Cullin1 is up-regulated and associated with poor patients' survival in hepatocellular carcinoma

Cullin1 (Cul1) is a scaffold protein of the ubiquitin E3 ligase Skp1/Cullin1/Rbx1/F-box protein complex, which ubiquitinates a broad range of proteins involved in cell-cycle progression, signal transduction, and transcription. To investigate the role of Cul1 in the development of hepatocellular carcinoma (HCC), we evaluated the Cul1 expression by immunohistochemistry using a tissue microarray (TMA) containing 90 cases HCC tissues and paired adjacent non-cancerous tissues. We analyzed the correlation between Cul1 expression and clinicopathologic variables and patients survival using two independent HCC cohorts TMA. Our data showed that Cul1 expression was apparently increased in HCC tissues compared with paired adjacent non-tumor tissues. We also demonstrated that Cul1 staining was significantly correlated with tumor size, histology grade and TNM stage. Furthermore, we showed a strong correlation between high Cul1 expression and worse 5-year overall and disease-specific survival rates in HCC patients. Finally, univariate and multivariate Cox proportional hazards regression analysis investigated that high Cul1 expression was a strong independent prognostic indicator of HCC. Our data indicated that Cul1 may be an important prognosis marker for human HCC.