title: Protein Expression Analysis of Melanocyte Differentiation Antigen TRP-2.
abstract: Melanocyte differentiation antigens, such as gp100, tyrosinase, and Melan-A and their corresponding antibodies HMB45, T311, and A103, are major diagnostic tools in surgical pathology. Little is known about tyrosinase-related protein 2 (TRP-2, or dopachrome tautomerase/DCT) another melanocyte differentiation antigen, which is an enzymatic component of melanogenesis. We identified a commercial reagent to TRP-2, monoclonal antibody (mAb) C-9 and undertook a comprehensive analysis to assess its specificity and usefulness for surgical pathology. Subsequently, we analyzed panels of normal tissues and tumors. We show that TRP-2 is regularly expressed in melanocytes of the normal skin. In cutaneous nevi, TRP-2 is present in junctional as well as in dermal nevocytes. In malignant tumors, C-9 reactivity is restricted to melanocytic and related lesions and present in 84% and 58% of primary and metastatic melanomas, respectively. Ten primary melanomas of the anorectal mucosa were all positive. Like the other melanocyte differentiation antigens, TRP-2 was absent in 6 desmoplastic melanomas. Also, only 2 of 9 angiomyolipomas were TRP-2 positive. We conclude that mAb C-9 is a valuable reagent for the analysis of TRP-2 expression in archival surgical pathology material. The expression pattern of TRP-2 in melanocytic and related lesions appears to parallel other melanocyte differentiation antigens, although the overall incidence is lower than other antigens, such as Melan-A or gp100.
authors.affiliation: *Department of Immunology, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, NY; †Ludwig Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, NY; ‡Division of Hematology/Oncology, Tisch Cancer Institute, Icahn School of Medicine, Mount Sinai Hospital, New York, NY; and §Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Francesca
authors.initials: F
authors.lastname: Avogadri
authors.forename: Sacha
authors.initials: S
authors.lastname: Gnjatic
authors.forename: Jodie
authors.initials: J
authors.lastname: Tassello
authors.forename: Denise
authors.initials: D
authors.lastname: Frosina
authors.forename: Nicole
authors.initials: N
authors.lastname: Hanson
authors.forename: Megan
authors.initials: M
authors.lastname: Laudenbach
authors.forename: Erika
authors.initials: E
authors.lastname: Ritter
authors.forename: Taha
authors.initials: T
authors.lastname: Merghoub
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Busam
authors.forename: Achim A
authors.initials: AA
authors.lastname: Jungbluth
mesh_terms: D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D014408:Biomarkers, Tumor / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis*; D008544:Melanocytes / Q000378:metabolism*; D008545:Melanoma / Q000378:metabolism; D009506:Nevus / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012867:Skin / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism; D059467:Transcriptome
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase