Down-regulated melanoma differentiation associated gene (mda-7) expression in human melanomas

Int J Cancer. 2001 Oct 1;94(1):54-9. doi: 10.1002/ijc.1437.


The melanoma differentiation associated gene-7 (mda-7) has a potential inhibitory role in melanoma progression, although the mechanisms underlying this effect are still unknown. mda-7 mRNA has been found to be present at higher levels in cultured normal melanocytes compared with metastatic melanoma cell lines. Furthermore, levels of mda-7 message have shown an inverse correlation with melanoma progression in human tumor samples, suggesting that mda-7 may be a novel tumor suppressor gene. We have designed this study to investigate MDA-7 protein expression in different stages of melanoma progression and to examine its antiproliferative effects in vitro. Our data demonstrate that MDA-7 protein can be found in normal melanocytes and early stage melanomas. It is also observed in smooth muscle cells in the skin. However, in keeping with a possible role as a tumor suppressor, MDA-7 expression is decreased in more advanced melanomas, with nearly undetectable levels in metastatic disease. We also investigated antitumor effects of overexpressed MDA-7 on human melanoma cells in vitro. Our results demonstrate that Ad-mda-7 induces apoptosis and G2/M cell cycle arrest in melanoma cells, but not in normal human melanocytes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis
  • Cell Differentiation
  • Cell Division
  • Cytoplasm / chemistry
  • Down-Regulation
  • G2 Phase
  • Gene Expression Regulation, Neoplastic*
  • Genes, Tumor Suppressor
  • Growth Substances / analysis
  • Growth Substances / genetics*
  • Growth Substances / physiology
  • Humans
  • Interleukins*
  • Melanocytes / chemistry*
  • Melanoma / metabolism*
  • Melanoma / pathology
  • Melanoma / secondary
  • Mitosis
  • Tumor Cells, Cultured


  • Growth Substances
  • Interleukins
  • interleukin-24