ABSTRACT
Objective To detect the microsatellite instability (MSI) of D9S166,D9S171,D9S941, D9S942 and IFNA located at chromosome 9p21 in gastric carcinoma with high-grade intraepithelial neoplasia and normal tissue,and investigate the correlation of p14,p15,p16 gene and the gastric carcinogenesis. Methods 55 cases of gastric carcinoma with high-grade intraepithelial neoplasia and normal tissue were se- lected to detect MSI by microdissection,polymerase chain reaction,denaturing polyaerylamide gel elec- trophoresis and silver nitrate staining technology of five microsatellite markers on 9p21.Results In the infor- mative cases,total ratio of MSI in gastric carcinoma was 27 % (64/233) and it was 18% (42/233) in high- grade intraepithelial neoplasia.The ratio of MSI was significantly higher in gastric carcinoma than that in high-grade intraepithelial neoplasia (P