title: Directed phenotype switching as an effective antimelanoma strategy.
abstract: Therapeutic resistance in melanoma and other cancers arises via irreversible genetic, and dynamic phenotypic, heterogeneity. Here, we use directed phenotype switching in melanoma to sensitize melanoma cells to lineage-specific therapy. We show that methotrexate (MTX) induces microphthalmia-associated transcription factor (MITF) expression to inhibit invasiveness and promote differentiation-associated expression of the melanocyte-specific Tyrosinase gene. Consequently, MTX sensitizes melanomas to a tyrosinase-processed antifolate prodrug 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), that inhibits the essential enzyme DHFR with high affinity. The combination of MTX and TMECG leads to depletion of thymidine pools, double-strand DNA breaks, and highly efficient E2F1-mediated apoptosis in culture and in vivo. Importantly, this drug combination delivers an effective and tissue-restricted antimelanoma therapy in vitro and in vivo irrespective of BRAF, MEK, or p53 status.
authors.affiliation: Department of Biochemistry and Molecular Biology A, School of Biology, Regional Campus of International Excellence Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain.
authors.forename: Magalí
authors.initials: M
authors.lastname: Sáez-Ayala
authors.forename: María F
authors.initials: MF
authors.lastname: Montenegro
authors.forename: Luis
authors.initials: L
authors.lastname: Sánchez-Del-Campo
authors.forename: María Piedad
authors.initials: MP
authors.lastname: Fernández-Pérez
authors.forename: Soledad
authors.initials: S
authors.lastname: Chazarra
authors.forename: Rasmus
authors.initials: R
authors.lastname: Freter
authors.forename: Mark
authors.initials: M
authors.lastname: Middleton
authors.forename: Antonio
authors.initials: A
authors.lastname: Piñero-Madrona
authors.forename: Juan
authors.initials: J
authors.lastname: Cabezas-Herrera
authors.forename: Colin R
authors.initials: CR
authors.lastname: Goding
authors.forename: José Neptuno
authors.initials: JN
authors.lastname: Rodríguez-López
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D004249:DNA Damage; D050687:E2F1 Transcription Factor / Q000502:physiology; D006801:Humans; D008545:Melanoma / Q000188:drug therapy* / Q000473:pathology; D008727:Methotrexate / Q000494:pharmacology; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics; D010641:Phenotype; D013942:Thymine Nucleotides / Q000378:metabolism
chemical_list: C529447:3-O-(3,4,5-trimethoxybenzoyl)epicatechin; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; C497234:MITF protein, human; D051739:Microphthalmia-Associated Transcription Factor; D013942:Thymine Nucleotides; D002392:Catechin; C024157:thymidine 5'-triphosphate; D008727:Methotrexate