MiRNA-20a-5p accelerates the proliferation and invasion of non-small cell lung cancer by targeting and downregulating KLF9.

Abstract

To uncover the role of microRNA-20a-5p (miRNA-20a-5p) in the progression of Non-small cell lung cancer (NSCLC) and the underlying mechanism. MiRNA-20a-5p level in NSCLC tissues and cell lines was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Its level in NSCLC patients with larger or smaller tumor size, and either with lymphatic metastasis or not was examined as well. Regulatory effects of miRNA-20a-5p on viability, cell cycle, and invasiveness of A549 and PC9 cells were assessed. The interaction between miRNA-20a-5p and KLF9 was explored by Dual-Luciferase Reporter Gene Assay and Spearman correlation test. At last, the role of miRNA-20a-5p/KLF9 axis in influencing the progression of NSCLC was determined. MiRNA-20a-5p was upregulated in NSCLC tissues and cell lines. Its level was much pronounced in NSCLC patients with larger tumor size or accompanied with lymphatic metastasis. Overexpression of miRNA-20a-5p in A549 cells enhanced viability, cell ratio in S phase, and invasiveness, while the knockdown of miRNA-20a-5p in PC9 cells achieved the opposite trends. KLF9 was confirmed to be the direct target of miRNA-20a-5p. There was a negative correlation between the expression levels of miRNA-20a-5p and KLF9 in NSCLC tissues. In addition, KLF9 overexpression could reverse the promotive effects of upregulated miRNA-20a-5p on the proliferation and invasiveness of A549 cells. On the contrary, the knockdown of KLF9 reversed the inhibitory effects of downregulated miRNA-20a-5p on cellular behaviors of PC9 cells. MiRNA-20a-5p stimulates NSCLC to proliferate and invade by targeting KLF9.