Alterations of miRNAs and other ncRNAs in human cancers
miRNAs are tiny RNA molecules of ~22 nt in length that bind to the 3’ untranslated regions of mRNAs, leading to translational repression and degradation of the target mRNA. Our discovery and resultant reporting of frequent let-7 alterations in association with poor prognosis and growth inhibitory activity of let-7 in human lung cancers have provided one of the earliest evidence for the involvement of miRNA alterations in human cancer development, which we believe is an excellent example of the high value we have placed on pioneering in new fields. We have also identified frequent overexpression of the miR-17-92 miRNA cluster with occasional gene amplification in human lung cancers, especially in small cell lung cancers. In addition to seeking additional involved miRNAs, our current efforts are focused on how such miRNA alterations play roles in the molecular pathogenesis of “hard-to-cure” cancers as well as how to translate those findings for use in a clinical environment. In addition, we are currently looking into the aberrations and roles of other types of non-coding RNAs in human cancers.