Analysis genetic changes in human endocrine tumors

为了阐明内分泌肿瘤发生的分子基础，我们分析了人类内分泌肿瘤中ras、p53和Gsalpha突变.应用聚合酶链反应-单链构象多态性（PCR-SSCP）技术检测了171例肿瘤组织中H-、K-、N-ras基因的突变。24例甲状腺滤泡性腺瘤中有4例含有突变的N-ras密码子61，1例含有突变的H-ras密码子61。19例嗜铬细胞瘤中有1例H-ras基因第13密码子突变。2例垂体癌中1例H-ras基因第12.2位密码子突变。应用PCR-SSCP技术对134例肿瘤和6株人内分泌癌细胞系的p53基因外显子5 ~ 10进行了研究，发现4例肿瘤（包括1例甲状旁腺腺瘤和3例甲状腺癌细胞系）存在p53基因外显子5 ~ 10的突变。3种肿瘤细胞系中，包括p53基因在内的正常等位基因均丢失. Gsalpha基因突变采用PCR-引物引入限制性内切酶分析（PIRA）方法，从197例肿瘤中筛选出Gsalpha基因第201或227位密码子突变。43例垂体GH腺瘤中4例、30例甲状腺乳头状癌中4例、19例肾上腺皮质腺瘤中1例存在Gsalpha突变。结论：ras、p53和Gsalpha基因突变可能不参与大量人类endocine肿瘤的发病。

To elucidate the molecular basis for endocrine tumorigenesis, ras, p53, and Gsalpha mutations in human endocrine tumors were analyzed.1. ras mutationsMutations of the H-, K-, N-ras genes were examined from 171 tumors by polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP). Four out of 24 thyroid follicular adenomas contained mutated N-ras codon 61, and one contained the mutated H-ras codon 61. One of the 19 pheochromocyttomas revealed mutation of the H-ras codon 13. One of the 2 pituitary carcinomas contained mutation of the H-ras codon 12.2. p53 mutationsExons 5 through 10 of the p53 gene were studied from 134 tumors and 6 human endocrine cancer-derived cell lines by PCR-SSCP.Mutations were detected in 4 tumors, including one parathyroid adenomas and 3 throid carcinoma cell lines. In all of 3 tumor cell lines, the normal allele including the p53 gene was lost.3. Gsalpha mutationsMutation at codons 201 or 227 of the Gsalpha gene were screened from 197 tumors by PCR-primer-introduced restriction analysis(PIRA). The Gsalpha mutations were present in 4 of 43 GH-secreting pituitary adenomas, 4 of 30 papillary thyroid carcinomas, and 1 of 19 adrenocortical adenomas.Conclusion : Mutation of the ras, p53, and Gsalpha genes may not involved in the pathogenesis of a large population of human endocine tumors.