by Kreizenbecket al. 0. 28 respectively). A switch of membranous expression from E-cadherin to N-cadherin from primary to metastatic melanoma Golotimod (SCV-07) was seen in eight patients (19%). Aberrant E-cadherin expression (defined as negative to weak membranous E-cadherin or positive nuclear E-cadherin expression) was more frequently observed in metastatic than in primary melanomas (p=0. 03). Multivariate analysis showed that absence of N-cadherin expression in primary melanomas and the presence of aberrant E-cadherin expression in primary melanomas and metastatic melanomas was associated with a significantly worse overall survival. Our data support the importance of E-cadherin and N-cadherin proteins in melanoma progression and patient survival. Keywords: Epithelialmesenchymal transition, E-cadherin, N-cadherin, melanoma, metastasis Melanoma is one of the deadliest types of cancer, with even shallow primary lesions able to progress from early invasion to metastasis and ultimately causing death. The ability at the time of diagnosis Mouse monoclonal to FMR1 to identify tumor characteristics that help predict propensity for metastasis would be useful in guiding the discussions about prognosis, as well as selecting patients who may benefit the most from systemic therapy. In addition , understanding the process by which metastases develop could potentially identify targets for therapeutic interventions. Epithelialmesenchymal transition (EMT), which was initially described in the context of embryonic development, is a means by which a cell changes morphologically and functionally from an epithelial to a mesenchymal phenotype. This change alters adhesive properties between it and adjacent cells necessary for the migration of the cell to distant sites (1). Thus EMT is involved in the initial steps of developing metastatic potential, when tumor cells escape from the microenvironmentvialoss of cellular adhesion and gain of motility. Following access to the circulatory or lymphatic system, tumor cells migrate to a new location, often in a visceral organ and establish metastases (2). Although melanocytes are derived from neural crest cells and are not epithelial in origin, EMT is a well-documented phenomenon contributing to the metastatic potential Golotimod (SCV-07) of malignant melanocytes (3, 4). Cadherins, or calcium-dependent adhesion molecules, are transmembrane glycoproteins involved in cellular adhesion, which in skin is adhesion of melanocytes and keratinocytes. In vitrostudies have shown that among other factors, down-regulation of membrane expression of epithelial, or E-cadherin, and increase in neural, or N-cadherin, are involved in the ability of a melanoma cell to migrate out of its nascent environment (5-8). One of the important early steps in melanoma development includes disruption of E-cadherin-mediated adhesive interaction between melanocytes and keratincoytes, accompanied by increased expression of N-cadherin, which facilitates proliferation and invasion of Golotimod (SCV-07) melanoma cells. Expression of N- and E-cadherins are regulated, in part, by ubiquitin carboxyl-terminal hydrolase (CYLD) gene and the zinc finger protein encoded by the snail family transcriptional repressor 1 (SNAI1) gene, respectively (9). The role of cadherins in EMT has been studied in multiple tumor types. A decrease in expression of E-cadherin has been observed in oral dysplasia and squamous cell carcinoma when compared to normal controls (10), and in early-stage primary tongue cancer it has been noted to portend later development of metastases after initial glossectomy (11). Breast cancer cells have been shown to have increased metastasis Golotimod (SCV-07) when they exhibit low expression of E-cadherin and high expression of N-cadherin (12). Studies involving analysis of melanocytic tumor tissue from primary lesions and metastases support the role of E-cadherin down-regulation in metastatic potential (11-14). These studies compared pooled primary lesions to metastases, or benign melanocytic lesions to melanomas (13-16), supporting the concept that down-regulation of E-cadherin is one aspect in a complicated process that allows a melanoma cell to escape from its site of origin in the skin epidermis. If E- and N-cadherin were strongly associated with melanoma metastatic potential, we hypothesize that the switch would be evident in paired primary and metastatic samples from the same patient. In order to confirm EMT in melanoma, we undertook what we believe to be the first reported evaluation of matched tissue samples from primary and metastatic sites of melanoma to confirm the presence of the E to N-cadherin switch and to determine if expression profiles are associated with survival. We also examined the expression patterns of E-cadherin and N-cadherin in 53 benign melanocytic nevi using a tissue microarray as control. == Materials and Methods == == Case selection == The tumor cases were selected from formalin-fixed, paraffin-embedded tissue blocks obtained from the Department of Pathology and Laboratory Medicine at Dartmouth-Hitchcock Medical Center. The tumor cohort characteristics are presented inTable.
