MicroRNA-100 functions as a tumor suppressor by inhibiting Lgr5 expression in colon cancer cells

Previous studies have demonstrated that microRNAs (miRNAs), a class of single-stranded RNA molecules that are 18-27 nucleotides in length, serve a critical function in tumorigenesis, including in the development of colon cancer. In the current study, miR-100 levels were demonstrated to be reduced in colon cancer tissues compared with the levels in matched adjacent normal tissues. Forced overexpression of miR-100 by transfection with miR-100 mimics substantially inhibited the proliferation, migration and invasion of SW480 and HCT116 cells, whereas reduced expression, resulting from transfection of antisense oligonucleotides, promoted these processes. At the molecular level, miR-100 was observed to reduce the levels of leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5), by binding to its 3-untranslated region. As a result of this, Wnt/-catenin signaling was affected by fluctuations in the level of miR-100 mimics or antisense. Collectively, the results of the current study elucidate a novel regulatory pathway involving miR-100 and Lgr5 in colon cancer cells, which may present a potential therapeutic target.