title: Selective expression of Syntaxin-7 protein in benign melanocytes and malignant melanoma.
abstract: To search for proteins expressed in human melanocytes and melanoma, we employed an antibody-based proteomics strategy to screen for protein expression in tissue microarrays containing normal tissues, cancer tissues and cell lines. Syntaxin-7 (STX7) was identified as a novel protein, not previously characterized in cells of melanocytic lineage, displaying a cell type-specific protein expression pattern. In tumor tissues, STX7 was expressed in malignant melanoma and lymphoma. The protein was further characterized regarding subcellular localization, specificity, tissue distribution pattern and potential as a diagnostic and prognostic marker using cell lines and tissue microarrays containing normal skin, melanocytic nevi and primary and metastatic melanoma. STX7 was expressed in normal melanocytes, various benign melanocytic nevi, atypical nevi and malignant melanoma. Analysis in two independent melanoma cohorts demonstrated STX7 expression in nearly all investigated tumors, although at varying levels (> 90% positive tumors). The expression level of STX7 protein was inversely correlated to tumor stage, suggesting that decreased expression of STX7 is associated with more aggressive tumors. In conclusion, we present protein profiling data for a novel protein showing high sensitivity and specificity for cells of the melanocytic lineage. The presented antibody-based proteomics approach can be used as an effective strategy to identify novel tumor markers and evaluate their potential clinical relevance.
authors.affiliation: Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, SE-75185 Uppsala, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Strömberg
authors.forename: Margrét
authors.initials: M
authors.lastname: Agnarsdóttir
authors.forename: Kristina
authors.initials: K
authors.lastname: Magnusson
authors.forename: Elton
authors.initials: E
authors.lastname: Rexhepaj
authors.forename: Asa
authors.initials: A
authors.lastname: Bolander
authors.forename: Emma
authors.initials: E
authors.lastname: Lundberg
authors.forename: Anna
authors.initials: A
authors.lastname: Asplund
authors.forename: Denise
authors.initials: D
authors.lastname: Ryan
authors.forename: Mairin
authors.initials: M
authors.lastname: Rafferty
authors.forename: William M
authors.initials: WM
authors.lastname: Gallagher
authors.forename: Mathias
authors.initials: M
authors.lastname: Uhlen
authors.forename: Michael
authors.initials: M
authors.lastname: Bergqvist
authors.forename: Fredrik
authors.initials: F
authors.lastname: Ponten
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D045744:Cell Line, Tumor; D006801:Humans; D008544:Melanocytes / Q000378:metabolism*; D008545:Melanoma / Q000378:metabolism*; D050765:Qa-SNARE Proteins / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D050765:Qa-SNARE Proteins