Breast Cancer Research and Treatment

, Volume 26, Issue 1, pp 15–21 | Cite as

Inhibition of growth and appearance of estrogen-dependent rat mammary tumors by 10-propargylestr-4-ene-3,17-dione, an aromatase inhibitor

  • S. J. Zimniski
  • M. E. Brandt
  • D. F. Covey
  • D. Puett


The aromatase inhibitor 10-propargylestr-4-ene-3,17-dione (PED) has been evaluatedin vivo as an anticancer agent. Prolonged administration of PED to rats bearing dimethylbenzanthracene-induced mammary tumors resulted in significant regression of hormone-responsive tumors within several days. Greater than 50% regression was generally observed after 14 days of treatment, irrespective of dose (1, 5, or 50mg/kg body weight/day). In addition to tumor regression, a significantly increased incidence in tumor stasis was observed over the course of PED treatment. While all doses of PED examined were equipotent for both tumor regression and stasis, a dose-dependent inhibition of new tumor formation was observed in PED-treated rats. In control animals an average of 1.2 new tumors was observed during the experimental period; in contrast, averages of 0.5 tumors appeared in animals receiving 1mg PED/kg body weight/day, 0.1 tumors at 5 mg/kg, and at 50mg of PED/kg body weight/day, no new tumors occurred during the time PED was administered. The effects of PED on both regression of existing tumors and appearance of new tumors were reversed by co-administration of estradiol. Thus, PED impairs estrogen-dependent mammary tumor growth, resulting in cessation of new growth and regression of responsive tumors.

Key words

aromatase aromatase inhibitors breast cancer estrogen estrous cycle tumor regression 


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Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • S. J. Zimniski
    • 1
  • M. E. Brandt
    • 1
  • D. F. Covey
    • 2
  • D. Puett
    • 1
  1. 1.The Reproductive Sciences and Endocrinology Laboratories, Departments of Biochemistry and Molecular Biology, Medicine, and Obstetrics and GynecologyUniversity of Miami School of MedicineMiamiUSA
  2. 2.Department of PharmacologyWashington University School of MedicineSt. LouisUSA

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