ALK positively regulates MYCN activity through repression of HBP1 expression

Oncogene. 2019 Apr;38(15):2690-2705. doi: 10.1038/s41388-018-0595-3. Epub 2018 Dec 11.

Abstract

ALK mutations occur in 10% of primary neuroblastomas and represent a major target for precision treatment. In combination with MYCN amplification, ALK mutations infer an ultra-high-risk phenotype resulting in very poor patient prognosis. To open up opportunities for future precision drugging, a deeper understanding of the molecular consequences of constitutive ALK signaling and its relationship to MYCN activity in this aggressive pediatric tumor entity will be essential. We show that mutant ALK downregulates the 'HMG-box transcription factor 1' (HBP1) through the PI3K-AKT-FOXO3a signaling axis. HBP1 inhibits both the transcriptional activating and repressing activity of MYCN, the latter being mediated through PRC2 activity. HBP1 itself is under negative control of MYCN through miR-17~92. Combined targeting of HBP1 by PI3K antagonists and MYCN signaling by BET- or HDAC-inhibitors blocks MYCN activity and significantly reduces tumor growth, suggesting a novel targeted therapy option for high-risk neuroblastoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaplastic Lymphoma Kinase / genetics*
  • Animals
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Down-Regulation / genetics
  • Forkhead Box Protein O3 / genetics
  • Gene Expression Regulation, Neoplastic / genetics
  • High Mobility Group Proteins / genetics*
  • Humans
  • Mice
  • MicroRNAs / genetics
  • Mutation / genetics
  • N-Myc Proto-Oncogene Protein / genetics*
  • Neuroblastoma / genetics*
  • Phosphatidylinositol 3-Kinases / genetics
  • Proto-Oncogene Proteins c-akt / genetics
  • Repressor Proteins / genetics*
  • Signal Transduction / genetics
  • Transcriptional Activation / genetics

Substances

  • Forkhead Box Protein O3
  • HBP1 protein, human
  • High Mobility Group Proteins
  • MYCN protein, human
  • MicroRNAs
  • N-Myc Proto-Oncogene Protein
  • Repressor Proteins
  • Phosphatidylinositol 3-Kinases
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • Proto-Oncogene Proteins c-akt