Effect And Mechanism Of Sodium Selenite On The Growth And Apoptosis And Htert Protein Expression Of Gastric Cancer SGC-7901 Line

ObjectiveTo investigate effect and mechanism of sodium selenite on human gastric cancer SGC-7901 cell growth, apoptosis and expression of hTERT.MethodsSGC-7901 cells were treated with different concentrations(0,0.5,2.5,5,8μmol/L)so dium selenite at 24h,48h.72h and 96h.the morphologic changes of SGC-7901 cells were observed by Phase contrast microscope;The impact of sodium selenite on S GC-7901 cells proliferation was tested by MTT assay. SGC-7901 cells apoptosis we re detected by flow cytometry with AnnexinV-FITC, PI double staining.hTERT prote in of SGC-7901 cells were stained by immunohistochemical SABC method.SGC-790 1hTERTmRNA expression were detected by RT-PCR.ResultsIn the blank control group, the SGC-7901 cells proliferation was like skin-type growth, such as paving stone-like, cell outlines was clear, the cell denseness was higher,growth was vigorous.Under the action of the sodium selenite, the morphology of SGC-7901 cells in the 0.5μmol/L,2.5μmol/L group did not change significantly, the cell proliferation was slower slightly.5μmol/L,8μmol/L group, some cells gradu ally became round and float, adhesive ability became weakened, the cell proliferatio n was slower significantly. Swell cells were appearing, some the cell debris floated in culture medium. The change was evidence with sodium selenite higher. MTT as say results showed that:absorbance values of SGC-7901 cells gradually decreased with the increasing concentration of sodium selenite, cultured 24h,48h,72h,96h la ter; the absorbance values were significantly lower than blank control group (P<0.0 1) when Na2SeO3 concentration higher than 2.5μmol/L cultured 24h and 72h later. The absorbance values were significantly lower (P<0.01) all sodium selenite groups than the normal control group at 48h,96h. Flow cytometry results showed that:D ifferent concentrations of sodium selenite facilitated SGC-7901 cells apoptosis in cul turing SGC-7901 cells 24h,48h,72h and 96h.Apoptosis rate was significantly higher (P<0.01) in 5μmol/L,8μmol/L sodium selenite group than in the blank control gro up. Immunocytochemistry results showed:sodium selenite reduced the mean optic de nsity (MOD)of hTERT protein in SGC-7901 cells; at 24h, the MOD was significant ly lower (P<0.01) in 5μmol/L,8μmol/L sodium selenite group than in blank control group; at 48h, was significantly lower (P<0.01), in 0.5μmol/L,5μmol/L,8μmol/L so dium selenite group than in blank control group; at 72h, was significantly lower (P <0.01) in 2.5μmol/L,5uμmol/L,8μmol/L sodium selenite group than in normal contro 1 group;at 96h,was significantly lower (P<0.01) in every sodium selenite group than in blank control group.At the same time, the hTERT protein's MOD was lowerwit h higher concentrations of sodium selenite.RT-PCR test results showed:SGC-7901 cel Is hTERT mRNA the expression was significantly lower in 5μmol/L,8μmol/L sodiu m selenite group than in the blank group at 24h(P<0.05), was significantly lower i n 2.5μmol/L,5μmol/L,8μmol/L sodium selenite groups than in blank group at 48h,7 2h,96h (P<0.05).ConclusionSodium selenite can inhibit SGC-7901 cell growth,induce SGC-7901 cell apopto sis, the mechanism maybe associated with reduction of hTERT expression.