The effects of transforming growth factor-β1 induced apoptosis of human gastric carcinoma cells related to Caspases

Abstract

Objective To investigate the effects of transforming growth factor-β1 (TGF-β1) induced apoptosis.Methods Apoptosis proportion of human gastric SGC7901 carcinoma cells induced by TGF-β1 was tested by flow cytometry,blocking Caspase-8 by RNA interference (RNAi) ,the expression of Caspase-8 was analyzed by Western blotting.Results The apoptosis rate of SGC7901 cells obviously increased with the treatment of TGF-β1,an active fragment of caspase-8 started to occur 12 h after TGF-β1 treatment,whereas the caspase-9 active fragment occurred 24 h after TGF-β1 treatment. After RNAi against Caspase-8,the expression of Caspase-8 was decreased,11.2％ of control group at 24 h,and then can not be detected at 48 h,72 h,re-emergence at 96 h,9.2％ of control group.Conclusion TGF-β1 induced the apoptosis of SGC7901 cells via Caspases pathway,caspase-8 may be the first caspase activated;Suppression of caspase-8 by RNAi can effectively block the TGF-β1/Caspases signal pathway,and subsequently inhibits the apoptosis of SGC7901 cells. Key words: Gastric carcinoma; Transforming growth factor-β1; Caspase; Apoptosis