Abstract: Colon cancer is the third leading cause of cancer-related deaths worldwide. Recent studies in our laboratory have demonstrated that arsenic trioxide is cytotoxic in human colon cancer (HT-29), lung (A549) and breast (MCF-7) carcinoma cells. The purpose of the present study is to investigate the effects of arsenic trioxide on DNA synthesis and the possible genotoxic effects on human colon cancer cells. HT-29 cells were cultured according to standard protocol, followed by exposure to various doses (0, 2, 4, 6, 8, 10, and 12 μg/mL) of arsenic trioxide for 24 h. The proliferative response (DNA synthesis) to arsenic trioxide was assessed by [3H]thymidine incorporation. The genotoxic effects of arsenic-induced DNA damage in a human colon cancer cell line was evaluated by the alkaline single cell gel electrophoresis. Results indicated that arsenic trioxide affected DNA synthesis in HT-29 cells in a biphasic manner; showing a slight but not significant increase in cell proliferation at lower levels of exposure (2, 4 and 6 µg/mL) followed by a significant inhibition of cell proliferation at higher doses (i.e., 8 and 10 µg/mL). The study also confirmed that arsenic trioxide exposure caused genotoxicity as revealed by the significant increase in DNA damage, comet tail-lengths, and tail moment when compared to non-exposed cells. Results of the [3H]thymidine incorporation assay and comet assay revealed that exposure to arsenic trioxide affected DNA synthesis and exhibited genotoxic effects in human colon cancer cells.
Keywords: Arsenic trioxide; HT-29 cells; [3H]thymidine incorporation assay; genotoxicity; comet assay
Export to BibTeX
MDPI and ACS Style
Stevens, J.J.; Graham, B.; Walker, A.M.; Tchounwou, P.B.; Rogers, C. The Effects of Arsenic Trioxide on DNA Synthesis and Genotoxicity in Human Colon Cancer Cells. Int. J. Environ. Res. Public Health 2010, 7, 2018-2032.
Stevens JJ, Graham B, Walker AM, Tchounwou PB, Rogers C. The Effects of Arsenic Trioxide on DNA Synthesis and Genotoxicity in Human Colon Cancer Cells. International Journal of Environmental Research and Public Health. 2010; 7(5):2018-2032.
Stevens, Jacqueline J.; Graham, Barbara; Walker, Alice M.; Tchounwou, Paul B.; Rogers, Christian. 2010. "The Effects of Arsenic Trioxide on DNA Synthesis and Genotoxicity in Human Colon Cancer Cells." Int. J. Environ. Res. Public Health 7, no. 5: 2018-2032.