Brn-2 represses microphthalmia-associated transcription factor expression and marks a distinct subpopulation of microphthalmia-associated transcription factor-negative melanoma cells

Cancer Res. 2008 Oct 1;68(19):7788-94. doi: 10.1158/0008-5472.CAN-08-1053.

Abstract

The origin of tumor heterogeneity is poorly understood, yet it represents a major barrier to effective therapy. In melanoma and in melanocyte development, the microphthalmia-associated transcription factor (Mitf) controls survival, differentiation, proliferation, and migration/metastasis. The Brn-2 (N-Oct-3, POU3F2) transcription factor also regulates melanoma proliferation and is up-regulated by BRAF and beta-catenin, two key melanoma-associated signaling molecules. Here, we show that Brn-2 also regulates invasiveness and directly represses Mitf expression. Remarkably, in melanoma biopsies, Mitf and Brn-2 each mark a distinct subpopulation of melanoma cells, providing a striking illustration of melanoma tumor heterogeneity with implications for melanoma therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Biomarkers, Tumor / genetics*
  • Biomarkers, Tumor / metabolism
  • Down-Regulation
  • Female
  • Gene Expression Regulation, Neoplastic
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Homeodomain Proteins / physiology*
  • Humans
  • Melanoma / genetics*
  • Melanoma / metabolism
  • Melanoma / pathology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Microphthalmia-Associated Transcription Factor / genetics*
  • Microphthalmia-Associated Transcription Factor / metabolism
  • Molecular Sequence Data
  • Neoplasm Invasiveness
  • POU Domain Factors / genetics
  • POU Domain Factors / metabolism
  • POU Domain Factors / physiology*
  • Protein Binding
  • Transplantation, Heterologous
  • Tumor Cells, Cultured

Substances

  • Biomarkers, Tumor
  • Homeodomain Proteins
  • Microphthalmia-Associated Transcription Factor
  • POU Domain Factors
  • transcription factor Brn-2