[Downregulation of HSP70 gene expression and apoptosis in human hepatocellular carcinoma SMMC-7721 cells induced by nimesulide in vitro].

AIM

To investigate the effect of nimesulide on cell apoptosis and possible mechanism in human hepatocellular carcinoma SMMC-7721 cells.

METHODS

SMMC-7721 cells were treated with nimesulide at different concentrations. Cell viability was assessed by MTT assay. Cell apoptosis rate was determined with flow cytometry. The cleavage activity of PARP and caspase-9 and the expression of HSP70 were evaluated using RT-PCR and Western blotting. The influence of HSP70 on cell apoptosis was observed using RNA interference silencing HSP70 expression.

RESULTS

Nimesulide significantly inhibited cell growth in SMMC-7721 cells in a time- and concentration-dependent manner, and induced cell apoptosis in a concentration-dependent manner. Moreover, nimesulide promoted the cleavage of caspase-9 and PARP and inhibited the mRNA and protein expression of HSP70. Through the specific inhibition on HSP70 gene with siRNA, cell apoptosis increased, and the apoptosis was enhanced by the cleavage activity of caspase-9 and PARP.

CONCLUSION

Nimesulide could inhibit cell growth and induce apoptosis in human hepatocellular carcinoma SMMC-7721 cells via the downregulation of HSP70.