MLANA/MART1 and SILV/PMEL17/GP100 are transcriptionally regulated by MITF in melanocytes and melanoma.
The clinically important melanoma diagnostic antibodies HMB-45, melan-A, and MITF (D5) recognize gene products of the melanocyte-lineage genes SILV/PMEL17/GP100, MLANA/MART1, and MITF, respectively. MITF encodes a transcription factor that is essential for normal melanocyte development and appears to regulate expression of several pigmentation genes. In this report, the possibility was examined that MITF might additionally regulate expression of the SILV and MLANA genes. Both genes contain conserved MITF consensus DNA sequences that were bound by MITF in vitro and in vivo, based on electrophoretic mobility shift assay and chromatin-immunoprecipitation. In addition, MITF regulated their promoter/enhancer regions in reporter assays, and up- or down-regulation of MITF produced corresponding modulation of endogenous SILV and MLANA in melanoma cells. Expression patterns were compared with these factors in a series of melanoma cell lines whose mutational status of the proto-oncogene BRAF was also known. SILV and MLANA expression correlated with MITF, while no clear correlation was seen relative to BRAF mutation. Finally, mRNA expression array analysis of primary human melanomas demonstrated a tight correlation in their expression levels in clinical tumor specimens. Collectively, this study links three important melanoma antigens into a common transcriptional pathway regulated by MITF.
Du
Jinyan
J
Department of Pediatric Hematology/Oncology, Dana-Farber Cancer Institute and Children's Hospital, Harvard Medical School, Boston, USA.
Miller
Arlo J
AJ
Widlund
Hans R
HR
Horstmann
Martin A
MA
Ramaswamy
Sridhar
S
Fisher
David E
DE
D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D006801:Humans; D058965:MART-1 Antigen; D008544:Melanocytes / Q000502:physiology*; D008545:Melanoma / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D051739:Microphthalmia-Associated Transcription Factor; D016297:Mutagenesis, Site-Directed; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D000090063:Proto-Oncogene Mas; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D058951:gp100 Melanoma Antigen
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D058965:MART-1 Antigen; C000715470:MAS1 protein, human; C497234:MITF protein, human; C548667:MLANA protein, human; D008562:Membrane Glycoproteins; D051739:Microphthalmia-Associated Transcription Factor; C497235:Mitf protein, mouse; C548668:Mlana protein, mouse; D009363:Neoplasm Proteins; C548637:PMEL protein, human; C548642:Pmel protein, mouse; D000090063:Proto-Oncogene Mas; D014157:Transcription Factors; D058951:gp100 Melanoma Antigen