Bacillus sonorinses derived exopolysaccharide enhances cell cycle arrest, apoptosis, necrosis, autophagy and COX-2 down regulation in liver cancer cells

Abstract

Background: Hepatocellular carcinoma (HCC) is one of the most serious types of cancer that accounts for numerous cancer deaths worldwide. HCC is poorly prognosed and is a highly chemotherapy-resistant tumor. Therefore, new treatments are urgently needed. Exopolysaccharides (EPS-1) produced from the novel Bacillus sonorensis strain was found to exhibit chemopreventive effects against cancer. Objective: Evaluating the anti-cancer cytotoxic effect of exopolysaccharides (EPS-1) produced by the newly studied Bacillus sonorensis strain SAmt2. Methods: The cytotoxic activity was investigated through cell cycle, apoptosis, and autophagy analyses using flow cytometry technique. Also, the effect of EPS-1 on Huh7 release of COX-2 was examined using ELISA. Results: Our results revealed that EPS-1exhibit an anti-proliferative effect on Huh7 cells through decreasing the percentage of cells at the S-phase and G2 phase, while increasing the cell population at the sub-G1 and G1 phases. Apoptosis analysis showed that EPS-1 increased necrotic and apoptotic cell fractions in EPS-1 treated Huh7. In addition, it induced significant autophagic cell death in the Huh7.Finally, antiproliferative and apoptosis induction results were supportedby ELISA assay results where the protein level of COX-2 was declined. Conclusion: : In conclusion, EPS-1 derived from B. sonorensis SAmt2, is a promising proliferation inhibitor of Huh7 cells with potential anticancer effects.

Keywords

• Flow cytometry
• COX-2
• Autophagy
• Hepatocellular carcinoma
• Apoptosis