title: Excess of NPM-ALK oncogenic signaling promotes cellular apoptosis and drug dependency.
abstract: Most of the anaplastic large-cell lymphoma (ALCL) cases carry the t(2;5; p23;q35) that produces the fusion protein NPM-ALK (nucleophosmin-anaplastic lymphoma kinase). NPM-ALK-deregulated kinase activity drives several pathways that support malignant transformation of lymphoma cells. We found that in ALK-rearranged ALCL cell lines, NPM-ALK was distributed in equal amounts between the cytoplasm and the nucleus. Only the cytoplasmic portion was catalytically active in both cell lines and primary ALCL, whereas the nuclear portion was inactive because of heterodimerization with NPM1. Thus, about 50% of the NPM-ALK is not active and sequestered as NPM-ALK/NPM1 heterodimers in the nucleus. Overexpression or relocalization of NPM-ALK to the cytoplasm by NPM genetic knockout or knockdown caused ERK1/2 (extracellular signal-regulated protein kinases 1 and 2) increased phosphorylation and cell death through the engagement of an ATM/Chk2- and γH2AX (phosphorylated H2A histone family member X)-mediated DNA-damage response. Remarkably, human NPM-ALK-amplified cell lines resistant to ALK tyrosine kinase inhibitors (TKIs) underwent apoptosis upon drug withdrawal as a consequence of ERK1/2 hyperactivation. Altogether, these findings indicate that an excess of NPM-ALK activation and signaling induces apoptosis via oncogenic stress responses. A 'drug holiday' where the ALK TKI treatment is suspended could represent a therapeutic option in cells that become resistant by NPM-ALK amplification.
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Ceccon
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Maria Elena Boggio
authors.initials: MEB
authors.lastname: Merlo
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Mologni
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Poggio
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Lydia M
authors.initials: LM
authors.lastname: Varesio
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Menotti
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Bombelli
authors.affiliation: Surgery and Translational Medicine department, University of Milano-Bicocca, Monza, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Rigolio
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Andrea D
authors.initials: AD
authors.lastname: Manazza
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Filomena
authors.initials: F
authors.lastname: Di Giacomo
authors.affiliation: Molecular Oncology Program, Centro Nacional de Investigaciones Oncológicas, Madrid, Spain.
authors.forename: Chiara
authors.initials: C
authors.lastname: Ambrogio
authors.affiliation: Tettamanti Research Centre, Pediatric Clinic, University of Milano-Bicocca, Monza, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Giudici
authors.affiliation: MetaSystems s.l.r., Milano, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Casati
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Mastini
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.|Department of Pathology, Children's Hospital and Harvard Medical School, Boston, USA.
authors.forename: Mara
authors.initials: M
authors.lastname: Compagno
authors.affiliation: Division of Molecular Histopathology, Addenbrooke's Hospital Cambridge, Cambridge, UK.
authors.forename: Suzanne D
authors.initials: SD
authors.lastname: Turner
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.|Section of Haematology, San Gerardo Hospital, Monza, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Gambacorti-Passerini
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.|Department of Pathology, Children's Hospital and Harvard Medical School, Boston, USA.
authors.forename: Roberto
authors.initials: R
authors.lastname: Chiarle
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.|Center for Experimental Research and Medical Studies (CERMS), Città della Salute e della Scienza, Torino, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Voena
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D000077547:Crizotinib; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D006834:Hydrazines / Q000494:pharmacology; D017728:Lymphoma, Large-Cell, Anaplastic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D016513:Mice, SCID; D018613:Microscopy, Confocal; D000090243:Nucleophosmin; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011720:Pyrazoles / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D034622:RNA Interference; D015398:Signal Transduction; D014183:Transplantation, Heterologous; D014230:Triazoles / Q000494:pharmacology
chemical_list: C468783:H2AX protein, human; D006657:Histones; D006834:Hydrazines; C000716967:NPM1 protein, human; C000715570:Npm1 protein, mouse; D015514:Oncogene Proteins, Fusion; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011725:Pyridines; D014230:Triazoles; D000090243:Nucleophosmin; C585161:selinexor; D000077547:Crizotinib; C107023:p80(NPM-ALK) protein; D011505:Protein-Tyrosine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases