Antitumor effects of a nonsteroidal aromatase inhibitor (CGS 16949A) on 7, 12-dimethylbenz[alpha]anthracene-induced mammary tumors in rats.
The effects of a nonsteroidal aromatase inhibitor, CGS 16949A, on female Sprague-Dawley (SD) rats with 7, 12-dimethylbenz[alpha]anthracene (DMBA)-induced mammary cancers were examined in relation to estrogen receptors (ER). Rat tumor sizes in each treated group were significantly smaller (P less than 0.05) and rat body weights in most treated groups were significantly increased (P less than 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 less than 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.
Iino
Y
Y
Department of Surgery, Gunma University School of Medicine, Maebashi.
Sugamata
N
N
Owada
S
S
Tago
T
T
Sato
H
H
Yokoe
T
T
Maemura
M
M
Morishita
Y
Y
Horiuchi
R
R
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D047072:Aromatase Inhibitors; D001835:Body Weight / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000097:blood; D017316:Fadrozole; D005260:Female; D007093:Imidazoles / Q000627:therapeutic use*; D008325:Mammary Neoplasms, Experimental / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*; D009570:Nitriles / Q000627:therapeutic use*; D009929:Organ Size / Q000187:drug effects; D011374:Progesterone / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen / Q000032:analysis; D013739:Testosterone / Q000097:blood; D014599:Uterus / Q000473:pathology
D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D007093:Imidazoles; D009570:Nitriles; D011960:Receptors, Estrogen; D004970:Estrone; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D015127:9,10-Dimethyl-1,2-benzanthracene; D017316:Fadrozole