Effects of mdig on proliferation and apoptosis of lung cancer cells.

Expression of mineral dust-induced gene (mdig) in lung cancer NCI-H1650 cells was detected to investigate the effects of mdig on proliferation and apoptosis of NCI-H1650 cells. NCI-H1650 lung cancer cells were cultured . The expression of mdig in NCI-H1650 cells was lowered using ribonucleic acid interference (RNAi) technique. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were used to detect the effects of mdig small interfering RNA (siRNA) on messenger RNA (mRNA) and the protein expression of mdig in lung cancer NCI-H1650 cells, respectively. The effect of mdig on the proliferation of NCI-H1650 cells was observed through 3-(4,5)-dimethylthiazol (-z-y1)-3,5-di-phenyl tetrazolium bromide (MTT) assay, and flow cytometry was used to detect the impact of mdig on cell cycle and apoptosis of NCI-H1650 cells. The influence of mdig on caspase-3 and poly (ADP-ribose) polymerase 1 (PARP1) proteins in NCI-H1650 cells were investigated via western blot analysis. The results of RT-qPCR and western blot analysis showed that mdig siRNA obviously inhibited the expression of mRNA and protein of mdig in NCI-H1650 cells. Results of the MTT assay showed mdig siRNA could significantly reduce the proliferation ability of NCI-H1650 cells. In addition cell cycle detection showed that mdig siRNA caused NCI-H1650 cell arrest at G1 phase. Apoptosis detection results indicated that mdig siRNA promoted apoptosis of NCI-H1650 cells. Western-blot analysis revealed that mdig siRNA upregulated the expression of cleaved caspase-3 and cleaved PARP1 proteins in NCI-H1650 cells. Mdig is highly expressed in lung cancer NCI-H1650 cells while mdig siRNA can inhibit proliferation of NCI-H1650 cells and accelerate apoptosis. The underlying mechanism may be related to inhibited cell cycle progression and upregulated expression of cleavage proteins (cleaved caspase-3 and cleaved PARP1).