Albino A P, Nanus D M, Mentle I R, Cordon-Cardo C, McNutt N S, Bressler J, Andreeff M
Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Oncogene. 1989 Nov;4(11):1363-74.
This study examined noncultured and cultured melanomas and related precursor specimens for (i) mutated ras genes using polymerase chain reaction (PCR) methodology, (ii) correlation of mutated ras genes with differentiation related phenotypic characteristics, (iii) expression of ras-encoded p21 proteins in tissues by immunoperoxidase analysis, (iv) quantitative expression of mutated and wild-type ras encoded p21 proteins by flow cytometry, and (v) correlation between p21 expression, the occurrence of ras mutations, and cell cycle kinetics. The results of these studies are (1) 24% of cultured malignant melanomas have activated ras genes, with N-ras being activated ten times as frequently as Harvey (Ha)-ras. Each example of an activated ras gene showed a mutation at the 61st codon of the protein, with the exception of one melanoma which showed a mutation at codon 13 of the N-ras gene; (2) all the melanomas displaying an activated ras gene had a similar cell surface phenotype and appear to come from a similar phase of differentiation; (3) 5-6% of noncultured primary and metastatic melanomas have mutated ras genes; (4) no ras gene mutations were found in any precursor lesion, specifically normal nevi and dysplastic nevi; (5) immunoperoxidase analysis of paraffin-embedded specimens indicated no quantitative or qualitative alterations in p21 expression that correlate with tumor progression; (6) there were no observable differences in p21 expression between melanoma cells growing exponentially or in plateau phase, or between melanoma cells with or without ras mutations; nor were any cell kinetic differences found between cells with and without mutated ras genes. These studies suggest that the role of ras mutations may be limited to an indirect involvement in the transformation of a subset of melanomas.
本研究检测了非培养及培养的黑色素瘤及相关前体标本，以进行以下研究：（i）使用聚合酶链反应（PCR）方法检测ras基因突变；（ii）突变的ras基因与分化相关表型特征的相关性；（iii）通过免疫过氧化物酶分析检测组织中ras编码的p21蛋白的表达；（iv）通过流式细胞术检测突变型和野生型ras编码的p21蛋白的定量表达；以及（v）p21表达、ras突变的发生与细胞周期动力学之间的相关性。这些研究结果如下：（1）24%的培养恶性黑色素瘤具有激活的ras基因，其中N-ras被激活的频率是哈维（Ha）-ras的10倍。除了一例黑色素瘤在N-ras基因的第13密码子处出现突变外，每个激活的ras基因实例均在该蛋白的第61密码子处出现突变；（2）所有显示激活的ras基因的黑色素瘤具有相似的细胞表面表型，且似乎来自相似的分化阶段；（3）5-6%的非培养原发性和转移性黑色素瘤具有ras基因突变；（4）在任何前体病变中均未发现ras基因突变，特别是正常痣和发育异常痣；（5）对石蜡包埋标本的免疫过氧化物酶分析表明，p21表达在定量或定性方面均无与肿瘤进展相关的改变；（6）在指数生长期或平台期生长的黑色素瘤细胞之间，或有或无ras突变的黑色素瘤细胞之间，p21表达均无明显差异；在有或无突变ras基因的细胞之间也未发现任何细胞动力学差异。这些研究表明，ras突变的作用可能仅限于间接参与一部分黑色素瘤的转化过程。
