胃癌组织p16基因微卫星DNA的不稳定性

目的 :检测胃癌组织中p16基因D9s171、D9s16 0 4微卫星位点杂合性缺失 (LOH) ,探讨p16基因微卫星不稳定性 (MI)与胃癌发生发展的关系。方法 :采用PCR 变性聚丙烯酰胺凝胶电泳 银染技术对 2 0例胃癌和癌旁组织LOH进行分析。结果 :癌组织D9s171和D9s16 0 4的LOH分别为 3例和 10例 ,癌旁组织分别为 2例和 4例。两位点LOH发生率差异无显著性 (P >0 .0 5 )。胃癌组织较癌旁组织LOH发生率明显增高 (P <0 .0 5 ) ;早期胃癌与进展期胃癌两个微卫星位点LOH的发生率分别为 5 0 % (4/ 8)和 5 8.3% (7/ 12 ) (P >0 0 5 ) ;两位点LOH发生存在相关性(P <0 0 5 )。结论 :D9s171,D9s16 0 4微卫星位点的LOH与胃癌的发生发展有关 ,而与癌细胞的分化程度或胃癌的临床分期无显著相关性

Study on microsatellite DNA instability in p16 gene of gastric cancer tissues

Aim:To detect the loss of heterozygosity (LOH) frequencies of microsatellite sites D9s171, D9s1604 in p16 gene of gastric cancer tissues and study the correlation between microsatellite instability (MI) of p16 gene and the development of gastric cancer. Methods:Using polymerase chain reaction (PCR) denaturing polyacrylamide gel electrophoresis silver staining, 20 samples of gastric cancer and adjacent cancer tissues were detected for LOH.Results:Three and 10 out of 20 samples of gastric cancer tissues exhibited LOH in D9s171 and D9s1604, while in adjacent cancer tissues the both sites were 2 and 4 samples respectively. The frequencies of LOH between 2 sites had no significant difference ( P >0.05). The frequency of LOH was higher in gastric cancer than that in adjacent cancer tissues ( P <0.05). No significant difference was noted between well differentiated gastric cancers and moderate/poorly differentiated gastric cancers ( P >0.05). The frequencies of LOH in early and advanced gastric cancer were 50%(4/8) and 58.3%(7/12) respectively( P >0 05). Statistically, the LOH frequencies of the two microsatellite sites were closely correlated ( P <0.05).Conclusion: The frequencies of LOH in the two microsatellite sites, D9s171 and D9s1604, in p16 gene are associated with the development of gastric cancer and no significant correlation is demonstrated between the LOH frequency and the cell differentiation types of tumor cells or clinical stages.