Expression of transcription factor Sp1 in hepatocellular carcinoma

Objective To determine whether the transcription factor Sp1 is differentially expressed in human hepatocellular carcinoma (HCC) and to investigate the potential pro-apoptotic effect of transforming growth factor beta 1 (TGFβ1) through Sp1 by using the HCC cell line HepG2.Methods The Sp1 expression patterns were detected by immunohistochemistry in tumors from 51 cases of HCC and 10 specimens of normal liver tissues.HepG2 cells in culture were stimulated by TGFβ1 and the change in Sp1 mRNA expression was detected by RT-PCR while the change in cell apoptosis rate was detected by flow cytometry.Statistical significance of changes were assessed by one-way ANOVA.Results The positive rate of Sp1 expression was significantly higher in HCC tissue than in normal liver tissues (P<0.01) .The level of Sp1 mRNA was significantly lower in HepG2 cells stimulated with TGFβ1 than in the control cells (P<0.01) , and the effect was TGFβ1 dose-dependent.The apoptosis rate of HepG2 cells increased in correspondence with increases in TGFβ1 concentration.Conclusion Overexpression of Sp1 may functionally contribute to HCC occurrence and development.TGFβ1 can induce apoptosis of HepG2 HCC cells in vitro, and this apoptotic effect may involve Sp1.