The Influence Of Helicobacter Pylori On Human Hepatocellular Carcinoma Cells HEPG2Proliferation And The Factor Expression Of TGF-β1/SMADS Signaling Pathway

Objective:To research on the influence of H. pylori on two kinds of phenomena:one is the cell proliferation and inhibition of human hepatoma cell line (HepG2); the other one is the expression of TGF-β1, TβRⅠ, TβRⅡ, Smad2, Smad3, Smad4, Smad7gene in the TGF-β1/Smads signal pathways.Methods:HepG2cells were cultured in vitro as well as H. pylori; CagA+H. pylori and CagA-H. pylori strains were identified by the method of PCR, CagA+H. pylori and CagA-H. pylori strains, with different concentrations, separately acted upon HepG2cells which were set as a negative control group without H. pylori during24hours; MTT assay the influence of CagA+H. pylori and CagA-H. pylori on HepG2cell proliferation, detect the expression of TGF-β1, TβRⅠ, TβRⅡ, Smad2, Smad3, Smad4, Smad7gene through the method of Real-time PCR.Results: The MTT results showed that when at the concentration of101,102CFU/ml, CagA+H. pylori and CagA-H. pylori cause the proliferation of HepG2cells, compared with the negative control group p<0.05, Opposite to the high concentration bacterial liquid (103,104,105,106CFU/ml)could prevent the cell growth, there were statistically significant difference compared to the negative control group p<0.05; at the same concentration, the proliferation(or inhibition) rate of HepG2cells in CagA+H. pylori group was higher than that CagA-H. pylori group (p<0.05).The expression of gene detected by the method of Real-time PCR showed that when at low concentrations (101,102CFU/ml), CagA+H. pylori and CagA-H. pylori cloud promote the expression of TGF-β1,Smad2,Smad7,inhibited the expression of TβRⅠ,TβRⅡ,Smad3,Smad4; however,high concentrations (103,104,105,106CFU/ml)of CagA+H. pylori and CagA-A. pylori did the reverse role, they promoted the expression of TβRⅠ,TβR Ⅱ,Smad3,Smad4, inhibited the expression of TGF-β1,Smad2,Smad7.The role of CagA+H. pylori promoted and inhibited gene expression in HepG2cells were significant than that CagA-H. pylori at the same concentration (p<0.05).Conclusions:1. low concentration of CagA+H. pylori and CagA-H. pylori promoted the growth of HepG2cells, while high concentration inhibited the growth of cells. At the same concentration, the proliferation (or inhibition) rate of HepG2cells in CagA+H. pylori group was higher than that CagA-H. pylori group.2. CagA+H. pylori and CagA-H. pylori promoted the expression of TGF-β1,Smad2,Smad7, inhibited the expression of TβRⅠ,TβRⅡ,Smad3,Smad4at low concentration, but there were an opposite effect when they in high concentration.The role of CagA+H. pylori promoted and inhibited gene expression in HepG2cells were significant than that CagA-H. pylori at the same concentration.3. The molecular mechanism of H.pylori acted on HepG2cells possibly by changing the expression of TGF-β1, TβRⅠ, TβRⅡ, Smad2, Smad3, Smad4, Smad7gene, then affected the biological activity of TGF-β1/Smads signaling pathway.