U87MG Cells Research Articles

A pH-Sensitive cRGD-PEG-siRNA Conjugated Compound Targeting Glioblastoma.

Glioblastoma ranks among the most prevalent primary intracranial tumors, characterized by high mortality and poor prognosis. Chemotherapy remains a key treatment strategy for gliomas, though most current drugs suffer from limited efficacy and significant toxicity. This study focuses on a cRGD-siEGFR coupling compound synthesized in a previous stage. Prior research indicated that cRGD-siEGFR molecules exhibited certain targeting and antitumor properties but faced issues of inadequate targeting, low efficacy, and high renal toxicity. To enhance antitumor efficacy and mitigate side effects, a pH-responsive, long-circulating, and highly targeted siRNA delivery system, the cRGD-PEG-siEGFR conjugate, was developed. The targeting, antitumor effects, and biological distribution of cRGD-PEG-siEGFR were examined. The results demonstrated that cRGD-PEG-siEGFR was effectively taken up by αvβ3-positive U87MG cells, specifically silenced EGFR gene expression, and exhibited antitumor effects. In normal physiological conditions, it avoided uptake by normal cells, thereby reducing side effects. Furthermore, in vivo biodistribution experiments revealed that cRGD-PEG-siEGFR, compared to cRGD-siEGFR, significantly decreased renal accumulation and exhibited prolonged circulation. Consequently, cRGD-PEG-siRNA emerges as a promising drug candidate with attributes of long circulation, high targeting, pH responsiveness, and substantial antitumor efficacy.

Histone deacetylase inhibition disrupts the molecular signature of the glioblastoma secretome related to extracellular vesicle-associated proteins and targets RAB7a and RAB14 in vitro

Glioblastoma (GBM) is the most aggressive brain tumor with a poor prognosis. While Histone Deacetylase inhibitors have shown promising results in inhibiting cancer cell invasion and promoting apoptosis, their effects on GBM secretion, specifically focusing on extracellular vesicles (EVs) secretion, remain largely unexplored. Using label-free NANOLC-MS/MS methodology, we identified significant changes in the abundance of membrane traffic regulatory proteins in the secretome of U87MG cells after the treatment with the HDAC inhibitor Trichostatin A (TSA). In silico analysis showed that TSA treatment disrupted the secretion pattern of EVs-associated proteins and cellular signaling pathways, both qualitatively and quantitatively. Notably, RAB14/RAB7a interaction was only observed in the secretome of cells treated with TSA. In vitro assays revealed that TSA treatment of glioma cells increased EVs secretion and intracellular protein levels of RAB7a and RAB14 without affecting gene expression, suggesting a role of these two EVs-associated proteins in grade IV glioma cells. Additionally, an integrative approach using clinical data highlighted a correlation between DNA mutations affecting vesicle traffic coding-genes and clinical and phenotypic outcomes in glioma patients. These findings provide insights into the interplay between epigenetics and GBM intracellular trafficking, potentially leading to improved strategies for targeting and modifying the complex signaling network established between GBM cells and the tumor cell microenvironment.

Combined machine learning models, docking analysis, ADMET studies and molecular dynamics simulations for the design of novel FAK inhibitors against glioblastoma

Gliomas, particularly glioblastoma (GBM), are highly aggressive brain tumors with poor prognosis and high recurrence rates. This underscores the urgent need for novel therapeutic approaches. One promising target is Focal adhesion kinase (FAK), a key regulator of tumor progression currently in clinical trials for glioma treatment. Drug development, however, is both challenging and costly, necessitating efficient strategies. Computer-Aided Drug Design (CADD), especially when combined with machine learning (ML), streamlines the processes of virtual screening and optimization, significantly enhancing the efficiency and accuracy of drug discovery. Our study integrates ML, docking analysis, ADMET (absorption, distribution, metabolism, elimination, and toxicity) studies to identify novel FAK inhibitors specific to GBM. Predictive models showed strong performance, with an R2 of 0.892, MAE of 0.331, and RMSE of 0.467 using protein-level IC50 data in combined CDK, CDK extended fingerprints, and substructure fingerprint counts derived from 1280 FAK inhibitors. Another model, based on IC50 data from 2608 compounds tested on U87-MG cells, achieved an R2 of 0.789, MAE of 0.395, and RMSE of 0.536. Using these models, we efficiently identified 275 potentially active compounds out of 5107 candidates. Subsequent ADMET analysis narrowed this down to 16 potential FAK inhibitors that meet the established drug-likeness criteria. Moreover, molecular dynamics (MD) simulations validated the stable binding interactions between the selected compounds and the FAK protein. This study highlights the effectiveness of combining ML, docking analysis, and ADMET studies to rapidly identify potential FAK inhibitors from large databases, providing valuable insights for the systematic design of FAK inhibitors.

STUDIES ON GLYCOGEN PHOSPHORYLASE AS A POTENTIAL MOLECULAR TARGET IN GLIOBLASTOMA

Abstract AIMS Glioblastoma (GB) is one of the most aggressive malignancies of the brain and spinal cord. Current standard of care has remained surgical resection of the tumour, followed by radiotherapy and/or chemotherapy. Crucial challenges in the effective treatment of GB include resistance to the main chemotherapeutic, temozolomide. Prognosis is poor with median survival remaining at 14.6 months. A now established hallmark of cancer is the ability of malignant cells to “modify, or reprogram, cellular metabolism”, such as glycolysis upregulation. This hallmark could suggest the potential of targeting a specific metabolic component within glycolysis, thus reduce energy production, resulting in possible apoptosis/suppressed proliferation. Glycogen phosphorylase (GP), an enzyme in glyconeolysis, could be inhibited for a therapeutic effect in GB. In this project, GP levels across the three different isoforms (PYGB, PYGL, and PYGM) and the effect of the GP inhibitor CP-91149 was investigated across three different GB cell lines. METHOD Cell viability of T98G, U251-MG, and U87-MG glioblastoma cell lines and SVGp19 human fetal glial cell line was measured after administration of CP-91149 for 24, 48, and 72 hours. Migration of T98G and U251 cells following treatment with CP-91149 was measured in a wound healing assay. Visualisation of the three GP isoforms was achieved through western blot and confirmed by immunocytochemistry. Flow cytometry was utilized to expand analysis on GP inhibition through assessing cell cycle before and after treatments. RESULTS Results showed CP-91149 had a significant dose-dependent effect in vitro on all cell lines. Inhibition of GP resulted in reduced cell migration, also in a dose-dependent manner. Western blot and immunocytochemistry analysis showed PYGL is the most predominant isoform of GP. CONCLUSION Future work in this project will aim to silence expression of GP in GB cell lines in order to compare the results with that yielded from cells treated with the GP inhibitor CP-91149.

Combination of heme oxygenase-1 inhibitors and temozolomide to improve the anticancer effect in glioblastoma

Heme oxygenase-1 (HO-1) is involved in the oncogenesis of glioblastoma (GBM). In this work, we investigated for the first time how the co-administration (combo) of the HO-1 inhibitors SI1/09 or LS6/42 with temozolomide (TMZ) or temozolomide acid (TMZ Ac) may influence the proliferation of U87MG GBM cell lines. Moreover, two novel TMZ/HO-1 inhibitors codrugs LS8/21 and LS8/24 were synthesised, characterised and tested. Results indicate that the combos TMZ or TMZ Ac with LS6/42, as well as the corresponding LS8/24, are more efficacious in reducing U87MG cell proliferation with respect to reference drugs, allowing a possible reduction of the TMZ dosage and related side effects in clinical practice. The chemical and enzymatic stability of the most potent codrug LS8/24 was evaluated. The observed high potency performed by both combos and LS8/24 in cells suggests that HO-1 inhibition may give additional contribution to the antiproliferative effect of TMZ.

Synthesis, characterization, and in-vitro bioimaging applications of green emissive AgInS2-based core multi and alloyed shell (AgInS2/CdS/ZnS and AgInS2/ZnS/CdS) nanocrystals

This study explores the synthesis, characterization, and preliminary bioimaging applications of green-emissive AgInS2-based nanocrystals (NCs) featuring core-multi and alloyed shell structures, specifically AgInS2/CdS/ZnS and AgInS2/ZnS/CdS. The nanocrystals were synthesized using a controlled hot-injection method, which ensured the formation of uniform core–shell structures. Detailed characterization through X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescence spectroscopy confirmed the successful development of these core-multi and alloyed shell architectures. The photoluminescence quantum yields (QY) were determined to be approximately 25 % for AgInS2/CdS/ZnS and 30 % for AgInS2/ZnS/CdS, highlighting their efficient luminescent properties. In preliminary bioimaging studies, these nanocrystals exhibited effective cellular imaging capabilities. They showed pronounced fluorescence with minimal background interference in A549 and U87MG cells, suggesting their potential for precise and targeted imaging applications. Despite these promising results, further investigation is needed to fully understand the specificity of these nanocrystals and their interaction mechanisms with various cell types. The observed quantum yields and targeted imaging capabilities indicate that AgInS2-based nanocrystals are promising candidates for advanced bioimaging technologies.

Co-delivery of temozolomide and quercetin with folic acid-conjugated exosomes in glioblastoma treatment.

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.

Methanolic Extract of Cimicifuga foetida Induces G1 Cell Cycle Arrest and Apoptosis and Inhibits Metastasis of Glioma Cells.

Glioblastoma multiforme (GBM) is among the most aggressive and challenging brain tumors, with limited treatment options. Cimicifuga foetida, a traditional Chinese medicine, has shown promise due to its bioactive components. This study investigates the anti-glioma effects of a methanolic extract of C. foetida (CF-ME) in GBM cell lines. The effects of CF-ME and its index compounds (caffeic acid, cimifugin, ferulic acid, and isoferulic acid) on GBM cell viability were assessed using MTT assays on U87 MG, A172, and T98G cell lines. The ability of CF-ME to induce cell cycle arrest, apoptosis, and autophagy and inhibit metastasis was evaluated using flow cytometry, Western blotting, and functional assays. Additionally, the synergistic potential of CF-ME with temozolomide (TMZ) was explored. CF-ME significantly reduced GBM cell viability in a dose- and time-dependent manner, induced G1 phase cell cycle arrest, promoted apoptosis via caspase activation, and triggered autophagy. CF-ME also inhibited GBM cell invasion, migration, and adhesion, likely by modulating epithelial-mesenchymal transition (EMT) markers. Combined with TMZ, CF-ME further enhanced reduced GBM cell viability, suggesting a potential synergistic effect. However, the individual index compounds of CF-ME exhibited only modest inhibitory effects, indicating that the full anti-glioma activity may result from the synergistic interactions among its components. CF-ME exhibited potent anti-glioma activity through multiple mechanisms, including cell cycle arrest, apoptosis, autophagy, and the inhibition of metastasis. Combining CF-ME with TMZ further enhanced its therapeutic potential, making it a promising candidate for adjuvant therapy in glioblastoma treatment.

211At radiolabeled APBA-FAPI for enhanced targeted-alpha therapy of glioma

Fibroblast activation protein-α (FAPα) is highly expressed in tumor-associated cells and has become one of the most attractive targeting sites in cancer diagnosis and therapy. To ameliorate the rapid metabolism of FAPα inhibitor (FAPI), here, a multifunctional binding agent was introduced to simultaneously achieve 211At radiolabeling and tumor retention prolongation of corresponding radiolabeled drug. 211At-APBA-FAPI was successfully synthesized by conjugating 211At with the designed FAPI carrier in satisfactory radiochemical yield (> 60%). 211At-APBA-FAPI exhibited excellent in vitro stability, significant tumor affinity and specific killing effect on FAPα-positive U87MG cells. Molecular docking reveals that FAPI decorated with albumin binder can bind with FAPα protein via multiple intermolecular interactions with a considerable binding energy of -9.66 kcal/mol. 211At-APBA-FAPI exhibits good targeting in murine xenograft models, showing obviously longer tumor retention than previously-reported radioastatinated compound. As a result, 211At-APBA-FAPI presents pronounced therapeutic effect with ignorable normal organs/tissues biotoxicity. All these indicate that introducing a multifunctional binding agent can effectively enhance the availability of FAPI for 211At conjugation and tumoricidal effect, providing vital hints for the translation of targeted-alpha therapy based on radiolabeled FAPI derivatives.

Responses to Herbal Compounds in Brain Cancer Cells: two Cell-Calcium Assays and a Molecular Docking Computation Study

Herbal plant secondary metabolites such as curcumin, resveratrol, and capsaicin are becoming increasingly popular as natural remedies. These herbal compounds are also known to act on the calcium signaling pathways, and therefore cell calcium assays can be used to study the relative interactions of these compounds with cellular receptors pertaining to natural remedies. To investigate this, Fluo-4, a fluorophore that specifically binds to Ca2+, was used to detect the increase in calcium signaling in human glioblastoma cells treated with curcumin, resveratrol, and capsaicin. The human cells used are U87 MG cells which expresses TRPV1, a pain receptor on the cell membrane. The increases of the fluorescence intensity in the cells treated with the three herbal compounds were measured using a bulk microplate assay, which generates data in a high throughput, and a microfluidic single-cell assay, which allows for the observation of the cell calcium changes in real-time. It was found that all three compounds would increase the intracellular Ca2+ concentrations on the two assays, with curcumin generating the highest increase, which confirms the greatest responses elicited by this herbal compound from the cell. Furthermore, the data obtained by a molecular docking computation study, which has been used to determine the binding affinities of the three compounds with the TRPV1 receptor, corroborate with the experimental finding of the highest cellular response due to curcumin.

A CYCLIC PEPTIDE TARGETS GLIOBLASTOMA BY BINDING TO ABERRANTLY EXPOSED SNAP25.

Disease-specific changes in tumors and other diseased tissues are an important target of research because they provide clues on the pathophysiology of the disease as well as uncovering potentially useful markers for diagnosis and treatment. Here, we report a new cyclic peptide, CESPLLSEC (CES), that specifically accumulated (homed) in intracranial U87MG and the WT-GBM model of glioblastoma from intravenous (IV) injection, associating with the vasculature. Affinity chromatography of U87MG tumor extracts on insolubilized CES peptide identified Synaptosomal Associated Protein 25 (SNAP25) as a candidate target molecule (receptor) for CES. Several results supported the identification of SNAP25 as the CES receptor. IV-injected FAM-CES colocalized with SNAP25 in the tumors, and direct binding studies showed specific CES peptide binding to recombinant human SNAP25. A CES peptide-drug conjugate designed for photodynamic therapy showed selective cytotoxicity to SNAP25+ glioblastoma cell lines. Specific accumulation of systemically injected anti-SNAP25 antibody in U87MG glioblastoma, and labeling of intact U87MG cells with anti-SNAP in flow cytometry showed that SNAP25 is available from the circulation but not in normal tissues and that it is present at the cell surface. Using an array of ECM proteins and surface plasmon resonance revealed that SNAP25 binds moderately to collagen V and strongly to collagen VI. Modeling studies suggested that CES and collagen VI compete for the same binding site on SNAP25. Our results introduce CES as a valuable targeting peptide for drug delivery, and its receptor SNAP25 as a possible molecular marker of interest for glioblastoma.

Protective effect of nanoemulsions containing CdTe quantum dots with potential application as a diagnostic agent.

A nanoemulsion containing CdTe quantum dots (NE-CdTe-QD) was developed to shield cells from cadmium toxicity and shown to be a promising candidate for brain tumor diagnosis. CdTe-QD was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. CdTe-QD exhibited high luminescence emission at 700nm, and their stability was maintained when encapsulated in lipidic/polymeric nanoemulsions (198 ± 2.0nm; PDI = 0.174; - 49.0mV). The biological effects of free and nanoemulsified CdTe-QD were tested in normal cells (NHF) and glioblastoma cell lines (U87-MG and T98G). Membrane colocalization of NE-CdTe-QD by T98G cells was observed. Instead, intracellular endoplasmic reticulum localization of NE-CdTe-QD was verified in U87-MG cells. Cell viability was reduced only when NE-CdTe-QD permeated the membrane of GBM cells, as observed in U87-MG cells, whereas no cytotoxic effects were observed in normal fibroblasts. Incorporating quantum dots directly into the brain cells is difficult. However, the nanoemulsions reduced the toxicity of CdTe-QD in zebrafish larvae and increased their circulation time, and direct injection into the zebrafish brain did not affect neural cell viability. This validates the potential application of these nanomaterials as diagnostic agents and satisfies the necessary criteria for their use as photosensitizers in photodynamic therapy.

Rosmarinic acid attenuates glioblastoma cells and spheroids’ growth and EMT/stem-like state by PTEN/PI3K/AKT downregulation and ERK-induced apoptosis

BackgroundGlioblastoma (GB) is a highly malignant type of brain cancer with a poor prognosis. Therapeutic strategies for GB are still limited. Rosmarinic acid (RA), a polyphenolic compound, is a promising experimental anticancer agent, but its specific protein targets for GB remain unclear. PurposeThis study aimed to elucidate the anticancer effects of RA in 2D- and 3D-GB cells and the underlying mechanisms. Methods3D-tumor spheroids (mimics in vivo tumors) were obtained by the hanging-drop/agarose method. RA's anti-glioma activity on U-87MG (p53-wt/PTEN-mt) and LN229 (p53-mt/PTEN-wt) cells was evaluated through cell viability, colony-formation, migration/invasion/angiogenesis assays, fluorescence imaging, and spheroid growth analysis. The underlying mechanism of the anticancer effects of RA was investigated by Western blot and immunofluorescence analysis. The MEK inhibitor U0126 was used to block ERK phosphorylation. ResultsRA treatments exerted anti-proliferative and pro-apoptotic effects on human GB cells. RA dose-dependently reduced angiogenesis and intracellular ROS levels, suppressed glioma growth, and migration/invasion in 2D-culture and cancer stem cell (CSC)-like 3D-spheroid culture (SPC). Repeated therapy in SPC was more effective by leading to disrupted structure than a single treatment. Treatments in SPC also suppressed epithelial-mesenchymal transition (EMT) and CSC-like properties. Strikingly, RA downregulated the SIRT1/FOXO1/NF-κB axis independently of p53 or PTEN function in both gliomas. Immunofluorescence labeling revealed decreased SIRT1 and NF-κB-p65 and increased FOXO1 and GAPDH proteins in nuclear location (associated with apoptosis). Surprisingly, RA increased p-ERK1/2 levels, but priming with U0126 abolished RA-mediated p-ERK upregulation; thus, autophagy and apoptosis induction in GB cells were prevented, and the growth of GB spheroids accelerated. Specifically, RA also inhibited the PTEN/PI3K/AKT pathway in U-87MG cells. Due to genetic differences in cells, U-87MG cells were more sensitive to RA treatments than LN229 cells. Meanwhile, our positive control drug trial results with FDA-approved temozolomide (TMZ) used in GB treatment showed that our test compound rosmarinic acid exhibited higher therapeutic effects than TMZ at lower doses. ConclusionSuppression of EMT, downregulation of SIRT1/FOXO1/NF-κB axis, inhibition of PTEN/PI3K/AKT signaling pathway, and ERK-induced apoptosis and autophagy were determined to be involved in stopping glioma progression. Our findings for the first time, revealed that RA may have potential therapeutic use by having multiple targets in human brain cancer with further clinical studies.

In vitro anti-inflammatory, anticancer effects and phytochemical characterisation of organic extracts from Aristolochia olivieri Colleg. ex Boiss

Natural extract plays a crucial role in our lives, major compound in the n-hexane (AR-H) and the ethyl acetate (AR-E) Aristolochia olivieri extracts was n-hexadecanoic acid, and of the methanol extract (AR-M) was pentacosane. The AR-M extract had a strong ability to induce mRNA expression of an inflammatory cytokine, IL-6, as an M1-like macrophage subset compared to the negative control (DMSO-treated cells). In contrast, AR-E treatment showed strong anti-inflammatory activity against macrophages. The AR-H extract had a moderate inflammatory effect against macrophages. The IC50 results of the anticancer assays ranged from 58.29 to 451.03 μg/mL for the three extracts. The anticancer action of the AR-E extract against U-87MG cells was higher (58.29 μg/mL) than that of AR-H and AR-M (156.38 and 196.14 μg/mL, respectively). The greater cytotoxicity effect observed with the AR-E extract against U-87MG can be linked to its high content of hexadecanoic acid (32.49%) and linolenic acid (12.90%).

Uncovering naringin’s anticancer mechanisms in glioblastoma via molecular docking and network pharmacology approaches

Naringin, a flavonoid, exhibits diverse therapeutic properties and has been proven to exert cytotoxic effects on cancer cells. Nevertheless, the precise mechanism of naringin maintaining its cytotoxic effect on glioblastoma (GBM) remains unknown. Thus, the current study aimed to establish a plausible cellular mechanism for Naringin’s inhibition of GBM. We employed various system biology techniques to forecast the primary targets, including gene ontology and cluster analysis, KEGG enrichment pathway estimation, molecular docking, MD (molecular dynamic) simulation and MMPBSA analysis. Glioblastoma target sequences were obtained via DisGeNet and Therapeutic Target Prediction, aligned with naringin targets, and analyzed for gene enrichment and ontology. Gene enrichment analysis identified the top ten hub genes. Further, molecular docking was conducted on all identified targets. For molecular dynamics modelling, we selected the two complexes that exhibited the most docking affinity and the two most prominent genes of the hub identified through analysis of the enrichment of genes. The PARP1 and ALB1 signalling pathways were found to be the main regulated routes. Naringin exhibited the highest binding potential of − 12.90 kcal/mol with PARP1 (4ZZZ), followed by ABL1 (2ABL), with naringin showing a − 8.4 kcal/mol binding score, as determined by molecular docking. The molecular dynamic approach and MM-PBSA investigation along with PCA study revealed that the complex of Naringin, with 4ZZZ (PARP1) and, 2ABL (ABL1), are highly stable compared to that of imatinib and talazoparib. Analyses of the signalling pathway suggested that naringin may have anticancer effects against GBM by influencing the protein PARP and ALB1 levels. Cytotoxicity assay was performed on two different glioblastoma cell lines C6 and U87MG cells. Naringin demonstrates a higher cytotoxic potency against U87MG human glioblastoma cells compared to C6 rat glioma cells.

FACT inhibitor CBL0137, administered in an optimized schedule, potentiates radiation therapy for glioblastoma by suppressing DNA damage repair.

Standard-of-care for glioblastoma remains surgical debulking followed by temozolomide and radiation. However, many tumors become radio-resistant while radiation damages surrounding brain tissue. Novel therapies are needed to increase the effectiveness of radiation and reduce the required radiation dose. Drug candidate CBL0137 is efficacious against glioblastoma by inhibiting histone chaperone FACT, known to be involved in DNA damage repair. We investigated the combination of CBL0137 and radiation on glioblastoma. In vitro, we combined CBL0137 with radiation on U87MG and A1207 glioblastoma cells using the clonogenic assay to evaluate the response to several treatment regimens, and the Fast Halo Assay to examine DNA repair. In vivo, we used the optimum combination treatment regimen to evaluate the response of orthotopic tumors in nude mice. In vitro, the combination of CBL0137 and radiation is superior to either alone and administering CBL0137 two hours prior to radiation, having the drug present during and for a prolonged period post-radiation, is an optimal schedule. CBL0137 inhibits DNA damage repair following radiation and affects the subcellular distribution of histone chaperone ATRX, a molecule involved in DNA repair. In vivo, one dose of CBL0137 is efficacious and the combination of CBL0137 with radiation increases median survival over either monotherapy. CBL0137 is most effective with radiation for glioblastoma when present at the time of radiation, immediately after and for a prolonged period post-radiation, by inhibiting DNA repair caused by radiation. The combination leads to increased survival making it attractive as a dual therapy.

FACT inhibitor CBL0137, administered in an optimized schedule, potentiates radiation therapy for glioblastoma by suppressing DNA damage repair.

Standard-of-care for glioblastoma remains surgical debulking followed by temozolomide and radiation. However, many tumors become radio-resistant while radiation damages surrounding brain tissue. Novel therapies are needed to increase the effectiveness of radiation and reduce the required radiation dose. Drug candidate CBL0137 is efficacious against glioblastoma by inhibiting histone chaperone FACT, known to be involved in DNA damage repair. We investigated the combination of CBL0137 and radiation on glioblastoma. In vitro, we combined CBL0137 with radiation on U87MG and A1207 glioblastoma cells using the clonogenic assay to evaluate the response to several treatment regimens, and the Fast Halo Assay to examine DNA repair. In vivo, we used the optimum combination treatment regimen to evaluate the response of orthotopic tumors in nude mice. In vitro, the combination of CBL0137 and radiation is superior to either alone and administering CBL0137 two hours prior to radiation, having the drug present during and for a prolonged period post-radiation, is an optimal schedule. CBL0137 inhibits DNA damage repair following radiation and affects the subcellular distribution of histone chaperone ATRX, a molecule involved in DNA repair. In vivo, one dose of CBL0137 is efficacious and the combination of CBL0137 with radiation increases median survival over either monotherapy. CBL0137 is most effective with radiation for glioblastoma when present at the time of radiation, immediately after and for a prolonged period post-radiation, by inhibiting DNA repair caused by radiation. The combination leads to increased survival making it attractive as a dual therapy.

Glioblastoma mesenchymal subtype enhances antioxidant defence to reduce susceptibility to ferroptosis

Glioblastoma (GBM) represents an aggressive brain tumor, characterized by intra- and inter-tumoral heterogeneity and therapy resistance, leading to unfavourable prognosis. An increasing number of studies pays attention on the regulation of ferroptosis, an iron-dependent cell death, as a strategy to reverse drug resistance in cancer. However, the debate on whether this strategy may have important implications for the treatment of GBM is still ongoing. In the present study, we used ferric ammonium citrate and erastin to evaluate ferroptosis induction effects on two human GBM cell lines, U-251 MG, with proneural characteristics, and T98-G, with a mesenchymal profile. The response to ferroptosis induction was markedly different between cell lines, indeed T98-G cells showed an enhanced antioxidant defence, with increased glutathione levels, as compared to U-251 MG cells. Moreover, using bioinformatic approaches and analysing publicly available datasets from patients’ biopsies, we found that GBM with a mesenchymal phenotype showed an up-regulation of several genes involved in antioxidant mechanisms as compared to proneural subtype. Thus, our results suggest that GBM subtypes differently respond to ferroptosis induction, emphasizing the significance of further molecular studies on GBM to better discriminate between various tumor subtypes and progressively move towards personalized therapy.

TUBB4A Inhibits Glioma Development by Regulating ROS-PINK1/Parkin-Mitophagy Pathway.

Glioma is a refractory malignant tumor with a powerful capacity for invasiveness and a poor prognosis. This study aims to investigate the role and mechanism of tubulin beta class IVA (TUBB4A) in glioma progression. The differential expression of TUBB4A in humans was obtained from databases and analyzed. Glioma cells U251-MG and U87-MG were intervened by pcDNA3.1(+) and TUBB4A overexpression plasmid. MTT, CCK8, LDH, wound healing, transwell, and western blotting were used to explore whether TUBB4A participates in the development of glioma. Reactive oxygen species (ROS) were detected by the DCFH-DA probe. Mitochondrial membrane potential (MMP) was examined by JC-1. It was found thatTUBB4A expression level correlated with tumor grade, IDH1 status,1p/19q status, and poor survival in glioma patients. In addition, TUBB4A overexpression inhibited the proliferation, migration, and invasion of U251-MG and U87-MG, while increasing the degree of apoptosis. Notably, TUBB4A overexpression promotes ROS generation and MMP depolarization, and induces mitophagy through the PINK1/Parkin pathway. Interestingly, mitochondria-targeted ROS scavenger reversed the effect of TUBB4A overexpression on PINK1/Parkin expression and mitophagy, whereas mitophagy inhibitor did not affect ROS production. And the effect of TUBB4A overexpression on mitophagy and glioma progression was consistent with that of PINK1/Parkin agonist. In conclusion,TUBB4A is a molecular marker for predicting the prognosis of glioma patients and an effective target for inhibiting glioma progression by regulating ROS-PINK1/Parkin-mitophagy pathway.

Brain-Targeted Cas12a Ribonucleoprotein Nanocapsules Enable Synergetic Gene Co-Editing Leading to Potent Inhibition of Orthotopic Glioblastoma.

Gene-editing technology shows great potential in glioblastoma (GBM) therapy. Due to the complexity of GBM pathogenesis, a single gene-editing-based therapy is unlikely to be successful; therefore, a multi-gene knockout strategy is preferred for effective GBM inhibition. Here, a non-invasive, biodegradable brain-targeted CRISPR/Cas12a nanocapsule is used that simultaneously targeted dual oncogenes, EGFR and PLK1, for effective GBM therapy. This cargo nanoencapsulation technology enables the CRISPR/Cas12a system to achieve extended blood half-life, efficient blood-brain barrier (BBB) penetration, active tumor targeting, and selective release. In U87MG cells, the combinatorial gene editing system resulted in 61% and 33% knockout of EGFR and PLK1, respectively. Following systemic administration, the CRISPR/Cas12a system demonstrated promising brain tumor accumulation that led to extensive EGFR and PLK1 gene editing in both U87MG and patient-derived GSC xenograft mouse models with negligible off-target gene editing detected through NGS. Additionally, CRISPR/Cas12a nanocapsules that concurrently targeted the EGFR and PLK1 oncogenes showed superior tumor growth suppression and significantly improved the median survival time relative to nanocapsules containing single oncogene knockouts, signifying the potency of the multi-oncogene targeting strategy. The findings indicate that utilization of the CRISPR/Cas12a combinatorial gene editing technique presents a practical option for gene therapy in GBM.