ALKBH5 promotes the progression of cisplatin-resistant oral squamous cell carcinoma by regulating FOXA1 expression via m6A RNA methylation : Funding.

BACKGROUND

Oral squamous cell carcinoma (OSCC) accounts for the vast majority of oral cancer cases. Accumulating evidence has implicated both AlkB homolog 5 (ALKBH5) and forkhead box protein A1 (FOXA1) in the emergence of cisplatin resistance in OSCC. This study aimed to define their functional roles and elucidate the underlying molecular mechanisms.

METHODS

The expression of ALKBH5, FOXA1, and YTHDF2 was assessed by qPCR and Western blot. Cisplatin-resistant cell lines (H357 CisR and SCC4 CisR) were established via stepwise dose escalation. To investigate key functional phenotypes, a series of assays were employed: CCK-8 for viability, colony formation for proliferation, and Transwell for migration and invasion. Bioinformatics (SRAMP, RM2Target) predicted m⁶A sites on FOXA1 and its binding with ALKBH5, which were validated by MeRIP-qPCR and RIP. FOXA1 mRNA stability was measured by actinomycin D assay.

RESULTS

ALKBH5 and FOXA1 were upregulated in cisplatin-resistant OSCC, with FOXA1 essential for maintaining oncogenic phenotypes. Bioinformatic and biochemical analyses confirmed FOXA1 as a direct target of ALKBH5. ALKBH5 demethylates FOXA1 mRNA, stabilizing its transcript and enhancing its expression by inhibiting YTHDF2-mediated degradation. Functionally, ALKBH5 overexpression reversed the tumor-suppressive effects of FOXA1 knockdown.

CONCLUSION

Our study demonstrates that ALKBH5 promotes cisplatin resistance in OSCC through m6A-dependent demethylation of FOXA1 transcripts, highlighting the ALKBH5-FOXA1 axis as a promising therapeutic target for overcoming this resistance.