Effect of MicroRNA-335 on the Metastasis, Invasion and Proliferation of Cells in Patients with Non-small Cell Lung Cancer

Objective: To investigate the effect of microRNA-335 on the metastasis, invasion and proliferation of cells in patients with non-small-cell lung cancer (NSCLC). Methods: Real-time PCR was performed to detect the expression differences of microRNA-335 between 12 pairs of NSCLC and normal cancerous peripheral tissues, and between SPCA-1 cells of NSCLC and 16HBE of normal pulmonary epithelial cells, while miR-335 expression in SPCA1 cells were down-regulated and proved by Lipofectamine 2000 transient transfection and realtime PCR, respectively. Scratch test, Transwell invasion assay as well as MTT and clone formation assays were applied to respectively determine the effect of miR-335 on the metastasis, invasion and proliferation of SPCA-1 cells. Results: Compared with para-carcinoma tissues and 16HBE cells, miR-335 expression was evidently higher in NSCLC and SPCA-1 cells. However, it decreased remarkably after transient transfection of anti-miR-335 by SPCA-1 cells with Lipofectamine 2000 for 24 h. Metastasis and invasion of SPCA-1 cells could be inhibited by suppressing miR-335 expression with suppression rates being (42.8 +/- 2.7)% and (73.25 +/- 4.4)%, respectively. However, the inhibition of miR-335 expression had no effect on the proliferation of SPCA-1 cells. Conclusion: miR-335 expresses highly in NSCLC and its low expression can obviously inhibit the metastasis and invasion of SPCA-1 cells, but has no effect on the proliferation.