Expression of Aquaporin 1 in Bladder Uroepithelial Cell Carcinoma and its Relevance to Recurrence

Objectives: To explore the expression of aquaporin 1 ($AQP_1$) in bladder uroepithelium cell carcinoma (BUCC) and its relevance to recurrence. Materials and Methods: Tissue samples from 45 BUCC patients who underwent total cystectomy or transurethral resection of bladder tumor (TURBT) and from 40 patients with non-bladder cancers who underwent special detection or treatments were collected. The level of expression of $AQP_1$ in BUCC tissues and normal bladder tissues was assessed by immunohistochemistry so as to analyze the relevance to pathological patterns and time of recurrence in BUCC patients. Results: The expression levels of $AQP_1$ normal bladder tissues and BUCC tissues were $2.175{\pm}0.693$ and $3.689{\pm}0.701$, respectively, and the difference was significant (t=9.99, P<0.0001). Marked increase was noted with BUCC histological grade and pathological stage (P<0.01). Moreover, the expression of $AQP_1$ was evidently higher in cancerous tissues with lymph node metastasis than in those without (P<0.01). With short-term recurrence, the positive cell expression rate of $AQP_1$ was higher in primary tissues, which increased obviously after recurrence. Additionally, the recurrent time of BUCC was negatively associated with the positive cell expression rate of $AQP_1$ and the difference between the expression of $AQP_1$ before and after recurrence (r=-0.843, F=39.302, P=0.000; r=-0.829, F=35.191, P=0.000). Conclusions: $AQP_1$, which reflects the grade, stage, lymph node metastasis and recurrence of BUCC, has potential guiding significance in the diagnosis and treatment of bladder cancarcinoma.