miR­671­3p is downregulated in non­small cell lung cancer and inhibits cancer progression by directly targeting CCND2.

ABSTRACT

MicroRNAs (miRNAs) are implicated in the development and progression of non­small cell lung cancer (NSCLC). A previous study suggested that miR­671­3p suppresses the development of breast cancer. However, the role of miR­671­3p in NSCLC remains largely unknown. In the present study, it was identified that miR­671­3p was significantly upregulated in NSCLC tissues compared with adjacent normal tissues by reverse transcription quantitative polymerase chain reaction (RT­qPCR). Similarly, decreased levels of miR­671­3p in NSCLC cell lines were observed compared with those in the non­tumorigenic human bronchial epithelial NL20 cell line. Cell Counting Kit­8 and Transwell invasion assays indicated that miR­671­3p overexpression suppressed the proliferation and invasion of A549 cells, and vice versa. Mechanistically, it was demonstrated that CCND2 was a direct target of miR­671­3p. RT­qPCR and western blot analysis indicated that miR­671­3p overexpression decreased the expression of CCND2 in A549 cells. Furthermore, rescue experiments demonstrated that the restoration of CCND2 may significantly reverse the suppressive roles of miR­671­3p overexpression on NSCLC cell proliferation and invasion. Taken together, the present study demonstrated that miR­671­3p exerted its tumor­suppressive roles via directly targeting CCND2 in NSCLC.