title: Therapeutic potential of ERK5 targeting in triple negative breast cancer.
abstract: Triple negative breast cancers (TNBCs) account for 15% of all breast cancers, and represent one of the most aggressive forms of the disease, exhibiting short relapse-free survival. In contrast to other breast cancer subtypes, the absence of knowledge about the etiopathogenic alterations that cause TNBCs force the use of chemotherapeutics to treat these tumors. Because of this, efforts have been devoted with the aim of incorporating novel therapies into the clinical setting. Kinases play important roles in the pathophysiology of several tumors, including TNBC. Since expression of the MAP kinase ERK5 has been linked to patient outcome in breast cancer, we analyzed the potential value of its targeting in TNBC. ERK5 was frequently overexpressed and active in samples from patients with TNBC, as well as in explants from mice carrying genetically-defined TNBC tumors. Moreover, expression of ERK5 was linked to a worse prognosis in TNBC patients. Knockdown experiments demonstrated that ERK5 supported proliferation of TNBC cells. Pharmacological inhibition of ERK5 with TG02, a clinical stage inhibitor which targets ERK5 and other kinases, inhibited cell proliferation by blocking passage of cells through G1 and G2, and also triggered apoptosis in certain TNBC cell lines. TG02 had significant antitumor activity in a TNBC xenograft model in vivo, and also augmented the activity of chemotherapeutic agents commonly used to treat TNBC. Together, these data indicate that ERK5 targeting may represent a valid strategy against TNBC, and support the development of trials aimed at evaluating the clinical effectiveness of drugs that block this kinase.
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer. CSIC-IBSAL-Universidad de Salamanca. Spain.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Ortiz-Ruiz
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer. CSIC-IBSAL-Universidad de Salamanca. Spain.
authors.forename: Stela
authors.initials: S
authors.lastname: Álvarez-Fernández
authors.affiliation: Tragara Pharmaceuticals, Carlsbad, CA, USA.
authors.forename: Tracy
authors.initials: T
authors.lastname: Parrott
authors.affiliation: Tragara Pharmaceuticals, Carlsbad, CA, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Zaknoen
authors.affiliation: Tragara Pharmaceuticals, Carlsbad, CA, USA.
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Burrows
authors.affiliation: Hospital Universitario de Albacete, and AECC Unit, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ocaña
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer. CSIC-IBSAL-Universidad de Salamanca. Spain.
authors.forename: Atanasio
authors.initials: A
authors.lastname: Pandiella
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer. CSIC-IBSAL-Universidad de Salamanca. Spain.
authors.forename: Azucena
authors.initials: A
authors.lastname: Esparís-Ogando
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000008:administration & dosage / Q000494:pharmacology; D000077143:Docetaxel; D005260:Female; D006576:Heterocyclic Compounds, 4 or More Rings / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D048054:Mitogen-Activated Protein Kinase 7 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D058990:Molecular Targeted Therapy; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011897:Random Allocation; D043823:Taxoids / Q000008:administration & dosage / Q000494:pharmacology; D064726:Triple Negative Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D014747:Vinblastine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D000077235:Vinorelbine; D023041:Xenograft Model Antitumor Assays
chemical_list: C570909:14-methyl-20-oxa-5,7,14,26-tetraazatetracyclo(19.3.1.1(2,6).1(8,12))heptacosa-1(25),2(26),3,5,8(27),9,11,16,21,23-decaene; D006576:Heterocyclic Compounds, 4 or More Rings; D047428:Protein Kinase Inhibitors; D043823:Taxoids; D000077143:Docetaxel; D014747:Vinblastine; D048054:Mitogen-Activated Protein Kinase 7; D002945:Cisplatin; D000077235:Vinorelbine