Rb基因多态性与食管癌遗传易感性的研究

Genetic polymorphisms of Rb and susceptibility of esophageal cancer

目的 探讨Rb基因 2 0内含子VNTR、17内含子RFLP的多态性与食管癌遗传易感性的关系。 方法 应用PCR技术对陕西正常人群 (5 6例 )、食管癌组织 (47例 )及癌旁组织 (31例 )Rb基因 2 0内含子VNTR位点、17内含子RFLP进行检测。 结果 在正常人群中Rb基因 2 0内含子共检测出 10个等位基因片段 ,等位基因片段范围在 330bp 2 6 0bp之间 ,杂合率为 70 0 % ,PIC为 86 0 % ;在癌组织中杂合率为 5 4 5 % ,PIC为 82 2 % ;在癌旁组织中杂合率为 74 1% ,PIC为 87 3% ,两个群体中基因多态分布差异有极显著性意义 (χ2 =30 1,df=9,P <0 0 1)。在正常人群中 17内含子共检测出 2个等位基因片段 :945bp(A)及 6 30bp加 315bp(B) ,基因型频率 :A/A :0 2 8,A/B :0 5 2 ,B/B :0 2 0 ,癌组织中基因型频率 :A/A :0 11,A/B :0 77,B/B :0 12 ,两群体中基因型频率分布差异有显著性 (χ2 =7 0 5 ,P <0 0 5 )。在配对的癌旁组织和癌旁组织中检测发现 :6例 (2 0 % )癌组织在该位点发生突变。 结论 该位点为高度多态的遗传标记 ,多态改变与食管癌的发生、增殖关系较密切。

Objective[WT5”BZ] To assess the possible association between the polymorphisms of Rb (intron 20,17) and susceptibility of esophageal cancer so as to provide clues for genetic markers of esophageal cancer. [WT5”HZ]Methods[WT5”BZ] Samples were taken from 56 normal Han people of Shaanxi, 47 esophageal cancer samples, and 31 pericancerous non tumor. DNAs were analysed by using PCR technique. [WT5”HZ]Results[WT5”BZ] Ten alleles fragments were found in Han population of Shannxi by using primer Rb gene (intron 20). PIC was 0 86. Heterozygosity was 0 7. In esophageal cancer tissues, PIC was 0 82. Heterozygosity was 0 55. In pericancerous non tumor, PIC was 0 87. Heterozygosity was 0 74. Distribution of genotype frequency was significantly different between Han population of Shaanxi and esophageal cancer ( P <0 01). Two alleles(945 bp, 630 bp+315 bp) fragments were found in Han population of Shaanxi by using primer Rb gene (intron 17). Genotype frequency of Han population of Shaanxi was A/A:0 28, A/B:0 52, B/B:0 20. Genotype frequency of esophageal cancer was A/A:0 11, A/B:0 77, B/B:0 12. Distribution of genotype frequency was significantly different between Han population of Shaanxi and esophageal cancer ( P <0 05). Mutation of Rb gene was found in 7 cases. [WT5”HZ]Conclusions[WT5”BZ] Polymorphism of Rb (intron 20) VNTR and Rb(intron17) could be used as valuable markers. There should bea relationship between polymorphism of Rb VNTR and esophageal cancer susceptibility. [WT5”HZ]