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

✍ Scribed by Suhendan Ekmekcioglu; Julie Ellerhorst; Abner M. Mhashilkar; Aysegul A. Sahin; Christine M. Read; Victor G. Prieto; Sunil Chada; Elizabeth A. Grimm

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: French
• Weight: 529 KB
• Volume: 94
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.1437

✦ Synopsis

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.