title: Quantitative analysis of melanocytic tissue array reveals inverse correlation between activator protein-2alpha and protease-activated receptor-1 expression during melanoma progression.
abstract: The identification of molecular markers of melanoma progression is needed to more accurately stage and identify treatments for patients with malignant melanoma. Previously, we demonstrated that loss of the activator protein-2alpha (AP-2alpha) expression results in overexpression of the protease-activated receptor-1 (PAR-1) in human melanoma cell lines. Here, we used a tissue microarray platform that consisted of 64 melanocytic lesions, including dysplastic nevi (N=21), primary melanoma (N=20), and metastatic melanoma (N=23). We analyzed the expression of AP-2 and PAR-1 simultaneously by immunofluorescent microscopy with an automated quantification laser scanning cytometer. AP-2 was highly expressed in normal cutaneous melanocytes and dysplastic nevi but not in melanoma metastases. We observed a significantly higher number of AP-2-positive cells in the dysplastic nevi (P=0.0013) and primary melanoma (P=0.0023) compared to the metastatic melanoma. In contrast, we observed a significantly higher percentage of PAR-1-positive cells in the metastatic melanoma compared to dysplastic nevi (P=0.0072) and primary melanoma (P=0.0138). Increased expression of PAR-1 in metastatic melanomas contributes to tumor progression by modulating expression of genes, such as IL-8, matrix metalloproteinase-2, vascular endothelial growth factor, platelet-derived growth factor, and integrins. These findings support our hypothesis that loss of AP-2 is a crucial event in the progression of human melanoma and contributes to the acquisition of the metastatic phenotype via upregulation of PAR-1.
authors.affiliation: Department of Leukemia, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Carmen S
authors.initials: CS
authors.lastname: Tellez
authors.forename: Darren W
authors.initials: DW
authors.lastname: Davis
authors.forename: Victor G
authors.initials: VG
authors.lastname: Prieto
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Gershenwald
authors.forename: Marcella M
authors.initials: MM
authors.lastname: Johnson
authors.forename: Marya F
authors.initials: MF
authors.lastname: McCarty
authors.forename: Menashe
authors.initials: M
authors.lastname: Bar-Eli
mesh_terms: D018450:Disease Progression; D004416:Dysplastic Nevus Syndrome / Q000378:metabolism / Q000473:pathology; D005455:Fluorescent Antibody Technique; D006801:Humans; D047569:Laser Scanning Cytometry; D008544:Melanocytes / Q000378:metabolism*; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology* / Q000556:secondary; D020411:Oligonucleotide Array Sequence Analysis; D044463:Receptor, PAR-1 / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology*; D050656:Transcription Factor AP-2 / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D044463:Receptor, PAR-1; D050656:Transcription Factor AP-2