Overexpression of MicroRNA-340-5p Attenuates Lung Cancer Cell Proliferation and Invasion through Wnt/Beta-Catenin Signaling Pathway

Numerous studies have screened and dysregulated the microRNA in various cancers via microarray assay. In this dysregulated microRNA, microRNA-340-5p attracted our attention due to its high conservation and fold change. MicroRNA-340-5p is abnormally expressed in several cancers and plays an important role. However, the expression and function of microRNA-340-5p in lung cancer are still unknown. Our aim was to explore the role of microRNA-340-5p in lung cancer and its underlying molecular mechanism. The lung cancer cell lines of human lung squamous cell carcinoma cell line SKMES1, human lung adenocarcinoma cell line A549, lung adenocarcinoma cells H23, human lung cancer cell line SPC-A1 and human squamous cell carcinoma H520 were used in present study. Real time polymerase chain reaction was performed to detect microRNA-340-5p and beta-catenin messenger RNA expression. Transwell assay was conducted to determine the invasion of human squamous cell carcinoma H520 cells under different treatment conditions. Our study showed that the expression of microRNA-340-5p in lung cancer tissues and was significantly lower than normal tissues. Moreover, overexpression of microRNA-340-5p could suppress the invasion and proliferation of lung cancer cells. We also confirmed that microRNA-340-5p and beta-catenin are negatively correlated in lung cancer tissues and the role of microRNA-340-5p in lung cancer can be reversed by overexpression of beta-catenin. Our results demonstrate that up-regulation of microRNA-340-5p attenuates lung cancer cell invasion and proliferation via inhibiting wingless-related integration site/beta-catenin pathway. The data will provide new insights for the treatment of lung cancer and new guidance for clinical treatment of lung cancer.