Novel insight into the functions of N6-methyladenosine modified lncRNAs in cancers (Review)

Emerging evidence has suggested that N6-methyladenosine (m6A) modification, a typical RNA methylation modification, controls the fate of modified transcripts and is involved in the pathogenesis of various human diseases, such as metabolic disorders, nephropathology, osteoarthritis and malignant tumours. Long noncoding RNAs (lncRNAs), transcripts of >200 nt in length, have also been indicated to be involved in various diseases by participating in processes such as epigenetic modifications, transcriptional alternations and posttranslational regulation. Recent studies revealed that lncRNAs were widely modified by m6A, which has a critical role in various cellular processes that are associated with numerous disorders, particularly human cancers. The present review first examined functions of m6A modification of lncRNAs, including changing the lncRNA structure, mediating transcriptional regulation, affecting mRNA precursor splicing, and regulating lncRNA stability and translation. Furthermore, the regulatory mechanisms of m6A-modified lncRNAs in cancers were summarized and the up-to-date detection methods and prediction tools for identifying m6A sites on lncRNAs were presented. In addition, viewpoints on potential future directions in the field were discussed, including more accurate detection methods, roles of lncRNAs-encoded micropeptides in cancers, the relationship between m6A-modified lncRNAs and the tumour microenvironment, and m6A-modified lncRNAs as potential biomarkers and therapeutic targets in human cancer.