Principles of RNA methylation and their implications for biology and medicine.

• RNA methylation exists in cancer, immune system diseases, neurological diseases, and viral infections. • Abnormal RNA methylation, especially m6A, reflects a variety of physiological and pathological changes in the body. • The "writer", "eraser" and "reader" have served as indicators of cancer occurrence, progression and prognosis. • The dynamic changes of m6A regulate the development of the central nervous system and neurodegeneration. RNA methylation is a post-transcriptional level of regulation. At present, more than 150 kinds of RNA modifications have been identified. They are widely distributed in messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), noncoding small RNA (sncRNA) and long-chain non-coding RNA (lncRNA). In recent years, with the discovery of RNA methylation related proteins and the development of high-throughput sequencing technology, the mystery of RNA methylation has been gradually revealed, and its biological function and application value have gradually emerged. In this review, a large number of research results of RNA methylation in recent years are collected. Through systematic summary and refinement, this review introduced RNA methylation modification-related proteins and RNA methylation sequencing technologies, as well as the biological functions of RNA methylation, expressions and applications of RNA methylation-related genes in physiological or pathological states such as cancer, immunity and virus infection, and discussed the potential therapeutic strategies. [ABSTRACT FROM AUTHOR]