Antitumor activity of selenium modification of bovine milk component β-Lg (Se-β-Lg) on H22 cells
In this study, apoptosis induction and antitumor activity of a novel complex seleno-β-lactoglobulin (Se-β-Lg) on H22 cells were explored. In vitro experiments, MTT assay showed that Se-β-Lg caused cytotoxicity on H22 cells in a concentration- and time-dependent manner and displayed few proliferation inhibition effects on normal liver L02 cells. Annexin V-FITC/PI and PI staining assay showed that Se-β-Lg induced the apoptosis changes of H22 cells from early to late apoptosis, and led to S phase cell cycle arrest. Western blot and Z-VAD-FMK inhibitor assay showed that Se-β-Lg triggered Fas/FasL-mediated caspase 8-dependent extrinsic death receptor pathway in H22 cells. In vivo experiments, Se-β-Lg effectively repressed the transplanted H22 solid tumor growth in a dose-dependent manner and exhibited few toxic effects on host animals. H&E and PI staining of tumor tissues assay showed that Se-β-Lg caused the occurrence of typical apoptosis morphology features and dose-dependently increased the proportion of apoptosis peaks (Sub-G1 peak) on H22 solid tumor, respectively. These results suggested that Se-β-Lg had capacity of inducing H22 tumor cells apoptosis in vitro and vivo, and supported that Se-β-Lg as a functional complex was applied in food field.