Identification of novel pathways and molecules able to down-regulate PHOX2B gene expression by in vitro drug screening approaches in neuroblastoma cells

Exp Cell Res. 2015 Aug 1;336(1):43-57. doi: 10.1016/j.yexcr.2015.03.025. Epub 2015 Apr 13.

Abstract

PHOX2B is a transcription factor involved in the regulation of neurogenesis and in the correct differentiation of the autonomic nervous system. The pathogenetic role of PHOX2B in neuroblastoma (NB) is supported by mutations in familial, sporadic and syndromic cases of NB and overexpression of PHOX2B and its target ALK in tumor samples and NB cell lines. Starting from these observations, we have performed in vitro drug screening approaches targeting PHOX2B overexpression as a potential pharmacological means in NB. In particular, in order to identify molecules able to decrease PHOX2B expression, we have evaluated the effects of 70 compounds in IMR-32 cell line stably expressing the luciferase gene under the control of the PHOX2B promoter. Curcumin, SAHA and trichostatin A showed to down-regulate the PHOX2B promoter activity which resulted in a decrease of both protein and mRNA expressions. In addition, we have observed that curcumin acts by interfering with PBX-1/MEIS-1, NF-κB and AP-1 complexes, in this work demonstrated for the first time to regulate the transcription of the PHOX2B gene. Finally, combined drug treatments showed successful effects in down-regulating the expression of both PHOX2B and its target ALK genes, thus supporting the notion of the effectiveness of molecule combination in tumor therapy.

Keywords: Curcumin; Drug screening; Gene expression regulation; Histone deacetylase; Neuroblastoma; PHOX2B.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Differentiation
  • Curcumin / pharmacology
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Drug Evaluation, Preclinical*
  • High-Throughput Screening Assays*
  • Histone Deacetylase Inhibitors / pharmacology
  • Homeodomain Proteins / antagonists & inhibitors*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Humans
  • Hydroxamic Acids / pharmacology
  • In Vitro Techniques
  • Myeloid Ecotropic Viral Integration Site 1 Protein
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Neuroblastoma / drug therapy*
  • Neuroblastoma / metabolism*
  • Neuroblastoma / pathology
  • Pre-B-Cell Leukemia Transcription Factor 1
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects*
  • Small Molecule Libraries / pharmacology*
  • Transcription Factor AP-1 / genetics
  • Transcription Factor AP-1 / metabolism
  • Transcription Factors / antagonists & inhibitors*
  • Transcription Factors / genetics
  • Tumor Cells, Cultured

Substances

  • DNA-Binding Proteins
  • Histone Deacetylase Inhibitors
  • Homeodomain Proteins
  • Hydroxamic Acids
  • MEIS1 protein, human
  • Myeloid Ecotropic Viral Integration Site 1 Protein
  • NBPhox protein
  • NF-kappa B
  • Neoplasm Proteins
  • Pre-B-Cell Leukemia Transcription Factor 1
  • Proto-Oncogene Proteins
  • RNA, Messenger
  • Small Molecule Libraries
  • Transcription Factor AP-1
  • Transcription Factors
  • PBX1 protein, human
  • trichostatin A
  • Curcumin