Overexpression of RING box protein-1 (RBX1) associated with poor prognosis of non-muscle-invasive bladder transitional cell carcinoma

Background and Objective RING box protein-1 (RBX1) is a key subunit of the ubiquitin E3 ligase Skp1/Cullin1/Rbx1/F-box protein complex. Altered expression RBX1 is shown to associate with tumorigenesis and tumor progression. This study detected RBX1 expression for association with clinical significance (such as clinicopathological data and survival of the patients) in non-muscle-invasive bladder transitional cell carcinoma (NMIBC). Methods A total of 70 primary NMIBC tissue specimens and 24 normal tissue specimens were recruited and analyzed immunohistochemically for expression of RBX1 protein and associated with clinicopathological data and survival of the patients. Results RBX1 was highly expressed in NMIBC, but was lowly expressed in the normal tissue. RBX1 expression was associated with high tumor grade and advanced clinical stage (P<0.01 and P<0.05, respectively). Moreover, patients with high RBX1 expression had shorter recurrence-free survival and progression-free survival rates (P<0.001 and P<0.01, respectively). Multivariate analysis demonstrated that RBX1 expression is an independent prognostic factor for tumor recurrence and progression of NMIBC (P<0.05). Conclusions Overexpression of RBX1 protein contributes to tumor progression and poor prognosis of NMIBC. J. Surg. Oncol. 2013;107:758761. (c) 2013 Wiley Periodicals, Inc.