Molecular rationale for the use of PI3K/AKT/mTOR pathway inhibitors in combination with crizotinib in ALK-mutated neuroblastoma

Oncotarget. 2014 Sep 30;5(18):8737-49. doi: 10.18632/oncotarget.2372.

Abstract

Mutations in the ALK tyrosine kinase receptor gene represent important therapeutic targets in neuroblastoma, yet their clinical translation has been challenging. The ALK(F1174L) mutation is sensitive to the ALK inhibitor crizotinib only at high doses and mediates acquired resistance to crizotinib in ALK-translocated cancers. We have shown that the combination of crizotinib and an inhibitor of downstream signaling induces a favorable response in transgenic mice bearing ALK(F1174L)/MYCN-positive neuroblastoma. Here, we investigated the molecular basis of this effect and assessed whether a similar strategy would be effective in ALK-mutated tumors lacking MYCN overexpression. We show that in ALK-mutated, MYCN-amplified neuroblastoma cells, crizotinib alone does not affect mTORC1 activity as indicated by persistent RPS6 phosphorylation. Combined treatment with crizotinib and an ATP-competitive mTOR inhibitor abrogated RPS6 phosphorylation, leading to reduced tumor growth and prolonged survival in ALK(F1174L)/MYCN-positive models compared to single agent treatment. By contrast, this combination, while inducing mTORC1 downregulation, caused reciprocal upregulation of PI3K activity in ALK-mutated cells expressing wild-type MYCN. Here, an inhibitor with potency against both mTOR and PI3K was more effective in promoting cytotoxicity when combined with crizotinib. Our findings should enable a more precise selection of molecularly targeted agents for patients with ALK-mutated tumors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaplastic Lymphoma Kinase
  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Cell Line, Tumor
  • Crizotinib
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm
  • Gene Amplification
  • Humans
  • Mechanistic Target of Rapamycin Complex 1
  • Mice, Inbred NOD
  • Mice, SCID
  • Molecular Targeted Therapy
  • Multiprotein Complexes / antagonists & inhibitors
  • Multiprotein Complexes / metabolism
  • Mutation*
  • N-Myc Proto-Oncogene Protein
  • Neuroblastoma / drug therapy*
  • Neuroblastoma / enzymology
  • Neuroblastoma / genetics
  • Neuroblastoma / pathology
  • Nuclear Proteins / genetics
  • Oncogene Proteins / genetics
  • Phosphatidylinositol 3-Kinase / metabolism
  • Phosphoinositide-3 Kinase Inhibitors*
  • Phosphorylation
  • Protein Kinase Inhibitors / administration & dosage
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Pyrazoles / administration & dosage
  • Pyridines / administration & dosage
  • RNA Interference
  • Receptor Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Receptor Protein-Tyrosine Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Ribosomal Protein S6 / metabolism
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / antagonists & inhibitors*
  • TOR Serine-Threonine Kinases / metabolism
  • Time Factors
  • Transfection
  • Xenograft Model Antitumor Assays

Substances

  • MYCN protein, human
  • Multiprotein Complexes
  • N-Myc Proto-Oncogene Protein
  • Nuclear Proteins
  • Oncogene Proteins
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Pyrazoles
  • Pyridines
  • Ribosomal Protein S6
  • Crizotinib
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • Phosphatidylinositol 3-Kinase
  • ALK protein, human
  • Alk protein, mouse
  • Anaplastic Lymphoma Kinase
  • Receptor Protein-Tyrosine Kinases
  • Mechanistic Target of Rapamycin Complex 1
  • Proto-Oncogene Proteins c-akt