Multi-omics analysis reveals that ALYREF-mediated m5C modification promotes platinum resistance in ovarian cancer via the NSUN2/ALYREF/LGR4 axis

Platinum resistance remains a major obstacle to effective treatment and improved prognosis in ovarian cancer. Although 5-methylcytosine (m⁵C) RNA modification has been implicated in chemoresistance, its precise functional role in ovarian cancer remains unclear. In this study, we integrated RNA-Seq and single-cell transcriptomic data from cisplatin-resistant ovarian cancer cell lines and patient samples, identifying the m⁵C reader protein ALYREF as a key regulator of platinum resistance. Functional studies using ALYREF and NSUN2 knockdown, overexpression, and mutant constructs-combined with multi-omics analyses (RNA-Seq, m⁵C-BIS-Seq, and RIP-Seq)-revealed that ALYREF binds to m⁵C-modified LGR4 mRNA, enhancing its stability and promoting activation of the Wnt/β-catenin signaling pathway. Critically, this regulatory mechanism is dependent on NSUN2-mediated m⁵C modification of LGR4 mRNA. Together, our findings demonstrate that the NSUN2/ALYREF/LGR4 axis mediates platinum resistance through m⁵C-dependent stabilization of LGR4 and downstream Wnt signaling activation. Thus, targeting ALYREF may represent a promising strategy to overcome platinum resistance in ovarian cancer.