miR-671-3p is downregulated in non-small cell lung cancer and inhibits cancer progression by directly targeting CCND2

Abstract

MicroRNAs (miRNAs) are implicated in the development and progression of non-small cell lung cancer (NSCLC). A previous study suggested that miR-671-3p suppresses the development of breast cancer. However, the role of miR-671-3p in NSCLC remains largely unknown. In the present study, it was identified that miR-671-3p was significantly upregulated in NSCLC tissues compared with adjacent normal tissues by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Similarly, decreased levels of miR-671-3p in NSCLC cell lines were observed compared with those in the non-tumorigenic human bronchial epithelial NL20 cell line. Cell Counting Kit-8 and Transwell invasion assays indicated that miR-671-3p overexpression suppressed the proliferation and invasion of A549 cells, and vice versa. Mechanistically, it was demonstrated that CCND2 was a direct target of miR-671-3p. RT-qPCR and western blot analysis indicated that miR-671-3p 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 miR-671-3p overexpression on NSCLC cell proliferation and invasion. Taken together, the present study demonstrated that miR-671-3p exerted its tumor-suppressive roles via directly targeting CCND2 in NSCLC.