Glioblastoma (GBM) poses a formidable challenge in the field of oncology because of its pronounced resistance to traditional therapeutic approaches. N6-methyladenosine (m 6 A) modification is a prevalent posttranscriptional modification that significantly influences cellular processes by modulating gene expression. However, the role of m 6 A in the regulation of the DNA damage response (DDR) in GBM cells remains unclear. Through integrated bioinformatics and functional studies, we identified the m 6 A reader YTHDF3 as a central regulator of the DDR in GBM, and the elevated expression levels of YTHDF3 were correlated with unfavorable clinical outcomes in GBM patients. Human GBM cell lines and patient-derived GBM cells (PDC) models were used to explore the biological function of YTHDF3. Following treatment with temozolomide (TMZ), the level of m 6 A modification was increased, facilitating YTHDF3-mediated DNA damage repair. The knockdown of METTL3 resulted in a reduction in functional m 6 A modification and suppressed the expression of DDR core factors, which are mediated by YTHDF3. Mechanistically, YTHDF3 recognizes the m 6 A binding site of DNA damage response genes (BRCA1, RAD51, RIF1 and 53BP1) and promotes their translation through m 6 A methylation, thereby initiating homologous recombination (HR) and nonhomologous end joining (NHEJ) repair to resist endogenous and exogenous DNA damage. Consequently, our study elucidates the crucial role of YTHDF3 in GBM and provides valuable insights into its significance in the DNA damage response and chemoresistance. ● The m 6 A reader YTHDF3 is upregulated in glioblastoma (GBM) and is associated with poor prognosis in GBM patients. ● YTHDF3 modulates the DNA damage response (DDR) in GBM cells through an m 6 A-dependent mechanism. ● Temozolomide (TMZ) treatment increases the level of m 6 A modification in GBM cells and facilitates the YTHDF3-mediated DNA damage repair. ● The knockdown of METTL3 led to a decrease in functional m 6 A modifications and inhibited the YTHDF3-mediated expression of core DDR factors. ● YTHDF3 recognizes the m 6 A binding site of DDR core genes (BRCA1, RAD51, RIF1 and 53BP1) and promotes their translation through m 6 A methylation. ● YTHDF3 knockdown combined with TMZ treatment aggravated DNA damage and synergically inhibited the malignant function of GBM cells.
Cheng et al. (Sun,) studied this question.