A molecular signature associated with prolonged survival in glioblastoma patients treated with regorafenib

Unlocking Hope: Anti-VEGFR inhibitors and their potential in glioblastoma treatment

PURPOSE

This systematic review summarizes evidence of VEGFR gene mutations and VEGF/VEGFR protein expression in glioblastoma multiforme (GBM) patients, alongside the efficacy and safety of anti-VEGFR tyrosine kinase inhibitors (TKIs) for GBM treatment.

METHODS

A comprehensive literature review was conducted using PubMed up to August 2023. Boolean operators and MeSH term "glioma," along with specific VEGFR-related keywords, were utilized following thorough examination of existing literature.

RESULTS

VEGFR correlates with glioma grade and GBM progression, presenting a viable therapeutic target. Regorafenib and axitinib show promise among studied TKIs. Other multi-targeted TKIs (MTKI) and combination therapies exhibit potential, albeit limited by blood-brain barrier penetration and toxicity. Combining treatments like radiotherapy and enhancing BBB penetration may benefit patients. Further research is warranted in patient quality of life and biomarker-guided selection.

CONCLUSION

While certain therapies hold promise for GBM, future research should prioritize personalized medicine and innovative strategies for improved treatment outcomes.

IFI35 regulates non-canonical NF-κB signaling to maintain glioblastoma stem cells and recruit tumor-associated macrophages

Glioblastoma (GBM) is the most aggressive malignant primary brain tumor characterized by a highly heterogeneous and immunosuppressive tumor microenvironment (TME). The symbiotic interactions between glioblastoma stem cells (GSCs) and tumor-associated macrophages (TAM) in the TME are critical for tumor progression. Here, we identified that IFI35, a transcriptional regulatory factor, plays both cell-intrinsic and cell-extrinsic roles in maintaining GSCs and the immunosuppressive TME. IFI35 induced non-canonical NF-kB signaling through proteasomal processing of p105 to the DNA-binding transcription factor p50, which heterodimerizes with RELB (RELB/p50), and activated cell chemotaxis in a cell-autonomous manner. Further, IFI35 induced recruitment and maintenance of M2-like TAMs in TME in a paracrine manner. Targeting IFI35 effectively suppressed in vivo tumor growth and prolonged survival of orthotopic xenograft-bearing mice. Collectively, these findings reveal the tumor-promoting functions of IFI35 and suggest that targeting IFI35 or its downstream effectors may provide effective approaches to improve GBM treatment.

Regorafenib and glioblastoma: a literature review of preclinical studies, molecular mechanisms and clinical effectiveness

Glioblastoma IDH wild type (GBM) is a very aggressive brain tumour, characterised by an infiltrative growth pattern and by a prominent neoangiogenesis. Its prognosis is unfortunately dismal, and the median overall survival of GBM patients is short (15 months). Clinical management is based on bulk tumour removal and standard chemoradiation with the alkylating drug temozolomide, but the tumour invariably recurs leading to patient's death. Clinical options for GBM patients remained unaltered for almost two decades until the encouraging results obtained by the phase II REGOMA trial allowed the introduction of the multikinase inhibitor regorafenib as a preferred regimen in relapsed GBM treatment by the National Comprehensive Cancer Network (NCCN) 2020 Guideline. Regorafenib, a sorafenib derivative, targets kinases associated with angiogenesis (VEGFR 1-3), as well as oncogenesis (c-KIT, RET, FGFR) and stromal kinases (FGFR, PDGFR-b). It was already approved for metastatic colorectal cancers and hepatocellular carcinomas. The aim of the present review is to focus on both the molecular and clinical knowledge collected in these first three years of regorafenib use in GBM.

REGOMA-OSS: a large, Italian, multicenter, prospective, observational study evaluating the efficacy and safety of regorafenib in patients with recurrent glioblastoma

BACKGROUND

In the randomized phase II REGOMA trial, regorafenib showed promising activity in patients with recurrent glioblastoma. We conducted a large, multicenter, prospective, observational study to confirm the REGOMA data in a real-world setting.

PATIENTS AND METHODS

The major inclusion criteria were histologically confirmed diagnosis of glioblastoma according to the World Health Organization (WHO) 2016 classification and relapse after radiotherapy with concurrent/adjuvant temozolomide treatment, good performance status [Eastern Cooperative Oncology Group performance status (ECOG PS 0-1)] and good liver function. Regorafenib was administered at the standard dose of 160 mg/day for 3 weeks on/1 week off. Brain magnetic resonance imaging was carried out within 14 days before starting regorafenib and every 8-12 weeks. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective response rate, disease control rate (DCR), safety and health-related quality of life. The Response Assessment in Neuro-Oncology (RANO) criteria were used for response evaluation and Common Terminology Criteria for Adverse Events (CTCAE) version 5 for assessment of adverse events (AEs).

RESULTS

From September 2020 to October 2022, 190 patients with recurrent glioblastoma were enrolled from 30 cancer centers in Italy: their median age was 58.5 years [interquartile range (IQR) 53-67 years], 68% were male and 85 (44.7%) were in optimal clinical condition (ECOG PS 0). The number of patients taking steroids at baseline was 113 (60%); the second surgery was carried out in 39 (20.5%). O6-methylguanine-DNA methyltransferase (MGMT) was methylated in 80 patients (50.3%) and 147 (92.4%) of the patients analyzed had isocitrate dehydrogenase (IDH) wild type. The median follow-up period was 20 months (IQR 15.6-25.5 months). The median OS was 7.9 months ([95% confidence interval (CI) 6.5-9.2 months] and the median PFS was 2.6 months (95% CI 2.3-2.9 months). Radiological response was partial response and stable disease in 13 (7.3%) and 26 (14.6%) patients, respectively, with a DCR of 21.9%. The median number of regorafenib cycles per patient was 3 (IQR 2.0-4.0). Grade 3-4 drug-related adverse events were reported in 22.6% of patients. A dose reduction due to AEs was required in 36% of patients. No deaths were considered as treatment-related AEs.

CONCLUSIONS

This large, real-world observational study showed similar OS with better tolerability of regorafenib in patients with relapsed glioblastoma compared with the REGOMA study.

MicroRNA‑203a‑3p improves bleomycin and pingyangmycin sensitivity by inactivating the PI3K/AKT pathway in hemangioma

MicroRNAs (miRs) have been found to play a fundamental role in the pathology and progression of hemangioma. Of note, miR-203a-3p prevents hemangioma progression via inactivation of the PI3K/AKT pathway. Bleomycin and pingyangmycin are drugs used in sclerotherapy, but certain hemangioma patients experience drug resistance, leading to poor clinical outcomes. The present study aimed to explore the impact of miR-203a-3p on bleomycin and pingyangmycin sensitivity in hemangioma, as well as the involvement of the PI3K/AKT pathway. miR-203a-3p or negative control mimics were transfected into human hemangioma endothelial cells, which were treated with 0-20 µM bleomycin or pingyangmycin. Subsequently, 740 Y-P, a PI3K/AKT pathway agonist, was added. Cell viability, rate of apoptosis and the expression levels of proteins involved in the PI3K/AKT pathway, including phosphorylated (p)-PI3K, PI3K, p-AKT and AKT, were detected. miR-203a-3p overexpression significantly decreased the half-maximal inhibitory concentration (IC50) values of bleomycin (5.84±0.87 vs. 14.23±2.17 µM; P<0.01) and pingyangmycin (5.13±0.55 vs. 12.04±1.86 µM; P<0.01), compared with untreated cells. In addition, under bleomycin or pingyangmycin treatment, miR-203a-3p overexpression significantly reduced the proportion of EdU positive cells (both P<0.05) and B-cell leukemia/lymphoma-2 (BCL2) protein expression levels (both P<0.05), whilst increasing cell apoptosis rate (both P<0.05) and cleaved caspase 3 protein expression levels (both P<0.05) compared with untreated controls. Furthermore, miR-203a-3p overexpression significantly inhibited the phosphorylation of PI3K and AKT (both P<0.05), an effect that was significantly diminished by 740 Y-P treatment (both P<0.01). In addition, 740 Y-P significantly increased IC50 values of bleomycin (P<0.01) and pingyangmycin (P<0.001) and also significantly increased the proportion of EdU-positive cells and BCL2 protein expression levels, while decreasing the apoptosis rate and cleaved caspase 3 protein expression levels in cells treated with bleomycin or pingyangmycin (all P<0.05). Of note, 740 Y-P weakened the effect of miR-203a-3p overexpression on the aforementioned cellular characteristics. The present study demonstrated that miR-203a-3p improved the sensitivity of cells to bleomycin and pingyangmycin treatment by inhibiting PI3K/AKT signaling in hemangioma.

Association Between Diverse Cell Death Patterns Related Gene Signature and Prognosis, Drug Sensitivity, and Immune Microenvironment in Glioblastoma

Glioblastoma (GBM) is the most invasive type of glioma and is difficult to treat. Diverse programmed cell death (PCD) patterns have a significant association with tumor initiation and progression. A novel prognostic model based on PCD genes may serve as an effective tool to predict the prognosis of GBM. The study incorporated 11 PCD patterns, namely apoptosis, necroptosis, pyroptosis, ferroptosis, cuproptosis, entotic cell death, netotic cell death, parthanatos, lysosome-dependent cell death, autophagy-dependent cell death, alkaliptosis, and oxeiptosis, to develop the model. To construct and validate the model, both bulk and single-cell transcriptome data, along with corresponding clinical data from GBM cases, were obtained from the TCGA-GBM, REMBRANDT, CGGA, and GSE162631 datasets. A cell death-related signature containing 14 genes was constructed with the TCGA-GBM cohort and validated in the REMBRANDT and CGGA datasets. GBM patients with a higher cell death index (CDI) were significantly associated with poorer survival outcomes. Two separate clusters associated with clinical outcomes emerged from unsupervised analysis. A multivariate Cox regression analysis was conducted to examine the association of CDI with clinical characteristics, and a prognostic nomogram was developed. Drug sensitivity analysis revealed high-CDI GBM patients might be resistant to carmustine while sensitive to 5-fluorouracil. Less abundance of natural killer cells was found in GBM cases with high CDI and bulk transcriptome data. A cell death-related prognostic model that could predict the prognosis of GBM patients with good performance was established, which could discriminate between the prognosis and drug sensitivity of GBM.

Cyclohexene oxide CA, a derivative of zeylenone, exhibits anti-cancer activity in glioblastoma by inducing G0/G1 phase arrest through interference with EZH2

Introduction: Due to its highly aggressiveness and malignancy, glioblastoma (GBM) urgently requires a safe and effective treatment strategy. Zeylenone, a natural polyoxygenated cyclohexenes compound isolated from Uvaria grandiflora, has exhibited potential biological activities in various human diseases, including tumors. Methods: We designed and synthesized a series of (+)-Zeylenone analogues and evaluated their anti-GBM roles through structural-activity analysis. Cell Counting Kit-8, TUNEL, transwell and flow cytometry were employed for investigating the anticancer effects of CA on GBM cells. Western blotting, molecular docking, qRT-PCR and ChIP assays were performed to reveal the underlying mechanisms by which CA regulates the GBM cell cycle. The nude mouse xenograft model, HE staining, immunohistochemistry and was used to evaluate the anticancer effect of CA in vivo. Results: We identified CA ((1R, 2R, 3S)-3-p-fluorobenzoyl-zeylenone) as having the lowest IC50 value in GBM cells. CA treatment significantly inhibited the malignant behaviors of GBM cells and induced G0/G1 phase arrest in vitro. Furthermore, we validated the molecular mechanism by which CA interferes with EZH2, attenuating the down-regulation of cyclin-dependent kinase inhibitors p27 and p16 by the PRC2 complex. By establishing orthotopic nude mice models, we further validated the inhibitory role of CA on tumorigenesis of GBM cells in vivo and its potential values to synergistically potentiate the anti-tumor effects of EZH2 inhibitors. Conclusion: Overall, this paper elucidated the anti-GBM effects and potential mechanisms of CA, and may provide a therapeutic drug candidate for GBM treatment.

Molecular Networks of Platinum Drugs and Their Interaction with microRNAs in Cancer

The precise mechanism of resistance to anti-cancer drugs such as platinum drugs is not fully revealed. To reveal the mechanism of drug resistance, the molecular networks of anti-cancer drugs such as cisplatin, carboplatin, oxaliplatin, and arsenic trioxide were analyzed in several types of cancers. Since diffuse-type stomach adenocarcinoma, which has epithelial-mesenchymal transition (EMT)-like characteristics, is more malignant than intestinal-type stomach adenocarcinoma, the gene expression and molecular networks in diffuse- and intestinal-type stomach adenocarcinomas were analyzed. Analysis of carboplatin revealed the causal network in diffuse large B-cell lymphoma. The upstream regulators of the molecular networks of cisplatin-treated lung adenocarcinoma included the anti-cancer drug trichostatin A (TSA), a histone deacetylase inhibitor. The upstream regulator analysis of cisplatin revealed an increase in FAS, BTG2, SESN1, and CDKN1A, and the involvement of the tumor microenvironment pathway. The molecular networks were predicted to interact with several microRNAs, which may contribute to the identification of new drug targets for drug-resistant cancer. Analysis of oxaliplatin, a platinum drug, revealed that the SPINK1 pancreatic cancer pathway is inactivated in ischemic cardiomyopathy. The study showed the importance of the molecular networks of anti-cancer drugs and tumor microenvironment in the treatment of cancer resistant to anti-cancer drugs.

Changing landscape of anti-angiogenic therapy: Novel approaches and clinical perspectives

Targeting angiogenesis has remained one of the important aspects in disease biology in general and cancer in particular. Currently (June 2023), over 593 clinical trials have been registered at ClinicalTrials.gov having inference of term 'angiogenesis'. A panel of 14 anti-angiogenic drugs have been approved by FDA for the treatment of variety of cancers and other human ailments. Although the anti-angiogenic therapy (AAT) has gained significant clinical attention as a promising approach in the treatment of various diseases, particularly cancer, however, sizable literature has accumulated in the recent past describing the aggressive nature of tumours after the drug holidays, evolving drug resistance and off-target toxicities. Nevertheless, the emergence of inscrutable compensatory or alternative angiogenic mechanisms is limiting the efficacy of anti-angiogenic drugs and focussing the therapeutic regime as a puzzle of 'Lernaean hydra'. This review offers an overview of recent updates on the efficacy of antiangiogenic therapy and the current clinical performance of aaRTK inhibitors. Additionally, it also explores the changing application landscape of AAT, focusing on its role in diabetic nephropathy, age-related macular degeneration and other neovascular ocular disorders. Combination therapy with antiangiogenic drugs and immune check point inhibitors (ICIs) has emerged as a potential strategy to enhance the therapeutic index of cancer immunotherapy. While clinical studies have demonstrated the clinical efficacy of this approach, they also highlight the complex and sometimes unpredictable adverse events associated with it. Normalizing tumour vasculature has been identified as a key factor in unlocking the full potential of ICIs, thereby providing hope for improved treatment outcomes. The future prospects and challenges of AAT have been described with special reference to integration of technological advances for enhancing its efficacy and applications beyond its discovery.

The E3 ubiquitin ligase RBCK1: Implications in the tumor immune microenvironment and antiangiogenic therapy of glioma

E3 ubiquitin ligases (E3s) play a pivotal role in regulating the specificity of protein ubiquitination, and their significant functions as regulators of immune responses against tumors are attracting considerable interest. RBCK1-an RBR E3 ligase-is involved in immune regulation and tumor development. However, the potential effect of RBCK1 on glioma remains enigmatic. In the present study, we performed comprehensive analyses of multilevel data, which disclosed distribution characteristics of RBCK1 in pan-cancer, especially in glioma. Functional roles of RBCK1 were further confirmed using immunohistochemistry, cell biological assays, and xenograft experiments. Aberrant ascending of RBCK1 in multiple types of cancer was found to remodel the immunosuppressive microenvironment of glioma by regulating immunomodulators, cancer immunity cycles, and immune cell infiltration. Notably, the MES-like/RBCK1High cell population, a unique subset of cells in the microenvironment, suppressed T cell-mediated cell killing in glioma. Elevated expression levels of RBCK1 suggested a glioma subtype characterized by immunosuppression and hypo-responsiveness to immunotherapy but manifesting surprisingly increased responses to anti-angiogenic therapy. In conclusion, anti-RBCK1 target therapy might be beneficial for glioma treatment. Moreover, RBCK1 assisted in predicting molecular subtypes of glioma and response rates of patients to different clinical treatments, which could guide personalized therapy.

Integrative Analysis of Inflammatory Response-Related Gene for Predicting Prognosis and Immunotherapy in Glioma

Inflammatory response plays a crucial role in the development and progression of gliomas. Whereas the prognostic esteem of inflammatory response-related genes has never been comprehensively explored in glioma, the RNA-seq information and clinical data of patients with glioma were extracted from TCGA, CGGA, and Rembrandt databases. The differentially expressed genes (DEGs) were picked out between glioma tissue and non-tumor brain tissue (NBT). Then, the least absolute shrinkage and selection operator (LASSO) regression analysis was performed to construct the prognostic signature in the TCGA cohort and verified in other cohorts. Kaplan-Meier survival analyses were conducted to compare the overall survival (OS) between the high and low-risk groups. Univariate and multivariate Cox analyses were subsequently used to confirm the independent prognostic factors of OS, and then, the nomogram was established based them. Furthermore, immune infiltration, immune checkpoints, and immunotherapy were also probed and compared between high and low-risk groups. The four genes were also analyzed by qRT-PCR, immunohistochemistry, and western blot trials between glioma tissue and NBT. The 39 DEGs were identified between glioma tissue and NBT, of which 31 genes are associated to the prognosis of glioma. The 8 optimal inflammatory response-related genes were selected to construct the prognostic inflammatory response-related signature (IRRS) through the LASSO regression. The effectiveness of the IRRS was verified in the TCGA, CGGA, and Rembrandt cohorts. Meanwhile, a nomogram with better accuracy was established to predict OS based on the independent prognostic factors. The IRRS was highly correlated with clinicopathological features, immune infiltration, and genomic alterations in glioma patients. In addition, four selective genes also verified the difference between glioma tissue and NBT. A novel prognostic signature was associated with the prognosis, immune infiltration, and immunotherapy effect in patients with gliomas. Thus, this study could provide a perspective for glioma prognosis and treatment.

Efficacy and safety of pharmacotherapy for recurrent high-grade glioma: a systematic review and network meta-analysis

Objective: To compare the efficacy and safety of treatments for patients with recurrent high-grade gliomas. Methods: Electronic databases including Pubmed, Embase, Cochrane Library and ClinicalTrials.gov were searched for randomized controlled trials (RCT) related to high-grade gliomas. The inclusion of qualified literature and extraction of data were conducted by two independent reviewers. The primary clinical outcome measures of network meta-analysis were overall survival (OS) while progression-free survival (PFS), objective response rate (ORR) and adverse event of grade 3 or higher were secondary measures. Results: 22 eligible trials were included in the systematic review, involving 3423 patients and 30 treatment regimens. Network meta-analysis included 11 treatments of 10 trials for OS and PFS, 10 treatments of 8 trials for ORR, and 8 treatments of 7 trials for adverse event grade 3 or higher. Regorafenib showed significant benefits in terms of OS in paired comparison with several treatments such as bevacizumab (hazard ratio (HR), 0.39; 95% confidence interval (CI), 0.21-0.73), bevacizumab plus carboplatin (HR, 0.33; 95%CI, 0.16-0.68), bevacizumab plus dasatinib (HR, 0.44; 95%CI, 0.21-0.93), bevacizumab plus irinotecan (HR, 0.4; 95%CI, 0.21-0.74), bevacizumab plus lomustine (90 mg/m²) (HR, 0.53; 95%CI, 0.33-0.84), bevacizumab plus lomustine (110 mg/m²) (HR, 0.21; 95%CI, 0.06-0.7), bevacizumab plus vorinostat (HR, 0.42; 95%CI, 0.18-0.99), lomustine (HR, 0.5; 95%CI, 0.33-0.76), and nivolumab (HR, 0.38; 95%CI, 0.19-0.73). For PFS, only the hazard ratio between bevacizumab plus vorinostat and bevacizumab plus lomustine (90 mg/m²) was significant (HR,0.51; 95%CI, 0.27-0.95). Lomustine and nivolumab conferred worse ORR. Safety analysis showed fotemustine as the best and bevacizumab plus temozolomide as the worst. Conclusion: The results suggested that regorafenib and bevacizumab plus lomustine (90 mg/m²) provide improvements in terms of survival but may have poor ORR in patients with recurrent high-grade glioma.

Exosomal miR-93-5p as an important driver of bladder cancer progression

Background

Tumor-derived exosomes are involved in the process of tumor metastasis and angiogenesis. MicroRNAs (miRNAs) are the most widely investigated factors in exosomes. Therefore, we hope to find a new therapeutic target in bladder cancer (BLCA), which has high incidence rate and mortality.

Methods

Exosomal microRNA(miR)-93-5p expression level, downstream target molecules, and biological functions were examined with bioinformatics technology. Exosomes were extracted by sequential differential centrifugation and verified by transmission electron microscopy. The exosomal miR-93-5p on cell proliferation, invasion, and angiogenesis abilities in 5637 and T24 cells was determined by Cell Counting Kit 8 (CCK-8), colony-forming assay, Transwell assay, and vascular ring formation assay. A mouse xenograft model with intratumor injection was adopted to evaluate the correlation between BLCA-derived exosomes and tumor growth in vivo.

Results

The results revealed that exosomes play an important role in the biological progression of BLCA, with miR-93-5p being a particularly important molecule. Compared to normal cells, more malignant cells release more exosomal miR-93-5p, and tumor-derived exosomal miR-93-5p could significantly promote cell proliferation, invasion, and angiogenesis in vitro and in vivo. We identified phosphatase and tensin homolog (PTEN) as the most significant target of miR-93-5p in BLCA and human umbilical vein endothelial cells.

Conclusions

Our study successfully revealed the biological role and mechanism of BLCA-derived exosomes in tumor progression. Target at tumor exosomes and exosomal miR-93-5p may be an effective treatment in BLCA.

Construction and characterization of a cuproptosis- and immune checkpoint-based LncRNAs signature for breast cancer risk stratification

BACKGROUND

Cuproptosis is the most recently identified form of cell death, and copper homeostasis is an important cancer therapeutic target. However, the therapeutic benefits of cuproptosis-targeted treatment in BRCA remain undetermined. This study utilized LncRNAs linked to cuproptosis genes and immune checkpoint genes to generate a BRCA predictive signature.

METHODS

We screened a population of LncRNAs that correlated with both cuproptosis genes and immune checkpoint genes and used ten of these LncRNAs to construct a prognosis-predictive signature. We then validated and proved the efficacy of the signature in predicting the prognosis of BRCA patients. We also unraveled the relationship between the signature and the immunological milieu, immune function, and susceptibility to chemotherapy.

RESULTS

The signature derived from the ten cuproptosis- and immune-related prognostic LncRNAs (CuImP-LncRNAs) can be implied to categorize patients into two groups, including the high- and low-risk groups. The value of the signature was validated, and the risk score was verified as an independent prognostic indicator. The TIME and TMB distribution patterns and chemosensitivity were depicted in the high- and low-risk groups, respectively. Patients of the high-risk group with a suppressive immunological intratumor context were more sensitive to a broad range of antitumor agents. In contrast, low-risk individuals with active immune function responded more favorably to immunotherapy.

CONCLUSION

Our findings provided a novel and effective model for predicting BRCA prognosis and the propensity to different treatment modalities, thus contributing to the optimization of personalized BRCA therapy in the future.

Clinical activity of regorafenib in elderly patients with recurrent glioblastoma

Glioblastoma multiforme is one of the most frequent and aggressive primary tumors in the central nervous system, representing >60% of all brain tumors in adults. Despite treatment, prognosis remains poor with most if not all patients experiencing disease recurrence and a 2-year survival rate of 27%. At present, no confirmed standard treatment exists for recurrent glioblastoma. Regorafenib is one of the few options available, based on results from the REGOMA trial. In the present study, a real-life retrospective investigation on the role of regorafenib in patients with recurrent glioblastoma (>60 years old) from two main Oncological Units in South Italy (Azienda Ospedaliera Universitaria Luigi Vanvitelli, Naples, Italy and Ospedale Civile San Giovanni di Dio, Frattamaggiore, Naples, Italy), was performed. The primary endpoint was overall survival (OS), whereas progression-free survival (PFS), objective response rate and disease control were secondary endpoints. Survival was then analyzed according to age, isocitrate dehydrogenase (IDH) and methylated methylguanine-DNA-methyltransferase (MGMT) status. A total of 56 patients met the eligibility criteria. The intention to treat population median PFS (mPFS) was 4.1 months and median OS (mOS) was 6.8 months. Age did not appear to have a significant influence on mPFS. mOS in MGMT-methylated patients was improved compared with that of the unmethylated group (7.7 months vs. 5.6 months). Both mOS and mPFS were longer in IDH-mutant patients. The present study was one of the first real life analyses of regorafenib in recurrent glioblastoma. The results were in line with the REGOMA trial. Age did not appear to be a prognostic factor, thus suggesting that treatment choice should not be different in elderly. MGMT methylation appeared to influence OS. To the best of our knowledge, this was the first report of regorafenib activity in older patients and, while the results were statistically significant, these should be confirmed in further studies.

Novel tumor necrosis factor-related long non-coding RNAs signature for risk stratification and prognosis in glioblastoma

Background

Tumor necrosis factor (TNF) is an inflammatory cytokine that can coordinate tissue homeostasis by co-regulating the production of cytokines, cell survival, or death. It widely expresses in various tumor tissues and correlates with the malignant clinical features of patients. As an important inflammatory factor, the role of TNFα is involved in all steps of tumorigenesis and development, including cell transformation, survival, proliferation, invasion and metastasis. Recent research has showed that long non-coding RNAs (lncRNAs), defined as RNA transcripts >200 nucleotides that do not encode a protein, influence numerous cellular processes. However, little is known about the genomic profile of TNF pathway related-lncRNAs in GBM. This study investigated the molecular mechanism of TNF related-lncRNAs and their immune characteristics in glioblastoma multiforme (GBM) patients.

Methods

To identify TNF associations in GBM patients, we performed bioinformatics analysis of public databases - The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA). The ConsensusClusterPlus, CIBERSORT, Estimate, GSVA and TIDE and first-order bias correlation and so on approaches were conducted to comprehensively characterize and compare differences among TNF-related subtypes.

Results

Based on the comprehensive analysis of TNF-related lncRNAs expression profiles, we constructed six TNF-related lncRNAs (C1RL-AS1, LINC00968, MIR155HG, CPB2-AS1, LINC00906, and WDR11-AS1) risk signature to determine the role of TNF-related lncRNAs in GBM. This signature could divide GBM patients into subtypes with distinct clinical and immune characteristics and prognoses. We identified three molecular subtypes (C1, C2, and C3), with C2 showing the best prognosis; otherwise, C3 showing the worst prognosis. Moreover, we assessed the prognostic value, immune infiltration, immune checkpoints, chemokines cytokines and enrichment analysis of this signature in GBM. The TNF-related lncRNA signature was tightly associated with the regulation of tumor immune therapy and could serve as an independent prognostic biomarker in GBM.

Conclusion

This analysis provides a comprehensive understanding of the role of TNF-related characters, which may improve the clinical outcome of GBM patients.

Characterization of Glioblastoma Cells Response to Regorafenib

Glioblastoma (GBM), the most malignant primary brain tumor in adults. Although not frequent, it has a relevant social impact because the peak incidence coincides with the age of professional maturity. A number of novel treatments have been proposed, yet clinical trials have been disappointing. Recently, a phase II clinical trial (REGOMA) demonstrated that the multikinase inhibitor regorafenib significantly increased the median overall survival (OS) of GBM patients when compared to lomustine-treated patients. On this basis, the National Comprehensive Cancer Network (NCCN) 2020 Guidelines included regorafenib as a preferred regimen in relapsed GBM treatment. Despite the use in GBM patients' therapy, little is known about the molecular mechanisms governing regorafenib effectiveness on the GBM tumor. Here we report an in vitro characterization of GBM tumor cells' response to regorafenib, performed both on cell lines and on patient-derived glioma stem cells (GSCs). Overall, regorafenib significantly reduced cell growth of 2D tumor cell cultures and of 3D tumor spheroids. Strikingly, this effect was accompanied by transcriptional regulation of epithelial to mesenchymal transition (EMT) genes and by an increased ability of surviving tumor cells to invade the surrounding matrix. Taken together, our data suggest that regorafenib limits cell growth, however, it might induce an invasive phenotype.

Systematic characterization and biological functions of non-coding RNAs in glioblastoma

Glioblastoma multiforme (GBM) is the most malignant and aggressive type of glioma. Non-coding RNAs (ncRNAs) are RNAs that do not encode proteins but widely exist in eukaryotic cells. The common characteristics of these RNAs are that they can all be transcribed from the genome without being translated into proteins, thus performing biological functions, particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs. Studies have found that ncRNAs are associated with the occurrence and development of GBM, and there is a complex regulatory network among ncRNAs, which can regulate cell proliferation, migration, apoptosis and differentiation, thus provide a basis for the development of highly specific diagnostic tools and therapeutic strategies in the future. The present review aimed to comprehensively describe the biogenesis, general features and functions of regulatory ncRNAs in GBM, and to interpret the potential biological functions of these ncRNAs in GBM as well as their impact on clinical diagnosis, treatment and prognosis and discusses the potential mechanisms of these RNA subtypes leading to cancer in order to contribute to the better design of personalized GBM therapies in the future.

Metabolic-related gene pairs signature analysis identifies ABCA1 expression levels on tumor-associated macrophages as a prognostic biomarker in primary IDHWT glioblastoma

Background

Although isocitrate dehydrogenase (IDH) mutation serves as a prognostic signature for routine clinical management of glioma, nearly 90% of glioblastomas (GBM) patients have a wild-type IDH genotype (IDH^WT) and lack reliable signatures to identify distinct entities.

Methods

To develop a robust prognostic signature for IDH^WT GBM patients, we retrospectively analyzed 4 public datasets of 377 primary frozen tumor tissue transcriptome profiling and clinical follow-up data. Samples were divided into a training dataset (204 samples) and a validation (173 samples) dataset. A prognostic signature consisting of 21 metabolism-related gene pairs (MRGPs) was developed based on the relative ranking of single-sample gene expression levels. GSEA and immune subtype analyses were performed to reveal differences in biological processes between MRGP risk groups. The single-cell RNA-seq dataset was used to examine the expression distribution of each MRG constituting the signature in tumor tissue subsets. Finally, the association of MRGs with tumor progression was biologically validated in orthotopic GBM models.

Results

The metabolic signature remained an independent prognostic factor (hazard ratio, 5.71 [3.542-9.218], P < 0.001) for stratifying patients into high- and low-risk levels in terms of overall survival across subgroups with MGMTp methylation statuses, expression subtypes, and chemo/ratio therapies. Immune-related biological processes were significantly different between MRGP risk groups. Compared with the low-risk group, the high-risk group was significantly enriched in humoral immune responses and phagocytosis processes, and had more monocyte infiltration and less activated DC, NK, and γδ T cell infiltration. scRNA-seq dataset analysis identified that the expression levels of 5 MRGs (ABCA1, HMOX1, MTHFD2, PIM1, and PTPRE) in TAMs increased with metabolic risk. With tumor progression, the expression level of ABCA1 in TAMs was positively correlated with the population of TAMs in tumor tissue. Downregulation of ABCA1 levels can promote TAM polarization towards an inflammatory phenotype and control tumor growth.

Conclusions

The metabolic signature is expected to be used in the individualized management of primary IDH^WT GBM patients.

Clinical and NGS predictors of response to regorafenib in recurrent glioblastoma

Predictive factors for response to regorafenib in recurrent glioblastoma, IDH-wildtype, are scarcely recognized. The objective of this study was to identify molecular predictive factors for response to regorafenib using a clinically available platform. We analyzed a prospective cohort of 30 patients harboring recurrent glioblastoma, IDH-wildtype, and treated with regorafenib. Next-generation sequencing (NGS) analysis was performed on DNA extracted from paraffin-embedded tissues using a clinically available platform. Moreover, MGMT methylation and EGFRvIII expression analyses were performed. Six-month progression-free survival (PFS) was 30% and median overall survival (OS) was 7.5 months, in line with literature data. NGS analysis revealed a mutation in the EGFR pathway in 18% of cases and a mutation in the mitogen-activated protein-kinase (MAPK) pathway in 18% of cases. In the remaining cases, no mutations were detected. Patients carrying MAPK pathway mutation had a poor response to regorafenib treatment, with a significantly shorter PFS and a nonsignificantly shorter OS compared to EGFR-mutated patients (for PFS, 2.5 vs 4.5 months, p = 0.0061; for OS, 7 vs 9 months, p = 0.1076). Multivariate analysis confirmed that MAPK pathway mutations independently predicted a shorter PFS after regorafenib treatment (p = 0.0188). The negative prognostic role of MAPK pathway alteration was reinforced when we combined EGFR-mutated with EGFRvIII-positive cases. Recurrent glioblastoma tumors with an alteration in MAPK pathway could belong to the mesenchymal subtype and respond poorly to regorafenib treatment, while EGFR-altered cases have a better response to regorafenib. We thus provide a molecular selection criterion easy to implement in the clinical practice.

β2-Microglobulin Maintains Glioblastoma Stem Cells and Induces M2-like Polarization of Tumor-Associated Macrophages

Glioblastoma (GBM) is a complex ecosystem that includes a heterogeneous tumor population and the tumor-immune microenvironment (TIME), prominently containing tumor-associated macrophages (TAM) and microglia. Here, we demonstrated that β2-microglobulin (B2M), a subunit of the class I major histocompatibility complex (MHC-I), promotes the maintenance of stem-like neoplastic populations and reprograms the TIME to an anti-inflammatory, tumor-promoting state. B2M activated PI3K/AKT/mTOR signaling by interacting with PIP5K1A in GBM stem cells (GSC) and promoting MYC-induced secretion of transforming growth factor-β1 (TGFβ1). Inhibition of B2M attenuated GSC survival, self-renewal, and tumor growth. B2M-induced TGFβ1 secretion activated paracrine SMAD and PI3K/AKT signaling in TAMs and promoted an M2-like macrophage phenotype. These findings reveal tumor-promoting functions of B2M and suggest that targeting B2M or its downstream axis may provide an effective approach for treating GBM.

SIGNIFICANCE

β2-microglobulin signaling in glioblastoma cells activates a PI3K/AKT/MYC/TGFβ1 axis that maintains stem cells and induces M2-like macrophage polarization, highlighting potential therapeutic strategies for targeting tumor cells and the immunosuppressive microenvironment in glioblastoma.

Immunomodulatory effects of regorafenib: Enhancing the efficacy of anti-PD-1/PD-L1 therapy

Anti-PD-1/PD-L1 therapy has shown significant benefits in the treatment of a variety of malignancies. However, not all cancer patients can benefit from this strategy due to drug resistance. Therefore, there is an urgent need for methods that can effectively improve the efficacy of anti-PD-1/PD-L1 therapy. Combining anti-PD-1/PD-L1 therapy with regorafenib has been demonstrated as an effective method to enhance its therapeutic effect in several clinical studies. In this review, we describe common mechanisms of resistance to anti-PD-1/PD-L1 therapy, including lack of tumor immunogenicity, T cell dysfunction, and abnormal expression of PD-L1. Then, we illustrate the role of regorafenib in modifying the tumor microenvironment (TME) from multiple aspects, which is different from other tyrosine kinase inhibitors. Regorafenib not only has immunomodulatory effects on various immune cells, but can also regulate PD-L1 and MHC-I on tumor cells and promote normalization of abnormal blood vessels. Therefore, studies on the synergetic mechanism of the combination therapy may usher in a new era for cancer treatment and help us identify the most appropriate individuals for more precise treatment.

Studies on Biological and Molecular Effects of Small-Molecule Kinase Inhibitors on Human Glioblastoma Cells and Organotypic Brain Slices

Glioblastoma is the most common and aggressive primary brain tumor. Multiple genetic and epigenetic alterations in several major signaling pathways—including the phosphoinositide 3-kinases (PI3K)/AKT/mTOR and the Raf/MEK/ERK pathway—could be found. We therefore aimed to investigate the biological and molecular effects of small-molecule kinase inhibitors that may interfere with those pathways. For this purpose, patient-derived glioblastoma cells were challenged with dactolisib, ipatasertib, MK-2206, regorafenib, or trametinib. To determine the effects of the small-molecule kinase inhibitors, assays of cell proliferation and apoptosis and immunoblot analyses were performed. To further investigate the effects of ipatasertib on organotypic brain slices harboring glioblastoma cells, the tumor growth was estimated. In addition, the network activity in brain slices was assessed by electrophysiological field potential recordings. Multi-kinase inhibitor regorafenib and both MK-2206 and dactolisib were very effective in all preclinical tumor models, while with respect to trametinib, two cell lines were found to be highly resistant. Only in HROG05 cells, ipatasertib showed anti-tumoral effects in vitro and in organotypic brain slices. Additionally, ipatasertib diminished synchronous network activity in organotypic brain slices. Overall, our data suggest that ipatasertib was only effective in selected tumor models, while especially regorafenib and MK-2206 presented a uniform response pattern.

Contribution of the Testosterone Androgen Receptor–PARD3B Signaling Axis to Tumorigenesis and Malignance of Glioblastoma Multiforme through Stimulating Cell Proliferation and Colony Formation

Background: Glioblastoma multiforme (GBM) is the most common and malignant brain tumor with very poor prognoses. After surgical resection of the primary tumor, rapid proliferation of residual glioblastoma cells is a critical cause explaining tumor malignance and recurrence. In this study, we evaluated de novo roles of the testosterone androgen receptor (AR)–PARD3B signaling axis in the tumorigenesis and malignance of human GBM and the possible related mechanisms. Methods: AR and PARD3B gene expressions and their correlations were mined from The Cancer Genome Atlas (TCGA) database and analyzed using the UALCAN system. Analyses using a real-time PCR, cell proliferation, and colony formation and a loss-of-function strategy by suppressing AR activity with its specific inhibitor, enzalutamide, were then carried out to determine roles of the testosterone AR–PARD3B signaling axis in tumor malignance. Results: Expressions of AR, PARD3B mRNA, and proteins in human GBM tissues were upregulated compared to normal human brain tissues. In contrast, levels of AR and PARD3B mRNA in most TCGA pan-cancer types were downregulated compared to their respective normal tissues. Interestingly, a highly positive correlation between AR and PARD3B gene expressions in human GBM was identified. The results of a bioinformatics search further showed that there were five AR-specific DNA-binding elements predicted in the 5′ promoter of the PARD3B gene. Regarding the mechanisms, exposure of human glioblastoma cells to testosterone induced AR and PARD3B gene expressions and successively stimulated cell proliferation and colony formation. Suppressing AR activity concurrently resulted in significant attenuations of testosterone-induced PARD3B gene expression, cell proliferation, and colony formation in human glioblastoma cells. Conclusions: This study showed the contribution of the testosterone AR–PARD3B signaling axis to the tumorigenesis and malignance of human GBM through stimulating cell proliferation and colony formation. Therefore, the AR-PARD3B signaling axis could be targeted for potential therapy for human GBM.

miRNAs in Serum Exosomes for Differential Diagnosis of Brain Metastases

Simple Summary

Current methods for the detection of brain malignancies often display low sensitivity and specificity. Noninvasive biomarkers can complement imaging techniques to improve the diagnosis of these tumors. The aim of this study was to identify circulating miRNAs in serum exosomes useful in all phases of the diagnostic and therapeutic path of patients with malignant brain lesions. Our data show a signature of exosomal miRNAs useful for the differential diagnosis of brain metastases and for monitoring tumor evolution over time.

Abstract

Circulating miRNAs are increasingly studied and proposed as tumor markers with the aim of investigating their role in monitoring the response to therapy as well as the natural evolution of primary or secondary brain tumors. This study aimed to evaluate the modulation of the expression of three miRNAs, miR-21, miR-222 and miR-124-3p, in the serum exosomes of patients with high-grade gliomas (HGGs) and brain metastases (BMs) to verify their usefulness in the differential diagnosis of brain masses; then, it focused on their variations following the surgical and/or radiosurgical treatment of the BMs. A total of 105 patients with BMs from primary lung or breast cancer, or melanoma underwent neurosurgery or radiosurgery treatment, and 91 patients with HGGs were enrolled, along with 30 healthy controls. A significant increase in miR-21 expression in serum exosomes was observed in both HGGs and BMs compared with healthy controls; on the other hand, miR-124-3p was significantly decreased in BMs, and it was increased in HGGs. After the surgical or radiosurgical treatment of patients with BMs, a significant reduction in miR-21 was noted with both types of treatments. This study identified a signature of exosomal miRNAs that could be useful as a noninvasive complementary analysis both in the differential diagnosis of BMs from glial tumors and in providing information on tumor evolution over time.

Synergistic Effects of A Combined Treatment of Glioblastoma U251 Cells with An Anti-miR-10b-5p Molecule and An AntiCancer Agent Based on 1-(3',4',5'-Trimethoxyphenyl)-2-Aryl-1H-Imidazole Scaffold

(1) Background: In the development of new and more effective anticancer approaches, combined treatments appear of great interest. Combination therapy could be of importance in the management of glioblastoma (GBM), a lethal malignancy that accounts for 42% of cancer of the central nervous system, with a median survival of 15 months. This study aimed to verify the activity on a glioblastoma cancer cell line of one of the most active compounds of a novel series of tubulin polymerization inhibitors based on the 1-(3′,4′,5′-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold, used in combination with a miRNA inhibitor molecule targeting the oncomiRNA miR-10b-5p. This microRNA was selected in consideration of the role of miR-10b-5p on the onset and progression of glioblastoma. (2) Methods: Apoptosis was analyzed by Annexin-V and Caspase 3/7 assays, efficacy of the anti-miR-10b-5p was assessed by determining the miR-10b-5p content by RT-qPCR. (3) Results: The results obtained show that a “combination therapy” performed by combining the use of an anti-miR-10b-5p and a 1-(3′,4′,5′-trimethoxyphenyl)-2-aryl-1H-imidazole derivative is an encouraging strategy to boost the efficacy of anticancer therapies and at the same time to reduce side effects.

Discovery and Validation of a Novel Metastasis-Related lncRNA Prognostic Signature for Colorectal Cancer

Background: Cancer metastasis-related chemoresistance and tumour progression are the leading causes of death among CRC patients. Therefore, it is urgent to identify reliable novel biomarkers for predicting the metastasis of CRC.

Methods: The gene expression and corresponding clinical data of CRC patients were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Univariate and multivariate analyses were performed to identify prognostic metastasis-related lncRNAs. Nomograms were constructed, and the predictive accuracy of the nomogram model was assessed by ROC curve analysis. Then, the R package “pRRophetic” was used to predict chemotherapeutic response in CRC patients. In addition, the CIBERSORT database was introduced to evaluate tumour infiltrating immune cells between the high—and low-risk groups. The potential roles of SNHG7 and ZEB1-AS1 in CRC cell lines were further confirmed by in vitro experiments.

Results: An 8-lncRNA (LINC00261, RP1-170O19.17, CAPN10-AS1, SNHG7, ZEB1-AS1, U47924.27, NIFK-AS1, and LINC00925) signature was constructed for CRC prognosis prediction, which stratified patients into two risk groups. Kaplan-Meier analysis revealed that patients in the higher-risk group had a lower survival probability than those in the lower-risk group [p < 0.001 (TCGA); P = 0.044 (GSE39582); and P = 0.0078 (GSE29621)] The AUCs of 1-, 3-, and 5-year survival were 0.678, 0.669, and 0.72 in TCGA; 0.58, 0.55, and 0.56 in GSE39582; and 0.75, 0.54, and 0.56 in GSE29621, respectively. In addition, the risk score was an independent risk factor for CRC patients. Nomograms were constructed, and the predictive accuracy was assessed by ROC curve analysis. This signature could effectively predict the immune status and chemotherapy response in CRC patients. Moreover, SNHG7 and ZEB1-AS1 depletion significantly suppressed the colony formation, migration, and invasion of CRC cells in vitro.

Conclusion: We constructed a signature that could predict the metastasis of CRC and provide certain theoretical guidance for novel therapeutic approaches for CRC.

Innovating Strategies and Tailored Approaches in Neuro-Oncology

Diffuse gliomas, the most frequent and aggressive primary central nervous system neoplasms, currently lack effective curative treatments, particularly for cases lacking the favorable prognostic marker IDH mutation. Nonetheless, advances in molecular biology allowed to identify several druggable alterations in a subset of IDH wild-type gliomas, such as NTRK and FGFR-TACC fusions, and BRAF hotspot mutations. Multi-tyrosine kinase inhibitors, such as regorafenib, also showed efficacy in the setting of recurrent glioblastoma. IDH inhibitors are currently in the advanced phase of clinical evaluation for patients with IDH-mutant gliomas. Several immunotherapeutic approaches, such as tumor vaccines or checkpoint inhibitors, failed to improve patients' outcomes. Even so, they may be still beneficial in a subset of them. New methods, such as using pulsed ultrasound to disrupt the blood-brain barrier, gene therapy, and oncolytic virotherapy, are well tolerated and may be included in the therapeutic armamentarium soon.

Treatment of Human Glioblastoma U251 Cells with Sulforaphane and a Peptide Nucleic Acid (PNA) Targeting miR-15b-5p: Synergistic Effects on Induction of Apoptosis

Glioblastoma multiforme (GBM) is a lethal malignant tumor accounting for 42% of the tumors of the central nervous system, the median survival being 15 months. At present, no curative treatment is available for GBM and new drugs and therapeutic protocols are urgently needed. In this context, combined therapy appears to be a very interesting approach. The isothiocyanate sulforaphane (SFN) has been previously shown to induce apoptosis and inhibit the growth and invasion of GBM cells. On the other hand, the microRNA miR-15b is involved in invasiveness and proliferation in GBM and its inhibition is associated with the induction of apoptosis. On the basis of these observations, the objective of the present study was to determine whether a combined treatment using SFN and a peptide nucleic acid interfering with miR-15b-5p (PNA-a15b) might be proposed for increasing the pro-apoptotic effects of the single agents. To verify this hypothesis, we have treated GMB U251 cells with SFN alone, PNA-a15b alone or their combination. The cell viability, apoptosis and combination index were, respectively, analyzed by calcein staining, annexin-V and caspase-3/7 assays, and RT-qPCR for genes involved in apoptosis. The efficacy of the PNA-a15b determined the miR-15b-5p content analyzed by RT-qPCR. The results obtained indicate that SFN and PNA-a15b synergistically act in inducing the apoptosis of U251 cells. Therefore, the PNA-a15b might be proposed in a “combo-therapy” associated with SFN. Overall, this study suggests the feasibility of using combined treatments based on PNAs targeting miRNA involved in GBM and nutraceuticals able to stimulate apoptosis.

Regorafenib for recurrent high-grade glioma: a unicentric retrospective analysis of feasibility, efficacy, and toxicity

We describe here 11 consecutive patients with recurrence of high-grade glioma treated with regorafenib at our university medical center. The majority of patients had MGMT promoter methylation (9/11 cases). Regorafenib was given as 2nd line systemic treatment in 6/11 patients and 3rd or higher line treatment in 5/11 patients. The median number of applied cycles was 2 with dosage reductions in 5/11. Response to treatment was observed in 4/11 (PR in 1/11, and SD in 3/11). Median overall survival for the cohort was 16.1 months, median progression-free survival 9.0 months, and median time to treatment failure 3.3 months. Side effects of any CTCAE grade were noted in all patients, hereby 6/11 with CTCAE °III-IV reactions. High-grade side effects were of dermatologic, cardiovascular, and hematologic nature. A mean treatment delay of 57.5 days (range 23-119) was noted between tumor board recommendation and treatment initiation due to the application process for off-label use in this indication. In conclusion, treatment with regorafenib in relapsed high-grade glioma is a feasible treatment option but has to be considered carefully due to the significant side effect profile.

The Metabolism Reprogramming of microRNA Let-7-Mediated Glycolysis Contributes to Autophagy and Tumor Progression

Cancer is usually a result of abnormal glucose uptake and imbalanced nutrient metabolization. The dysregulation of glucose metabolism, which controls the processes of glycolysis, gives rise to various physiological defects. Autophagy is one of the metabolic-related cellular functions and involves not only energy regeneration but also tumorigenesis. The dysregulation of autophagy impacts on the imbalance of metabolic homeostasis and leads to a variety of disorders. In particular, the microRNA (miRNA) Let-7 has been identified as related to glycolysis procedures such as tissue repair, stem cell-derived cardiomyocytes, and tumoral metastasis. In many cancers, the expression of glycolysis-related enzymes is correlated with Let-7, in which multiple enzymes are related to the regulation of the autophagy process. However, much recent research has not comprehensively investigated how Let-7 participates in glycolytic reprogramming or its links to autophagic regulations, mainly in tumor progression. Through an integrated literature review and omics-related profiling correlation, this review provides the possible linkage of the Let-7 network between glycolysis and autophagy, and its role in tumor progression.

A Ferroptosis-Related Prognostic Risk Score Model to Predict Clinical Significance and Immunogenic Characteristics in Glioblastoma Multiforme

Background

Ferroptosis is a recently identified cell death pathway, and the susceptibility to ferroptosis inducers varies among cancer cell types. There have been recent attempts to clarify the mechanisms implicated in ferroptosis, glioma invasion, and the immune microenvironment but little is known about ferroptosis regulation in GBM.

Methods

Screening ferroptosis-related genes from published reports and existing databases, we constructed an integrated model based on the RNA-sequencing data in GBM. The association of FRGPRS and overall survival is identified and validated across several different datasets. Genomic and clinical characteristics, immune infiltration, enriched pathways, pan-cancer, drug resistance, and immune checkpoint inhibitor therapy are compared among various FRGPRS subgroups.

Results

We identified and confirmed the influences of five ferroptosis key hub genes in the FRGPRS model. The FRGPRS model could serve to predict overall survival and progression-free survival in GBM patients, and high FRGPRS was associated with comparatively stronger immunity, higher proportions of tumour tissue, and good cytolytic immune and chemotherapeutics response in GBM patients.

Conclusions

The five ferroptosis key hub genes constituting the FRGPRS model could serve to predict overall survival and progression-free survival in patients with GBM and help guide timely and efficacious therapeutic strategies customised and optimised for each individual patient. This discovery may lay the foundation for the development and optimisation of other iterations of this model for the improved forecasting, detection, and treatment of other malignancies notorious for their drug resistance and immune escape.

LncRNA RBPMS-AS1 promotes NRGN transcription to enhance the radiosensitivity of glioblastoma through the microRNA-301a-3p/CAMTA1 axis

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RBPMS-AS1 and CAMTA1 are lowly expressed in GBM patients.

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RBPMS-AS1 and CAMTA1 enhance the radiosensitivity of GBM.

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miR-301a-3p diminishes the radiosensitivity of GBM.

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RBPMS-AS1 enhances CAMTA1 expression in GBM cells through sponging miR-301a-3p.

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CAMTA1 promotes NRGN transcription.

Objective

Glioblastoma (GBM) is the most frequent brain malignancy with high incidence, and long noncoding RNAs (lncRNAs) exerts functions in GBM. In this research, we focused on the capabilities of lncRNA RBPMS-AS1 in radiosensitivity of GBM.

Methods

RBPMS-AS1 and CAMTA1 expression levels were determined in GBM tissues and cells. StarBase v3.0 database was searched for predicting miRNAs that simultaneously bound to RBPMS-AS1 and CAMTA1. pcDNA3.1-RBPMS-AS1, pcDNA3.1-CAMTA1, miR-301a-3p mimic, or pcDNA3.1-RBPMS-AS1/pcDNA3.1-CAMTA1 and miR-301a-3p mimic were transfected into GBM cells to test radiosensitivity, cell proliferation and apoptosis. The interactions of miR-301a-3p with RBPMS-AS1 and CAMTA1, as well as CAMTA1 and NRGN, were confirmed. In vivo imaging technology was utilized to detect tumor growth in orthotopic xenograft tumors, and Ki67 expression was tested in intracranial tumors.

Results

RBPMS-AS1 and CAMTA1 levels were reduced in GBM tissues and cells. miR-301a-3p had a binding site with both RBPMS-AS1 and CAMTA1 and it was the most significantly-upregulated one. Upregulation of RBPMS-AS1 or CAMTA1 enhanced the radiosensitivity and cell apoptosis while suppressing proliferation of GBM cells. Conversely, miR-301a-3p overexpression diminished the radiosensitivity and cell apoptosis while inducing proliferation of GBM cells. Overexpression of RBPMS-AS1 or CAMTA1 reversed the effects of overexpressed miR-301a-3p in GBM cells. Mechanistically, RBPMS-AS1 enhanced CAMTA1 expression in GBM cells through sponging miR-301a-3p, and CAMTA1 promoted NRGN expression. In animal experiments, overexpressed RBPMS-AS1 inhibited tumor growth and the positive expression of Ki67 both before and after radiation therapy.

Conclusion

RBPMS-AS1 promotes NRGN transcription through the miR-301a-3p/CAMTA1 axis and enhances the radiosensitivity of GBM.

Regorafenib in Recurrent Glioblastoma Patients: A Large and Monocentric Real-Life Study

Simple Summary

In the last years, treatments for recurrent glioblastoma patients have shown limited efficacy in terms of OS. In the REGOMA trial, regorafenib demonstrated encouraging results in this setting of population. Indeed, in this randomized, phase 2 study the OS was significantly improved in the regorafenib arm compared with the standard lomustine treatment. Noteworthy, based on the REGOMA trial results, regorafenib was included in the NCCN 2021 guidelines as a preferred regimen for recurrent glioblastoma patients. To date, no studies have analyzed the impact of regorafenib in patients treated outside of clinical trials. We performed a large study in order to evaluate the safety and efficacy of regorafenib in the real-life population of recurrent GBM patients. Our results were superimposable to the ones reported in the REGOMA trial and regorafenib should be considered as an interesting drug in a population with a very poor prognosis and an unmet clinical need.

Abstract

Despite multimodal treatment with surgery and radiochemotherapy, the prognosis of glioblastoma remains poor, and practically all glioblastomas relapse. To date, no standard treatment exists for recurrent glioblastoma patients and traditional therapies have showed limited efficacy. Regorafenib is an oral multi-targeted tyrosine kinase inhibitor showing encouraging benefits in recurrent GBM patients enrolled in the REGOMA trial. We performed a large study to investigate clinical outcomes and the safety of regorafenib in a real-life population of recurrent glioblastoma patients. Patients receiving regorafenib outside clinical trials at the Veneto Institute of Oncology were retrospectively reviewed. The major inclusion criteria were: histologically confirmed diagnosis of glioblastoma, prior first line therapy according to “Stupp protocol”, Eastern Cooperative Oncology Group (ECOG) performance status score ≤1. According to the original schedule, patients received regorafenib 160 mg once daily for the first 3 weeks of each 4-week cycle. The primary endpoints of the study were overall survival and safety. A total of 54 consecutive patients were enrolled. The median age was 56, MGMT methylated status was found in 28 out of 53 available patients (52.8%), IDH mutation in 5 (9.3%) and 22 patients were receiving steroids at baseline. The median overall survival was 10.2 months (95% CI, 6.4–13.9), the OS-12 was 43%. Age, MGMT methylation status and steroid use at baseline were not statistically significant on a multivariate analysis for OS. Patients reporting a disease control as best response to regorafenib demonstrated a significant longer survival (24.8 months vs. 6.2 months for patients with progressive disease, p = 0.0001). Grade 3 drug-related adverse events occurred in 10 patients (18%); 1 patient (2%) reported a grade 4 adverse event (rash maculo-papular). No death was considered to be drug-related. This study reported the first large “real-life” experience of regorafenib in recurrent glioblastoma. Overall, our results are close to the ones reported in the previous phase 2 study, despite the fact that we had a longer survival. We showed the encouraging activity and tolerability of this treatment in recurrent glioblastoma patients when used as a second-line treatment.

Efficacy of osimertinib plus bevacizumab in glioblastoma patients with simultaneous EGFR amplification and EGFRvIII mutation

BACKGROUND

Amplification of EGFR and its active mutant EGFRvIII are common in glioblastoma (GB). While EGFR and EGFRvIII play critical roles in pathogenesis, targeted therapy with EGFR-tyrosine kinase inhibitors or antibodies has shown limited efficacy. To improve the likelihood of effectiveness, we targeted adult patients with recurrent GB enriched for simultaneous EGFR amplification and EGFRvIII mutation, with osimertinib/bevacizumab at doses described for non-small cell lung cancer.

METHODS

We retrospectively explored whether previously described EGFRvIII mutation in association with EGFR gene amplification could predict response to osimertinib/bevacizumab combination in a subset of 15 patients treated at recurrence. The resistance pattern in a subgroup of subjects is described using a commercial next-generation sequencing panel in liquid biopsy.

RESULTS

There were ten males (66.7%), and the median patient's age was 56 years (range 38-70 years). After their initial diagnosis, 12 patients underwent partial (26.7%) or total resection (53.3%). Subsequently, all cases received IMRT and concurrent and adjuvant temozolomide (TMZ; the median number of cycles 9, range 6-12). The median follow-up after recurrence was 17.1 months (95% CI 12.3-22.6). All patients received osimertinib/bevacizumab as a second-line intervention with a median progression-free survival (PFS) of 5.1 months (95% CI 2.8-7.3) and overall survival of 9.0 months (95% CI 3.9-14.0). The PFS6 was 46.7%, and the overall response rate was 13.3%. After exposure to the osimertinib/bevacizumab combination, the main secondary alterations were MET amplification, STAT3, IGF1R, PTEN, and PDGFR.

CONCLUSIONS

While the osimertinib/bevacizumab combination was marginally effective in most GB patients with simultaneous EGFR amplification plus EGFRvIII mutation, a subgroup experienced a long-lasting meaningful benefit. The findings of this brief cohort justify the continuation of the research in a clinical trial. The pattern of resistance after exposure to osimertinib/bevacizumab includes known mechanisms in the regulation of EGFR, findings that contribute to the understanding and targeting in a stepwise rational this pathway.

Multimodal Role of PACAP in Glioblastoma

Glioblastoma multiforme (GBM) is the deadliest form of brain tumors. To date, the GBM therapeutical approach consists of surgery, radiation-therapy and chemotherapy combined with molecules improving cancer responsiveness to treatments. In this review, we will present a brief overview of the GBM classification and pathogenesis, as well as the therapeutic approach currently used. Then, we will focus on the modulatory role exerted by pituitary adenylate cyclase-activating peptide, known as PACAP, on GBM malignancy. Specifically, we will describe PACAP ability to interfere with GBM cell proliferation, as well as the tumoral microenvironment. Considering its anti-oncogenic role in GBM, synthesis of PACAP agonist molecules may open new perspectives for combined therapy to existing gold standard treatment.

Synergistic effects of the combined treatment of U251 and T98G glioma cells with an anti‑tubulin tetrahydrothieno[2,3‑c]pyridine derivative and a peptide nucleic acid targeting miR‑221‑3p

In the development of novel and more effective anti-cancer approaches, combined treatments appear to be of great interest, based on the possibility of obtaining relevant biological or therapeutic effects using lower concentrations of single drugs. Combination therapy may prove to be of utmost significance in the management of glioblastoma (GBM), a lethal malignancy that accounts for 42% of cancer cases of the central nervous system, with a median survival rate of 15 months. As regards novel therapeutic approaches, the authors have recently demonstrated that peptide nucleic acids (PNAs) that target microRNA (miRNA/miR)-221 are very active in inducing the apoptosis of glioma cells. Furthermore, in a recent study, the authors described two novel series of tubulin polymerization inhibitors based on the 4,5,6,7-tetrahydrothieno[2,3-c]pyridine and 4,5,6,7-tetrahydrobenzo[b]thiophene scaffold, which exerted a potent anti-proliferative effect on a variety of tumor cell lines. The present study aimed to verify the activity on glioblastoma cancer cell lines of one of the most active compounds tested, corresponding to 2-(3′, 4′, 5′-trimethoxyanilino)-3-cyano/alkoxycarbonyl-6-substituted-4 5,6,7-tetrahydrothiene[2,3-c] pyridine (compound 3b), used in combination with an anti-miR-221-3p PNA, already demonstrated to be able to induce high levels of apoptosis. To the best of our knowledge, the results obtained herein demonstrate for the first time a 'combination therapy' performed by the combined use of a PNA targeting miR-221 and the tetrahydrothiene[2,3-c]pyridine derivative 3b, supporting the concept that the combined treatment of GBM cells with a PNA against a specific upregulated oncomiRNA (in the present study a PNA targeting miR-221-3p was used) and anti-tubulin agents (in the present study derivative 3b was used) is an encouraging strategy which may be used to enhance the efficacy of anticancer therapies and at the same time, to reduce side-effects.

Serum Exosomal microRNA-21, 222 and 124-3p as Noninvasive Predictive Biomarkers in Newly Diagnosed High-Grade Gliomas: A Prospective Study

Simple Summary

Diagnosis of relapse during post-surgery monitoring of patients with High-grade glioma is often challenging. This study was aimed to identify circulating biomarkers providing information about response to therapy and early diagnosis of progression during follow-up of these patients. Our findings, showing upregulation of exosomal miRNAs associated with relapse represent a proof of principle that these biomarkers may be clinically useful tools for diagnosing and monitoring of gliomas.

Abstract

Background: High-grade gliomas (HGG) are malignant brain tumors associated with frequent recurrent disease. Clinical management of HGG patients is currently devoid of blood biomarkers for early diagnosis, monitoring therapeutic effects and predicting recurrence. Different circulating miRNAs, both free and associated with exosomes, are described in patients with HGG. We previously identified miR-21, miR-222 and miR-124-3p purified from serum exosomes as molecular signature to help pre-operative clinical diagnosis and grading of gliomas. The aim of the present study was to verify this signature as a tool to assess the effect of treatment and for the early identification of progression in newly diagnosed HGG patients. Material and Methods: Major inclusion criteria were newly diagnosed, histologically confirmed HGG patients, no prior chemotherapy, ECOG PS 0-2 and patients scheduled for radiochemotherapy with temozolomide as first-line treatment after surgery. RANO criteria were used for response assessment. Serum was collected at baseline and subsequently at each neuroradiological assessment. mir-21, -222 and -124-3p expression in serum exosomes was measured in all samples. Results: A total number of 57 patients were enrolled; 41 were male, 52 with glioblastoma and 5 with anaplastic astrocytoma; 18 received radical surgery. HGG patients with higher exosomal miRNA expression displayed a statistically significant lower progression-free survival and overall survival. Increased expression of miR-21, -222 and -124-3p during post-operative follow-up was associated with HGG progression. Conclusions: These data indicate that miR-21, -222 and -124-3p in serum exosomes may be useful molecular biomarkers for complementing clinical evaluation of early tumor progression during post-surgical therapy in patients with HGG.

Comprehensive Molecular Characterization of Chinese Patients with Glioma by Extensive Next-Generation Sequencing Panel Analysis

Background

Tremendous efforts have been made to explore biomarkers for classifying and grading glioma. However, the majority of the current understanding is based on public databases that might not accurately reflect the Asian population. Here, we investigated the genetic landscape of Chinese glioma patients using a validated multigene next-generation sequencing (NGS) panel to provide a strong rationale for the future classification and prognosis of glioma in this population.

Methods

We analyzed 83 samples, consisting of 71 initial treatments and 12 recurrent surgical tumors, from 81 Chinese patients with gliomas by performing multigene NGS with an Acornmed panel targeting 808 cancer-related hotspot genes, including genes related to glioma (hotspots, selected exons or complete coding sequences) and full-length SNPs located on chromosomes 1 and 19.

Results

A total of 76 (91.57%) glioma samples had at least one somatic mutation. The most commonly mutated genes were TP53, TERT, IDH1, PTEN, ATRX, and EGFR. Approximately one-third of cases exhibited more than one copy number variation. Of note, this study identified the amplification of genes, such as EGFR and PDGFRA, which were significantly associated with glioblastoma but had not been previously used for clinical classification (P<0.05). Significant differences in genomic profiles between different pathological subtypes and WHO grade were observed. Compared to the MSKCC database primarily comprised of Caucasians, H3F3A mutations and MET amplifications exhibited higher mutation rates, whereas TERT mutations and EGFR and CDKN2A/B copy number variations presented a lower mutation rate in Chinese patients with glioma (P<0.05).

Conclusion

Our multigene NGS in the simultaneous evaluation of multiple relevant markers revealed several novel genetic alterations in Chinese patients with glioma. NGS-based molecular analysis is a reliable and effective method for diagnosing brain tumors, assisting clinicians in evaluating additional potential therapeutic options, such as targeted therapy, for glioma patients in different racial/ethnic groups.

A Signature of Nine lncRNA Methylated Genes Predicts Survival in Patients With Glioma

Glioma is one of the most common malignant tumors of the central nervous system, and its prognosis is extremely poor. Aberrant methylation of lncRNA promoter region is significantly associated with the prognosis of glioma patients. In this study, we investigated the potential impact of methylation of lncRNA promoter region in glioma patients to establish a signature of nine lncRNA methylated genes for determining glioma patient prognosis. Methylation data and clinical follow-up data were obtained from The Cancer Genome Atlas (TCGA). The multistep screening strategy identified nine lncRNA methylated genes that were significantly associated with the overall survival (OS) of glioma patients. Subsequently, we constructed a risk signature that containing nine lncRNA methylated genes. The risk signature successfully divided the glioma patients into high-risk and low-risk groups. Compared with the low-risk group, the high-risk group had a worse prognosis, higher glioma grade, and older age. Furthermore, we identified two lncRNAs termed PCBP1-AS1 and LINC02875 that may be involved in the malignant progression of glioma cells by using the TCGA database. Loss-of-function assays confirmed that knockdown of PCBP1-AS1 and LINC02875 inhibited the proliferation, migration, and invasion of glioma cells. Therefore, the nine lncRNA methylated genes signature may provide a novel predictor and therapeutic target for glioma patients.

NPC2 as a Prognostic Biomarker for Glioblastoma Based on Integrated Bioinformatics Analysis and Cytological Experiments

Glioblastoma (GBM) is one of the most common and fatal malignancies worldwide, while its prognostic biomarkers are still being explored. This study aims to identify potential genes with clinical and prognostic significance by integrating bioinformatics analysis and investigating their function in HNSCC. Based on the Single-cell RNA sequencing (scRNA-seq) results of H3K27M-glioma cells, computational bioinformatics methods were employed for selecting prognostic biomarker for GBM. The protein NPC2 (NPC Intracellular Cholesterol Transporter 2), which has been shown to be related to lipoprotein metabolism and innate immune system, was identified to be upregulated in GBM. NPC2 showed a relatively higher expression in GBM samples, and a negative correlation with tumor purity and tumor infiltrating immune cells. Additionally, NPC2 was knocked down in U87-MG and U251 cells line, and cell proliferation and migration capability were evaluated with CCK-8, scratch and transwell assay, respectively. Cytological experiments has shown that NPC2 overexpression inhibited GBM cells proliferation and migration, indicating its important role in GBM progression. This is the first investigation into the prognostic value of NPC2 interact with GBM. The potential molecular factor NPC2 have been identified as a prognostic biomarker for GBM.

Recurrent Glioblastoma: From Molecular Landscape to New Treatment Perspectives

Glioblastoma is the most frequent and aggressive form among malignant central nervous system primary tumors in adults. Standard treatment for newly diagnosed glioblastoma consists in maximal safe resection, if feasible, followed by radiochemotherapy and adjuvant chemotherapy with temozolomide; despite this multimodal treatment, virtually all glioblastomas relapse. Once tumors progress after first-line therapy, treatment options are limited and management of recurrent glioblastoma remains challenging. Loco-regional therapy with re-surgery or re-irradiation may be evaluated in selected cases, while traditional systemic therapy with nitrosoureas and temozolomide rechallenge showed limited efficacy. In recent years, new clinical trials using, for example, regorafenib or a combination of tyrosine kinase inhibitors and immunotherapy were performed with promising results. In particular, molecular targeted therapy could show efficacy in selected patients with specific gene mutations. Nonetheless, some molecular characteristics and genetic alterations could change during tumor progression, thus affecting the efficacy of precision medicine. We therefore reviewed the molecular and genomic landscape of recurrent glioblastoma, the strategy for clinical management and the major phase I-III clinical trials analyzing recent drugs and combination regimens in these patients.

What is New in Neuro-oncology?

Neuro-oncology is a rapidly developing field. A continuous evolution in the understanding of the molecular underpinnings of central nervous system tumors has helped reconfigure the classification of brain tumors. More importantly, it has laid the path forward for the development and investigation of new therapeutics. The authors discuss the classification of brain tumors and novel therapies in brain tumors as well as promising treatments underway.