Japanese Journal of Clinical Oncology 21:153-159 (1991)
© 1991 Foundation for Promotion of Cancer Research
research-article |
Antitumor Effects of a Nonsteroidal Aromatase Inhibitor (CGS 16949A) on 7,12-Dimethylbenz[
]anthracene-induced Mammary Tumors in Rats
1Department of Surgery, Gunma University School of Medicine 39-22, Showamachi 3-chome, Maebashi 371
2Department of Pharmaceutical Chemistry, Institute of Endocrinology, Gunma University 39-22, Showamachi 3-chome, Maebashi 371
*For reprints and all correspondence
Received July 20, 1990; accepted January 9, 1991
The effects of a nonsteroidal aromatase inhibitor, CGS 16949A, on female Sprague-Dawley (SD) rats with 7, 12-dimethylbenz[
]anthracene (DMBA)-induced mammary cancers were exmined in relation to estrogen receptors (ER). Rat tumor sizes in each treated group were significantly smaller (P<0.05) and rat body weights in most treated groups were significantly increased (P<0.05) compared to those in the control group (no treatment) at all measurement points during treatment. Rat uterine weights in each treated group decreased significantly compared with those in the control group (P<0.05). There was no significant difference between ER-positive and ER-negative groups in tumor size, body weight or uterine weight. At increased doses of CGS 16949A in the experiment, further increases in testosterone levels and further decreases in estradiol levels were shown to occur. The results suggest the mechanisms of CGS 16949A action not to be influenced by the presence or absence of ER, but to be due to its potent aromatase inhibition of the conversion of androgens to estrogens.
Key Words: Aromatase inhibitor CGS 16949A 7,12 Dimethylbenz[
]anthracene-induced rat mammary cancer Estrogen receptor