Expression of CUL1 correlates with tumour‐grade and recurrence in urothelial carcinoma
The cullin family of proteins was first identified in 1996 as being required for cell cycle exit in Caenorhabditis elegans5 and for the G1‐to‐S‐phase transition in budding yeast.6 Members of the cullin family (Cullin‐1, Cullin‐2, Cullin‐3, Cullin‐4A, Cullin‐4B, Cullin‐5, Cullin‐7, PARC and APC2) provide the scaffold of Cullin‐Ring Ligase (CRL) complexes responsible for a large portion of ubiquitin‐proteasome system (UPS)‐mediated proteolysis. The family members are characterized by an evolutionarily conserved cullin‐homology domain, and serve as molecular scaffolds to facilitate the assembly of multimeric CRLs. Cullin‐1 (CUL1) is the most extensively characterized member of the cullin family and a key component of SCF E3s, which are composed of four proteins, cullin1/Cdc53, Rbx1/Roc1/Hrt1, Skp1 and an F‐box protein, and has an indispensable role in both cell cycle progression and early embryogenesis.
The use of molecular markers for characterization of UBC allows improved and a more complete insight in the nature of cancer than use of histologic evaluation alone. The aim of this research was to further clarify the relationship between CUL1 expression and biological behaviour of UBC and the clinical outcome of the disease. We examined the expression of CUL1 in 132 UBCs using immunohistochemistry, and correlated the results with clinicopathological factors of the disease.