Apoptotic threshold of hepatoma cell lines induced by As_2O_3 and CDA- II

Objective To study the apoptosis threshold of hepatoma cell lines induced by arsenic trioxide (As2O3) and cell differentiation agent- II (CDA- II ). Methods Hepatoma cell lines were cultured with 1.0-5.0 μmol/L As2O3 and 1. 0-5. 0 g/L CDA- II for various durations. Using immunofluo-rescence staining of Hoechst 33 258 in hepatoma cells, flow cytometry and DNA gel eletrophoresis were applied to detect the apoptosis rate. Results After treatmeant with As2O3 or CDA-II + As2O3, there were dispersive fluorescences in normal cells' nuclei and compact paniculate fluorescences in apoptosis cells' nuclei by immunofluorescence staiming of Hoechst 33 258; agarose electrophoresis showed marked DNA ladder; flow cytometry analysis revealed a sub-G1 cell peak. The apoptotic threshold of hepatoma cells was 5.0 @mol/L As2O3 or 1.0 μmol/L As2O3 + 1.0 g/L CDA- II . Conclusion CDA- II and As2O3 can induce apoptosis of the hepatoma cells, and display a significant synergic effect.