Synergistic activity of ALK and mTOR inhibitors for the treatment of NPM-ALK positive lymphoma

Oncotarget. 2016 Nov 8;7(45):72886-72897. doi: 10.18632/oncotarget.12128.


ALK-positive Anaplastic Large Cell Lymphoma (ALCL) represents a subset of Non-Hodgkin Lymphoma whose treatment benefited from crizotinib development, a dual ALK/MET inhibitor. Crizotinib blocks ALK-triggered pathways such as PI3K/AKT/mTOR, indispensable for survival of ALK-driven tumors.Despite the positive impact of targeted treatment in ALCL, resistant clones are often selected during therapy. Strategies to overcome resistance include the design of second generation drugs and the use of combined therapies that simultaneously target multiple nodes essential for cells survival. We investigated the effects of combined ALK/mTOR inhibition. We observed a specific synergistic effect of combining ALK inhibitors with an mTOR inhibitor (temsirolimus), in ALK+ lymphoma cells. The positive cooperation resulted in an increased inhibition of mTOR effectors, compared to single treatments, a block in G0/G1 phase and induction of apoptosis. The combination was able to prevent the selection of resistant clones, while long-term exposure to single agents led to the establishment of resistant cell lines, with either ALK inhibitor or temsirolimus. In vivo, mice injected with Karpas 299 cells and treated with low dose combination showed complete regression of tumors, while only partial inhibition was obtained in single agents-treated mice. Upon treatment stop the combination was able to significantly delay tumor relapses. Re-challenge of relapsed tumors at a higher dose led to full regression of xenografts in the combination group, but not in mice treated with lorlatinib alone. In conclusion, our data suggest that the combination of ALK and mTOR inhibitors could be a valuable therapeutic option for ALK+ ALCL patients.

Keywords: ALK/ALCL; TKI; resistance; synergy; targeted therapy.

MeSH terms

  • Anaplastic Lymphoma Kinase
  • Animals
  • Antineoplastic Agents / pharmacology*
  • Cell Cycle / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Disease Models, Animal
  • Drug Synergism
  • Female
  • Humans
  • Lymphoma / drug therapy
  • Lymphoma / genetics
  • Lymphoma / metabolism*
  • Lymphoma / pathology
  • Mice
  • Protein Kinase Inhibitors / pharmacology*
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Protein-Tyrosine Kinases / metabolism*
  • Receptor Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Recurrence
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / antagonists & inhibitors*
  • TOR Serine-Threonine Kinases / metabolism
  • Tumor Burden
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Protein Kinase Inhibitors
  • p80(NPM-ALK) protein
  • ALK protein, human
  • Alk protein, mouse
  • Anaplastic Lymphoma Kinase
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases
  • TOR Serine-Threonine Kinases