title: Augmentation of cytotoxicity using combinations of interferons (types I and II), tumor necrosis factor-alpha, and tamoxifen in MCF-7 cells.
abstract: The cytotoxic effect of a combination of interferons (type I and II) and tumor necrosis factor (TNF), with an antiestrogenic drug, tamoxifen (TAM), was investigated in the estrogen receptor positive human breast carcinoma cell line, MCF-7. Cytotoxicity was measured by the MTT assay. In an attempt to define the molecular basis for the interaction between the interferons (IFNs) and TNF or any one of the cytokines with TAM, the induction characteristics of a number of IFN-induced mRNAs in response to IFNs, TNF, and TAM were studied. We observed an augmentation of the cytotoxic effect of TNF when it was combined with TAM. There appears to be an overlap in signalling mechanisms of IFNs and TNF as two of the IFN-inducible genes, 1-8 and 6-16 are also induced by TNF. mRNA 1-8 was induced by both IFN-alpha (type I) and IFN-gamma (type II). We conclude that TNF potentiates the cytotoxic effects of TAM in MCF-7 cells and that the three cytokines IFN-alpha, IFN-gamma, and TNF share some pathways that lead to specific induction of some cytokine responsive genes.
authors.affiliation: Breast Cancer Research Laboratory, Memorial Sloan Kettering Cancer Center, New York, NY 10021.
authors.forename: R K
authors.initials: RK
authors.lastname: Tiwari
authors.forename: G Y
authors.initials: GY
authors.lastname: Wong
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: D
authors.initials: D
authors.lastname: Miller
authors.forename: M P
authors.initials: MP
authors.lastname: Osborne
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D004357:Drug Synergism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007370:Interferon Type I / Q000008:administration & dosage / Q000494:pharmacology*; D007371:Interferon-gamma / Q000008:administration & dosage / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013629:Tamoxifen / Q000008:administration & dosage / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D007370:Interferon Type I; D014409:Tumor Necrosis Factor-alpha; D013629:Tamoxifen; D007371:Interferon-gamma