Effects of PAR-2 agonist peptide on proliferation and cytosolic calcium level in hepatoma cells / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effects of PAR-2 agonist peptide on the proliferation and cytosolic calcium concentration ([Ca~(2+)]_c) in human hepatoma cells HepG2. METHODS: Human hepatoma cell line HepG2 was cultured. The cells were treated with PAR-2 agonist peptide SLIGKV-NH_2 and the reverse PAR-2 agonist peptide VKGILS-NH_2, respectively. The [Ca~(2+)]_c of hepatoma cells were measured by microfluorimetric techniques based on calcium indicator fura-2/AM. The influences on proliferation of hepatoma cells were determined by MTT method. The changes of cell cycle were evaluated by flow cytometry, and the changes of cyclin D1 mRNA expression were detected by RT-PCR. RESULTS: After treated with 50 μmol/L SLIGKV-NH_2, a rapid rise of [Ca~(2+)]_c in HepG2 cells was induced (P<0.01), percent S phase, G_2/M phase and proliferation index (PI) of HepG2 cells were elevated (P<0.01), and cyclin D1 mRNA expression was significantly upregulated (P<0.01). The proliferation rates of HepG2 cells treated with 1-50 μmol/L SLIGKV-NH_2 were significantly increased, and the effect was in a dose-dependent manner (P<0.01 or P<0.05). No statistical significance of the difference between VKGILS-NH_2 and control group was observed (P>0.05). CONCLUSION: PAR-2 agonist peptide induces the rise of [Ca~(2+)]_c in HepG2 cells, upregulates the expression of cyclin D1 mRNA, accelerates the progress of cell cycle, promotes the synthesis of DNA and the proliferation of hepatoma cells via activating PAR-2 in vitro.