LAUSR

Abstract Background EPHA2 tyrosine kinase receptor is implicated in tumor progression, stemness phenotype and resistance to treatment in a wide range of cancers. We investigated the effects of GLPG1790, a new selective Eph receptor inhibitor, in colorectal cancer (CRC) across the 4 consensus molecular subtypes (CMS). Methods We tested the antiproliferative effect of GLPG 1790 used alone or in combination with either 5-fluorouracil, oxaliplatin or SN38 (the active metabolite of irinotecan) in a panel of 11 CRC cell lines encompassing the 4 consensus molecular subtypes (CMS). Cell cycle analysis was performed in order to understand possible cell cycle perturbation after treatment. Pathway analysis using western blot (WB) was also performed. We then evaluated the expression of stemness genes upon treatment using qRT-PCR. Results GLPG 1790 is active in CRC cell lines, with the strongest activity in the cell lines from the CMS4/mesenchymal-like cluster. Combination with chemotherapeutics is not synergistic according to Chou-Talalay model. The selective inhibitor elicits a persistent inactivation of EPHA2 receptor, associated to G0-G1 cell cycle block in the sensitive cell lines. Furthermore, GLPG 1790 is able to decrease the expression of cancer stem cell genes in cell lines belonging to the CMS4 group. Conclusions EPHA2 blockade using the selective inhibitor GLPG 1790 has a strong antiproliferative effect in the chemorefractory subgroup of CMS4/mesenchymal-like CRC cell lines, associated to a G0-G1 cell cycle arrest. The stronger efficacy of GLPG1790 on the mesenchymal-like subtype is probably due to the impairment of cancer cell stemness and induction of cell differentiation after treatment. Legal entity responsible for the study The authors. Funding Universita della Campania "Luigi Vanvitelli"; Galapagos NV (drug supply); Associazione Italiana per la Ricerca sul Cancro (AIRC). Disclosure P.P. Vitiello: Travel/Accommodation/Expenses: Amgen; Research grant/Funding (institution): Bayer; Research grant/Funding (institution): Merck; Research grant/Funding (institution): Roche; Research grant/Funding (institution): Servier; Research grant/Funding (institution): Ipsen; Travel/Accommodation/Expenses: BMS; Travel/Accommodation/Expenses: Sanofi. C. Cardone: Research grant/Funding (institution): Amgen; Research grant/Funding (institution): Bayer; Research grant/Funding (institution): Ipsen; Research grant/Funding (institution): Merck; Research grant/Funding (institution): Roche. D. Ciardiello: Travel/Accommodation/Expenses: Sanofi. L. Poliero: Travel/Accommodation/Expenses: BMS. C. Borrelli: Travel/Accommodation/Expenses: BMS. N. Zanaletti: Travel/Accommodation/Expenses: BMS. P. Vitale: Travel/Accommodation/Expenses: BMS. T. Troiani: Honoraria (self), Research grant/Funding (institution): Roche; Honoraria (self), Research grant/Funding (institution): Merck; Honoraria (self), Research grant/Funding (institution): Bayer; Honoraria (self), Travel/Accommodation/Expenses: Amgen; Travel/Accommodation/Expenses: Servier; Travel/Accommodation/Expenses: Sanofi; Travel/Accommodation/Expenses: Novartis. F. Ciardiello: Advisory/Consultancy, Research grant/Funding (institution): Amgen; Advisory/Consultancy, Research grant/Funding (institution): Bayer; Advisory/Consultancy, Research grant/Funding (institution): Roche; Advisory/Consultancy, Research grant/Funding (institution): Merck; Advisory/Consultancy: Servier; Advisory/Consultancy: Pfizer; Research grant/Funding (institution): Ipsen. E. Martinelli: Honoraria (self), Research grant/Funding (institution): Amgen; Honoraria (self), Research grant/Funding (institution): Merck; Honoraria (self), Research grant/Funding (institution): Bayer; Honoraria (self), Research grant/Funding (institution): Roche; Honoraria (self), Honoraria (institution): Servier. All other authors have declared no conflicts of interest.