Lassam N J, From L, Kahn H J
Department of Medicine, University of Toronto, Ontario, Canada.
Cancer Res. 1993 May 15;53(10 Suppl):2235-8.
Overexpression of the p53 gene product has been observed in a high percentage of malignant melanomas. To evaluate the role of this protein in the development of melanoma, we examined p53 expression in benign, premalignant, and malignant melanocytic lesions. Using the antibodies DO-7 and 1801, which recognize both wild-type and most mutant forms of the p53 protein, we analyzed by immunohistochemical staining 26 benign nevi, 34 dysplastic nevi from patients at low risk for the development of melanoma, 22 dysplastic nevi from patients at high risk for the development of melanoma, 61 primary melanomas (including 15 that arose from dysplastic nevi), and 10 metastatic melanomas. Expression of the p53 protein was not observed in any of the benign or dysplastic nevi. Of the primary melanomas only 3 (5%) demonstrated nuclear staining, whereas 70% of the metastatic melanomas showed a positive reaction for p53. These data suggest that overexpression of the p53 gene product is a late event in the progression of melanoma and consequently indicate that expression of this protein cannot be used as a marker to identify patients at high risk for the subsequent development of melanoma.
在高比例的恶性黑色素瘤中观察到p53基因产物的过表达。为了评估该蛋白在黑色素瘤发生发展中的作用，我们检测了良性、癌前和恶性黑素细胞病变中的p53表达。使用能识别p53蛋白野生型和大多数突变形式的DO-7和1801抗体，我们通过免疫组织化学染色分析了26例良性痣、34例黑色素瘤低风险患者的发育异常痣、22例黑色素瘤高风险患者的发育异常痣、61例原发性黑色素瘤（包括15例由发育异常痣发展而来的）以及10例转移性黑色素瘤。在任何良性或发育异常痣中均未观察到p53蛋白的表达。在原发性黑色素瘤中，只有3例（5%）显示核染色，而70%的转移性黑色素瘤对p53呈阳性反应。这些数据表明，p53基因产物的过表达是黑色素瘤进展中的晚期事件，因此表明该蛋白的表达不能用作识别黑色素瘤后续高风险患者的标志物。
