微卫星DNA不稳定性与胃癌早期诊断的研究

目的　研究MSI在胃癌发生中的作用及其与胃癌临床病理特征之间的关系 ,探讨采用MSI筛选胃癌高危人群和早期诊断胃癌的可能性。方法　采用PCR、PCR 变性聚丙烯酰胺凝胶及硝酸银染色方法检测 30例胃癌及相应的 14例癌旁肠化生组织的MSI。结果　胃癌MSI阳性率为36 6 7% (11/ 30 ) ,D2S12 3和BAT2 6的MSI阳性率略高于其他位点 ;癌旁肠化生组织MSI阳性率为2 1 4 3% (3/ 14 )。 3例MSI阳性肠化生标本对应的胃癌组织均为MSI H ,MSS胃癌对应的肠化生组织也为MSS ;MSI与胃癌患者的年龄、性别、胃癌分期、淋巴结转移及组织分型无关 (P >0 0 5 ) ,与胃癌的分化程度和发生部位有关 :高 中分化胃癌MSI H检出率 4 7 0 6 % (8/ 17)显著高于低分化胃癌7 6 9% (1/ 13) (P <0 0 5 ) ;胃窦胃癌MSI H阳性率 4 7 37% (9/ 19)显著高于胃体及胃底胃癌 0 % (0 /11) (P =0 0 1)。结论　肠化生组织中MSI的进行性积累可能在一部分胃癌的发生中起作用 ,MSI可能是胃癌发生的早期分子事件。

Study of microsatellite instability and early diagnosis of gastric cancer

Objective To investigate the role of microsatellite instability(MSI)in carcinogenesis of gastric cancer(GC) and its relationship with clinicopathological features of GC,also to evaluate the possibility of examining MSI for screening and early diagnosis of GC.Methods MSI was examined in 30 surgically resected GC specimens and 14 corresponding paratumor intestinal metaplasia(IM)samples using PCR,PCR-denatured polyacrylamide gel based methods.Results MSI was detected in 36.67%(11/30)of GC and 21.43%(3/14)of IM samples respectively.All the corresponding GC tissues of MSI + IM samples were MSI-H.All the IM samples from MSS GC showed MSS either.No significant correlation was found between MSI status and age,sex,clinical stage,lymph node metastasis and histological types of GC(P>0.05),but there seems a correlation between MSI and differentiation,location of GC.The incidence of MSI-H in well or moderately differentiated GC(8/17,47.06%)was significantly higher than that in poorly differentiated GC(1/13,7.69%)( P< 0.05),and MSI-H occurred more frequently in GC located in antrum(9/19,47.37%)than that in body and fundus(0/11,0%)( P= 0.01).Conclusion The progressive accumulation of MSI in areas of IM may contribute to gastric carcinogenesis and MSI may be an early and imoprtant molecular event in gastric carcinogenesis.