Novel insights on m6A RNA methylation in tumorigenesis: a double-edged sword

N6-methyladenosine (m.sup.6A), the most prevalent modification of mammalian RNA, has received increasing attention. Although m.sup.6A has been shown to be associated with biological activities, such as spermatogenesis modulation, cell spermatogenesis and pluripotency, Drosophila sex determination, and the control of T cell homeostasis and response to heat shock, little is known about its roles in cancer biology and cancer stem cells. Recent articles have noted that some genes have abnormal m.sup.6A expression after tumorigenesis, including genes ABS2, RARA, MYB, MYC, ADAM19 and FOX1. Abnormal changes in the m.sup.6A levels of these genes are closely related to tumour occurrence and development. In this review, we summarized the 'dual edge weapon' role of RNA methylation in the tumorigenesis. We discussed RNA methylation could lead to not only tumour progression but also tumour suppression. Moreover, we clarified that the abnormal changes in the m.sup.6A enrichment of specific loci contribute to tumour occurrence and development, thereby representing a novel anti-cancer strategy by restoration to balanced RNA methylation in tumour cells. Keywords: RNA methylation, m.sup.6A, Tumorigenesis