An overview of glioblastoma multiforme and temozolomide resistance: can LC-MS-based proteomics reveal the fundamental mechanism of temozolomide resistance?

Preclinical approach of two novel tetrahydroquinoline derivatives targeting GPER and Bcl-2 for anti-glioblastoma therapy

Glioblastoma multiforme (GBM), is a rapidly growing and aggressive brain tumor that can arise de novo in the brain or evolve from lower-grade astrocytoma. This malignancy represents a medical challenge due to the tumor´s localization in the brain, high rates of Temozolomide (TMZ) resistance, and extensive malignant cell parenchymal infiltration, among other factors. Consequently, new drug discovery efforts have focused on targeting pivotal pharmacological targets such as GPER and Bcl-2, presenting a promising strategy for developing new GBM treatments. Herein, we present the results of an improved structure guided design of anti-glioblastoma compounds, L-06 and L-37, both containing the tetrahydroquinoline scaffold and a sulfonamide moiety recognized by GPER and Bcl-2 binding sites, respectively. Both compounds were evaluated in a battery of in vitro assays to measure their anti-glioblastoma activity. L-06 and L-37 were subjected to chemical stability testing under forced degradation conditions indicated minimal degradation from 0.15 to 13.6%. Additionally, antiproliferative evaluation in 2D cell culture yielded IC50 values between 39 and 67 µM in GBM cell lines LN18 and U373, consistent with Gossypol, a well-known Bcl-2 inhibitor. G-15 and L-37 to a greater extent than L-06, inhibit neurospheres formation in glioblastoma stem cells (Gli4) cultured in a proliferation medium. Moreover, in 3D antiproliferative assays using glioblastoma stem cells on non-aligned nanofibers L-37 showed better inhibitory effect than L-06. Interestingly, L-06 than L-37 exhibited an antimigratory effect on glioblastoma stem cells loaded onto aligned nanofibers at concentrations where no antiproliferative activity were observed, unlike G-15, a poorly water soluble GPER antagonist. Collectively, these findings establish a preclinical foundation for L-37 and L-06 as potential anti-glioblastoma agents and support their further investigation as therapeutic candidates.

Potent Therapeutic Activity of NEO212 in Preclinical Models of Human and Canine Leukaemia and Lymphoma

Haematological cancer types, such as leukaemia and lymphoma, represent diseases that are life-threatening to canine and human patients alike, and better treatments are needed. We are developing a novel anticancer agent, NEO212, a conjugate of two cancer drugs, the alkylating agent temozolomide (TMZ) and the monoterpene perillyl alcohol (POH). NEO212 has revealed robust therapeutic activity in preclinical tumour models harbouring different human cancer types. In the comparative preclinical study presented here, a two-species (canine and human) and two-cancer (leukaemia and lymphoma) analysis was performed to determine whether the promising therapeutic activity of NEO212 would span species and cancer types. We investigated the activity of NEO212 in human and canine leukaemia and lymphoma cell lines in vitro and in corresponding mouse models in vivo. Our results show that in vitro NEO212 is significantly more potent than TMZ and POH in all cell lines and exerts activity even against strongly TMZ-resistant tumour cells. In vivo, oral NEO212 strikingly extends the survival of mice harbouring human or canine leukaemia or lymphoma cells. At the same time, NEO212 is well tolerated in dogs at dosages higher than those that achieved therapeutic activity in mouse models. Our study introduces NEO212 as a novel oral cancer drug candidate for both human and veterinary oncology applications.

Distinct spatial N-glycan profiles reveal glioblastoma-specific signatures

This study explored the complex interactions between glycosylation patterns, tumour biology, and therapeutic responses to temozolomide (TMZ) in human malignant glioma, specifically CNS WHO grade 3 oligodendroglioma (ODG) and glioblastoma (GB). Using spatial imaging of N-glycans in formalin-fixed paraffin-embedded (FFPE) tissue sections via MALDI-MSI, we analysed the N-glycome in primary and recurrent GB tissues and orthotopic xenografts of patient-derived brain tumour-initiating cells (BTIC) sensitive or resistant to TMZ. We identified unique N-glycosylation profiles, with nontumor brain (NTB) and ODG showing higher levels of bisecting and tri-antennary structures, while GB exhibited more tetra-antennary and sialylated N-glycans. Distinctive sialylation patterns were observed, with specific α2,6 and α2,3 isomeric linkages significantly altered in GB. Moreover, comparative analysis of primary and recurrent GB tissues revealed elevated high mannose N-glycans in primary GB and fucosylated bi- and tri-antennary N-glycans in recurrent GB tissues. Next, in the orthotopic xenografts of TMZ-sensitive and TMZ-resistant patient brain tumour initiating cells (BTIC), we identified potential N-glycan markers for TMZ treatment response and resistance. Finally, we found significantly altered expression of genes involved in N-glycan biosynthesis in malignant glioma, highlighting the crucial role of N-glycans in glioma and therapy resistance. This study lays the foundation for developing glycosylation-based diagnostic biomarkers and targeted therapies, potentially improving clinical outcomes for GB patients. © 2025 The Pathological Society of Great Britain and Ireland.

Adiponectin facilitates the cell cycle, inhibits cell apoptosis and induces temozolomide resistance in glioblastoma via the Akt/mTOR pathway

Adiponectin (ADN) regulates DNA synthesis, cell apoptosis and cell cycle to participate in the pathology and progression of glioblastoma. The present study aimed to further explore the effect of ADN on temozolomide (TMZ) resistance in glioblastoma and the underlying mechanism of action. Glioblastoma cell lines (U251 and U87-MG cells) were treated with ADN and TMZ at different concentrations; subsequently, 3.0 µg/ml ADN and 1.0 mM TMZ were selected as the optimal concentrations for the experimental conditions. LY294002 (a PI3K inhibitor) was added to ADN or ADN + TMZ-treated glioblastoma cell lines. Cell growth rate was determined using the Cell Counting Kit-8 assay, the apoptotic rate and cell cycle were evaluated using Annexin V/propidium iodide and cell cycle assays, and p-Akt (Thr308), p-Akt (Ser473), Akt, p-mTOR, c-caspase 3, caspase 3, Bax, cyclin B1 and cyclin D1 expression was determined by western blotting. Adiponectin receptor (ADIPOR) 1 and ADIPOR2 were expressed in glioblastoma cell lines. The glioblastoma cell line growth rate was increased by ADN in a concentration- and time-dependent manner. ADN inhibited glioblastoma cell line apoptosis and facilitated cell cycle. Of note, ADN activated the Akt/mTOR pathway and the addition of LY294002 reversed the effect of ADN, indicating that ADN activated the Akt/mTOR pathway to suppress apoptosis and promote cell cycle in glioblastoma cell lines. Notably, TMZ inhibited glioblastoma cell line growth, promoted apoptosis and increased G2 phase cell cycle arrest. However, the addition of ADN reversed the effect of TMZ in glioblastoma cell lines, disclosing that ADN induced TMZ resistance. Markedly, ADN-mediated TMZ resistance was further attenuated by LY294002, suggesting that ADN activated the Akt/mTOR pathway to induce TMZ resistance in glioblastoma cell lines. In conclusion, ADN activated the Akt/mTOR pathway to facilitate cell cycle, inhibit cell apoptosis and induce TMZ resistance in glioblastoma.

Mesenchymal Stem Cell-Derived Exosomes in Cancer Resistance Against Therapeutics

Mesenchymal stem cells (MSCs) are specialized cells that can differentiate into various types of cells. MSCs can be utilized to treat cancer. However, a MSC is considered a double-edged sword, because it can promote tumor progression and support cancer cell growth. Likewise, MSC-derived exosomes (MSC-Exos) carry various intracellular materials and transfer them to other cells. MSC-Exos could also cause tumor progression, including brain cancer, breast cancer, hepatic cancer, lung cancer, and colorectal cancer, and develop resistance against therapies, mainly chemotherapy, radiotherapy, and immunotherapy. An MSC-Exo promotes tumor development and causes drug resistance in various cancer types. The mechanisms involved in cancer drug resistance vary depending on the cancer cell heterogeneity and complexity. In this article, we have explained the various biomarkers and mechanisms involved in the tumor and resistance development through MSC-Exos in different cancer types.

Toward a Theranostic Approach for the Brain Tumor Toxicity Profile of Polymer-Shelled Microbubbles

The establishment of theranostic devices by combining multimodal real-time intraoperative imaging for brain tumor surgery with targeted drug delivery may provide therapeutic advantages for patients with malignant gliomas. Our group has recently developed a new generation of novel microbubbles (MBs), with an air core and a crosslinked poly(vinyl alcohol) shell, called PVA MBs. The PVA MB surface was engineered to support near-infrared (NIR) imaging with a fluorescence probe (C790) for the surgical microscope. The attachment to a cyclic pentapeptide containing the RGD sequence promotes active adhesion and direct targeting of endothelial tumor integrins. The conjugation of temozolomide (TMZ), an alkylating chemotherapy proven to be effective against malignant gliomas, provides a unique therapeutic advantage. The potential toxicity of this novel technology was assessed in rats by intravenous injections of two doses of naked MBs and MBs equipped with RGD for targeting tumor integrins, NIR fluorescence (CF790) for real-time visualization, and TMZ as a cytotoxic component, at two time points, 10 min and 7 days, for potential acute and chronic responses in rats [(1) MB, (2) MB-C790-RGD, and (3) MB-C790-RGD-TMZ]. No mortality occurred during the 7-day study period in any of the dosing groups. Decreased hemoglobin and hematocrit levels and increased triglyceride levels were noticed in the high-dose naked MBs and MBs-CF790-RGD groups. These findings may be associated with their enlarged spleen and liver, observed during necropsy. Histopathology examination in the high-dose animals showed the development of treatment-related changes seen mostly 7 days post dosing, consisting of granulomatous inflammation and foreign body reaction. Accordingly, we concluded that the low-dose tested items appeared to be safe. The results allow us to proceed with planning for an efficacy study before making the first attempt to use this technology in clinical practice.

Enhancing glioblastoma therapy: unveiling synergistic anticancer effects of Onalespib - radiotherapy combination therapy

Background

Glioblastoma (GBM) is the deadliest form of brain cancer, impacting both adults and children, marked by exceptionally high morbidity and mortality rates, even with current standard treatments such as surgery, radiation therapy, and chemotherapy. Therefore, there is a pressing need for new therapeutic strategies to improve survival and reduce treatment side effects. In this study, we investigated the effect of HSP90 inhibition in combination with radiotherapy in established and patient-derived glioblastoma cell lines.

Methods

Potential radiosensitizing effects of the HSP90 inhibitor Onalespib were studied in XTT and clonogenic survival assays as well as in tumor-mimicking multicellular spheroid models. Further, migration capacity and effects on protein expression were studied after exposure to Onalespib and radiation using Proximity Extension Assay analysis.

Results

HSP90 inhibition with Onalespib synergistically enhanced the radiosensitivity of glioblastoma cells grown in 2D and 3D models, resulting in increased cell death, reduced migration capacity and activation of the apoptotic signaling pathway. The proteomic analysis of glioblastoma cells treated with Onalespib, radiation, and their combination revealed significant alterations in protein expression profiles, involved in growth signaling, immune modulation pathways and angiogenesis. Moreover, the combination treatment indicated potential for enhancing cell cycle arrest and apoptosis, suggesting promising anti-tumor effects.

Conclusion

These findings demonstrate that HSP90 inhibition may be a promising strategy to enhance the efficacy of radiotherapy in the treatment of GBM, potentially leading to improved outcomes for patients battling this challenging disease.

Olaparib: A Chemosensitizer for the Treatment of Glioblastoma

Glioblastoma (GBM) is the most prevalent and deadly primary brain tumor. The current treatment for GBM includes adjuvant chemotherapy with temozolomide (TMZ), radiation therapy, and surgical tumor excision. There is still an issue because 50% of patients with GBM who get TMZ have low survival rates due to TMZ resistance. The activation of several DNA repair mechanisms, such as Base Excision Repair (BER), DNA Mismatch Repair (MMR), and O-6- Methylguanine-DNA Methyltransferase (MGMT), is the main mechanism via which TMZ resistance develops. The zinc-finger DNA-binding enzyme poly (ADP-ribose) polymerase-1 (PARP1), which is activated by binding to DNA breaks, affects the activation of the MGMT, BER, and MMR pathway deficiency, which results in TMZ resistance in GBM. PARP inhibitors have been studied recently as sensitizing medications to increase TMZ potency. The first member of the PARP inhibitor family to be identified was Olaparib. It inhibits PARP1 and PARP2, which causes apoptosis in cancer cells and DNA strand break. Olaparib is currently investigated as a radio- and/or chemo-sensitizer in addition to being used as a single agent because it may increase the cytotoxic effects of other treatments. This review addresses Olaparib and its significance in treating TMZ resistance in GBM.

Bibliometric and visualization analysis in the field of epigenetics and glioma (2009-2024)

Introduction

Glioma represents the most prevalent primary malignant tumor in the central nervous system, a deeper understanding of the underlying molecular mechanisms driving glioma is imperative for guiding future treatment strategies. Emerging evidence has implicated a close relationship between glioma development and epigenetic regulation. However, there remains a significant lack of comprehensive summaries in this domain. This study aims to analyze epigenetic publications pertaining to gliomas from 2009 to 2024 using bibliometric methods, consolidate the extant research, and delineate future prospects for investigation in this critical area.

Methods

For the purpose of this study, publications spanning the years 2009 to 2024 were extracted from the esteemed Web of Science Core Collection (WoSCC) database. Utilizing advanced visualization tools such as CiteSpace and VOSviewer, comprehensive data pertaining to various aspects including countries, authors, author co-citations, countries/regions, institutions, journals, cited literature, and keywords were systematically visualized and analyzed.

Results

A thorough analysis was conducted on a comprehensive dataset consisting of 858 publications, which unveiled a discernible trend of steady annual growth in research output within this specific field. The nations of the United States, China, and Germany emerged as the foremost contributors to this research domain. It is noteworthy that von Deimling A and the Helmholtz Association were distinguished as prominent authors and institutions, respectively, in this corpus of literature. A rigorous keyword search and subsequent co-occurrence analysis were executed, ultimately leading to the identification of seven distinct clusters: "epigenetic regulation", "DNA repair", "DNA methylation", "brain tumors", "diffuse midline glioma (DMG)", "U-87 MG" and "epigenomics". Furthermore, an intricate cluster analysis revealed that the primary foci of research within this field were centered around the exploration of glioma pathogenesis and the development of corresponding treatment strategies.

Conclusion

This article underscores the prevailing trends and hotspots in glioma epigenetics, offering invaluable insights that can guide future research endeavors. The investigation of epigenetic mechanisms primarily centers on DNA modification, non-coding RNAs (ncRNAs), and histone modification. Furthermore, the pursuit of overcoming temozolomide (TMZ) resistance and the exploration of diverse emerging therapeutic strategies have emerged as pivotal avenues for future research within the field of glioma epigenetics.

CD2AP promotes the progression of glioblastoma multiforme via TRIM5-mediated NF-kB signaling

CD2-associated protein (CD2AP) is a scaffolding/adaptive protein that regulates intercellular adhesion and multiple signaling pathways. Although emerging evidence suggests that CD2AP is associated with several malignant tumors, there is no study investigating the expression and biological significance of CD2AP in glioblastoma multiforme (GBM). Here by studying public datasets, we found that CD2AP expression was significantly elevated in GBM and that glioma patients with increased CD2AP expression had a worse prognosis. We also confirmed the increase of CD2AP expression in clinical GBM samples and GBM cell lines. CD2AP overexpression in GBM cells promoted their proliferation, colony formation, migration, and invasion in vitro and their tumorigenesis in vivo, and reduced cell apoptosis both at basal levels and in response to temozolomide. While CD2AP knockdown had the opposite effects. Mechanistically, we revealed that CD2AP interacted with TRIM5, an NF-κB modulator. CD2AP overexpression and knockdown increased and decreased TRIM5 levels as well as the NF-κB activity, respectively. Moreover, downregulation of TRIM5 reversed elevated NF-κB activity in GBM cells with CD2AP overexpression; and inhibition of the NF-κB activity attenuated malignant features of GBM cells with CD2AP overexpression. Our findings demonstrate that CD2AP promotes GBM progression through activating TRIM5-mediated NF-κB signaling and that downregulation of CD2AP can attenuate GBM malignancy, suggesting that CD2AP may become a biomarker and the CD2AP-TRIM5-NF-κB axis may become a therapeutic target for GBM.

Mechanistic Insights on Metformin and Arginine Implementation as Repurposed Drugs in Glioblastoma Treatment

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

Soloxolone para-methylanilide effectively suppresses aggressive phenotype of glioblastoma cells including TGF-β1-induced glial-mesenchymal transition in vitro and inhibits growth of U87 glioblastoma xenografts in mice

Soloxolone amides are semisynthetic triterpenoids that can cross the blood-brain barrier and inhibit glioblastoma growth both in vitro and in vivo. Here we investigate the impact of these compounds on processes associated with glioblastoma invasiveness and therapy resistance. Screening of soloxolone amides against glioblastoma cells revealed the ability of compound 7 (soloxolone para-methylanilide) to inhibit transforming growth factor-beta 1 (TGF-β1)-induced glial-mesenchymal transition Compound 7 inhibited morphological changes, wound healing, transwell migration, and expression of mesenchymal markers (N-cadherin, fibronectin, Slug) in TGF-β1-induced U87 and U118 glioblastoma cells, while restoring their adhesiveness. Confocal microscopy and molecular docking showed that 7 reduced SMAD2/3 nuclear translocation probably by direct interaction with the TGF-β type I and type II receptors (TβRI/II). In addition, 7 suppressed stemness of glioblastoma cells as evidenced by inhibition of colony forming ability, spheroid growth, and aldehyde dehydrogenase (ALDH) activity. Furthermore, 7 exhibited a synergistic effect with temozolomide (TMZ) on glioblastoma cell viability. Using N-acetyl-L-cysteine (NAC) and flow cytometry analysis of Annexin V-FITC-, propidium iodide-, and DCFDA-stained cells, 7 was found to synergize the cytotoxicity of TMZ by inducing ROS-dependent apoptosis. Further in vivo studies showed that 7, alone or in combination with TMZ, effectively suppressed the growth of U87 xenograft tumors in mice. Thus, 7 demonstrated promising potential as a component of combination therapy for glioblastoma, reducing its invasiveness and increasing its sensitivity to chemotherapy.

Revolutionizing Brain Tumor Care: Emerging Technologies and Strategies

Glioblastoma multiforme (GBM) is one of the most aggressive forms of brain tumor, characterized by a daunting prognosis with a life expectancy hovering around 12-16 months. Despite a century of relentless research, only a select few drugs have received approval for brain tumor treatment, largely due to the formidable barrier posed by the blood-brain barrier. The current standard of care involves a multifaceted approach combining surgery, irradiation, and chemotherapy. However, recurrence often occurs within months despite these interventions. The formidable challenges of drug delivery to the brain and overcoming therapeutic resistance have become focal points in the treatment of brain tumors and are deemed essential to overcoming tumor recurrence. In recent years, a promising wave of advanced treatments has emerged, offering a glimpse of hope to overcome the limitations of existing therapies. This review aims to highlight cutting-edge technologies in the current and ongoing stages of development, providing patients with valuable insights to guide their choices in brain tumor treatment.

Therapeutic Implications of Targeting YY1 in Glioblastoma

The transcription factor Yin Yang 1 (YY1) plays a pivotal role in the pathogenesis of glioblastoma multiforme (GBM), an aggressive form of brain tumor. This review systematically explores the diverse roles of YY1 overexpression and activities in GBM, including its impact on the tumor microenvironment (TME) and immune evasion mechanisms. Due to the poor response of GBM to current therapies, various findings of YY1-associated pathways in the literature provide valuable insights into novel potential targeted therapeutic strategies. Moreover, YY1 acts as a significant regulator of immune checkpoint molecules and, thus, is a candidate therapeutic target in combination with immune checkpoint inhibitors. Different therapeutic implications targeting YY1 in GBM and its inherent associated challenges encompass the use of nanoparticles, YY1 inhibitors, targeted gene therapy, and exosome-based delivery systems. Despite the inherent complexities of such methods, the successful targeting of YY1 emerges as a promising avenue for reshaping GBM treatment strategies, presenting opportunities for innovative therapeutic approaches and enhanced patient outcomes.

Iloperidone and Temozolomide Synergistically Inhibit Growth, Migration and Enhance Apoptosis in Glioblastoma Cells

Glioblastoma (GBM) is a fatal astrocytic glioma with poor prognosis and treatment resistance. Repurposing potential FDA-approved drugs like anti-psychotics can address the concerns in a timely and cost-effective manner. Epidemiological studies have shown that patients with schizophrenic using anti-psychotics have a low incidence of GBM. Therefore, we aimed to investigate the therapeutic potential of atypical anti-psychotic Iloperidone (ILO) alone and in combination with Temozolomide (TMZ) against GBM. The study assessed the growth inhibitory effect of ILO, TMZ, and their combination (ILO + TMZ) on U-87MG and T-98G cell lines using an MTT assay. The drug interaction coefficient (CDI) was determined, and doses with synergistic effects were used for subsequent experiments, including migratory, invasion, and TUNEL assays. The expressions of DRD2, β-catenin, Dvl2, Twist, and Slug were assessed by RTq-PCR, whereas the β-catenin protein expression was also determined by immunocytochemistry. ILO (p < 0.05) and TMZ (p < 0.01) significantly inhibited the growth of U-87MG cells at all tested doses. The combination of 60 µM of both drugs showed synergistic activity with CDI < 1. The inhibition of migration and apoptosis was more pronounced in the case of combination treatment (p < 0.001). Inhibition of the invading cells was also found to be significant in ILO- and combination-treated groups (p < 0.001). ILO and combination treatment also significantly downregulated the expression of DRD2, while TMZ upregulated the expression (p < 0.001). The expressions of β-catenin (p < 0.001), Dvl2 (p < 0.001), Twist (p < 0.001), and Slug (p < 0.001) were also significantly downregulated in all treatment groups as compared to the vehicle control. The data suggest that ILO possesses strong growth inhibitory activity, possibly due to its effect on DRD2 and β-catenin expression and has the potential to be repurposed against GBM.

HSPA5 and FGFR1 genes in the mesenchymal subtype of glioblastoma can improve a treatment efficacy

Tyrosine kinase inhibitors (TKIs) have emerged as a potential treatment strategy for glioblastoma multiforme (GBM). However, their efficacy is limited by various drug resistance mechanisms. To devise more effective treatments for GBM, genetic characteristics must be considered in addition to pre-existing treatments. We performed an integrative analysis with heterogeneous GBM datasets of genomic, transcriptomic, and proteomic data from DepMap, TCGA and CPTAC. We found that poor prognosis was induced by co-upregulation of heat shock protein family A member 5 (HSPA5) and fibroblast growth factor receptor 1 (FGFR1). Co-up regulation of these two genes could regulate the PI3K/AKT pathway. GBM cell lines with co-upregulation of these two genes showed higher drug sensitivity to PI3K inhibitors. In the mesenchymal subtype, the co-upregulation of FGFR1 and HSPA5 resulted in the most malignant subtype of GBM. Furthermore, we found this newly discovered subtype was correlated with homologous recombination deficiency (HRD) In conclusion, we discovered novel druggable candidates within the group exhibiting co-upregulation of these two genes in GBM, suggest potential strategies for combination therapy.

Cytoplasmic Shotgun Proteomic Points to Key Proteins and Pathways in Temozolomide-Resistant Glioblastoma Multiforme

Temozolomide (TMZ) is the first line of chemotherapy to treat primary brain tumors of the type glioblastoma multiforme (GBM). TMZ resistance (TMZR) is one of the main barriers to successful treatment and is a principal factor in relapse, resulting in a poor median survival of 15 months. The present paper focuses on proteomic analyses of cytosolic fractions from TMZ-resistant (TMZR) LN-18 cells. The experimental workflow includes an easy, cost-effective, and reproducible method to isolate subcellular fraction of cytosolic (CYTO) proteins, mitochondria, and plasma membrane proteins for proteomic studies. For this study, enriched cytoplasmic fractions were analyzed in replicates by nanoflow liquid chromatography tandem high-resolution mass spectrometry (nLC-MS/MS), and proteins identified were quantified using a label-free approach (LFQ). Statistical analysis of control (CTRL) and temozolomide-resistant (TMZR) proteomes revealed proteins that appear to be differentially controlled in the cytoplasm. The functions of these proteins are discussed as well as their roles in other cancers and TMZ resistance in GBM. Key proteins are also described through biological processes related to gene ontology (GO), molecular functions, and cellular components. For protein-protein interactions (PPI), network and pathway involvement analyses have been performed, highlighting the roles of key proteins in the TMZ resistance phenotypes. This study provides a detailed insight into methods of subcellular fractionation for proteomic analysis of TMZ-resistant GBM cells and the potential to apply this approach to future large-scale studies. Several key proteins, protein-protein interactions (PPI), and pathways have been identified, underlying the TMZ resistance phenotype and highlighting the proteins' biological functions.

Molecular Targeted Therapies in Glioblastoma Multiforme: A Systematic Overview of Global Trends and Findings

This systematic review assesses current molecular targeted therapies for glioblastoma multiforme (GBM), a challenging condition with limited treatment options. Using PRISMA methodology, 166 eligible studies, involving 2526 patients (61.49% male, 38.51% female, with a male-to-female ratio of 1.59/1), were analyzed. In laboratory studies, 52.52% primarily used human glioblastoma cell cultures (HCC), and 43.17% employed animal samples (mainly mice). Clinical participants ranged from 18 to 100 years, with 60.2% using combined therapies and 39.8% monotherapies. Mechanistic categories included Protein Kinase Phosphorylation (41.6%), Cell Cycle-Related Mechanisms (18.1%), Microenvironmental Targets (19.9%), Immunological Targets (4.2%), and Other Mechanisms (16.3%). Key molecular targets included Epidermal Growth Factor Receptor (EGFR) (10.8%), Mammalian Target of Rapamycin (mTOR) (7.2%), Vascular Endothelial Growth Factor (VEGF) (6.6%), and Mitogen-Activated Protein Kinase (MEK) (5.4%). This review provides a comprehensive assessment of molecular therapies for GBM, highlighting their varied efficacy in clinical and laboratory settings, ultimately impacting overall and progression-free survival in GBM management.