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

Abstract

BackgroundHepatocellular 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. ObjectiveEvaluating the anti-cancer cytotoxic effect of exopolysaccharides (EPS-1) produced by the newly studied Bacillus sonorensis strain SAmt2. MethodsThe 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. ResultsOur 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.