N⁶-Methyladenosine: A Novel RNA Imprint in Human Cancer

N⁶-Methyladenosine (m⁶A), a pervasive posttranscriptional modification which is reversible, has been among hotspot issues in the past several years. The balance of intracellular m⁶A levels is dynamically maintained by methyltransferase complex and demethylases. Meanwhile, m⁶A reader proteins specifically recognize modified residues and convey messages so as to set up an efficient and orderly network of m⁶A regulation. The m⁶A mark has proved to affect every step of RNA life cycle, from processing in nucleus to translation or degradation in cytoplasm. Subsequently, disorders in m⁶A methylation are directly related to aberrant RNA metabolism, which results in tumorigenesis and altered drug response. Therefore, uncovering the underlying mechanism of m⁶A in oncogenic transformation and tumor progression seeks opportunities for novel targets in cancer therapy. In this review, we conclude the extensive impact of m⁶A on RNA metabolism and highlight its relevance with human cancer, implicating the far-reaching value in clinical application.