NSUN4 Suppresses Ferroptosis Through m5C-Dependent Stabilization of C-MYC and Activation of the PI3K/Akt Signaling Pathway in Cervical Cancer

Objectives: This study aimed to investigate the biological role and molecular mechanism of the RNA m5C methyltransferase NSUN4 in cervical cancer progression, with a focus on its involvement in ferroptosis regulation. Methods: Differential expression and survival analyses were performed using TCGA and GEPIA datasets. Functional enrichment and GSEA identified pathways associated with NSUN4 dysregulation. NSUN4 expression was validated in clinical tissues by qRT-PCR, Western blot, and immunohistochemistry. Gain- and loss-of-function assays, including CCK-8, colony formation, and Transwell assays, were conducted to assess cell proliferation and invasion. Furthermore, a nude mouse subcutaneous xenograft model was established to validate the oncogenic role of NSUN4 in vivo. Ferroptosis was evaluated using specific inhibitors and measurement of GSH and ferroptosis-related proteins. RIP, m5C-RIP, RNA stability, and dual-luciferase assays were performed to explore the underlying mechanism. Results: NSUN4 was markedly upregulated in cervical cancer tissues and correlated with poor prognosis. Functionally, NSUN4 enhanced tumor cell growth, migration, and invasion while inhibiting ferroptosis. Mechanistically, NSUN4 bound to and stabilized C-MYC mRNA via m5C methylation, activating the PI3K/Akt signaling pathway and promoting ferroptosis resistance. Conclusions: NSUN4 promotes cervical cancer progression by stabilizing C-MYC mRNA through m5C modification, leading to PI3K/Akt activation and suppression of ferroptosis. These findings identify NSUN4 as a novel oncogenic regulator and potential therapeutic target in cervical cancer.