Supplementary Material for: Expression of AQP1 Was Associated with Apoptosis and Survival of Patients in Gastric Adenocarcinoma

Rationale and Objective: Recently, interest in the role of aquaporin 1 (AQP1) in human gastrointestinal carcinogenesis has developed. However, to date no studies have examined relationships between AQP1 expression and specific characteristics of gastric adenocarcinoma. Methods: We investigated 109 specimens of primary gastric adenocarcinoma and their corresponding normal gastric mucosa using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to determine AQP1 expression. We then evaluated disease free survival (DFS) and overall survival (OS) in these patients in association with AQP1 expression. Results: Both immunohistochemical and RT-PCR analyses identified increased AQP1 expression in tumors from patients with gastric adenocarcinoma (p < 0.001). The 3-year DFS and OS rates were higher in the AQP1-negative group than in the positive group (DFS: 77.2 vs. 52.8%, p < 0.001; OS: 85.1 vs. 70.7%, p < 0.001). The 5-year DFS and OS rates exhibited a similar trend (p < 0.001). Subgroup analysis of patients with early gastric adenocarcinoma (stages I and II) revealed a total 5-year OS of 90.0%, with 5-year OS being higher in the AQP1-negative group than in the positive group (95.2 vs. 84.2%). Furthermore, incidence of tumor recurrence following surgical treatment was significantly higher in the AQP1-positive group (4/19, 21.1%) compared with the negative group (0/21, 0%). Conclusions: Our study demonstrates that AQP1 plays an important role in gastric adenocarcinoma and may therefore represent a novel therapeutic target and prognostic marker in this disease.