Methylation of RNA N 6 -methyladenosine in modulation of cytokine responses and tumorigenesis.

Among myriads of distinct chemical modification in RNAs, the dynamic, reversible and fine-tuned methylation of N6 -methyladenosine (m6 A) is the most prevalent modification in eukaryotic mRNAs. This RNA mark is generated by proteins that act as m6 A writers and can be reversed by proteins that act as m6 A erasers. The RNA m6 A modification is also mediated by another group of proteins capable of recognizing m6 A that act as m6 A readers. The m6 A modification exerts direct control over the RNA metabolism including mRNA processing, mRNA exporting, translation initiation, mRNA stability and the biogenesis of long-non-coding RNA (LncRNA), thereby can influence various aspects of cell function. Evidently, m6 A is intimately associated with cancer development and progression such as self-renewal capacity of cancer stem cells, proliferation, apoptosis and therapeutic resistance, and immune response. In this review, we will discuss the regulation and function of m6 A, the various functions ascribed to these proteins and the emerging concepts that impact our knowledge of these proteins and their roles in the epitranscriptome. Conceivably, m6 A may play pivotal roles in cytokine and immune response and carcinogenesis.