Effect of zindoxifene on experimental prostatic tumours of the rat.
The anti-oestrogen zindoxifene was originally developed as a drug for the treatment of hormone-dependent mammary carcinomas. Experiments with rats bearing androgen-dependent prostatic tumours revealed anti-neoplastic activity of zindoxifene on these tumours also. Therefore, the inhibitory effect of this drug was studied in various prostatic tumour models in comparison to the anti-oestrogen tamoxifen and to castration. The growth of the hormone-dependent Dunning R3327 H tumour was strongly inhibited by zindoxifene (4 mg/kg), which was more effective than tamoxifen (43% T/C vs 87% T/C, the ratios of tumour weights in control and drug-treated rats). Zindoxifene was able to delay the relapse of these tumours by 7 weeks in comparison to castration. The experiments with Noble Nb-R prostatic tumours showed that administration of zindoxifene (5 mg) is superior to castration (5% T/C vs 52% T/C). The growth of tumours in castrated rats was completely inhibited by administration of zindoxifene. Therefore a peripheral mode of action has to be assumed.
Schneider
M R
MR
Institut of Pharmazie, Universität Regensburg, Federal Republic of Germany.
Schiller
C D
CD
Humm
A
A
von Angerer
E
E
D000230:Adenocarcinoma / Q000188:drug therapy*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002369:Castration; D004054:Diethylstilbestrol / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000188:drug therapy; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy*; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D051381:Rats; D011916:Rats, Inbred F344; D013629:Tamoxifen / Q000494:pharmacology
D000970:Antineoplastic Agents; D004965:Estrogen Antagonists; D007211:Indoles; D013629:Tamoxifen; C041791:zindoxifene; D004054:Diethylstilbestrol