Latest updates on cellular and molecular biomarkers of gliomas

IDH mutation and MGMT methylation status in glioblastoma and other gliomas patients: a Russian retrospective cohort study

Glioma is a devastating type of brain tumor with high malignancy, an extremely high mortality rate, and a recurrence risk. Molecular markers are known to have a major role in classification, prognosis, survival rate, and therapy determination for different glioma subtypes. The aim of this study was to investigate the association of gliomas' main genetic markers: isocitrate dehydrogenase (IDH) mutations and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status with the survival rate in Russian patients with glioblastoma and other glial tumors. According to histological subtype, included glioma patients were divided into two groups: glioblastoma (n = 90) and other gliomas (n = 40). IDH mutations were screened by high-resolution melting-curve analysis (HRM) followed by direct sequencing, and MGMT methylation was detected with pyrosequencing. Our data showed that IDH mutations are significantly more frequent among patients with other gliomas compared to glioblastoma patients (p < 0.001). Patients with mutated IDH gene have a significantly higher progression-free survival (PFS) and overall survival (OS) rates than those with wild-type genes. MGMT promoter methylation status was found to be significantly associated with PFS, but not OS. The presence of IDH mutation with a methylated MGMT promoter significantly increased patients' PFS and OS. To our knowledge, this is the first study to investigate the association of IDH and MGMT genetic biomarkers with glioma in the Russian population. Our findings could be used in future studies to improve glioma prognosis and classification and reach a personalized treatment protocols depending on multiple molecular biomarkers.

Metabolomic profiling of plasma from glioma and meningioma patients based on two complementary mass spectrometry techniques

INTRODUCTION

Extracranial and intracranial tumors are a diverse group of malignant and benign neoplasms, influenced by multiple factors. Given the complex nature of these tumors and usually late or accidental diagnosis, minimally invasive, rapid, early, and accurate diagnostic methods are urgently required. Metabolomics offers promising insights into central nervous system tumors by uncovering distinctive metabolic changes linked to tumor development.

OBJECTIVES

This study aimed to elucidate the role of altered metabolites and the associated biological pathways implicated in the development of gliomas and meningiomas.

METHODS

The study was conducted on 95 patients with gliomas, 68 patients with meningiomas, and 71 subjects as a control group. The metabolic profiling of gliomas and meningiomas achieved by integrating untargeted metabolomic analysis based on GC-MS and targeted analysis performed using LC-MS/MS represents the first comprehensive study. Three comparisons (gliomas or meningiomas vs. controls as well as gliomas vs. meningiomas) were performed to reveal statistically significant metabolites.

RESULTS

Comparative analysis revealed 97, 56, and 27 significant metabolites for gliomas vs. controls, meningiomas vs. controls and gliomas vs. meningiomas comparison, respectively. Moreover, among above mentioned comparisons unique metabolites involved in arginine biosynthesis and metabolism, the Krebs cycle, and lysine degradation pathways were found. Notably, 2-aminoadipic acid has been identified as a metabolite that can be used in distinguishing two tumor types.

CONCLUSIONS

Our results provide a deeper understanding of the metabolic changes associated with brain tumor development and progression.

Bioinformatic and clinical experimental assay uncovers resistance and susceptibility mechanisms of human glioblastomas to temozolomide and identifies new combined and individual survival biomarkers outperforming MGMT promoter methylation

Background

Glioblastoma (GBM) is the most aggressive and lethal central nervous system (CNS) tumor. The treatment strategy is mainly surgery and/or radiation therapy, both combined with adjuvant temozolomide (TMZ) chemotherapy. Historically, methylation of MGMT gene promoter is used as the major biomarker predicting individual tumor response to TMZ.

Objectives

This research aimed to analyze genes and molecular pathways of DNA repair as biomarkers for sensitivity to TMZ treatment in GBM using updated The Cancer Genome Atlas (TCGA) data and validate the results on experimental datasets.

Methods

Survival analysis of GBM patients under TMZ therapy and hazard ratio (HR) calculation were used to assess all putative biomarkers on World Health Organization CNS5 reclassified TCGA project collection of molecular profiles and experimental multicenter GBM patient cohort. Pathway activation levels were calculated for 38 DNA repair pathways. TMZ sensitivity pathway was reconstructed using a human interactome model built using pairwise interactions extracted from 51,672 human molecular pathways.

Results

We found that expression/activation levels of seven and six emerging gene/pathway biomarkers served as high-quality positive (HR < 0.61) and negative (HR > 1.63), respectively, patient survival biomarkers performing better than MGMT methylation. Positive survival biomarkers were enriched in the processes of ATM-dependent checkpoint activation and cell cycle arrest whereas negative-in excision DNA repair. We also built and characterized gene pathways which were informative for GBM patient survival following TMZ administration (HR 0.18-0.44, p < 0.0009; area under the curve 0.68-0.9).

Conclusion

In this study, a comprehensive analysis of the expression of 361 DNA repair genes and activation levels of 38 DNA repair pathways revealed 13 potential survival biomarkers with increased prognostic potential compared to MGMT methylation. We algorithmically reconstructed the TMZ sensitivity pathway with strong predictive capacity in GBM.

GQIcombi application to subdue glioma via differentiation therapy

Current therapy protocols fail to cure high-grade gliomas and prevent recurrence. Therefore, novel approaches need to be developed. A re-programing of glioma cell fate is an alternative attractive way to stop tumor growth. The two-step protocol applies the antiproliferative GQ bi-(AID-1-T) and small molecule inducers with BDNF to trigger neural differentiation into terminally differentiated cells, and it is very effective on GB cell cultures. This original approach is a successful example of the "differentiation therapy". To demonstrate a versatility of this approach, in this publication we have extended a palette of cell cultures to gliomas of II, III and IV Grades, and proved an applicability of that version of differential therapy for a variety of tumor cells. We have justified a sequential mode of adding of GQIcombi components to the glioma cells. We have shown a significant retardation of tumor growth after a direct injection of GQIcombi into the tumor in rat brain, model 101/8. Thus, the proposed strategy of influencing on cancer cell growth is applicable to be further translated for therapy use.

Post-translational protein lactylation modification in health and diseases: a double-edged sword

As more is learned about lactate, it acts as both a product and a substrate and functions as a shuttle system between different cell populations to provide the energy for sustaining tumor growth and proliferation. Recent discoveries of protein lactylation modification mediated by lactate play an increasingly significant role in human health (e.g., neural and osteogenic differentiation and maturation) and diseases (e.g., tumors, fibrosis and inflammation, etc.). These views are critically significant and first described in detail in this review. Hence, here, we focused on a new target, protein lactylation, which may be a "double-edged sword" of human health and diseases. The main purpose of this review was to describe how protein lactylation acts in multiple physiological and pathological processes and their potential mechanisms through an in-depth summary of preclinical in vitro and in vivo studies. Our work aims to provide new ideas for treating different diseases and accelerate translation from bench to bedside.

Circular RNA circTIE1 drives proliferation, migration, and invasion of glioma cells through regulating miR-1286/TEAD1 axis

Recent studies have verified that circRNAs (circular RNAs) play a critical role in glioma occurrence and malignant progression. However, numerous circRNAs with unknown functions remain to be explored with further research. qPCR (quantitative real-time polymerase chain reaction) was employed to detect circTIE1 expression in glioma tissues, NHAs (normal human astrocytes), and glioma cellular lines (U87, U118, U251, T98G, LN229). Cell viability was evaluated by CCK-8 assay. Cellular proliferation was evaluated by a 5-ethynyl-2'-deoxyuridine (EdU) proliferation assay. Cell migration and aggression were both evaluated by transwell and migration assays. The direct binding and regulation among circTIE1, miR-1286 and TEAD1 was identified by western blotting, qPCR, luciferase reporter assay, and RNA immunoprecipitation (RIP) assay. Xenografts were generated by injecting glioma cells orthotopically into the brains of nude mice. Immunohistochemistry staining was implemented to evaluate the expression of the proliferation markers ki67 and TEAD1. We found that circTIE1 (circBase ID: hsa_circ_0012012) was upregulated in glioma tissues and glioma cellular lines in contrast to NBT (normal brain tissues) and NHA. CircTIE1 knockdown inhibited glioma cell viability, proliferation, migration and aggression both in vitro and in vivo. Mechanistically, circTIE1 could upregulate TEAD1 expression via miR-1286 sponging, and TEAD1 is a well-known functional gene that could promote malignant advancement in glioma. This research found a novel circRNA, circTIE1, which is an essential marker of glioma progression and diagnosis and may be anticipated to become a crucial target for molecular targeted therapy of glioma.