miR-137 inhibits the proliferation of human non-small cell lung cancer cells by targeting SRC3

Non‑small cell lung cancer (NSCLC) is the most common type of lung cancer. The results of the present study demonstrate that high expression of microRNA (miR)‑137 and low expression of steroid receptor coactivator‑3 (SRC3) had a significant negative correlation in 40 NSCLC tissue samples. In addition, cell colony formation and proliferation was significantly reduced in miR‑137‑transfected A549 and NCI‑H838 cells compared with scramble‑transfected NSCLC cell lines. miR‑137 was identified to induce G1/S cell cycle arrest and dysregulate the mRNA expression of cell cycle‑associated proteins (proliferating cell nuclear antigen, cyclin E, cyclin A1, cyclin A2 and p21) in NSCLC cells. Notably, miR‑137 could significantly suppress SRC3 3' untranslated region (UTR) luciferase‑reporter activity, an effect that was not detectable when the putative 3'‑UTR target‑site was mutated, further clarifying the molecular mechanisms underlying the role of miR‑137 in NSCLC. In conclusion, the results of the present study suggest that miR‑137 suppresses NSCLC cell proliferation by partially targeting SRC3.