High expression of constitutive photomorphogenic 1 (COP1) is associated with poor prognosis in bladder cancer

The present study was to investigate the expression and prognostic value of constitutive photomorphogenic 1 (COP1) in bladder cancer. In our study, real-time quantitative PCR (RT-PCR) was performed to detect 10 pairs of fresh bladder cancer (BCa) and adjacent noncancerous tissues. In addition, immunohistochemistry was utilized to detect the expression of COP1 in 174 clinical bladder cancer samples. What is more, the correlation of COP1 expression and clinicopathological features and clinical outcomes were analyzed. The expression levels of COP1 in clinical bladder cancer were much higher than that in paired adjacent noncancerous tissues (p < 0.0001). High expression of COP1 was closely related with differentiation (p = 0.040) and recurrence (p = 0.001) of patients with bladder cancer. Kaplan-Meier analysis revealed that the expression of COP1 was closely correlated with overall survival (p = 0.048) of bladder cancer, while, recurrence-free survival (p = 0.201). Moreover, Cox multivariate regression analyses showed that COP1 expression was an independent predictor of overall survival (OS; p = 0.027, hazard ratio = 2.127, confidence interval 0.814 to 9.736). Based on our data, the present study suggests that high expression of COP1 may be a novel biological indicator for evaluation of poor prognosis in bladder cancer.