KRAS 3'-UTR variants and stratification of breast-cancer risk.

摘要

In the past 15 years, a novel form of gene regulation has been discovered that is driven by the interaction of short, non-coding RNAs known as microRNAs (miRNAs) with target mRNA transcripts. On the basis of imperfect basepairing with the 3'-untranslated regions (UTRs) of target mRNAs, miRNAs negatively regulate both protein translation and mRNA stability. One of the first miRNAs to be discovered was let-7- First described as a regulator of developmental timing in the nematode, several studies in the past few years have suggested a role for the let-7 miRNA family in tumorigenesis.1"3 Expression of mature let-7-family miRNAs is suppressed in various cancer types. Moreover, this suppression frequently occurs via overactivation of the L/N28 oncogene, which specifically blocks the processing of let-7 into a functional miRNA.