散发性肾癌中VHL基因的两个单核苷酸多态位点分析和杂合性缺失检测

Analysis of two single nucleotide polymorphisms in von Hippel-Lindau gene and detection of loss of heterozygosity in Chinese sporadic renal cell carcinoma

目的检测79例散发性肾癌中抑癌基因VHL内部的两个单核苷酶多态(singlenucleotidepolymorphism,SNP)位点并分析杂合性缺失(lossofheterozygosity,LOH)发生情况,探讨VHL基因LOH与肾癌临床病理特征的关系。方法从肿瘤和正常肾组织中提取DNA,应用聚合酶链反应-限制性片段长度多态性方法检测VHL基因5′端SNP位点rs779805和3′端SNP位点rs1642742的基因型。在两个位点的杂合子中进行LOH检测,并分析VHL基因LOH与临床病理特征的关系。结果我们计算了两个位点的基因型、基因频率、杂合度、多态信息含量等遗传学参数。综合两个位点发现杂合子29例,其中12例(41.4%)存在LOH。VHL基因LOH与肾癌发生年龄、性别、临床分期、病理分级无显著相关性。结论在散发性肾癌中,VHL基因LOH是肿瘤发生的重要机理,其发生率达41.4%,VHL基因LOH与肾癌分期、分级无关。

Objective To exam two single nucleotide polymorphism(SNP) in VHL gene and intragenic loss of heterozygosity (LOH) of VHL gene in 79 Chinese sporadic renal cell carcinomas(RCCs), and to analyze the relationships between VHL LOH and clinicopathological parameters. Methods The authors extracted tumor and normal tissue DNA and detected two genotypes of intragenic SNP sites, rs779805 in the 5′ terminal and rs 1642742 in the 3′ terminal of VHL gene by polymerase chain reaction-restriction fragment length polymorphism, then analyzed VHL LOH by comparing tumor tissue versus normal tissue in heterozygosities. Subsequently the relationships between VHL LOH and clinicopathological parameters of RCCs were analyzed. Results The computed heritage parameters of two SNPs, included genotype frequency, allele frequency, heterozygosity, and polymorphism information content. Twenty-nine heterozygosities were detected in 79 RCCs. LOH was found in 41.4%(12/29) of RCCs. No significant relationships between VHL LOH and age, sex, tumor stage, pathological grade were found. Conclusion LOH of VHL gene is an important genetic event in Chinese sporadic renal carcinoma, and the LOH frequency is 41.4%. VHL LOH has no influence on stage and grade of RCC.