miR-641 Functions as a Tumor Suppressor by Targeting MDM2 in Human Lung Cancer

Lung cancer is the leading cause of deaths due to cancer. Studies suggest an important role of microRNAs (miRNAs) in a variety of cancers, including lung cancer. In the present study, we evaluated the role of miR-641 in human lung cancer A549 cells. Quantitative RT-PCR and Western blot were used to measure mRNA and protein expression, respectively. Cell viability and cell apoptosis were respectively measured by MTT assay and flow cytometry. In addition, luciferase activity assay was used to identify the target of miR-641. The expression of miR-641 was downregulated in lung cancer tissues and lung cancer cell lines (p < 0.05 or p < 0.01). Overexpression of miR-641 significantly inhibited proliferation and induced apoptosis of lung cancer cells (p < 0.05, p < 0.01, or p < 0.001). MDM2 was identified as a direct target of miR-641. Overexpression of miR-641 decreased the expression of MDM2 and increased the expression of p53 in lung cancer cells.