ALKBH5-HOXA10 loop-mediated JAK2 m6A demethylation and platinum resistance in epithelial ovarian cancer

Abstract

Background: Chemotherapy resistance remains a barrier in improving the prognosis of epithelial ovarian cancer (EOC), but its mechanism remains to be elucidated. ALKBH5 has been recently proven to be an RNA N6-methyladenosine (m6A) demethyltransferase associated with various cancers, but its role in cancer therapeutic resistance remains unclear. This study aimed to investigate the role of AlkB homolog 5 (ALKBH5) in platinum-resistant EOC.Methods: Functional assays were performed both in vitro and in vivo. RNA sequencing (RNA-seq), m6A-modified RNA immunoprecipitation sequencing (MeRIP-seq), chromatin immunoprecipitation, RNA immunoprecipitation, and luciferase reporter and actinomycin-D assays were performed to investigate RNA/RNA interaction and m6A modification of the ALKBH5-HOXA10 loop.Results: ALKBH5 was upregulated in platinum-resistant EOC and promoted cancer cell cisplatin resistance both in vivo and in vitro. Notably, HOXA10 was found to be the upstream transcription factor of ALKBH5 and formed a loop with ALKBH5., and its overexpression facilitated EOC cell chemoresistance both in vivo and in vitro. HOXA10 overexpression was found to facilitate EOC cell chemoresistance both in vivo and in vitro. Collective results of MeRIP-seq and RNA-seq showed that JAK2 is an m6A-modified gene targeted by ALKBH5. The JAK2/STAT3 signaling pathway was activated by overexpression of the ALKBH5-HOXA10 loop, and this resulted in EOC chemoresistance. Cell sensitivity to cisplatin was rescued by ALKBH5 and HOXA10 knockdown or inhibition of the JAK2/STAT3 signaling pathway in EOC cells overexpressing ALKBH5-HOXA10.Conclusions: The ALKBH5-HOXA10 loop jointly activates the JAK2/STAT3 signaling pathway by mediating JAK2 m6A demethylation, promoting EOC resistance to platinum. Thus, inhibition of the expression of the ALKBH5-HOXA10 loop maybe a potential strategy to overcome platinum resistance in EOC.