Synergistic antitumour effect of a combination of toremifene and interferon-alpha on ZR-75-1 human breast cancer cells: dependence on interferon-alpha subtype.
We investigated the effect of toremifene, interferon-alpha2a, interferon-alpha2b and interferon-alpha2c, singly and in combination for their effect on the growth of ZR-75-1 human breast cancer cells. Median effect analysis was used to determine synergistic or additive effects. Anti-proliferative studies showed that the growth of ZR-75-1 cells was inhibited to a greater extent by combination treatment with toremifene plus interferon-alpha2a, resulting in a synergistic interaction (CI <1) for all concentrations tested. A combination of toremifene plus interferon-alpha2b resulted in a synergistic interaction (CI <1) for the two highest concentrations of toremifene (10(-6) and 10(-7) M) and an additive effect (CI approximately equal to 1) for the lower concentrations (10(-8) to 10(-10) M). When toremifene was combined with interferon-alpha2c no additive or synergistic interaction was determined.
Martin
J H J
JH
Division of Biomedical Sciences, School of Applied Sciences, University of Wolverhampton, Wolverhampton, WV1 1SB, UK. cs1950@wlv.ac.uk
Symonds
A
A
D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004357:Drug Synergism; D005260:Female; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D011994:Recombinant Proteins; D017312:Toremifene / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D018931:Antineoplastic Agents, Hormonal; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D017312:Toremifene; C554129:interferon alfa-2c