Cytotoxicity of tamoxifen in normal and tumoral cell lines and its ability to induce cellular transformation in vitro

Authors

  • Leandro Petinari,

    Corresponding author
    1. Department of Cell Biology, Institute of Biology, State University of Campinas, (UNICAMP), P.O. Box 6109, ZIP Code 13084-971, Campinas, SP, Brazil
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  • Luciana Konecny Kohn,

    1. Division of Pharmacology and Toxicology, CPQBA, State University of Campinas, (UNICAMP), Campinas, SP, Brazil
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  • João Ernesto De Carvalho,

    1. Division of Pharmacology and Toxicology, CPQBA, State University of Campinas, (UNICAMP), Campinas, SP, Brazil
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  • Selma Candelária Genari

    1. Department of Cell Biology, Institute of Biology, State University of Campinas, (UNICAMP), P.O. Box 6109, ZIP Code 13084-971, Campinas, SP, Brazil
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Corresponding author. Tel./fax: +55-19-3788-6111. leopet@unicamp.br

Abstract

Tamoxifen (TAM) is a non-steroidal anti-estrogen used to treat patients with estrogen receptor-positive breast cancer and as a chemopreventive agent against breast cancer in high risk pre- and post-menopausal women. However, recent studies have shown that tamoxifen causes endometrial and hepatic cancer. In this study, we examined the effects of tamoxifen (5, 10, 25 and 50 μM) on the growth and proliferation of nine tumoral cell lines (UACC62, MCF-7, NCI-460, K-562, OVCAR-03, PC-03, HT-29, 786-0, NCI-ADR) and non-tumoral cell lines (3T3, V79, MDCK, VERO). Chinese hamster lung fibroblasts (V79) were the most sensitive lineage to tamoxifen, with 21.6% of the cells showing apoptosis at 50 μM TAM. Microscopic analysis showed that, the cellular transformation caused by TAM in V79 cells was similar to that seen with 7,12-dimethylbenz(a)anthracene, thus indicating the carcinogenicity of TAM.

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