Relationship Between Helicobacter Pylori Infection And Expression Of MMP-9 And GST-π In Different Gastric Mucosa Lesions

Objective Helicobacter pylori(HP) has been believed to be a carcinogen of gastric carcinoma.However,its mechanism was yet not clearly understood.This study was designed to investigate the relationship between H.pylori infection and expression of matrix metalloproteinase-9(MMP-9) and Glutathione S-transferase –π(GST-π) in different gastric mucosa lesions.and elucidate the probable mechanism of gastric carcinogenesis relating with HP infection. Methods A total of 113 cases were available for the study including 10 cases of chronic gastritis, 18 cases of intestinal metaplasia ,25 cases of mild dysplasia,25 cases of modest or severe dysplasia and 38 cases of gastric carcinoma; H.pylori was determined with the rapid urease test, Warthin-Starry method or 14C urease breath test; And streptavidin-peroxidase(SP) immunohistochemical method was used to detect the expression of MMP-9 and GST-π.The chi-square test and the Fisher's exact probability test were used to compare the frequencies. Results (1) The expression of MMP-9 increased as gastric mucosa lesions developed from chronic gastritis, intestinal metaplasia, dysplasia, gastric carcinoma(p<0.01). The MMP-9 expression rate was 10.0% in chronic gastritis, 16.67% in intestinal metaplasia, 44.0% in mild dysplasia, 63.64% in modest or severe dysplasia and 89.47% in gastric carcinoma; The GST-πexpression rate was 0% in chronic gastritis,72.22% in intestinal metaplasia ,68% in mild dysplasia,45.45% in modest or severe dysplasia and 44.73% in gastric carcinoma. The GST-πexpression rate decreased from intestinal metaplasia →mild dysplasia→modest or severe dysplasia→gastric carcinoma→chronic gastritis. (2) The expression of MMP-9 in Dys I and DysII-III with H.pylori infection was 69.23% and 85.71%, respectively,significantly higher than that without infection (16.67%,25.00%,all p<0.05). The expression of GST-πin IM and Dys I with H.pylori infection was 90.91% and 92.31% respectively, significantly higher than non-infection groups(42.86%,41.67%,all p<0.05). Conlusion HP infection could enhance the gastric mucosa damage caused by MMP-9 and decrease the gastric mucosa protection role of GST-π, thus giving chances for gastic carcinogenesis. GST-πcould be a useful tumour marker in the early disgnosis of gastric cancer. The MMP-9 expression was significantly correlated with invasion ,metastasis of gastric cancer.