Objective: To investigate the changeable patterns of microsatellite instability(MSI)in intestinal metaplasia(IM)and gastric cancer(GC)and the role of MSI in gastric carcinogenesis. Methods: Silver staining single str...Objective: To investigate the changeable patterns of microsatellite instability(MSI)in intestinal metaplasia(IM)and gastric cancer(GC)and the role of MSI in gastric carcinogenesis. Methods: Silver staining single strand conformation polymorphism-polymeriase chain reaction(PCR-SSCP)was used to screen MSI markers at 5 loci in formalin-fixed,paraffin-embedded tissues of GC(n=30),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 and in 8(20%)out of IM samples.Three(10%)tumors and one(2.5%)IM displayed high-frequency MSI(two or more loci altered).Low-frequency MSI(one loci altered)was detected in 4(13.3%)of the tumors and in 7(17.5%)IM samples.GC with MSI was associated with distal location of the tumors but age,sex,differentiation,lymph nodes metastasis and TNM stage(P=0.044).MSI was more likely detected in moderate-grade IM than in mild-grade IM tissues(34.8% versus 0; P=0.013); and MSI had a tendency to be easily detected in female with IM. Conclusion: The progressive accumulation of MSI in areas of IM may contribute to GC development,representing an important molecular event in the multistep gastric carcinogenesis.展开更多
文摘Objective: To investigate the changeable patterns of microsatellite instability(MSI)in intestinal metaplasia(IM)and gastric cancer(GC)and the role of MSI in gastric carcinogenesis. Methods: Silver staining single strand conformation polymorphism-polymeriase chain reaction(PCR-SSCP)was used to screen MSI markers at 5 loci in formalin-fixed,paraffin-embedded tissues of GC(n=30),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 and in 8(20%)out of IM samples.Three(10%)tumors and one(2.5%)IM displayed high-frequency MSI(two or more loci altered).Low-frequency MSI(one loci altered)was detected in 4(13.3%)of the tumors and in 7(17.5%)IM samples.GC with MSI was associated with distal location of the tumors but age,sex,differentiation,lymph nodes metastasis and TNM stage(P=0.044).MSI was more likely detected in moderate-grade IM than in mild-grade IM tissues(34.8% versus 0; P=0.013); and MSI had a tendency to be easily detected in female with IM. Conclusion: The progressive accumulation of MSI in areas of IM may contribute to GC development,representing an important molecular event in the multistep gastric carcinogenesis.
