[The apoptotic mechanism of hepatocellular carcinoma cell line (HepG2) induced by arsenic trioxide].

ABSTRACT

OBJECTIVE: To explore the apoptotic mechanism of human hepatic carcinoma cell line HepG2 induced by arsenic trioxide (As2O3). METHODS: The human hepatoma cell line HepG2 was treated with 0, 2.5, 5 and 10 micromol/L arsenic trioxide for 24 h. Cytotoxicity was tested by MTT assay (additional 25 and 50 micromol/L arsenic trioxide treatment groups), cellular apoptosis were detected by flow cytometry, reactive oxygen species (ROS) level were quantified by DCFH-DA fluorescent probe staining and glutathione content were measured by DTNB method with commercial kits. Western blot assay was used to detect the protein expression of gamma-glutamylcysteine synthetase (gamma-GCS, GCLC and GCLM subunits) and nuclear factor erythroid 2-related factor 2 (Nrf2). RESULTS: With the increase of arsenic trioxide concentration, cellular survival, glutathione content and gamma-GCS (GCLC and GCLM subunits) protein expression level decreased (P < 0.05); while cellular apoptotic rate, reactive oxygen species level and Nrf2 protein expression increased (P < 0.05). CONCLUSION: Arsenic trioxide induces the apoptosis of human hepatoma cell line HepG2 through ROS induction, gamma-GCS expression inhibition and cellular glutathione content depletion.