Ube2s expression is elevated in hepatocellular carcinoma and predicts poor prognosis of the patients

Ube2s belongs to the ubiquitin-conjugating (E2) enzyme family of the ubiquitin system. Expression and function of Ube2s in human malignancies was largely unknown. Here we report our investigation of Ube2s expression in human non-tumor liver and hepatocellular carcinoma tissues using immunohistochemistry. Ube2s expression was detected in nuclear and cytoplasm. The positive rate of Ube2s in normal liver tissues was 19.2% (5/26). The positive rate of Ube2s expression in liver tissues with hepatocirrhosis (33.3% (6/18)) was higher than that in normal liver tissues (P<0.05). Ube2s expression in hepatocellular carcinoma (59.1% (39/66)) was higher than that in normal liver tissues and liver tissues with hepatocirrhosis (P<0.05). There were 35 cases (53.0%) showing nuclear expression, 21 cases (31.8%) showing cytoplasm expression, 17 cases (25.8%) showing both nuclear and cytoplasm expression, 18 cases (27.3%) showing only nuclear expression and 4 cases (6.1%) showing only cytoplasm expression in hepatocellular carcinoma tissues. Ube2s expression was significantly associated with higher AFP levels (>100 ng/ml), advanced TNM stages (II+III), higher ABCL stages (B+C) in hepatocellular carcinoma (P<0.05). Kaplan Meier analysis showed that Ube2s expression was significantly associated with shorter survival time of patients (P<0.05). These results indicate that Ube2s may be involved in oncogenesis and development of hepatocellular carcinoma and may be a potential cancer marker and therapy target.