Activated ALK signals through the ERK-ETV5-RET pathway to drive neuroblastoma oncogenesis

Oncogene. 2018 Mar;37(11):1417-1429. doi: 10.1038/s41388-017-0039-5. Epub 2018 Jan 11.

Abstract

Activating mutations of the ALK receptor occur in a subset of neuroblastoma tumors. We previously demonstrated that Alk mutations cooperate with MYCN overexpression to induce neuroblastoma in mice and identified Ret as being strongly upregulated in MYCN/Alkmut tumors. By a genetic approach in vivo, we now document an oncogenic cooperation between activated Ret and MYCN overexpression in neuroblastoma formation. We show that MYCN/RetM919T tumors exhibit histological features and expression profiles close to MYCN/Alkmut tumors. We show that RET transcript levels decrease precedes RET protein levels decrease upon ALK inhibition in neuroblastoma cell lines. Etv5 was identified as a candidate transcription factor regulating Ret expression from murine MYCN/Alkmut tumor transcriptomic data. We demonstrate that ETV5 is regulated both at the protein and mRNA levels upon ALK activation or inhibition in neuroblastoma cell lines and that this regulation precedes RET modulation. We document that ALK activation induces ETV5 protein upregulation through stabilization in a MEK/ERK-dependent manner. We show that RNAi-mediated inhibition of ETV5 decreases RET expression. Reporter assays indicate that ETV5 is able to drive RET gene transcription. ChIP-seq analysis confirmed ETV5 binding on the RET promoter and identified an enhancer upstream of the promoter. Finally, we demonstrate that combining RET and ALK inhibitors reduces tumor growth more efficiently than each single agent in MYCN and AlkF1178L-driven murine neuroblastoma. Altogether, these results define the ERK-ETV5-RET pathway as a critical axis driving neuroblastoma oncogenesis downstream of activated ALK.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaplastic Lymphoma Kinase / genetics*
  • Anaplastic Lymphoma Kinase / metabolism
  • Animals
  • Carcinogenesis / genetics*
  • Carcinogenesis / pathology
  • Cells, Cultured
  • DNA-Binding Proteins / physiology
  • Female
  • Gain of Function Mutation* / physiology
  • HEK293 Cells
  • Humans
  • MAP Kinase Signaling System / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Nude
  • Mice, Transgenic
  • Neuroblastoma / genetics*
  • Neuroblastoma / pathology
  • Proto-Oncogene Proteins c-ret / physiology
  • Signal Transduction / genetics
  • Transcription Factors / physiology
  • Xenograft Model Antitumor Assays

Substances

  • DNA-Binding Proteins
  • ETV5 protein, human
  • Transcription Factors
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • Proto-Oncogene Proteins c-ret
  • RET protein, human