Clinical significance of UNC5B expression in bladder cancer

UNC5B is a membrane-bound receptor of the neural guidance factor netrin-1 family, with important roles in angiogenesis, neurogenesis, embryonic development, cancer, inflammation and various pathologies. However, its effect on bladder cancer has not been reported. To investigate the association of UNC5B expression with bladder cancer prognosis, 100 cases of clinical bladder cancer and adjacent noncancerous tissue samples, and four bladder cancer cell lines were selected using RT-PCR, Western blot, immunofluorescence and immunohistochemistry to investigate differential expression and cellular positioning of UNC5B, and its relationship with clinicopathological parameters. In 72 % of cases, UNC5B was expressed in both bladder cancer and adjacent noncancerous tissue samples. Expression of UNC5B in bladder cancer tissues increased significantly as cancer stage increased (P < 0.05); UNC5B emerged more in bladder cancer cell lines with lower degrees of malignancy than those with higher degrees of malignancy; UNC5B expression in bladder cancer cells was significantly reduced compared to normal bladder cells (P < 0.05). UNC5B mRNA was down-expressed in about 28 % of bladder cancer tissues. Low UNC5B expression was an independent risk factor for postoperative recurrence in patients with different stages and grades bladder cancer. Furthermore, patients with lower UNC5B expression in tumors had significantly higher recurrence rate after curative surgery and poorer prognosis than those with higher UNC5B expression, suggesting that UNC5B could be used to predict prognosis and recurrence.