Genomewide m⁶A mapping uncovers dynamic changes in the m⁶A epitranscriptome of cisplatin-treated apoptotic HeLa cells

Abstract

Cisplatin, which is a traditional cancer therapeutic drug, induces apoptosis by modulating a diverse array of gene regulatory mechanisms. However, cisplatin-mediated changes in the m6A methylome is unknown. We employed m6A miCLIP-seq to investigate the effect of m6A methylation events under cisplatin-mediated apoptotic conditions in HeLa cells. Our high-resolution approach revealed numerous m6A marks on 972 target mRNAs with an enrichment on 132 apoptotic mRNAs. Following validation of site-specific m6A events on candidate RNAs, we tracked the fate of candidate mRNAs under METTL3 knockdown and cisplatin treatment conditions. We detected perturbations in the translational efficiency of PMAIP1 and PHLDA1 transcripts based on the polysome profile analyses. Congruently, PMAIP1 and p53 amounts were dependent on METTL3. Additionally, cisplatin-mediated apoptosis was sensitized by METTL3 knockdown. These results suggest that apoptotic pathways are modulated by m6A methylation events and METTL3-p53-PMAIP1 axis modulates cisplatin-mediated apoptosis in HeLa cells.