The Role Of Mitochondrial Mediated Apoptosis Pathway In Human Cancer SGC-7901Aoptosis Induced By Sodium Selenite

ObjectiveTo study the changes of Bax/Bcl-2and CytC and mitochondrial membrane potentialin human cancer SGC-7901cell aoptosis induced by sodium selenite. To investigate theeffect of mitochondrial mediated apoptosis pathway in human cancer SGC-7901apoptosisinduced by sodium selenite.MethodsHuman gastric cancer SGC-7901cell lines divided into normal control group,2.5、5.0、10.0μmol/L sodium selenite group. The cell lines maintained after treatment withdifferent sodium selenite concentration group for a long time of24,48h. The changes ofmitochondrion membrane potential with Rhodamine123probes staining were detected byflow cytometry. Bax/Bcl-2、 Cytc protein of SGC-7901cells was stained byimmunohistochemical streptavidin-biotin-peroxidase complex (SABC) method. Bax/Bcl-2,Cytoplasm Cytc and mitochondria Cytc protein of SGC-7901cells was stained by Westernblot imprinting method.ResultsThe results of mitochondrial membrane potential changes detected by flow cytometryshow that: at24h,48h, mitochondrial membrane potential is gradually lower with higherconcentration of sodium selenite (P<0.05). At the same time, the membrane potential of5.0μmol/L、10μmol/L sodium selenite groups droped was significantly higher than2.5μmol/L sodium selenite groups.The results of Cytc protein distribution detected by Immunocytochemistry SABCmethod and cytoplasm Cytc and mitochondrial Cytc protein content variation detected by Western blot imprinting method show that: sodium selenite can improve the expression ofCytc protein in SGC–7901cells. at24h, the MOD of Bax protein is significantlyhigher(P<0.05) in5.0,10.0μmol/L sodium selenite group than normal control group; at48h, the MOD of Bax protein is significantly higher(P<0.05) in every sodium selenitegroup than normal control group; Western blot imprinting method show that: at24h and48h, the cytoplasm Cytc protein levels is significantly higher in every sodium selenitegroup than normal control group（P<0.05）, the mitochondrial Cytc protein levels issignificantly lower in every sodium selenite group than normal control group（P<0.05）. Atthe same time,the Cytc protein,s MOD was gradually rise,the cytoplasm Cytc proteinexpression intensity gradually strengthen, mitochondrial Cytc protein expression intensitygradually weakened with higher concentration of sodium selenite.The results of Bax protein distribution detected by Immunocytochemistry SABCmethod and Western blot imprinting method show that: sodium selenite can improve themean optic density(MOD) of Bax protein expression in SGC–7901cells. at24h, theMOD of Bax protein is significantly higher(P<0.05) in10.0μmol/L sodium selenite groupthan normal control group; at48h, the MOD of Bax protein is significantly higher(P<0.05)in5.0,10.0μmol/L sodium selenite group than normal control group. Western blotimprinting method show that: at24h and48h, the Bax protein levels is significantly higherin every sodium selenite group than normal control group（P<0.05）. At the same time,theBax protein,s MOD and protein expression intensity were gradually higher with higherconcentration of sodium selenite.The results of Bcl-2protein distribution detected by Immunocytochemistry SABCmethod and Western blot imprinting method show that: sodium selenite can reduced themean optic density(MOD) of Bcl-2protein expression in SGC–7901cells. at24h, theMOD of Bax protein is significantly higher(P<0.05) in5.0,10.0μmol/L sodium selenitegroup than normal control group; at48h, the MOD of Bax protein is significantlyhigher(P<0.05) in5.0,10.0μmol/L sodium selenite group than normal control group.Western blot imprinting method show that: at24h and48h, the Bcl-2protein levels issignificantly lower in every sodium selenite group than normal control group（P<0.05）. Atthe same time,the Bcl-2protein,s MOD and protein expression intensity were graduallylowerer with higher concentration of sodium selenite.ConclusionSodium selenite may be by reduce the mitochondrial membrane potential, regulatingBax/Bcl-2gene expression, to promote Cytc release from mitochondria to the cytoplasm, Induced human gastric cancer SGC-7901cell apoptosis through mitochondrial-dependentpathway.