Survival Of Glioblastoma Patients Research Articles

DIFFERENTIAL TREATMENT EFFECTS OF STANDARD AND HYPOFRACTIONATED RADIATION REGIMENS IN GLIOBLASTOMA PATIENTS.

The identification of the subgroups with differential treatment effects (DTE) is important for decisionmaking in personalized treatment. The DTE analysis assists in identifying patients who are more likely to benefit from a particular treatment regimen. The aim of the study was to analyze DTE in terms of the survival of glioblastoma (GBM) patients in the groups of standard radiotherapy (SRT) and hypofractionated radiotherapy (HRT) by the multicluster modeling of homogenous groups while retaining the statistical characteristics of the overall primary study cohort. The cohort of 159 patients with newly diagnosed GBM stratified according to the radiotherapy regimen (HRT group (n = 110/69.2%); SRT group (n = 49/30.8%)) was evaluated retrospectively. Forty-eight subgroups (multiclusters) were created by enumerating all possible combinations of 5 significant covariates (age, sex, the radicality of the surgical resection, chemotherapy, and Karnofsky performance status) of the Cox model. The DTE for the cancerspecific survival (CSS) within 48 modeled multiclusters were studied by comparing the interpolated Weibull CSS curves according to the Kolmogorov - Smirnov test. The findings showed that the SRT group was superior to the HRT group by CSS only in 3 of the modeled clusters presenting clinical scenarios with a non-radical tumor resection, no chemotherapy, and low Karnofsky functional status (≤ 70 scores) (Cluster 10: male aged < 60; Cluster 21: female aged ≥ 60; Cluster 22: male aged ≥ 60). Most of the studied clinical variants (45 of 48 multiclusters) did not demonstrate a significant difference when comparing the interpolated Weibull curves of the CSS for the SRT and HRT groups according to the Kolmogorov - Smirnov test (p ≥ 0.05). We propose a novel multicluster modeling approach that addresses DTE in relatively small samples of GBM patients receiving SRT or HRT. This original analytical method can be taken into consideration while designing new well-powered prospective trials aimed at the subgroup analysis in GBM patients who will be most beneficial from personalized treatment strategies.

MGMT methylation and its prognostic significance in inoperable IDH-wildtype glioblastoma: the MGMT-GBM study

IntroductionThe methylation of the O6-Methylguanine-DNA Methyltransferase (MGMT) promoter is a valid biomarker for predicting response to therapy with alkylating agents and, independently, prognosis in IDH-wildtype(IDH-w) glioblastoma. We aim to study the impact of its methylation in overall survival of the unresectable IDH-w glioblastoma undergoing biopsy and systemic treatment.MethodsWe collected six-year retrospective (2017–2023) data at a quaternary neurosurgery center for patients undergoing biopsy as the only surgical procedure for an unresectable IDH wildtype glioblastoma. Data was collected from patient records including neuro-oncology multidisciplinary team meeting (MDT) documentation. Patients were grouped into categories according to different types of treatment received after biopsy (no treatment, chemotherapy (CT), radiotherapy (RT), chemoradiotherapy (CRT), chemoradiotherapy with adjuvant temozolomide (CRT with adjuvant TMZ), EORTC-NCIC protocol followed by second line treatment) and according to methylation status (unmethylated (< 5%), borderline methylated (5–15%) and strongly methylated (> 15%)). Survival analysis was performed.Results166 glioblastoma IDH wildtype patients were included in the study with mean age of 62.5 years (M: F = 1.5: 1). 70 (49.3%) patients had unmethylated MGMT status (< 5%), 29 (20.4%) patients had borderline methylated MGMT status (5–15%) and 43 (30.2%) patients had methylated MGMT status (> 15%). 36 (25.3%) patients did not receive any treatment post biopsy, 13 (9.1%) received CT only, 27 (19%) RT only, 12 (8.4%) CRT, 33 (23.2%) CRT with adjuvant TMZ, whereas 21 (14.7%) received EORTC-NCIC protocol along with second line treatment.In biopsy only group, there was no notable difference in survival outcomes among the different methylation statuses. For biopsy and any-other-form-of-treatment methylated groups showed a distinct trend of better survival compared to the borderline or unmethylated groups. Overall, methylated patients had better survival as compared to unmethylated or borderline groups.ConclusionMethylated MGMT status are predictors for better overall survival in unresectable IDH wildtype glioblastoma patients undergoing biopsy and treatment regardless of the treatment modality.

Construction and validation of cell cycle-related prognostic genetic model for glioblastoma.

Glioblastoma (GBM) is a common primary malignant brain tumor and the prognosis of these patients remains poor. Therefore, further understanding of cell cycle-related molecular mechanisms of GBM and identification of appropriate prognostic markers and therapeutic targets are key research imperatives. Based on RNA-seq expression datasets from The Cancer Genome Atlas database, prognosis-related biological processes in GBM were screened out. Gene Set Variation Analysis (GSVA), LASSO-COX, univariate and multivariate Cox regression analyses, Kaplan-Meier survival analysis, and Pearson correlation analysis were performed for constructing a predictive prognostic model. A total of 58 cell cycle-related genes were identified by GSVA and analysis of differential expression between GBM and control samples. By univariate Cox and LASSO regression analyses, 8 genes were identified as prognostic biomarkers in GBM. A nomogram with superior performance to predict the survival of GBM patients was established regarding risk score, cancer status, recurrence type, and mRNAsi. This study revealed the prognostic value of cell cycle-related genes in GBM. In addition, we constructed a reliable model for predicting the prognosis of GBM patients. Our findings reinforce the relationship between cell cycle and GBM and may help improve the prognostic assessment of patients with GBM. Our predictive prognostic model, based on independent prognostic factors, enables tailored treatment strategies for GBM patients. It is particularly useful for subgroups with uncertain prognosis or treatment challenges.

Key Genes Involved in the Beneficial Mechanism of Hyperbaric Oxygen for Glioblastoma and Predictive Indicators of Hyperbaric Oxygen Prolonging Survival in Glioblastoma Patients.

The prognosis of glioblastoma is poor, and therapy-resistance is largely attributed to intratumor hypoxia. Hyperbaric oxygen (HBO) effectively alleviates hypoxia. However, the sole role of HBO in glioblastoma remains controversial. We previously reported that HBO can promote apoptosis, shorten protrusions, and delay growth of glioblastoma, but the molecular mechanism is unclear. We aimed to test candidate genes in HBO-exposed glioblastoma cells and to analyze their correlation with the survival of glioblastoma patients. Glioblastoma cell lines exposed to repetitive HBO or normobaric air (NBA) were collected for RNA isolation and microarray data analysis. GO analysis, KEGG pathway analysis and survival analysis of the differentially expressed genes (DEGs) were performed. HBO not only inhibited hypoxia-inducing genes including CA9, FGF11, PPFIA4, TCAF2 and SLC2A12, but also regulated vascularization by downregulating the expression of COL1A1, COL8A1, COL12A1, RHOJ and FILIP1L, ultimately attenuated hypoxic microenvironment of glioblastoma. HBO attenuated inflammatory microenvironment by reducing the expression of NLRP2, CARD8, MYD88 and CD180. HBO prevented metastasis by downregulating the expression of NTM, CXCL12, CXCL13, CXCR4, CXCR5, CDC42, IGFBP3, IGFBP5, GPC6, MMP19, ADAMTS1, EFEMP1, PTBP3, NF1 and PDCD1. HBO upregulated the expression of BAK1, PPIF, DDIT3, TP53I11 and FAS, whereas downregulated the expression of MDM4 and SIVA1, thus promoting apoptosis. HBO upregulated the expression of CDC25A, MCM2, PCNA, RFC33, DSCC1 and CDC14A, whereas downregulated the expression of ASNS, CDK6, CDKN1B, PTBP3 and MAD2L1, thus inhibiting cell cycle progression. Among these DEGs, 17 indicator-genes of HBO prolonging survival were detected. HBO is beneficial for glioblastoma. Glioblastoma patients with these predictive indicators may prolong survival with HBO therapy. These potential therapeutic targets especially COL1A1, ADAMTS1 and PTBP3 deserve further validation.

Quantitative assessment of residual tumor is a strong and independent predictor of survival in methylated glioblastoma following radiochemotherapy with CCNU/TMZ.

Maximum tumor resection improves overall survival (OS) in patients with glioblastoma. The extent of resection (EOR) is historically dichotomized. The RANO resect group recently proposed criteria for volumetry-based EOR assessment in patients that were treated according to Stupp´s protocol. The purpose of this study was (1) to investigate the prognostic value of EOR in patients receiving combined chemotherapy with lomustine (CCNU)/temozolomide (TMZ), and (2) to analyse the prognostic performance of binary EOR assessment compared to volumetric assessment. 78 patients with newly diagnosed MGMT-methylated GBM undergoing tumor resection followed by radiochemotherapy with CCNU/TMZ were included in this study. Residual contrast-enhancing (CE) tumor volume after the first resection was measured and its influence on OS and PFS was analysed using uni- and multivariable Cox regression analysis as well as two-sided log rank test. Patients were divided into RTV ≤1 cm³, >1 cm³ - ≤5 cm³ and >5 cm³ following the proposed criteria of the RANO resect group. Prolonged OS was associated with age <60 years, low RTV, and gross total resection (GTR). Residual tumor volume (RTV) had a superior prognostic value compared to binary EOR assessment. Patients with total or near total resection of CE tumor (≤1 cm³ RTV) showed prolonged OS (median 54.4 months, 95% CI 46.94-not reached), with a 5-year survival rate of 49%. Low RTV is associated with increased survival in glioblastoma patients undergoing radiochemotherapy with CCNU/TMZ. This study demonstrates the applicability of the recently proposed RANO resect criteria in this subgroup of patients.

Significance of radiation therapy in frontal glioblastoma patients and exploration of optimal treatment modality: a real-world multiple-center study based on propensity score matching.

Glioblastoma (GBM) exhibits diffuse and invasive growth patterns, with a 5-year overall survival (OS) rate of 5-10%. In addition, approximately 40 percent of GBMs are localized in the frontal lobe, a region closely linked to essential life functions including cognition, so that it cannot be completely eradicated through surgical intervention, leading to very poor prognosis. Postoperative therapy is an essential treatment modality. The aim of this study is to explain the possible role of radiation therapy (RT) in the treatment of frontal GBM, providing more evidence for clinical application. In the study, patient information pertaining to frontal GBM patients was collected from the Surveillance, Epidemiology, and End Results (SEER) database for the period 2000 to 2018 with 9,904 patients deemed appropriate for inclusion in this study. A 1:2 propensity score matching analysis was conducted to balance the non-radiotherapy and radiotherapy group. This study is a retrospective study. Before matching, the median OS, tumor specific survival (TSS) and hazard ratio (HR) were 3 months, 3 months and 4.408 [95% confidence interval (CI): 3.762-4.535, P<0.001] in the non-RT group compared to those of 13 months, 14 months and 2.463 (95% CI: 2.247-2.936, P<0.001) in the RT group. After matching, the median OS, TSS and HR were 3 months, 4 months and 1.433 (95% CI: 1.387-1.692, P<0.001) in the non-RT group compared to those of 8 months, 8 months and 1.427 (95% CI: 1.374-1.682, P<0.001) in the RT group. Radiotherapy is an important local therapy, which can significantly improve the tumor-specific survival and OS of frontal GBM patients. With the arrival of the era of precision radiotherapy, the continuous progress of radiotherapy technology may bring more benefits to frontal GBM patients.

Radiogenomics based survival prediction of small-sample glioblastoma patients by multi-task DFFSP model.

In this paper, the multi-task dense-feature-fusion survival prediction (DFFSP) model is proposed to predict the three-year survival for glioblastoma (GBM) patients based on radiogenomics data. The contrast-enhanced T1-weighted (T1w) image, T2-weighted (T2w) image and copy number variation (CNV) is used as the input of the three branches of the DFFSP model. This model uses two image extraction modules consisting of residual blocks and one dense feature fusion module to make multi-scale fusion of T1w and T2w image features as backbone. Also, a gene feature extraction module is used to adaptively weight CNV fragments. Besides, a transfer learning module is introduced to solve the small sample problem and an image reconstruction module is adopted to make the model anatomy-aware under a multi-task framework. 256 sample pairs (T1w and corresponding T2w MRI slices) and 187 CNVs of 74 patients were used. The experimental results show that the proposed model can predict the three-year survival of GBM patients with the accuracy of 89.1 %, which is improved by 3.2 and 4.7 % compared with the model without genes and the model using last fusion strategy, respectively. This model could also classify the patients into high-risk and low-risk groups, which will effectively assist doctors in diagnosing GBM patients.

Identification and validation of potential prognostic biomarkers in glioblastoma via the mesenchymal stem cell infiltration level.

Mesenchymal stem cells (MSCs) are key components in promoting glioblastoma (GBM) progression. This study aimed to explore new therapeutic targets and related pathogenic mechanisms based on different MSCs infiltration levels in GBM patients. We estimated the relationship between cell infiltration and prognosis of GBM. Subsequently, key risk genes were identified and prognostic models were constructed by LASSO-Cox analysis. The risk genes were validated by five independent external cohorts, single-cell RNA analysis, and immunohistochemistry of human GBM tissues. TIDE analysis predicted responsiveness to immune checkpoint inhibitors in different risk groups. The MSCs infiltration level was negatively associated with survival in GBM patients. LOXL1, LOXL4, and GUCA1A are key risk genes that promote GBM progression and may act through complex intercellular communication. This research has provided a comprehensive study for exploring the MSCs infiltration environment on GBM progression, which could shed light on novel biomarkers and mechanisms involved in GBM progression.

Opportunities and Challenges of Small Molecule Inhibitors in Glioblastoma Treatment: Lessons Learned from Clinical Trials.

Glioblastoma (GBM) is the most prevalent central nervous system tumour (CNS). Patients with GBM have a dismal prognosis of 15 months, despite an intensive treatment schedule consisting of surgery, chemoradiation and concurrent chemotherapy. In the last decades, many trials have been performed investigating small molecule inhibitors, which target specific genes involved in tumorigenesis. So far, these trials have been unsuccessful, and standard of care for GBM patients has remained the same since 2005. This review gives an overview of trials investigating small molecule inhibitors on their own, combined with chemotherapy or other small molecule inhibitors. We discuss possible resistance mechanisms in GBM, focussing on intra- and intertumoral heterogeneity, bypass mechanisms and the influence of the tumour microenvironment. Moreover, we emphasise how combining inhibitors can help overcome these resistance mechanisms. We also address strategies for improving trial outcomes through modifications to their design. In summary, this review aims to elucidate different resistance mechanisms against small molecule inhibitors, highlighting their significance in the search for novel therapeutic combinations to improve the overall survival of GBM patients.

Association between dichotomized VASARI feature and overall survival in glioblastoma patients: a single-institution propensity score matching analysis

ObjectivesThis study aimed to investigate the intra- and inter-observer consistency of the Visually Accessible Rembrandt Images (VASARI) feature set before and after dichotomization, and the association between dichotomous VASARI features and the overall survival (OS) in glioblastoma (GBM) patients.MethodsThis retrospective study included 351 patients with pathologically confirmed IDH1 wild-type GBM between January 2016 and June 2022. Firstly, VASARI features were assessed by four radiologists with varying levels of experience before and after dichotomization. Cohen’s kappa coefficient (κ) was calculated to measure the intra- and inter-observer consistency. Then, after adjustment for confounders using propensity score matching, Kaplan-Meier curves were used to compare OS differences for each dichotomous VASARI feature. Next, patients were randomly stratified into a training set (n = 211) and a test set (n = 140) in a 3:2 ratio. Based on the training set, Cox proportional hazards regression analysis was adopted to develop combined and clinical models to predict OS, and the performance of the models was evaluated with the test set.ResultsEleven VASARI features with κ value of 0.61–0.8 demonstrated almost perfect agreement after dichotomization, with the range of κ values across all readers being 0.874–1.000. Seven VASARI features were correlated with GBM patient OS. For OS prediction, the combined model outperformed the clinical model in both training set (C-index, 0.762 vs. 0.723) and test set (C-index, 0.812 vs. 0.702).ConclusionThe dichotomous VASARI features exhibited excellent inter- and intra-observer consistency. The combined model outperformed the clinical model for OS prediction.

AB045. E2F6 promotes temozolomide resistance in glioblastoma by enrichment in CARD6 and POSTN promoter region.

Glioblastoma (GBM) is the most aggressive primary malignant brain tumor. Temozolomide (TMZ) is the most used first-line chemotherapeutic agent for GBM after surgery, but acquired resistance to TMZ frequently leads to treatment failure and is a major challenge in the clinical treatment of GBM. Increasing evidence suggests that E2F transcription factor 6 (E2F6) is associated with a variety of tumor malignant biological behaviors and drug resistance, but its biological function and underlying molecular mechanisms in GBM are unknown. The study investigated the levels of E2F6 in both TMZ-sensitive and TMZ-resistant GBM cells and tissues using Western blotting and immunofluorescence assays. In vitro experiments were conducted to explore the impact of E2F6 on TMZ resistance and glioma stem cell stemness. These experiments included Western blotting, colony formation assay, flow cytometry assay, and TdT-mediated dUTP nick-end labeling (TUNEL) assay. Bioinformatic analyses were conducted to investigate the mechanism behind the high expression of E2F6 in TMZ-resistant cells and its correlation with caspase recruitment domain 6 (CARD6) and disulfide-linked cell adhesion protein (POSTN). The study employed bioinformatic analyses, messenger RNA (mRNA) sequencing, chromatin immunoprecipitation sequencing assay, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. To examine the function of E2F6, an intracranial xenograft tumor mouse model was used for in vivo experiments. It was found that CARD6 and POSTN were significantly associated with TMZ resistance and survival of GBM patients. E2F6 was up-regulated in TMZ-resistant cells and tissues. Knockdown of E2F6 down-regulated the expression of CARD6, promoted TMZ-induced apoptosis, and enhanced chemo-sensitivity, whereas its overexpression significantly increased TMZ resistance in vitro and in vivo. In addition, E2F6 can promote TMZ resistance through stem-like properties acquisition. We identified a signaling pathway related to E2F6 and POSTN, which maintains the self-renewal of GBM stem cells (GSCs). E2F6 concentrates in the promoter region of POSTN, thereby regulating the expression of GSCs-related genes cluster of differentiation 133 (CD133), Nestin, and sex-determining region Y-box 2 (SOX2), which may be involved in tumor metabolism and drug resistance processes. Down-regulation of E2F6 down-regulated the expression of POSTN and inhibited tumor growth in nude mice. These results suggest that the E2F6-CARD6/POSTN signaling axis regulates the malignant biological behaviors of GBM and TMZ resistance. These findings are expected to provide promising therapeutic targets for CARD6 overcoming GBM TMZ resistance.

AB023. Early diagnosis and treatment lead to improve survival of glioblastoma patients.

Glioblastoma (GBM) is one of the worst prognostic cancers and one of the reasons is that GBM patients rapidly deteriorated and half of them had a Karnofsky performance status (KPS) with 70 or less at the initial presentation. We discuss the significance of early diagnosis and treatment to the clinical outcomes of GBM patients. Data of IDH-wildtype GBM patients treated at our institution between 2010 and 2019 were retrospectively reviewed. Patients were classified into early or late diagnosis groups with a threshold of 14 days from initial symptoms. Also, patients were divided into early, intermediate, and late surgery groups with thresholds of 21 and 35 days. Patients were also divided into two groups: neurosurgeon and non-neurosurgeon groups, based on the primary doctor whom patients sought for an initial evaluation. Representative symptoms and patient prognosis were examined. Of 153 patients, 72 and 81 were classified into the early and late diagnosis groups. The proportion of patients with preoperative KPS scores ≥90 was 48.6% and 29.6% in the early and late diagnosis groups (P=0.01). Median overall survival was significantly longer in the early surgery group (n=43) than in the late surgery group (n=86) (28.4 vs. 18.7 months, P=0.006). The neurosurgeon group exhibited a significantly shorter duration from the first hospital visit to the first surgery than the non-neurosurgeon group (18 vs. 29 days, P<0.001). Furthermore, the overall survival of the neurosurgeon group was significantly more prolonged than that of the non-neurosurgeon group (22.9 vs. 14.0 months, P=0.04). Early diagnosis and surgery within 3 weeks from the initial symptoms are associated with improved patient survival. Early GBM treatment will be beneficial for patients with GBM. A short duration from the first hospital visit to the first surgery is essential in enhancing GBM patient prognosis.

Knockdown of Anoikis-Associated Gene OCIAD2 Reduces Proliferation and Migration of Glioblastoma Cell Lines.

Glioblastoma (GBM) severely disrupts the quality of life of patients. Anoikis represents a significant mechanism in cancer invasion and metastasis. Our study focused on the prognostic relationship between the anoikis-associated gene and GBM and its effect on GBM cell progression. We downloaded 656 and 979 GBM sample data from TCGA and CGGA cohort datasets, respectively. Fifteen anoikis-associated genes were obtained from the GeneCards database and were subsequently clustered to identify differential genes associated with them. After LAASO screening, the expression values of the 5 differential genes were the sum of LASSO regression coefficients. Survival analysis and ROC curve analysis of anoikis scores were performed using the TCGA training and CGGA validation sets. The prognostic factors were analyzed using Cox regression analysis in GBM. Moreover, CCK-8, colony formation, wound healing, and transwell assay were used to evaluate GBM cell proliferation and migration. Significant differences were observed in the 5-year survival of GBM patients between the two subgroups. Then, our analysis demonstrated that high OCIAD2, FTLP3, IGFBP2, and H19 levels were associated with lower 5-year GBM survival rates, whereas high SFRP2 levels were associated with higher survival rates. Univariate Cox analysis indicated that GBM risk was linked to both anoikis score and grade, while multivariate Cox analysis indicated that GBM risk was associated with both anoikis score and age. Additionally, OCIAD2 was highly expressed in U251MG and T98G cells. Moreover, OCIAD2 silencing inhibited GBM cell proliferation and migration. This study demonstrated the potential of the anoikis-associated gene OCIAD2 as a prognostic biomarker for GBM. Furthermore, we validated in vitro that OCIAD2 promoted GBM cell progression.

ALDH5A1/miR-210 axis plays a key role in reprogramming cellular metabolism and has a significant correlation with glioblastoma patient survival

BackgroundGlioblastoma (GBM) is the most aggressive among the tumors of the central nervous system (CNS), and has a dismal prognosis. Altered metabolism, especially the increased rate of aerobic glycolysis promotes rapid proliferation of GBM cells. Here, we investigated the role of aldehyde dehydrogenase 5 family member A1 (ALDH5A1), a mitochondrial enzyme in the aspect of GBM metabolism. We also studied the regulatory mechanisms of altered ALDH5A1 expression in GBM.Approach and resultsWe show that ALDH5A1 is significantly downregulated in GBM patients in a grade dependent manner as compared to control brain and its low expression is associated with poor prognosis. It is significantly downregulated under hypoxia and is a direct target of the hypoxia induced microRNA: miR-210. Ectopic overexpression of ALDH5A1 in GBM cell lines U-87 MG and T98G markedly reduced their proliferation, 3D spheroid forming ability, and formation of reactive oxygen species (ROS). ALDH5A1 upregulation increased the oxygen consumption rate (OCR), and reduced the extracellular acidification rate (ECAR) of GBM cells while miR-210 overexpression showed the opposite. A significant downregulation in the transcript levels of LDHA, PDK1, and SLC2A1; coupled with lower glucose uptake and lactate production upon ALDH5A1 overexpression reveals that ALDH5A1 significantly reduces the glycolytic capacity of GBM cells. Total ATP generated in 24 h was more when miR-210 was overexpressed, while a slight decrease in ATP formation was observed upon ALDH5A1 upregulation. Interestingly, we also observed that ALDH5A1 expression is elevated and miR-210 levels are downregulated in IDH-mutant glioma as compared to its wild-type form.ConclusionOverall, our findings suggest that miR-210 mediated downregulation of ALDH5A1 plays a critical role in tumor metabolism and helps maintaining a high glycolytic phenotype in GBM.

Early 2-Factor Transcription Factors Associated with Progression and Recurrence in Bevacizumab-Responsive Subtypes of Glioblastoma.

The early 2-factor (E2F) family of transcription factors, including E2F1 through 8, plays a critical role in apoptosis, metabolism, proliferation, and angiogenesis within glioblastoma (GBM). However, the specific functions of E2F transcription factors (E2Fs) and their impact on the malignancy of Bevacizumab (BVZ)-responsive GBM subtypes remain unclear. This study used data from The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), European Molecular Biology Laboratory's European Bioinformatics Institute (EMBL-EBI), and Gene Expression Omnibus (GEO) to explore the impact of eight E2F family members on the clinical characteristics of BVZ-responsive GBM subtypes and possible mechanisms of recurrence after BVZ treatment. Using machine learning algorithms, including TreeBagger and deep neural networks, we systematically predicted and validated GBM patient survival terms based on the expression profiles of E2Fs across BVZ-responsive GBM subtypes. Our bioinformatics analyses suggested that a significant increase in E2F8 post-BVZ treatment may enhance the function of angiogenesis and stem cell proliferation, implicating this factor as a candidate mechanism of GBM recurrence after treatment. In addition, BVZ treatment in unresponsive GBM patients may potentially worsen disease progression. These insights underscore that E2F family members play important roles in GBM malignancy and BVZ treatment response, highlighting their potential as prognostic biomarkers, therapeutic targets, and recommending precision BVZ treatment to individual GBM patients.

A proteomic approach supports the clinical relevance of TAT-Cx43266-283 in glioblastoma

Glioblastoma (GBM) is the most frequent and aggressive primary brain cancer. The Src inhibitor, TAT-Cx43266-283, exerts antitumor effects in in vitro and in vivo models of GBM. Because addressing the mechanism of action is essential to translate these results to a clinical setting, in this study we carried out an unbiased proteomic approach. Data-independent acquisition mass spectrometry proteomics allowed the identification of 190 proteins whose abundance was modified by TAT-Cx43266-283. Our results were consistent with the inhibition of Src as the mechanism of action of TAT-Cx43266-283 and unveiled antitumor effectors, such as p120 catenin. Changes in the abundance of several proteins suggested that TAT-Cx43266-283 may also impact the brain microenvironment. Importantly, the proteins whose abundance was reduced by TAT-Cx43266-283 correlated with an improved GBM patient survival in clinical datasets and none of the proteins whose abundance was increased by TAT-Cx43266-283 correlated with shorter survival, supporting its use in clinical trials.

The Role of Mesenchymal Reprogramming in Malignant Clonal Evolution and Intra-Tumoral Heterogeneity in Glioblastoma.

Glioblastoma (GBM) is the most common yet uniformly fatal adult brain cancer. Intra-tumoral molecular and cellular heterogeneities are major contributory factors to therapeutic refractoriness and futility in GBM. Molecular heterogeneity is represented through molecular subtype clusters whereby the proneural (PN) subtype is associated with significantly increased long-term survival compared to the highly resistant mesenchymal (MES) subtype. Furthermore, it is universally recognized that a small subset of GBM cells known as GBM stem cells (GSCs) serve as reservoirs for tumor recurrence and progression. The clonal evolution of GSC molecular subtypes in response to therapy drives intra-tumoral heterogeneity and remains a critical determinant of GBM outcomes. In particular, the intra-tumoral MES reprogramming of GSCs using current GBM therapies has emerged as a leading hypothesis for therapeutic refractoriness. Preventing the intra-tumoral divergent evolution of GBM toward the MES subtype via new treatments would dramatically improve long-term survival for GBM patients and have a significant impact on GBM outcomes. In this review, we examine the challenges of the role of MES reprogramming in the malignant clonal evolution of glioblastoma and provide future perspectives for addressing the unmet therapeutic need to overcome resistance in GBM.

Targeting ARNT attenuates chemoresistance through destabilizing p38α-MAPK signaling in glioblastoma

Glioblastoma (GBM) is the most aggressive and lethal brain tumor in adults. This study aimed to investigate the functional significance of aryl hydrocarbon receptor nuclear translocator (ARNT) in the pathogenesis of GBM. Analysis of public datasets revealed ARNT is upregulated in GBM tissues compared to lower grade gliomas or normal brain tissues. Higher ARNT expression correlated with the mesenchymal subtype and poorer survival in GBM patients. Silencing ARNT using lentiviral shRNAs attenuated the proliferative, invasive, and stem-like capabilities of GBM cell lines, while ARNT overexpression enhanced these malignant phenotypes. Single-cell RNA sequencing uncovered that ARNT is highly expressed in a stem-like subpopulation and is involved in regulating glycolysis, hypoxia response, and stress pathways. Mechanistic studies found ARNT activates p38 mitogen-activated protein kinase (MAPK) signaling to promote chemoresistance in GBM cells. Disrupting the ARNT/p38α protein interaction via the ARNT PAS-A domain restored temozolomide sensitivity. Overall, this study demonstrates ARNT functions as an oncogenic driver in GBM pathogenesis and represents a promising therapeutic target.

Profiling of Tumor-Infiltrating Immune Cells and Their Impact on Survival in Glioblastoma Patients Undergoing Immunotherapy with Dendritic Cells.

Glioblastomas (GBM) are the most common primary malignant brain tumors, comprising 2% of all cancers in adults. Their location and cellular and molecular heterogeneity, along with their highly infiltrative nature, make their treatment challenging. Recently, our research group reported promising results from a prospective phase II clinical trial involving allogeneic vaccination with dendritic cells (DCs). To date, six out of the thirty-seven reported cases remain alive without tumor recurrence. In this study, we focused on the characterization of infiltrating immune cells observed at the time of surgical resection. An analytical model employing a neural network-based predictive algorithm was used to ascertain the potential prognostic implications of immunological variables on patients' overall survival. Counterintuitively, immune phenotyping of tumor-associated macrophages (TAMs) has revealed the extracellular marker PD-L1 to be a positive predictor of overall survival. In contrast, the elevated expression of CD86 within this cellular subset emerged as a negative prognostic indicator. Fundamentally, the neural network algorithm outlined here allows a prediction of the responsiveness of patients undergoing dendritic cell vaccination in terms of overall survival based on clinical parameters and the profile of infiltrated TAMs observed at the time of tumor excision.

Cellular diversity through space and time: adding new dimensions to GBM therapeutic development.

The current median survival for glioblastoma (GBM) patients is only about 16 months, with many patients succumbing to the disease in just a matter of months, making it the most common and aggressive primary brain cancer in adults. This poor outcome is, in part, due to the lack of new treatment options with only one FDA-approved treatment in the last decade. Advances in sequencing techniques and transcriptomic analyses have revealed a vast degree of heterogeneity in GBM, from inter-patient diversity to intra-tumoral cellular variability. These cutting-edge approaches are providing new molecular insights highlighting a critical role for the tumor microenvironment (TME) as a driver of cellular plasticity and phenotypic heterogeneity. With this expanded molecular toolbox, the influence of TME factors, including endogenous (e.g., oxygen and nutrient availability and interactions with non-malignant cells) and iatrogenically induced (e.g., post-therapeutic intervention) stimuli, on tumor cell states can be explored to a greater depth. There exists a critical need for interrogating the temporal and spatial aspects of patient tumors at a high, cell-level resolution to identify therapeutically targetable states, interactions and mechanisms. In this review, we discuss advancements in our understanding of spatiotemporal diversity in GBM with an emphasis on the influence of hypoxia and immune cell interactions on tumor cell heterogeneity. Additionally, we describe specific high-resolution spatially resolved methodologies and their potential to expand the impact of pre-clinical GBM studies. Finally, we highlight clinical attempts at targeting hypoxia- and immune-related mechanisms of malignancy and the potential therapeutic opportunities afforded by single-cell and spatial exploration of GBM patient specimens.