【摘要】 目的　探讨微卫星不稳定性 (MSI)在胃癌及癌前病变组织中的发生规律及其在胃癌发生过程中的作用。方法　对 30例胃癌、30例异型增生、4 0例肠上皮化生组织标本分别提取病变及相应正常组织的DNA ,应用银染PCR SSCP技术检测 5个微卫星位点的不稳定性。结果　胃癌组织MSI的发生率为 2 3 3% ,胃窦癌MSI的发生率显著高于贲门癌 (P =0 0 4 4 )。异型增生组织的MSI发生率为 30 % ,肠上皮化生组织MSI发生率为 2 0 % ,且全部出现在中度以上肠化生组织中。结论　MSI是胃癌多步骤发生过程中的早期分子事件 ,可能有助于胃黏膜细胞恶性转化表型的获得 ,在胃癌的形成过程中具有重要作用更多还原

【Abstract】 Objective To detect the micro satellite instability (MSI) from the precancerous and cancerous lesions (GC) and its effect on carcinogenesis.Methods Silver staining single strand conformation polymorphism polymerize chain reaction (PCR SSCP) was used to screen MSI markers at 5 loci in formalin fixed,paraffin embedded tissues of GC (n=30), dysplasia (n=30), intestinal metaplasia (IM) ( n =40) and corresponding normal gastric tissues.Results The abnormal shifting of the single strand DNA was identified in 7(23 3%)out of GC, in 9 (30%) out of dysplasia and in 8(20%) out of IM samples respectively. GC with MSI was associated with distal location of the tumors ( P =0 044). MSI was not detected in low grade IM tissues.Conclusion MSI may be of an early event during gastric carcinogenesis. It contributes probably to the acquisition of a transformed cell phenotype and to the development of gastric cancer.更多还原