Estrogenic Potential of Certain Pyrethroid Compounds in the MCF-7 Human Breast Carcinoma Cell Line

• Published in: Environmental health perspectives Vol. 107; no. 3; pp. 173 - 177
• Main Authors: Go, Vera, Garey, Joan, Wolff, Mary S., Beatriz G. T. Pogo
• Format: Journal Article
• Language: English
• Published: United States National Institute of Environmental Health Sciences. National Institutes of Health. Department of Health, Education and Welfare 01.03.1999
• Subjects: Breast cancer; Breast Neoplasms - chemically induced; Breast Neoplasms - metabolism; Carcinogens; Carcinoma - chemically induced; Carcinoma - metabolism; Cell Division - drug effects; Cell growth; Cell lines; Dose response relationship; Dose-Response Relationship, Drug; endocrine system; Estrogens; Female; Gene Expression Regulation, Neoplastic - drug effects; Humans; Insecticides - adverse effects; Nitriles; Pyrethrins; Pyrethrins - adverse effects; Rats; Receptors, Estrogen - biosynthesis; Receptors, Estrogen - drug effects; Receptors, Estrogen - genetics; RNA; RNA, Messenger - analysis; Solvents; Standard deviation; Tumor Cells, Cultured - drug effects
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.99107173

Estrogens, whether natural or synthetic, clearly influence reproductive development, senescence, and carcinogenesis. Pyrethroid insecticides are now the most widely used agents for indoor pest control, providing potential for human exposure. Using the MCF-7 human breast carcinoma cell line, we studied the estrogenic potential of several synthetic pyrethroid compounds in vitro using pS2 mRNA levels as the end point. We tested sumithrin, fenvalerate, d-trans allethrin, and permethrin. Nanomolar concentrations of either sumithrin or fenvalerate were sufficient to increase pS2 expression slightly above basal levels. At micromolar concentrations, these two pyrethroid compounds induced pS2 expression to levels comparable to those elicited by 10 nM 17β-estradiol (five-fold). The estrogenic activity of sumithrin was abolished with co-treatment with an antiestrogen (ICI 164,384), whereas estrogenic activity of fenvalerate was not significantly diminished with antiestrogen co-treatment. In addition, both sumithrin and fenvalerate were able to induce cell proliferation of MCF-7 cells in a dose-response fashion. Neither permethrin nor d-trans allethrin affected pS2 expression. Permethrin had a noticeable effect on cell proliferation at 100 μM, whereas d-trans allethrin slightly induced MCF-7 cell proliferation at 10 μM, but was toxic at higher concentrations. Overall, our studies imply that each pyrethroid compound is unique in its ability to influence several cellular pathways. These findings suggest that pyrethroids should be considered to be hormone disruptors, and their potential to affect endocrine function in humans and wildlife should be investigated.