Study on the mechanism of inhibiting proliferation of hepatocellular carcinoma HepG2 cells by Grifola polysaccharide

Abstract

Objective: To observe the effects of Grifola frondosa polysaccharides (GFP) on proliferation, apoptosis, cell cycle, expression of cyclin and apoptotic proteins of hepatocellular carcinoma HepG2 cells of human, and to explore the mechanism of its inhibition on proliferation of HepG2 cells. Methods: The experiment was divided into PGF/control group. Different concentrations of PGF solution were used to interfere with human hepatocellular carcinoma cells HepG2 in vitro. MTT assay was used to detect the effects of different concentrations of PGF on the survival of HepG2 cells. The apoptosis rate and cell cycle distribution of HepG2 cells induced by PGF were detected by flow cytometry. The expressions of Bcl-2, Bax and Caspase3, Cyclin-A1 and Cyclin-B1 were detected by immunohistochemistry. Results: Compared with the control group, PGF could effectively decreased proliferation of human hepatoma HepG2 in a concentration-dependent manner. Cell cycle detection showed that the proportion of S phase in each group was 24.71%, 28.78%, 36.26 and 42.39%, respectively, indicating that cells were blocked in S phase. The immunocytochemical results showed that the expression of Cyclin A1 protein decreased significantly, and the expression of cyclin-B1 was not significantly different before and after treatment. Flow cytometry showed that the apoptosis rates in control group and PGF group were 0, 18.0%, 30.5% and 49.5%, respectively. The difference between PGF group and control group was significant. Immunocytochemical results showed that PGF could significantly inhibit the expression of mitochondrial apoptosis inhibitor Bcl-2, increase the expression of pro-apoptotic factor Bax in a concentration-dependent manner, and up-regulate the percentage of Bcl-2/Bax to induce apoptosis of hepatocellular carcinoma cells. Conclusion: PGF can inhibit the proliferation of human hepatoma HepG2 cells by inducing apoptosis, inhibiting the proliferation of cancer cells, blocking cell cycle, inhibiting the expression of Bcl-2, and upregulating the expression of Bax and Caspase3.