ETV6-NTRK3 transformation requires insulin-like growth factor 1 receptor signaling and is associated with constitutive IRS-1 tyrosine phosphorylation

Oncogene. 2002 Aug 22;21(37):5684-95. doi: 10.1038/sj.onc.1205669.

Abstract

Congenital fibrosarcoma (CFS) and cellular mesoblastic nephroma (CMN) are pediatric spindle cell malignancies that share two specific cytogenetic abnormalities: trisomy of chromosome 11 and a t(12;15)(p13;q25) translocation. The t(12;15) rearrangement creates a transcriptionally active fusion gene that encodes a chimeric oncoprotein, ETV6-NTRK3 (EN). EN transforms NIH3T3 fibroblasts through constitutive activation of both the Ras-mitogen-activated protein kinase (MAPK) pathway and the phosphatidylinositol-3'kinase (PI3K)-Akt pathway. However, the role of trisomy 11 in CFS and CMN remains unknown. In this study we demonstrate elevated expression of the chromosome 11p15.5 insulin-like growth factor 2 gene (IGF2) in CFS and CMN tumors. Moreover, we present evidence that an intact IGF signaling axis is essential for in vitro EN-mediated transformation. EN only very weakly transformed so-called R-murine fibroblasts derived from mice with a targeted disruption of the IGF1 receptor gene (IGFRI), but transformation activity was fully restored in R- cells engineered to re-express IGFRI (R+ cells). We also observed that the major IGFRI substrate, insulin-receptor substrate-1 (IRS-1), was constitutively tyrosine phosphorylated and could be co-immunoprecipitated with EN in either R- or R+ cells expressing the EN oncoprotein. IRS-1 association with Grb2 and PI3K p85, which link IGFRI to the Ras-MAPK and PI3K-Akt pathways, respectively, was enhanced in both cell types in the presence of EN. However, activation of the Ras-MAPK and PI3K-Akt pathways was markedly attenuated in EN-expressing R- cells compared to EN-transformed R+ cells. This suggests that IRS-1 may be functioning as an adaptor in EN signal transduction, but that a link to EN transformation pathways requires the presence of IGFRI. Our findings indicate that an intact IGF signaling axis is essential for EN transformation, and are consistent with a role for trisomy 11 in augmenting this pathway in EN expressing tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Animals
  • Cell Transformation, Neoplastic*
  • DNA-Binding Proteins / physiology*
  • GRB2 Adaptor Protein
  • Insulin Receptor Substrate Proteins
  • Insulin-Like Growth Factor II / genetics
  • MAP Kinase Kinase 1
  • MAP Kinase Kinase 2
  • Mice
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Tyrosine Kinases / metabolism
  • Proteins / physiology
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Proto-Oncogene Proteins c-ets
  • Receptor, IGF Type 1 / physiology*
  • Receptor, trkC / physiology*
  • Repressor Proteins / physiology*
  • Signal Transduction
  • Tyrosine / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • DNA-Binding Proteins
  • ETS translocation variant 6 protein
  • GRB2 Adaptor Protein
  • Grb2 protein, mouse
  • Insulin Receptor Substrate Proteins
  • Irs1 protein, mouse
  • Phosphoproteins
  • Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Repressor Proteins
  • Tyrosine
  • Insulin-Like Growth Factor II
  • Protein-Tyrosine Kinases
  • Receptor, IGF Type 1
  • Receptor, trkC
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • MAP Kinase Kinase 1
  • MAP Kinase Kinase 2
  • Map2k1 protein, mouse
  • Mitogen-Activated Protein Kinase Kinases