MiR-221-3p promotes the cell growth of non-small cell lung cancer by targeting p27

Abstract

Emerging evidence suggests the critical function of microRNA s in regulating the growth of cancer cells. In the present study, it was demonstrated that miR- 221-3p was overexpressed in non-small cell lung cancer (NSCLC ) tissues and cell lines compared with that noted in the normal controls. Downregulation of miR- 221-3p suppressed the proliferation, colony formation and invasion of NSCLC cells. To further understand the molecular mechanisms underlying the potential oncogenic function of miR- 221-3p in NSCLC , the downstream targets of miR- 221-3p were predicted using bioinformatic databases. The prediction suggested the cell cycle regulator p27 as one of the targets of miR- 221-3p. Molecular experiments showed that miR- 221-3p was able to bind with the 3'-untranslated region (UTR) of p27 and decreased the expression of p27 in NSCLC cells. Consistent with the suppressive role of p27 in controlling cell cycle progression, overexpression of miR- 221-3p decreased the expression of p27 and promoted cell cycle progression from G1 to S phase. Collectively, our findings identified miR-221-3p as a novel regulator of NSCLC cell growth via modulating the expression of p27.