Expression And Significance Of MsrA In Gastric Cancer

BackgroundGastric cancer is the second most common malignancy of male tumors, and the fourth of female tumors all over the world. Yet the pathogeny and pathogenesis of gastric cancer is not well elucidated. According to genetic and molecular biology studies ,the incidence of gastric cancer is related to the heterozygosity loss and mutation of tumor suppressor genes. Analyzing the heterozygosity loss marked by Microsatellite polymorphism may help to identify new tumor suppressor genes. MsrA is one of methionine sulfoxide reductases . Human MsrA genes locate in chromosome 8p22 - 23. Heterozygosity loss of 8p occurs frequently in various tumors, such as breast, lung, liver,gastric,and colorectal carcinomas. And the heterozygosity loss mainly occurs in 8p22-p23.2 and 8p12 -p21. It iss speculated that MsrA may play a role on tumor suppression.Presently,the expression of MsrA in gastric cancer and the significance have not been reported. ObjectiveTo investigate the expression of MsrA in gastric cancer tissues and normal adjacent mucosa,and to explore the relationship of MsrA and gastric cancer.Methods(1) Using immunohistochemistry detects the expression of MsrA in 57 cases of gastric cancer and adjacent tissues. (2) Using real-time RT-PCR detects the expression of MsrA mRNA in 57 cases of gastric cancer and adjacent tissues.Results(1)Results of immunohistochemistry: the positive rates of the expression of MSRA in cancer tissue and normal adjacent mucosa were 63.2% and 96.5% respectively. The difference between the two group was significant (P< 0.001). (2)Results of real-time RT-PCR: The median quantity of MsrA mRNA in the gastric cancer tissue was 3.757 (2-△CT×100000) , while the median quantity of MsrA mRNA in normal adjacent mucosa was 5.240, the difference between the two group was significant (P =0.016). (3)The quantity of MsrA mRNA in gastric cancer between different clinical stages exhibited little difference. (4) The difference of MsrA mRNA between tumors with different differentiation was little significant.(5)The difference of MsrA mRNA between tumors with lymph node metastasis and tumors without lymph node metastasis is not significant.Conclusion:1. MsrA is expressed both in gastric cancer tissue and normal adjacent mucosa.2. The expression of MsrA is down-regulated in gastric cancer.