Targeting autophagy enhances the anti-tumoral action of crizotinib in ALK-positive anaplastic large cell lymphoma

// Geraldine Mitou 1, 2, 3, * , Julie Frentzel 1, 2, 3, * , Aurore Desquesnes 4 , Sophie Le Gonidec 4, 7 , Talal AlSaati 5 , Isabelle Beau 6 , Laurence Lamant 1, 2, 3, 7, 8, 10 , Fabienne Meggetto 1, 2, 3, 10 , Estelle Espinos 1, 2, 3, 7, 10 , Patrice Codogno 9 , Pierre Brousset 1, 2, 3, 7, 8, 10 , Sylvie Giuriato 1, 2, 3, 10 1 Inserm, UMR1037 CRCT, F-31000 Toulouse, France 2 Universite Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France 3 CNRS, ERL5294 CRCT, F-31000 Toulouse, France 4 Phenotyping Service, INSERM-US006 ANEXPLO/CREFRE, Toulouse, France 5 INSERM/UPS - US006/CREFRE, Service d’Histopathologie, CHU Purpan, Toulouse, France 6 INSERM UMRS 1185; Faculte de Medecine Paris Sud, Le Kremlin-Bicetre, France 7 Universite Toulouse III - Paul Sabatier, Toulouse, France 8 Department of Pathology, IUCT, Toulouse, France 9 Institut Necker Enfants-Malades, INSERM U1151-CNRS UMR 8253, Paris, France 10 European Research Initiative on ALK-related malignancies (ERIA) * These authors have contributed equally to this work Correspondence to: Sylvie Giuriato, e-mail: sylvie.giuriato@inserm.fr Keywords: anaplastic large cell lymphoma, NPM-ALK, autophagy, crizotinib, cytoprotection Received: March 02, 2015      Accepted: August 07, 2015      Published: August 17, 2015 ABSTRACT Anaplastic Lymphoma Kinase-positive Anaplastic Large Cell Lymphomas (ALK+ ALCL) occur predominantly in children and young adults. Their treatment, based on aggressive chemotherapy, is not optimal since ALCL patients can still expect a 30% 2-year relapse rate. Tumor relapses are very aggressive and their underlying mechanisms are unknown. Crizotinib is the most advanced ALK tyrosine kinase inhibitor and is already used in clinics to treat ALK-associated cancers. However, crizotinib escape mechanisms have emerged, thus preventing its use in frontline ALCL therapy. The process of autophagy has been proposed as the next target for elimination of the resistance to tyrosine kinase inhibitors. In this study, we investigated whether autophagy is activated in ALCL cells submitted to ALK inactivation (using crizotinib or ALK-targeting siRNA). Classical autophagy read-outs such as autophagosome visualization/quantification by electron microscopy and LC3-B marker turn-over assays were used to demonstrate autophagy induction and flux activation upon ALK inactivation. This was demonstrated to have a cytoprotective role on cell viability and clonogenic assays following combined ALK and autophagy inhibition. Altogether, our results suggest that co-treatment with crizotinib and chloroquine (two drugs already used in clinics) could be beneficial for ALK-positive ALCL patients.