ESTROGENIC AND DNA-DAMAGING ACTIVITY OF RED NO-3 IN HUMAN BREAST-CANCER CELLS

Exposure to pesticides, dyes, and pollutants that mimic the growth pro moting effects of estrogen may cause breast cancer. The pesticide DDT and the food colorant Red No. 3 were found to increase the growth of H TB 133 but not estrogen receptor (ER) negative human breast cells (HTB 125) or rat liver epithelial cells (RLE). Red No. 3, beta-estradiol, and DDT increase ER site-specific DNA binding to the estrogen response element in HTB 133 cells and increase cyclin-dependent kinase 2 activ ity in MCF-7 breast cancer cells. Site-specific DNA binding by p53 in RLE, HTB 125, HTB 133, and MCF-7 cells was increased when they were tr eated with Red No. 3, which suggests that cellular DNA was damaged by this colorant. Red No. 3 increased binding of the ER from MCF-7 cells to the estrogen-responsive element. Consumption of Red No. 3, which ha s estrogenlike growth stimulatory properties and may be genotoxic, cou ld be a significant risk factor in human breast carcinogenesis.