Immunohistochemical expression of BCL-2 in melanomas and intradermal nevi.
The BCL-2 gene is the prototype of a newly described family of oncogenes involved in tumorigenesis by blocking apoptosis, or programmed cell death. Overexpression of BCL-2 protein was originally described in follicular B-cell lymphomas bearing the 14;18 translocation. BCL-2 overexpression has also been described in other lymphomas and more rarely in neoplasms outside the lymphoid tissue. The aim of this paper is to determine the immunohistochemical expression of BCL-2 in intradermal nevi and primary invasive and metastatic melanoma. Formalin-fixed and paraffin-embedded tissues from 4 cutaneous melanoma metastases, 10 primary invasive melanomas, and 10 intradermal melanocytic nevi were immunolabeled with monoclonal antibodies directed against BCL-2 protein (Dako, clone 124) and Ki-67 antigen (Amac, clone MIB-1), after antigen retrieval techniques. Morphologically normal epidermal melanocytes expressed BCL-2, as did nevi and melanomas in virtually all cells. However, whereas the labeling in normal melanocytes and nevus cells showed a uniformly strong reactivity, melanoma cells showed a variable but mainly weak reactivity. Ki-67 antigen expression was restricted to melanomas. The widespread expression of BCL-2 suggests that this oncoprotein cannot be involved in the malignant transformation of melanocytic cells. It seems likely that the decreased BCL-2 expression detected in melanomas may reflect one further step of tumor progression in melanocytic neoplasms.
Saenz-Santamaría
M C
MC
Department of Pathology, New York Hospital-Cornell Medical Center, New York 10021.
Reed
J A
JA
McNutt
N S
NS
Shea
C R
CR
D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen; D008545:Melanoma / Q000473:pathology* / Q000556:secondary; D009363:Neoplasm Proteins / Q000032:analysis; D018330:Nevus, Intradermal / Q000473:pathology*; D009687:Nuclear Proteins / Q000032:analysis; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D019253:Proto-Oncogene Proteins c-bcl-2; D012878:Skin Neoplasms / Q000473:pathology*
D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2