No abstract

N6-methyladenosine (m6A) is the most prevalent internal modification of eukaryotic messenger RNAs (mRNAs). The m6A modification in RNA can be catalyzed by methyltransferases, or removed by demethylases, which are termed m6A writers and erasers, respectively. Selective recognition and binding by distinct m6A reader proteins lead mRNA to divergent destinies. m6A has been reported to influence almost every stage of mRNA metabolism and to regulate multiple biological processes. Accumulating evidence strongly supports the correlation between aberrant cellular m6A level and cancer. We summarize here that deregulation of m6A modification, resulting from aberrant expression or function of m6A writers, erasers, readers or some other protein factors, is associated with carcinogenesis and cancer progression. Understanding the regulation and functional mechanism of mRNA m6A modification in cancer development may help in developing novel and efficient strategies for the diagnosis, prognosis and treatment of human cancers.

DIS3L2, in which mutations have been linked to Perlman syndrome, is an RNA-binding protein with 3′-5′ exoribonuclease activity. It contains two CSD domains and one S1 domain, all of which are RNA-binding domains, and one RNB domain that is responsible for the exoribonuclease activity. The 3′ polyuridine of RNA substrates can serve as a degradation signal for DIS3L2. Because DIS3L2 is predominantly localized in the cytoplasm, it can recognize, bind, and mediate the degradation of cytoplasmic uridylated RNA, including pre-microRNA, mature microRNA, mRNA, and some other non-coding RNAs. Therefore, DIS3L2 plays an important role in cytoplasmic RNA surveillance and decay. DIS3L2 is involved in multiple biological and physiological processes such as cell division, proliferation, differentiation, and apoptosis. Nonetheless, the function of DIS3L2, especially its association with cancer, remains largely unknown. We summarize here the RNA substrates degraded by DIS3L2 with its exonucleolytic activity, together with the corresponding biological functions it is implicated in. Furthermore, we discuss whether DIS3L2 can function independently of its 3′-5′ exoribonuclease activity, as well as its potential tumor-suppressive or oncogenic roles during cancer progression.