Inhibition of growth and appearance of estrogen-dependent rat mammary tumors by 10-propargylestr-4-ene-3,17-dione, an aromatase inhibitor.
The aromatase inhibitor 10-propargylestr-4-ene-3,17-dione (PED) has been evaluated in 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 50 mg/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 1 mg PED/kg body weight/day, 0.1 tumors at 5 mg/kg, and at 50 mg 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.
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Florida 33101.
S J
SJ
Zimniski
M E
ME
Brandt
D F
DF
Covey
D
D
Puett
D015127:9,10-Dimethyl-1,2-benzanthracene; D000735:Androstenedione / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D047072:Aromatase Inhibitors; D002455:Cell Division / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens; D004971:Estrus / Q000187:drug effects; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy* / Q000201:enzymology; D009376:Neoplasms, Hormone-Dependent / Q000139:chemically induced / Q000188:drug therapy* / Q000201:enzymology; D010293:Pargyline / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D004967:Estrogens; D000735:Androstenedione; D004958:Estradiol; D015127:9,10-Dimethyl-1,2-benzanthracene; D010293:Pargyline; C033071:plomestane