Cell cycle arrest and apoptosis induced by arsenic trioxide in colorectal cancer cell line HT-29

Objective: To study the effect of arsenic trioxide(As2O3)on the cell proliferation,cell cycle,and cell apoptosis in colorectal can-cer cell line HT-29.Methods: The cell proliferation and the cell cycle and apoptosis of HT-29 cells were determined by MTT assay and flow cytometry,respectively.The morphological changes of HT-29 cells were observed under light microscope.Results: As2O3 inhibited the prolife-ration of HT-29 cells in a dose-and time-dependent manner,and the 50% inhibitory concentrations(IC50)were 40.03,13.76,and 4.53 μmol/L 24,48,and 72 hours after the administration of As2O3,respectively.G2/M phase arrest and cell apoptosis were induced by As2O3,and sub-G0G1 phase cells increased with the decrease of G2/M phase cells 24 hours after the administration of As2O3.The number of mitotic and apoptotic cells increased 12 to 72 hours after the administration of 0.5 to 5 μmol/L of As2O3.Conclusion: As2O3 could inhibit the prolifera-tion of colorectal cancer cell line HT-29 and induce G2/M phase arrest and cell apoptosis.