Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melan-A is a previously defined, melanocyte differentiation antigen, and an anti-Melan-A murine monoclonal antibody, A103, was recently developed by our group. In this study, we evaluated A103 immunoreactivity on formalin-fixed, paraffin-embedded tissues, exploring the potential of A103 in the diagnosis of metastatic melanoma. Seventy-five metastatic melanomas, 10 primary melanomas, and 10 benign melanocytic nevi were tested. The reactivity of A103 was compared with HMB-4, an anti-gp100 antibody. Results showed that all nevi were A103 positive, and most primary melanomas were A103 and HMB45 positive. Of 75 metastatic melanomas, 61 (81%) were A103 positive, and 56 (75%) were HMB45 positive. Of 19 HMB45-negative lesions, 8 were A103 positive; of 14 A103-negative lesions, 3 were HMB45 positive. Eleven metastatic lesions, as well as 2 of 10 primary melanomas, were dual negative. These negative cases consisted mainly of the spindle cell and desmoplastic variants. Of the positive cases, A103 showed homogeneous staining in a significantly higher proportion of cases than HMB45 (72% versus 52%). In addition, focal staining with less than 5% reactive tumor cells was seen more frequently in HMB45 (12 of 56) than in A103 (5 of 61). These results indicated that A103 can be used as a first-line antibody in the diagnosis of metastatic melanoma. Our results also showed that A103 reacted with angiomyolipoma, which is known to be HMB45 positive. Of normal tissues, unexpected A103 reactivity was observed in the adrenal cortex, granulosa and theca cells of the ovary, and Leydig cells of the testis. This A103 immunoreactivity in benign and neoplastic tissues of nonmelanocytic origin, the basis of which is unclear, could also be of potential diagnostic value.
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PMID:A103: An anti-melan-a monoclonal antibody for the detection of malignant melanoma in paraffin-embedded tissues. 1032 95

Tyrosinase is a key enzyme in melanin biosynthesis and represents a marker of melanocytic differentiation. We previously generated T311, a murine monoclonal antibody to the tyrosinase recombinant protein. This study was performed to evaluate T311 as a diagnostic immunohistochemical reagent for use on formalin-fixed paraffin-embedded pathological material. We analyzed the specificity of the antibody on a panel of normal and neoplastic tissues, and we assessed its sensitivity in a large number of metastatic and primary malignant melanomas, nevi, three angiomyolipomas, and two vitiligo specimens. T311 revealed intense reactivity on paraffin-embedded material. Immunoreactivity was limited to cells of melanocytic differentiation and no immunostaining was present in unrelated normal tissues and tumors. Eighty-four percent of metastatic malignant melanomas were immunoreactive with T311 and showed predominantly a homogeneous expression pattern. However, in primary melanomas of the desmoplastic/spindle cell type, T311 revealed a poor immunoreactivity. Nevi showed intense staining at the junctional zone, while the dermal component revealed decreasing reactivity towards deeper areas. Only one angiomyolipoma was focally immunoreactive with T311. Vitiligo specimens were immunonegative. We conclude that T311 is a specific and sensitive marker for the detection of melanocytic lesions in formalin-fixed paraffin-embedded tissues and a useful serological reagent for diagnostic pathology.
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PMID:T311--an anti-tyrosinase monoclonal antibody for the detection of melanocytic lesions in paraffin embedded tissues. 1078 67

PNL2 is a novel monoclonal antibody, which has recently been introduced as an immunohistochemical reagent to stain melanocyte and tumors derived thereof. In the present study, we analyzed the immunoreactivity of this mAb in various normal tissues, melanocytic nevi, primary and metastatic melanoma, nonmelanocytic tumors, including histologic mimickers of melanoma as well as angiomyolipoma, and multiple cell lines derived from different tumors types. We used several tissue microarray panels as well as selected conventional sections from tissue blocks. For metastatic melanoma, immunoreactivity for PNL2 was compared with A103 (Melan-A/MART-1), T311 (tyrosinase), HMB45 (gp100), and D5 (MITF). Positive staining with PNL2 was found in normal melanocytes and neutrophils, but no other normal cell type. Among melanocytic lesions, both benign nevi as well as primary malignant melanomas, especially epithelioid variants thereof, were commonly immunopositive. Only 1 of 13 desmoplastic melanomas reacted with PNL2. PNL2 showed high sensitivity for metastatic melanoma (87%). In comparison, 82% of metastatic melanomas were positive for A103, 76% for HMB45, 92% for T311, and 84% for D5. The combined use of all five reagents minimized the number of immunonegative cases. None of the selected nonmelanocytic tumors (carcinomas or soft tissue neoplasms) was positive for PNL2 in this series except for angiomyolipomas and chronic myeloid leukemias and 1 single case of a malignant peripheral nerve sheath tumor with heterologous differentiation (malignant Triton tumor). Despite its reactivity with neutrophils, PNL2 appears to be a valuable supplementary reagent for the diagnosis of melanocytic tumors.
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PMID:Immunohistochemical analysis of novel monoclonal antibody PNL2 and comparison with other melanocyte differentiation markers. 1572 10

Identification of metastatic melanoma can be difficult because of its considerable morphologic variation and mimicry of a wide variety of other tumors. The more melanoma-specific melanoma markers, MelanA/MART-1, HMB45, and tyrosinase, used in addition to S100 protein, all have limitations in sensitivity and specificity. In this study, we evaluated 2 new melanoma markers, monoclonal antibodies KBA62 and PNL2 to yet unidentified antigens, using a large panel of metastatic melanomas (n=214), desmoplastic melanomas (n=34), gastrointestinal mucosal melanomas (n=54), benign nevi (n=27), clear cell sarcomas (n=16), and nonmelanocytic tumors (n=1218). Immunoreactivity for KBA62 and PNL2 was found in all pigmented nevi and in 86% and 90% of metastatic melanomas, respectively. Mucosal melanomas showed a similar rate of PNL2 immunoreactivity but somewhat less frequent KBA62 positivity (72%). In addition, KBA62 was found to be a sensitive diagnostic marker for desmoplastic melanoma (28 of 34; 82%), whereas PNL2 was only rarely positive (2 of 34; 6%). KBA62-positive normal tissues included pericytes, vascular and parenchymal smooth muscles, and basal cells of complex epithelia, including myoepithelia, whereas PNL2 labeled only melanocytes and neutrophils. Among nonmelanocytic tumors, those that were KBA62 positive were nodular fasciitis, leiomyoma and leiomyosarcoma, gastrointestinal stromal tumors, benign and malignant nerve sheath tumors, synovial sarcoma, and subsets of various carcinomas, especially those with squamous cell/stratified epithelial differentiation. PNL2 positivity in nonmelanocytic tumors was more restricted but occurred consistently in angiomyolipoma and other perivascular epitheloid cell tumor and in chronic myeloid leukemia tissue infiltrates. KBA62 may assist in the identification of desmoplastic melanomas, but its widespread occurrence in nonmelanomas limits utility. PNL2 is highly specific for melanomas but lacks reactivity with desmoplastic melanomas. It is also an excellent supplementary marker for perivascular epitheloid cell tumor at various sites.
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PMID:KBA62 and PNL2: 2 new melanoma markers-immunohistochemical analysis of 1563 tumors including metastatic, desmoplastic, and mucosal melanomas and their mimics. 2206 29