significance: Therapy for glioblastoma would be advanced by incorporating molecularly targeted kinase-directed agents, similar to standard of care strategies in other tumor types. Here, we identify a kinase targeting approach to inhibit the metabolism and growth of glioblastoma., (©2024 The Authors; Published by the American Association for Cancer Research.)

Glioblastoma (GB) remains a formidable challenge and requires new treatment strategies. The vital part of the Ubiquitin-proteasome system (UPS) in cellular regulation has positioned it as a potentially crucial target in GB treatment, given its dysregulation oncolines. The Ubiquitin-specific proteases (USPs) in the UPS system were considered due to the garden role in the cellular processes associated with oncolines and their vital function in the apoptotic process, cell cycle regulation, and autophagy. The article provides a comprehensive summary of the evidence base for targeting USPs as potential factors for neoplasm treatment. The review considers the participation of the UPS system in the development, resulting in the importance of p53, Rb, and NF-κB, and evaluates specific goals for therapeutic administration using midnight proteasomal inhibitors and small molecule antagonists of E1 and E2 enzymes. Despite the slowed rate of drug creation, recent therapeutic discoveries based on USP system dynamics hold promise for specialized therapies. The review concludes with an analysis of future wanderers and the feasible effects of targeting USPs on personalized GB therapies, which can improve patient hydration in this current and unattractive therapeutic landscape. The manuscript emphasizes the possibility of USP oncogene therapy as a promising alternative treatment line for GB. It stresses the direct creation of research on the medical effectiveness of the approach., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Background: The existence of a functional relationship between a certain thyroid hormone analogue and cancer cell radioresistance has been shown by Leith and coworkers. The hormone analogue with relevance to malignant cells' radioresistance is tetraiodothyroacetic acid (tetrac). Tetrac is the deaminated derivative of L-thyroxine (T4), the principal product of the thyroid gland. Preclinical studies demonstrated that tetrac and chemically modified tetrac (CMT), e.g. a fluorobenzyl-conjugated tetrac analogue, restores radiosensitivity in certain radioresistant tumor cells. Due to their molecular, physico-chemical, and biological properties, actions of CMT analogues are believed to be initiated at the thyroid hormone analogue receptor site on plasma membrane integrin αvβ3., Objective: To explore possible molecular mechanisms of the potentially therapeutically beneficial effect of CMT on cancer cells' sensitivity to radiation, we analyzed actions of CMT analogues on expression of selected sets of genes that have been previously implicated in radioresistance of malignant cells., Discussion and Conclusions: In the current study, we report that genome-wide gene expression profiling analysis of human glioblastoma (GBM) and acute myelocytic leukemia (AML) cell lines exposed in vitro to noncytotoxic doses of CMT has identified decreased expression of discrete trios of genes each of which was previously linked to cancer cells' radioresistance. Following the CMT treatment in AML cells, expression of PARP9, PARP15 and STAT3 genes was significantly reduced, while in GBM cells, expression of PRKDC, EGFR and CCNDI was significantly decreased by the drug. Notably, a broader spectrum of genes implicated in cancer cells' radioresistance was observed in primary patient-derived GBM cells after the CMT treatment. Extensive additional experimental and clinical studies are indicated, including analyses of individual patient tumor genomics and of an array of different tumor types to define the sub-sets of tumors manifesting radioresistance in which tetrac-based agents may be expected to enhance therapeutic effects of radiation.

Glioblastoma (GBM) is a primary intracranial malignant tumor with the highest mortality and morbidity among all malignant central nervous system tumors. Tanshinone IIA is a fat-soluble active ingredient obtained from Salvia miltiorrhiza, which has an inhibitory effect against various cancers. We designed and synthesized a novel L-shaped ortho-quinone analog TE5 with tanshinone IIA as the lead compound and tested its antitumor activity against GBM. The results indicated that TE5 effectively inhibited the proliferation, migration, and invasion of GBM cells, and demonstrated low toxicity in vitro. We found that TE5 may bind to androgen receptors and promote their degradation through the proteasome. Inhibition of the PI3K/AKT signaling pathway was also observed in TE5 treated GBM cells. Additionally, TE5 arrested the cell cycle at the G2/M phase and induced mitochondria-dependent apoptosis. In vivo experiments further confirmed the anti-tumor activity, safety, and effect on androgen receptor level of TE5 in animal models of GBM. Our results suggest that TE5 may be a potential therapeutic drug to treat GBM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Successful treatment of glioblastoma multiforme (GBM), an aggressive form of primary brain neoplasm, mandates the need to develop new therapeutic strategies. In this study, we investigated the potential of PBI-05204 in targeting GBM stem cells (GSCs) and the underlying mechanisms. Treatment with PBI-05204 significantly reduced both the number and size of tumor spheres derived from patient-derived GSCs (GBM9, GSC28 and TS543), and suppressed the tumorigenesis of GBM9 xenografts. Moreover, PBI-05204 treatment led to a significant decrease in the expression of CD44 and NANOG, crucial markers of progenitor stem cells, in GBM9 and GSC28 GSCs. This treatment also down-regulated GRP78 expression in both GSC types. Knocking down GRP78 expression through GRP78 siRNA transfection in GBM9 and GSC28 GSCs also resulted in reduced spheroid size and CD44 expression. Combining PBI-05204 with GRP78 siRNA further decreased spheroid numbers compared to GRP78 siRNA treatment alone. PBI-05204 treatment led to increased expression of pRIP1K and pRIP3K, along with enhanced binding of RIPK1/RIPK3 in GBM9 and GSC28 cells, resembling the effects observed in GRP78-silenced GSCs, suggesting that PBI-05204 induced necroptosis in these cells. Furthermore, oleandrin, a principle active cardiac glycoside component of PBI-05204, showed the ability to inhibit the self-renewal capacity in GSCs. These findings highlight the potential of PBI-05204 as a promising candidate for the development of novel therapies that target GBM stem cells., Competing Interests: Declaration of competing interest R. A. Newman and P. Yang are consultants for Phoenix Biotechnology, Inc. The other authors disclosed no potential conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)