title: Translation Elongation Factor eEF1A2 is a Novel Anticancer Target for the Marine Natural Product Plitidepsin.
abstract: eEF1A2 is one of the isoforms of the alpha subunit of the eukaryotic Elongation Factor 1. It is overexpressed in human tumors and is endowed with oncogenic properties, favoring tumor cell proliferation while inhibiting apoptosis. We demonstrate that plitidepsin, an antitumor agent of marine origin that has successfully completed a phase-III clinical trial for multiple myeloma, exerts its antitumor activity by targeting eEF1A2. The drug interacts with eEF1A2 with a KDof 80 nM and a target residence time of circa 9 min. This protein was also identified as capable of binding [14C]-plitidepsin in a cell lysate from K-562 tumor cells. A molecular modelling approach was used to identify a favorable binding site for plitidepsin at the interface between domains 1 and 2 of eEF1A2 in the GTP conformation. Three tumor cell lines selected for at least 100-fold more resistance to plitidepsin than their respective parental cells showed reduced levels of eEF1A2 protein. Ectopic expression of eEF1A2 in resistant cells restored the sensitivity to plitidepsin. FLIM-phasor FRET experiments demonstrated that plitidepsin localizes in tumor cells sufficiently close to eEF1A2 as to suggest the formation of drug-protein complexes in living cells. Altogether, our results strongly suggest that eEF1A2 is the primary target of plitidepsin.
authors.affiliation: Departamento de Biología Celular y Farmacogenómica, Pharma Mar S.A., Colmenar Viejo, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Losada
authors.affiliation: Departamento de Biología Celular y Farmacogenómica, Pharma Mar S.A., Colmenar Viejo, Madrid, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Muñoz-Alonso
authors.affiliation: Departamento de Química Física Biológica, Instituto de Química-Física "Rocasolano" (CSIC), Madrid, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: García
authors.affiliation: Departamento de Ciencias Biomédicas, Unidad Asociada al IQM-CSIC, Universidad de Alcalá, Madrid, Spain.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Sánchez-Murcia
authors.affiliation: Departamento de Biología Celular y Farmacogenómica, Pharma Mar S.A., Colmenar Viejo, Madrid, Spain.
authors.forename: Juan Fernando
authors.initials: JF
authors.lastname: Martínez-Leal
authors.affiliation: Departamento de Biología Celular y Farmacogenómica, Pharma Mar S.A., Colmenar Viejo, Madrid, Spain.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Domínguez
authors.affiliation: Departamento de Química Física Biológica, Instituto de Química-Física "Rocasolano" (CSIC), Madrid, Spain.
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Lillo
authors.affiliation: Departamento de Ciencias Biomédicas, Unidad Asociada al IQM-CSIC, Universidad de Alcalá, Madrid, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Gago
authors.affiliation: Departamento de Biología Celular y Farmacogenómica, Pharma Mar S.A., Colmenar Viejo, Madrid, Spain.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Galmarini
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001665:Binding Sites / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D047630:Depsipeptides / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D009101:Multiple Myeloma / Q000188:drug therapy*; D020648:Peptide Elongation Factor 1 / Q000037:antagonists & inhibitors*; D010456:Peptides, Cyclic; D000072417:Protein Domains / Q000502:physiology; D011817:Rabbits
chemical_list: D000970:Antineoplastic Agents; D047630:Depsipeptides; C503234:EEF1A2 protein, human; D020648:Peptide Elongation Factor 1; D010456:Peptides, Cyclic; C098980:plitidepsin