Introduction. Glioblastoma (GBM), the most widespread and aggressive primary brain tumor with survival time typically less than two years [1]. Therefore, a deeper understanding of the molecular processes underlying the onset and progression of GBM is also required to identify more effective therapeutic and diagnostic strategies. RNA methylation, a post-transcriptional modification, has emerged as a crucial regulator of gene expression, RNA stability, and protein translation, thus influencing cellular processes, including those implicated in oncogenesis [2]. This study focuses on several modifications: m6A and m7G, dynamically controlled by methyltransferases ("writers"), demethylases ("erasers"), and “readers”. Furthermore, the transcription factor SOX2, essential for stem cell maintenance and implicated in tumor initiation and progression, is frequently overexpressed in gliomas [3,4]. Investigating a modified form lacking the C-terminal domain provides insights into SOX2’s effects on glioma cell survival and proliferation. This study explores the potential of RNA methylation regulators and SOX2 as novel targets in glioma diagnosis and therapy.
Aim. To investigate the expression and functional significance of specific RNA methylation regulators as well as modified SOX2 variant in glioma, evaluating their potential as diagnostic and therapeutic biomarkers.
Methods. Gene expression levels were quantified in both tumor tissue samples from 54 glioma patients and U87 and U87 SOX2ΔC glioblastoma cell lines using qRT-PCR. Cell migration was assessed using a wound-healing assay. Publicly available RNA sequencing data from experiments involving ALKBH5 knockdown were analyzed bioinformatically to identify differentially expressed genes and affected biological pathways.
Results. Analysis of patient tumor samples revealed significantly reduced expression of ALKBH5 (p<0.01), FTO (p<0.0001), and BUD23 (p<0.002) in higher-grade gliomas. In contrast, increased expression of these RNA methylation regulators was positively associated with patient survival (ALKBH5 p<0.02; FTO p<0.001 BUD23, p<0.003), suggesting their potential as valuable prognostic biomarkers. In modified U87 cell line, SOX2ΔC overexpression led to a significant increase in ALKBH5 expression (p=0.03) and a decrease in BUD23 expression (p=0.03), demonstrating a regulatory link between SOX2 and these methylation regulators. Over 53% of transcripts showed significant transcriptome changes as a result of ALKBH5 knockdown, including genes essential for cell division, and DNA replication and repair. Notably, some of these dysregulated genes, such as TOP2A are established targets in other cancer therapies, suggesting their potential repurposing for glioma treatment.
Conclusions. ALKBH5, FTO, and BUD23 are promising prognostic biomarkers. Targeting these methylation regulators and SOX2 offers potential for improved glioma treatment and early diagnosis.