title: Effects of tamoxifen and interferon-beta or the combination on tumor-induced angiogenesis.
abstract: Inhibition of angiogenesis by anti-tumor agents may play a role in tumor growth arrest. Tamoxifen and interferon-alpha/beta (IFN-alpha/beta) exhibit potentiated anti-proliferative activity against tumor cells. However, additional host-mediated effects such as modulation of angiogenesis may also inhibit tumor growth in vivo. The effect of tamoxifen and IFN-beta on angiogenesis induced by 2 human tumors, MCF-7 breast carcinoma (estradiol dependent) and NIH-OVCAR-3 ovarian carcinoma (estradiol independent), was assessed. Treatment of nude mice bearing MCF-7 tumors with tamoxifen resulted in a 68% decrease in the number of vessels at the tumor periphery. Treatment with IFN-beta yielded a 33% reduction. Treatment of nude mice bearing NIH-OVCAR-3 tumors with tamoxifen resulted in a 73% decrease in the number of vessels. Treatment with IFN-beta yielded a 57% reduction. Combination treatment resulted in augmented anti-angiogenic effects. As single agents, both tamoxifen and IFN-beta inhibited xenograft tumor growth. Ten weeks of tamoxifen treatment resulted in growth inhibition of MCF-7 and NIH-OVCAR-3 carcinomas by 85% and 66%, respectively. Ten weeks of IFN-beta treatment resulted in inhibition of growth of MCF-7 and NIH-OVCAR-3 carcinomas by 67% and 88%, respectively. The combination of tamoxifen and IFN-beta completely prevented growth of MCF-7 and NIH-OVCAR-3 carcinomas. The anti-angiogenic effects of tamoxifen and IFN-beta were additive. Inhibition of angiogenesis was detectable before measurable effects on tumor volume in both MCF-7 and NIH-OVCAR-3 tumors. Potentiation of anti-angiogenic effects by tamoxifen and IFN-beta, possibly resulting from enhanced IFN-induced gene expression, may contribute to anti-tumor activity in both estradiol-dependent and estradiol-independent tumors in vivo.
authors.affiliation: Department of Microbiology and Immunology, Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Lindner
authors.forename: E C
authors.initials: EC
authors.lastname: Borden
mesh_terms: D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000098:blood supply* / Q000473:pathology / Q000628:therapy; D002455:Cell Division / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D016899:Interferon-beta / Q000627:therapeutic use*; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000473:pathology / Q000517:prevention & control*; D010051:Ovarian Neoplasms / Q000098:blood supply* / Q000473:pathology / Q000628:therapy; D010052:Ovariectomy; D013629:Tamoxifen / Q000627:therapeutic use*; D014183:Transplantation, Heterologous
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen; D016899:Interferon-beta