MicroRNA-145 inhibits migration and induces apoptosis in human non-small cell lung cancer cells through regulation of the EGFR/PI3K/AKT signaling pathway

Abstract

In the present study, the therapeutic effects and the underlying molecular mechanisms of microRNA (miR)-145 were investigated in non-small cell lung cancer (NSCLC) cells. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to examine miR-145 expression. An MTT assay and flow cytometry were used to investigate cell proliferation and apoptosis, respectively. The protein expression of Bax, epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K) and phosphorylated-protein kinase B (AKT) was examined by western blot analysis. miR-145 expression was downregulated in patients with NSCLC who were treated with chemotherapy. The downregulation of miR-145 in A549 cells reduced lactate dehydrogenase (LDH) expression, apoptosis, caspase-3/-9 levels and Bax protein expression, while it increased cell proliferation. Upregulation of miR-145 in A459 cells increased LDH, apoptosis, caspase-3/-9 levels and Bax protein expression, while it inhibited cell proliferation. The EGFR/PI3K/AKT signaling pathway was suppressed by miR-145 upregulation in A549 cells and induced by miR-145 downregulation. The EGFR inhibitor suppressed the EGFR/PI3K/AKT signaling pathway and increased the anticancer effects of miR-145 upregulation in A549 cells. The PI3K inhibitor suppressed the PI3K/AKT signaling pathway and reversed the anticancer effects of miR-145 upregulation in A549 cells. In conclusion, the present study demonstrated that miR-145 regulates the EGFR/PI3K/AKT signaling pathway in patients with NSCLC.