Gliomas are aggressive primary brain tumors with high morbidity and mortality [1]. Despite advances in oncology, their complex biology limits effective treatment options, making gliomas a key focus of cancer research. Epigenetic modifications, including RNA methylation (m6A and 5mC), have been implicated in tumor progression, yet their specific roles in gliomas remain unclear [2]. This study investigates m6A and 5mC RNA methylation profiles in gliomas and their potential as biomarkers for tumor malignancy and clinical outcomes.
Methods: Total RNA was extracted from glioma tissue samples (n = 30; grade II = 20, grade IV = 8) and cell cultures (n = 8; commercial glioblastoma cell lines = 4, glioma stem cell cultures = 2, neural stem cell cultures = 3) using TRIzol reagent. Poly(A) RNA was isolated with magnetic oligo(dT) beads, and m6A/5mC modifications were quantified via ELISA-based colorimetric and fluorometric assays. Statistical analyses, including Kolmogorov-Smirnov, unpaired t-test, Mann-Whitney U test, and Kaplan-Meier survival analysis, assessed correlations between methylation levels, tumor grade, and clinical characteristics.
Results: m6A levels were significantly lower in grade II gliomas and neural stem cell lines and highest in grade IV gliomas and GBM cell lines (p < 0.05). Female patients exhibited significantly higher m6A levels compared to males (p = 0.011), but no association with survival was observed. 5mC levels were significantly higher in tumor samples than in cell lines (p < 0.05), and elevated 5mC was correlated with shorter survival in grade IV gliomas (p = 0.0299).
Conclusion: Distinct m6A and 5mC RNA methylation profiles were observed in gliomas, suggesting their involvement in tumor progression. The association between 5mC levels and survival highlights its potential prognostic value, warranting further investigation into RNA methylation as a biomarker for glioma malignancy.