Study On Microsatellite Instability In Gastric Cancer And High-grade Intraepithelial Neoplasia Tissues

Objective: To detect the microsatellite instability (MSI) in gastric carcinoma with high-grade intraepithelial neoplasia and normal tissue, To observe the variational conditions of MSI in the developed progresses of gastric carcinoma. To explore the genic variety in the developed progresses of gastric carcinoma. And to explore the variational regulations of MSI in gastric carcinoma with high-grade intraepithelial neoplasia and normal tissue and the relationship between MSI, clinic pathological features and the family medical history of digestive tube cancer.Method: 55 cases of gastric carcinoma with high-grade intraepithelial neoplasia and normal tissue were selected to detect MSI by microdissection, polymerase chain reaction, denaturing polyacrylamide gel electrophoresis and silver nitrate staining technology of ten microsatellite markers on chromosome 9 and the relationship between MSI rate rate and clinicopathologic parameters, enteron family history were analyzed. All analysis were carried out using SPSS12.0 software.Results: 1.In the informative cases, total frequency of MSI in high-grade intraepithelial neoplasia was 28% and it was 38% in gastric carcinoma. In high-grade intraepithelial neoplasia, MSI was detected as follows: D9S175(38%),D9S1876(38%),D9S166(36%),D9S1118(33%),D9S1822(33%),IFNA(27%),D9S171(21%),D9S941(18%),D9S910(14%),D9S942(11%). In gastric cancer, MSI was detected as follows: D9S171(50%),D9S175(48%),D9S1876(47%),D9S1118(45%),D9S166(42%),IFNA(41%),D9S1822(40%),D9S910(26%),D9S941(22%),D9S942(15%). 2. In gastric carcinoma, MSI has statistical difference in gastric carcinoma family medical history and the position of the tumor. MSI has no statistical difference in the sex of patient,transfusion of tumor,size of tumor and pathological typing. In gastric carcinoma with high-grade intraepithelial neoplasia, MSI has statistical difference in gastric carcinoma differentiated degree and family medical history.Conclusions: 1. MSI maybe is the distinct molecular mechanism in the course of gastric carcinoma's occurrence and development, and has correlation with some kind pathological feature. 2. Gastric carcinoma with high-grade intraepithelial neoplasia has MSI. And this indicate that maybe MSI is pristine and important molecular event in the course of gastric carcinoma's occurrence. 3. In gastric carcinoma, it has altofrequent MSI in chromosomal 9p21 zone. This indicate that some tumor depressive gene related with gastric carcinoma was in this 9p21 zone. 4. Chromosomal 9q13-31 zone has some unknown depressive gene related with gastric carcinoma. 5. The frequency of MSI in cases with enteron family history was significantly higher than in cases with no enteron family history.