METTL14 Suppresses CRC Progression via Regulating N6-Methyladenosine-Dependent Primary miR-375 Processing

Epigenetic alterations contributed to human carcinogenesis immensely. N6-methyladenosine (m6A) is one of the most preventive and abundant modifications on RNA molecules present in eukaryotes. However, the biological function of m6A methylation in colorectal cancer (CRC) remains largely unclear. Here, we found that METTL14 was downregulated in CRC tissues and cell lines, and closely correlated with overall survival (OS). METTL14 knockdown significantly reduced m6A levels in total RNAs and promoted CRC cell growth and metastasis, whereas METTL14 overexpression markedly increased m6A levels in total RNA and inhibited CRC cell growth and metastasis. Furthermore, we demonstrated that miR-375 was a downstream target of METTL14. We also verified that METTL14 suppressed CRC cell growth via the miR-375/Yes-associated protein 1 (YAP1) pathway, as well as inhibited CRC cell migration and invasion through the miR-375/SP1 pathway. Taken together, our studies showed an important role for METTL14 in CRC progression and provided novel insight into m6A modification in CRC progression.