In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 66, No. 13 ( 2006-07-01), p. 6884-6891
Abstract:
Clinically relevant animal models of mammary carcinogenesis are crucial for the development and evaluation of new breast cancer chemopreventive agents. The neu-induced retroviral rat mammary carcinogenesis model is based on the direct in situ transfer of the activated neu oncogene into the mammary epithelium using a replication-defective retroviral vector. The resulting mammary carcinomas in intact Wistar-Furth rats exhibit a mixed hormonal response in the same proportion as has been observed in women. In intact rats, ∼50% of mammary carcinomas can be prevented by tamoxifen treatment. In ovariectomized animals, the mammary carcinomas are hormonally nonresponsive and cannot be prevented by tamoxifen. We evaluated the efficacy of retinoic X receptor–selective retinoids (rexinoids) in this novel model of mammary carcinogenesis. The rexinoids LG100268 and bexarotene (LG1069, Targretin) were highly efficacious in the prevention of neu-induced mammary carcinomas. Dietary LG100268 at 100 mg/kg diet decreased tumor multiplicity by 32% (P = 0.0114) in intact rats and 50% (P & lt; 0.0001) in ovariectomized rats. Bexarotene treatment at a dose of 250 mg/kg diet was associated with reductions in tumor multiplicity of 84% (P & lt; 0.0001) and 86% (P & lt; 0.0001) in intact and ovariectomized animals, respectively. In addition to tumor multiplicity, proliferation and apoptosis were modulated by bexarotene treatment independently of estrogen signaling. The neu-induced retroviral rat mammary carcinogenesis model represents a valuable addition to existing rodent chemoprevention models. The model is useful for assessing the efficacy of chemopreventive agents, specifically those compounds that target hormonally nonresponsive tumors. (Cancer Res 2006; 66(13): 6884-91)
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/0008-5472.CAN-05-1823
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2006
detail.hit.zdb_id:
2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
Permalink
