MicroRNA-182 modulates chemosensitivity of human non-small cell lung cancer to cisplatin by targeting PDCD4

BACKGROUND Overexpression of microRNA-182 (miR-182) is found in various human cancers, including non-small cell lung cancer (NSCLC). Our aim is to investigate the association of miR-182 expression with the sensitivity of NSCLC to cisplatin. METHODS TaqMan RT-PCR or Western blot assay was performed to detect the expression of mature miR-182 and programmed cell death 4 (PDCD4) protein. miR-182 and (or) PDCD4 depleted cell lines were generated using miR-182 inhibitor and (or) siRNA. The viabilities of treated cells were analyzed using MTT assay. RESULTS The expression level of miR-182 in A549 cell line was significantly higher than that in NHBE cell line (p < 0.01). Transfection of miR-182 inhibitor induced sensitivity of A549 cells to cisplatin. A549 cells transfected with PDCD4 siRNA became more resistant to cisplatin therapy. We found an increase PDCD4 protein level following the transfection of miR-182 inhibitor using Western blot analysis. In addition, the enhanced growth-inhibitory effect by miR-182 inhibitor was weakened after the addition of PDCD4 siRNA. CONCLUSIONS The results of the present study demonstrated that overexpression of miR-182 may involve in chemoresistance of NSCLC cells to cisplatin by down-regulating PDCD4. VIRTUAL SLIDES The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1793467320130186.