Cell Proliferative and Cell Cycle Effects of Atrazine Using Human Breast Cell Lines |Biomedgrid

Breast cancer is one of the leading causes of cancer related deaths in women. Several risk factors can increase breast cancer occurrences and strong evidence has shown that exposure to endocrine disrupting chemicals including atrazine can lead to breast cancer etiology. This study examined the effect of low level/environmentally relevant concentrations of atrazine on two breast cell lines (MCF-7, an estrogen responsive breast cancer cell line and MCF-10A, a non-cancerous human breast epithelial cell line) by studying cytotoxicity, proliferation and cell cycle events. To study cytotoxicity, cells were exposed to atrazine within a concentration range of 0.315 μg/L to 100,000 μg/L for 96 h and cell proliferation as well as the LC50 were calculated at 24, 48,72 and 96 h using the RT-CES. Cell cycle was studied by exposing the cell to 3 μg/L atrazine, and nuclei was isolated and analyzed using a BD FACSCalibur. The percentage nuclei in the cell cycle was calculated using Modfit LT 3.0. Results showed that there was an overall decreased in LC50 over time in both cell lines. Exposure of MCF-7 and MCF-10A to 3 μg/L of atrazine for 96 h, stimulated an increase in cell proliferation compared to control. Lower concentrations of atrazine showed even stronger impact on cell proliferation. However, ATR induced more cell proliferation in MCF-7 than in MCF-10A. Significant increases were recorded in the percent nuclei in G1 and G2 phases of MCF-7 cells exposed to ATR. Increase in the percent nuclei was only recorded in the G1 phase in MCF- 10A cells exposed to ATR. This adds to the body of evidence that ATR may indeed play a significant role in the onset and progression of cancer