Effect of staphylococcal enterotoxin A on cell cycle process and apoptosis in human hepatoma SSMC7721 Cell

Abstract

Objective We detected the proliferation inhibition effect of staphylococcal enterotoxin A (SEA) on human liver cancer SSMC7721 cell lines in vitro to provide a theoretical basis for the therapy of liver cancer.Methods We applied MTT colorimetric method to assay the SSMC7721 cell's proliferation inhibition rate treated by different concentrations (0 μg/L,20 μg/L,40 μg/L and 80 μL) of SEA.We decided the changes of the cell cycle progression by flow cytometry and the apoptosis rate by fluorescence microscopy.Results When the SSMC7721 cells were treated with different concentrations(20 μg/L,40 μg/L and 80 μg/L) of SEA,cell proliferation inhibition rates were (18.4 ± 1.3) ％,(35.5 ± 0.9) ％,(46.7 ±1.6) ％ respectively and the statistical differences were significant compared to the control group(P ＜ 0.01),and the proliferation is in an obvious dose dependent manner.Flow cytometry results indicated that the cells in the G0/G1 period increased;the cells in the S period decreased;the cells in the G2/M period increased.Cell apoptosis rates after treatment by 20 μg/L,40 μg/L and 80 μg/L SEA increased to 12.5％,19.4％ and 23.2％.respectively from 1.0％ without SEA treatment.Conclusion SEA can significantly increase the cells proliferation inhibition rate and inhibit the cell's transformation from G1 to S period in SSMC7721 cell and induce the SSMC7721 cell's apoptosis. Key words: Staphylococcal enterotoxin A; SSMC7721 cell; Cell cycle; Apoptosis