Differential Expression and Significance of Endoplasmic Reticulum Golgi Intermediate Compartment 1 in Precancerous Gastric Lesions and Gastric Cancer.

BACKGROUND:We investigated the expression of endoplasmic reticulum Golgi intermediate compartment 1 (ERGIC1) in precancerous gastric lesions and gastric cancer and the function of ERGIC in human gastric cancer cell lines. MATERIALS AND METHODS:A total of 160 subjects were enrolled. The expression of ERGIC1 was assayed using immunohistochemistry. Overexpression of ERGIC1 in SGC-7901 and BGC-823 cells was used to evaluate the function of ERGIC1. RESULTS:Most normal gastric mucosal tissues and the tissues with mild dysplasia showed strong expression of ERGIC1 (80% and 73.3%, respectively) assayed using immunohistochemistry. In the majority of gastric tissues with moderate and severe dysplasia, ERGIC1 was moderately positive (83.3% and 66.7%, respectively), whereas in a small proportion of gastric tissues with severe dysplasia (16.7%) and of the gastric cancer tissues (22.5%), ERGIC1 was weakly positive. No expression of ERGIC1 was found in the gastric tissues of a small proportion of severe dysplasia (16.7%) and in the most of the gastric cancer (67.5%) patients. Semiquantitative analysis revealed a gradual reduction in the expression score of ERGIC1 from normal gastric mucosal tissues to tissues from early gastric cancer. In addition, overexpression of ERGIC1 in SGC-7901 and BGC-823 cells inhibited the cell proliferation by 27.5% and 30%, respectively, on day 5. On the other hand, overexpression of ERGIC1 in both cell lines enhanced the apoptosis by 33.5% and 53.2%, respectively, as compared to control cells. CONCLUSION:These results suggested that ERGIC1 might play an inhibitory role in the initiation and progression of gastric cancer.