title: Activating mutations in ALK kinase domain confer resistance to structurally unrelated ALK inhibitors in NPM-ALK-positive anaplastic large-cell lymphoma.
abstract: OBJECTIVE
  Crizotinib, the first FDA-approved ALK inhibitor, showed significant antitumor activity in young patients with anaplastic large-cell lymphoma (ALCL) frequently displaying ALK rearrangement. However, long-term therapeutic benefits of crizotinib are limited due to development of drug resistance. CH5424802--more potent and selective ALK inhibitor--comprises a good candidate for second-line treatment in crizotinib-relapsed patients. The aim of this study was to determine possible mechanisms of resistance to ALK inhibitors that can appear in ALCL patients.
  
  
  METHODS
  ALK+ ALCL cell lines resistant to crizotinib (Karpas299CR) and to CH5424802 (Karpas299CHR) were established by long-term exposure of Karpas299 cells to these inhibitors. Next, alterations in their sensitivity to ALK, HSP90 and mTOR inhibitors were investigated by cell viability and BrdU incorporation assays and immunoblot analysis.
  
  
  RESULTS
  cDNA sequencing of ALK kinase domain revealed activating mutations-I1171T in Karpas299CR and F1174C in Karpas299CHR. The resistant cells displayed diminished sensitivity to structurally unrelated ALK inhibitors-crizotinib, CH5424802 and TAE684. Nevertheless, CH5424802 and TAE684 were still more potent against the resistant cells than crizotinib. Moreover, Karpas299CR and Karpas299CHR cells remained sensitive to HSP90 or mTOR inhibitors.
  
  
  CONCLUSIONS
  Resistance mediated by activating mutations in ALK kinase domain may emerge in ALCL patients during ALK inhibitors treatment. However, more potent second-generation ALK inhibitors, HSP90 or mTOR inhibitors may represent an effective therapy for relapsed ALK+ ALCL patients.
authors: Innovative Drugs R&D Department, Celon Pharma Inc., Mokra 41a, 05-092, Lomianki/Kielpin, Poland.
authors: Daria
authors: D
authors: Zdzalik
authors: Barbara
authors: B
authors: Dymek
authors: Paulina
authors: P
authors: Grygielewicz
authors: Pawel
authors: P
authors: Gunerka
authors: Anna
authors: A
authors: Bujak
authors: Monika
authors: M
authors: Lamparska-Przybysz
authors: Maciej
authors: M
authors: Wieczorek
authors: Karolina
authors: K
authors: Dzwonek
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002227:Carbazoles / Q000737:chemistry / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D000077547:Crizotinib; D019008:Drug Resistance, Neoplasm; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D017728:Lymphoma, Large-Cell, Anaplastic / Q000188:drug therapy / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D010750:Phosphoproteins / Q000378:metabolism; D010880:Piperidines / Q000737:chemistry / Q000494:pharmacology; D040081:Protein Array Analysis; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011720:Pyrazoles / Q000737:chemistry / Q000494:pharmacology; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology; D011743:Pyrimidines / Q000737:chemistry / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D002227:Carbazoles; D018841:HSP90 Heat-Shock Proteins; C516714:NVP-TAE684; D010750:Phosphoproteins; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011725:Pyridines; D011743:Pyrimidines; D000077547:Crizotinib; C107023:p80(NPM-ALK) protein; C546842:MTOR protein, human; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D058570:TOR Serine-Threonine Kinases; C582670:alectinib