The m6A Demethylase ALKBH5 Maintains Stemness and Therapeutic Resistance of Glioblastoma Stem Cells [Polysome-seq]

One prevalent modification, N6-methyladenosine (m6A), is a dynamic and reversible process regulated by methyltransferases (the "writers"), demethylases (the "erasers"), and m6A-binding proteins (the "readers"). Its abnormal changes are closely associated with the development and progression of human cancers. m6A demethylases, such as FTO and ALKBH5, eliminate the m6A modification from RNA, thus regulating the overall levels of this modification. Here, we show that the m6A demethylase ALKBH5 is highly expressed after ionizing radiation treatment. We conducted polysome profiling alongside RNA sequencing in both control and ALKBH5-KO GSC 83 cells and identified genes with differential translational efficiency due to ALKBH5 KO. We further elucidated that genes, whose translational efficiencies (TEs) were down-regulated after ALKBH5 knockout, were enriched in stemness properties and DNA repair. Overall, our findings imply that ALKBH5 facilitates the selective translation of mRNAs encoding pathways related to stemness and resistance to therapeutic interventions. Overall design: Polysome-seq profiling of wildtype and ALKBH5-KO GSC 83 cells