The M6A methyltransferase METTL3 promotes the development and progression of prostate carcinoma via mediating MYC methylation

N6-methyladenosine (m(6)A) is the richest modification in mammalian messenger RNAs (mRNAs), and exerts key roles in many biological processes, including cancer development, whereas its roles in prostate carcinoma (PCa) remain to be unclear. Here, we found that m(6)A modifications are increased in PCa and methyltransferase-like 3 (METTL3), but not other major m(6)A modification genes including METTL14, fat mass and obesity-associated protein (FTO) and AlkB homolog 5 (ALKBH5), was the major dysregulated gene associated with abnormal m(6)A modification. In addition, METTL3 up-regulation acted as a poor prognostic factor for overall survival and disease-free survival in PCa patients. Knockdown of METTL3 significantly inhibited PCa cells proliferation, migration, and invasion. In addition, over-expression of METTL3, but not its catalytic mutant form, significantly promoted PCa cells growth and progression. Mechanistically, we revealed that METTL3 enhanced MYC(c-myc) expression by increasing m(6)A levels of MYC mRNA transcript, leading to oncogenic functions in PCa. Importantly, PCa cells growth and progression inhibition by METTL3 knockdown were restored through over-expression of MYC. Our results uncovered a METTL3/m(6)A/MYC axis and provided insight into the mechanisms of PCa progression.