Effects of Gekko sulfated polysaccharide–protein complex on human hepatoma SMMC-7721 cells: Inhibition of proliferation and migration

Abstract

Aim of the study Gekko swinhonis Guenther has been used as an anti-cancer drug in traditional Chinese medicine for hundreds of years. Here we investigated the structural characterization and anti-cancer effects of sulfated polysaccharide–protein complex (GSPP) isolated from Gekko swinhonis Guenther. Materials and methods The structure of GSPP was characterized by high performance liquid chromatography, gas chromatography, gas chromatography–mass spectrometry, β-elimination reaction, and NMR spectroscopy. SMMC-7721 cells were used to assess the influence of GSPP on hepatocellular carcinoma. Cell proliferation and survival was determined by trypan blue exclusion assay. Cell migration was performed by wound-healing and transwell assay. The secretion of IL-8 was detected by an enzyme-linked immunosorbent assay kit. Flow cytometry was used to analyze intracellular calcium concentration, as well as cell cycle distribution and apoptosis. Confocal microscopy was used to assess the localization and configuration of actin filaments. Results GSPP was chemically characterized as a sulfated polysaccharide–protein complex with O-glycopeptide linkages. Our results showed that GSPP inhibited the proliferation of SMMC-7721 cells and blocked cells in the S phase. No direct toxicity against cells was observed. Furthermore, GSPP inhibited the migration of SMMC-7721 cells with the reduction of intracellular calcium. Actin filaments were polymerized and accumulated in the cytoplasm of the treated cells, whereas the secretion of IL-8 was not significantly changed after GSPP exposure. Conclusion We describe an identified sulfated polysaccharide–protein complex, and demonstrate its direct effect on hepatocellular carcinoma cell migration via calcium-mediated regulation of the actin cytoskeleton reorganization.