title: Methotrexate inhibits the viability of human melanoma cell lines and enhances Fas/Fas-ligand expression, apoptosis and response to interferon-alpha: rationale for its use in combination therapy.
abstract: Melanoma, a highly aggressive form of cancer, is notoriously resistant to available therapies. Methotrexate (MTX), an antifolate, competitively inhibits DNA synthesis and is effective for several types of cancer. In cutaneous T-cell lymphoma (CTCL), MTX increases Fas death receptor by decreasing Fas promoter methylation by blocking the synthesis of SAM, the principal methyl donor for DNMTs, resulting in enhanced Fas-mediated apoptosis. The objective of this study was to explore the effects of MTX in human melanoma. MTX variably inhibited the survival of melanoma cells and induced apoptosis as evident by annexin V positivity and senescence associated β-galactosidase activity induction. Furthermore, MTX caused increased transcript and protein levels of extrinsic apoptotic pathway factors Fas and Fas-ligand, albeit at different levels in different cell lines. Our pyrosequencing studies showed that this increased expression of Fas was associated with Fas promoter demethylation. Overall, the ability of MTX to up-regulate Fas/FasL and enhance melanoma apoptosis through extrinsic as well as intrinsic pathways might make it a useful component of novel combination therapies designed to affect multiple melanoma targets simultaneously. In support of this concept, combination therapy with MTX and interferon-alpha (IFNα) induced significantly greater apoptosis in the aggressive A375 cell line than either agent alone.
authors.affiliation: Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; The Paul P. Carbone Comprehensive Cancer Center, Madison, WI, USA.
authors.forename: Minakshi
authors.initials: M
authors.lastname: Nihal
authors.affiliation: Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; The Paul P. Carbone Comprehensive Cancer Center, Madison, WI, USA; Wm. S. Middleton VA Medical Centre, Madison, WI, USA. Electronic address: gwood@dermatology.wisc.edu.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Wood
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016922:Cellular Senescence / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D053222:Fas Ligand Protein / Q000378:metabolism*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage*; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D008727:Methotrexate / Q000008:administration & dosage*; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000008:administration & dosage; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism*
chemical_list: C491901:FAS protein, human; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D019014:fas Receptor; D008727:Methotrexate
keywords: Apoptosis; DNA methylation; Fas/FasL; Melanoma; Methotrexate