bcl-2 protein expression in melanocytic neoplasms of the skin.
Since the discovery of bcl-2 proto-oncogene in follicular lymphomas, the protein product has been detected in a variety of normal tissues including skin, where it is expressed in basal keratinocytes. Recent studies indicate that bcl-2 protein is detected in nonlymphoid malignancies such as neuroblastoma and carcinomas of the lung and prostate. This study investigates the presence of bcl-2 protein in benign and malignant melanocytic neoplasms of the skin. Immunohistochemical analysis of bcl-2 protein expression was performed on 39 nevi and 60 malignant melanomas, including 21 metastases. There was diffuse strong immunopositivity for bcl-2 protein in 100% of nevi and 65% (43/60) of primary and metastatic melanomas. bcl-2 protein was diffusely expressed in 67% (30/39) of primary melanomas and 54% (11/21) of metastases. Although bcl-2 immunoreactivity was observed in all levels of primary cutaneous malignant melanomas, in 43% (9/21) of deep melanomas (Clark level > or = III), and 100% (7/7) of thick tumors (thickness > or = 4.00 mm), there was focal loss of immunoreactivity. Metastatic melanomas showed focal loss of bcl-2 expression in 10% (2/21) of cases and total loss of bcl-2 protein in 39% (8/21). We conclude from our results that bcl-2 protein is expressed by benign and malignant melanocytic tumors of the skin, but there is loss of bcl-2 protein expression with increasing tumor progression.
Ramsay
J A
JA
Department of Medicine, Women's College Hospital, University of Toronto, Ontario, Canada.
From
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Kahn
H J
HJ
D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology* / Q000556:secondary; D009508:Nevus, Pigmented / Q000378:metabolism / Q000473:pathology; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*
D014408:Biomarkers, Tumor; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2