METTL3‑mediated N6‑methyladenosine modification of MMP9 mRNA promotes colorectal cancer proliferation and migration.

N6‑methyladenosine (m⁶A) is the predominant chemical modification of eukaryotic mRNA, dynamically mediated by the RNA methyltransferase, methyltransferase-like 3 (METTL3). m⁶A modification plays a critical role in cancer progression through post‑transcriptional regulation in various types of cancer. However, the role of METTL3 and its associated m⁶A modification in colorectal tumorigenesis remains to be fully elucidated. In the present study, it was demonstrated that METTL3 expression and the m⁶A levels were both upregulated in colorectal cancer (CRC) and positively associated with clinical progression, based on the bioinformatics analysis of cancer databases. Furthermore, knockdown and overexpression of METTL3 notably affected CRC cell viability, apoptosis and migration in vitro. Similarly, xenograft animal models confirmed that METTL3 promoted CRC tumorigenicity in vivo. Mechanistically, it was revealed that the m⁶A modification of matrix metallopeptidase 9 (MMP9) mRNA mediated by METTL3 promoted its expression in CRC by decreasing its degradation. Collectively, the findings of the present study suggested that the METTL3/MMP9 axis could serve as a novel promising therapeutic candidate for CRC.