
Induction of 16alpha-/2-hydroxyestrone metabolite ratios in MCF-7 cells by pesticides, carcinogens, and antiestrogens does not predict mammary carcinogens.
Author(s) -
Andrew McDougal,
Stephen Safe
Publication year - 1998
Publication title -
environmental health perspectives
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.257
H-Index - 282
eISSN - 1552-9924
pISSN - 0091-6765
DOI - 10.1289/ehp.98106203
Subject(s) - carcinogen , metabolite , chemistry , dmba , medicine , endocrinology , toxicology , biology , biochemistry , carcinogenesis , gene
The effects of several pesticides, mammary carcinogens, and antiestrogens on 17beta-estradiol (E2), 16alpha- and 2-hydroxylase activities, and 16alpha-/2-hydroxyestrone (OHE1) ratios were investigated in MCF-7 cells using a radiometric assay. The mammary carcinogens 7,12-dimethylbenz[a]anthracene (DMBA) and benzo[a]pyrene (BaP), respectively, increased and decreased 16alpha-/2-OHE1 ratios at some concentrations. The 16alpha-/2-OHE1 metabolite ratios for 10(-5) M kepone, atrazine, p,p'-DDE, o,p'-DDE, o,p'-DDT, and beta-hexachlorocyclohexane were 1.82 +/- 0.060, 0.71 +/- 0.027, 0.66 +/- 0.030, 1.56 +/- 0.089, 1.14 +/- 0.059, and 0.69 +/- 0.052 (mean +/- standard error), respectively, and did not show any specific trend. The effects of a series of direct and indirect acting antiestrogens on 16alpha-/2-OHE1 metabolite ratios were also investigated, and the results were compound specific. Indole-3-carbinol, tamoxifen, 4'-hydroxytamoxifen, and 9-cis,retinoic acid decreased the ratio; the effects of all trans-retinoic acid and 2,3,7,8-tetrachlorodibenzo-p-dioxin were concentration dependent; the antiestrogen ICI 182,780 increased the 16alpha-/2-OHE1 metabolite ratio. The results indicate that in MCF-7 cells treated with pesticides, mammary carcinogens, and antiestrogens, there were both increased and decreased 16alpha-/2-OHE1 metabolite ratios for each class of chemicals and the assay did not predict mammary carcinogens.