Relationship between expression of Dnmt1 and caveolin-1 in gastric carcinomas

Objective To investigate the expression of Dnmt1 and caveolin-1 proteins in normal gastric mucosa,gastric atypical hyperplasia and gastric carcinoma tissues,and the relationship between both proteins expression. Methods The expression of Dnmt1 and caveolin-1 proteins in 20 normal gastric cases,40 gastric atypical hyperplasia cases,70 gastric carcinoma cases were detected by SP immunohistochemical method. Results Dnmt1 expression showed an increasing tendency in normal gastric mucosa,gastric atypical hyperplasia and gastric carcinoma tissues gradually,and there were statistical differences between groups (χ2=34.710,P0.01). However,caveolin-1 expression exhibited a decreasing tendency (χ2=41.806,P0.01).χ2 test and Fisher's exact ratio test demonstrated that in the malignant progression of gastric carcinoma,there was no significant correlation between the expression of Dnmt1 protein and the clinicopathological parameters of tumors:gender,ages,vessel invasion and invasive depths (P0.05),whereas there was statistical significance in lymph node metastasis (P0.05). The expression of caveolin-1 protein was significantly different between the cases with different invasion depths,lymph node metastasis,vessel invasion,but not between the cases with different gender and ages. Spearman rank correlation analysis indicated that the expression of caveolin-1 protein was negatively correlated with Dnmt1 protein (rs=-0.390,P0.05). Conclusion The silence of caveolin-1 in gastric carcinoma may be caused by the overexpression of Dnmt1 that leads to the methylation of caveolin-1,and it may play a critical role in the carcinogenesis and progression of gastric carcinomas.