The Expression And Distribution Of Aquaporins(aqps) In Gastric Cancer Tissue

Objective: To investigate the expression of AQPs in human gastric adenocarcinoma cell lines,as well as the expression and distribution of aquaporins (AQPs) in human gastric carcinoma and analyze its clinical significance.Methods: The expression of aquaporins in mRNA level was detected in human gastric adenocarcinoma cell lines (MKN45, AGS and SGC7901) and human gastric mucosal epithelial cell line GES-1 by reverse transcription PCR (RT-PCR). We screened the expression profile of AQP0 ~ AQP12 in gastric adenocarcinoma tissues and corresponding normal mucosa from 89 patients with gastric cancer by RT-PCR, western blot analysis, immunochemical assay and immunofluorescence. The relationship between AQPs expression and clinicopathologic characteristics of patients was evaluated.Results: The mRNA of AQP0, 1, 3, 4, 5, 7 and 11 was expressed in well-differentiated gastric adenocarcinoma cell lines (AGS and SGC7901) and GES-1. But in poorly differentiated cell line MKN45, only AQP3 mRNA was detected. Based on RT-PCR, of 13 aquaporins examined, AQP1, 3, 4, 5 and 11 were expressed in human gastric cancers or normal gastric tissues, and AQP3, 4 and 5 exhibited differential expression between human gastric carcinomas and corresponding normal tissues, which was confirmed by western blot analyses. Immunohistochemical assay showed that AQP4 protein was expressed mainly in the membrane of parietal cell and chief cell in the normal gastric mucosa, and absent in carcinoma tissues. AQP3 and AQP5 were detected remarkably stronger in the carcinoma tissues than that in normal mucosa by immunofluorescence. AQP3 expression in cases with undifferentiated tumor was more than that in cases with well-differentiated tumor. Both AQP3 and AQP5 expression were associated with lymph node metastasis and lymphovascular invasion in patients. No other demographic or clinicopathologic variables including tumor size, tumor location and depth of invasion were related to AQP3 or AQP5 expressionConclusion: These findings of differential expressions of aquaporins and their correlation with clinicopathologic characteristics implicated aquaporins might play a role in human gastric carcinogenesis.