Combined effects of 13-cis-retinoic acid, tamoxifen and interferon on the growth of human breast cancer cells.
We studied the effect of 13-cis-retinoic acid (13-cRA) alone and in combination with interferons (IFNs) and tamoxifen (TAM) in two established human breast cancer cell lines: the estrogen-sensitive CG-5 and the estrogen-insensitive MDA-MB-453 cells. 13-cRA (10(-9)-10(-5) M) significantly reduced the growth of both cell lines in a dose-dependent fashion, after 3 and 6 days of treatment. When the retinoid (10(-9)-10(-5) M) was combined with natural beta-IFN (100-1000 IU/ml) for 6 days, we observed a growth inhibition more pronounced than that produced by each of the two single agents in both CG-5 and MDA-MB-453 cells. Only in the former model was the inhibitory effect synergistic at all the drug concentrations used. Association of 13-cRA (10(-9)-10(-5) M) and recombinant alpha2a-IFN (100-1000 IU/ml) or TAM (10(-7)-10(-6) M) did not determine an additive or synergistic effect on the growth of CG-5 cells.
Lama
G
G
Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Facoltà di Medicina e Chirurgia, Roma, Italy.
Angelucci
C
C
Recchia
F
F
Sica
G
G
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000648:ultrastructure; D002455:Cell Division / Q000187:drug effects; D004334:Drug Administration Schedule; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage; D015474:Isotretinoin / Q000008:administration & dosage; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy* / Q000473:pathology / Q000648:ultrastructure; D011960:Receptors, Estrogen / Q000502:physiology; D011994:Recombinant Proteins; D013629:Tamoxifen / Q000008:administration & dosage; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011960:Receptors, Estrogen; D011994:Recombinant Proteins; D013629:Tamoxifen; D015474:Isotretinoin