Novel insights into the m(6)A-RNA methyltransferase METTL3 in cancer

N6-methyladenosine (m(6)A) is a prevalent internal RNA modification in higher eukaryotic cells. As the pivotal m(6)A regulator, RNA methyltransferase-like 3 (METTL3) is responsible for methyl group transfer in the progression of m(6)A modification. This epigenetic regulation contributes to the structure and functional regulation of RNA and further promotes tumorigenesis and tumor progression. Accumulating evidence has illustrated the pivotal roles of METTL3 in a variety of human cancers. Here, we systemically summarize the interaction between METTL3 and RNAs, and illustrate the multiple functions of METTL3 in human cancer. METLL3 is aberrantly expressed in a variety of tumors. Elevation of METTL3 is usually associated with rapid progression and poor prognosis of tumors. On the other hand, METTL3 may also function as a tumor suppressor in several cancers. Based on the tumor-promoting effect of METTL3, the possibility of applying METTL3 inhibitors is further discussed, which is expected to provide novel insights into antitumor therapy.