MicroRNA-107 may regulate lung cancer cell proliferation and apoptosis by targeting TP53 regulated inhibitor of apoptosis 1

Lung Cancer causes over 1.6 million mortalities worldwide annually. MicroRNAs (miRs) are involved in various types of cancer-associated processes. The present study investigated the possible mechanism of miR-107 in the development of lung Cancer in order to identify novel targets for clinical treatment. The expression levels of miR-107 and its putative target gene TP53 regulated inhibitor of Apoptosis 1 (TRIAP1) were measured in lung Cancer tumor tissues and non-tumor adjacent tissues. Subsequently, the association between TRIAP1 and miR-107 was investigated using a dual-luciferase reporter assay. Following transfection, the effects of miR-107 and TRIAP1 on the proliferation and Apoptosis of lung Cancer cell lines in vitro were investigated using Cell Counting Kit-8 and flow cytometry assays, respectively. Furthermore, the regulatory effect of miR-107 on the expression levels of TRIAP1 and associated proteins was analyzed using a western blot assay. The results revealed lower expression levels of miR-107 and higher expression levels of TRIAP1 in lung Cancer tumor tissues compared with non-tumor adjacent tissues. The dual-luciferase reporter assay demonstrated that TRIAP1 is a target gene of miR-107. Additionally, the results revealed that overexpression of miR-107 resulted in a lower proliferation rate and higher Apoptosis rate of A549 cells, compared with the negative control (NC) and control groups (P<0.01). The variation of cell proliferation and Apoptosis induced by miR-107 mimics was reversed by co-transfection with pcDNA3.1-TRIAP1. Furthermore, the expression levels of cyclin D1 and proliferating cell nuclear antigen were markedly decreased in the miR-107 mimics group compared with the NC group (P<0.01). The expression levels of BCL2 associated X Apoptosis regulator, tumor protein p53 and Caspase 3 were upregulated and the expression levels of TRIAP1 and BCL2 Apoptosis regulator were significantly reduced in the miR-107 mimics group compared with the NC group (P<0.01). The results of the present study suggested that miR-107 regulates lung Cancer cell proliferation and Apoptosis by targeting TRIAP1.