Biochemical and morphological characteristics of selenite-induced apoptosis in human hepatoma Hep G2 cells.

Selenium is a cellular growth inhibitor in many mammary tumor cells. To comprehend the mechanism for the selenium-induced cell death, we examined the effects of sodium selenite, which has been one of the most extensively investigated selenium compounds, in human hepatoma Hep G2 cells.Cell viability gradually decreased after treatment with sodium selenite within the concentration range of 10-50 microM. Low (10 mM) selenite has shown a high-percentage laddering pattern compared to the high (25 microM) cytotoxic selenium concentration in agarose gel electrophoresis. G2/M-phase enrichment was also concentration dependent. The most consistent transmission electron microscopic finding was the existence of large lysosomes. Based on these data, we hypothesize that sodium selenite predominantly shows its apoptotic effect over hydrogen selenite accumulation.