The Study And Underlying Molecular Mechanisms Of Apoptosis And Autophagy By Sodium Selenite In A549Human Lung Carcinoma Cells

ObjectiveTo investigate the effects of sodium selenite on the cell autophagy and apoptosis ofA549cells and to elucidate its molecular mechanisms.MethodsA549cells were cultured and treated in vitro. During the experiments,A549cells wererandomly divided into five groups, including the blank control group, the sodium selenitetreatment group at concentration of0.5、2.5、5.0、8.0μmol/L. After the cells are treated for24h、48h hours, the cells viability is measured by the MTT assay. Western blotting andimmunohistochemical SABC method is used to determine Beclin1、 Lc3and Cytcexpression.ResultsBoth culturing for24h and48h with sodium selenite,the cell viability was decreasedsignificantly as comparing with that of the blank control group as control(P<0.01) and in aconcentration and time-dependent manner.Immunohistochemical results of Cytc showed: sodium selenite increased the greyvalue of Cytc protein in A549cells;At24hours, the grey value of Cytc protein wassignificantly higher(P<0.05) in5.0、8.0μmol/L sodium selenite group than in blankcontrol group; At48hours, the grey value of Cytc protein was significantlyhigher(P<0.05)in every sodium selenite group than in blank control group. The result ofwestern blotting was similar to that from immunocytochemical method.Immunohistochemical results of Beclin1showed: sodium selenite increased the greyvalue of Beclin1protein in A549cells;At24hours, the grey value of Beclin1protein wassignificantly higher(P<0.05) in8.0μmol/L sodium selenite group than in blank controlgroup; At48hours, the grey value of Beclin1protein was significantly higher(P<0.05)in5.0、8.0μmol/L sodium selenite group than in blank control group. The result of western blotting was similar to that from immunocytochemical method.Immunohistochemical results of LC3showed: sodium selenite increased the greyvalue of LC3protein in A549cells;At24hours, the grey value of LC3protein wassignificantly higher(P<0.05) in5.0、8.0μmol/L sodium selenite group than in blankcontrol group; At48hours, the grey value of LC3protein was significantlyhigher(P<0.05)in5.0、8.0μmol/L sodium selenite group than in blank control group.The result of western blotting was similar to that from immunocytochemical method.ConclusionsSodium selenite could significantly inhibit the growth of A549cells through inducingcell autophagy and apoptosis in vitro, which mechanism may depend on mitochondrialapoptotic pathway, and increased Beclin1and LC3protein level.