High UBCH10 Protein Expression as a Marker of Poor Prognosis in Esophageal Squamous Cell Carcinoma

Background/Aim: Ubiquitin-conjugating enzyme H10 (UBCH10) is required in the cell-cycle transition from metaphase to anaphase. Therefore, we investigated whether its expression level in cancerous esophageal lesions affected prognosis of patients with esophageal squamous-cell carcinoma. Materials and Methods: Paraffin-embedded tissue samples from 121 patients with esophageal squamous cell carcinoma were stained with antibody to UBCH10 for immunohistochemical analysis. Results: UBCH10 was expressed in cancerous and dysplastic lesions, but not in normal tissue. Patients were grouped according to expression: High (N=33) or low (N=88), depending on the staining pattern. There were significant differences between the groups in terms of invasion into lymphatic vessels, number of metastatic lymph nodes, TNM classification, and stages, as well as in survival: the 50% survival rate in the high expression group was 2.3 years, whereas it was 9.9 years for the low-expression group (p<0.0001). Even with multivariate adjusting for stage 0 to stage IV using the Cox proportional hazard model, patients belonging to the high- expression group had a poor prognosis (Hazard ratio=2.5; 95% Confidence Interval=1.3-4.5; p=0.004). Conclusion: High protein expression of UBCH10 is a marker of poor prognosis in esophageal squamous cell carcinoma. Esophageal squamous cell carcinoma is an aggressive type of cancer, with a poor prognosis (1, 2), although survival continues to improve (3). Novel molecular-targeting agents are desired to further improve the prognosis of patients with esophageal cancer. Recently, a variety of candidate molecules have been listed by our and other groups, such as endothelin (4), Cluster of differentiation 147, metalloproteinase-2 (5), vascular-endothelial growth factor (6), Fas expression (7), C-X-C chemokine receptor 4 (8), Mut-L-homologon-1/Mut-S-homologon-2 (9), endoglin (10); these have not yet succeeded in drug development. To screen for key molecules to aid the prediction of prognosis of patients with esophageal cancer, we carried-out and reported gene expression profiling in esophageal cancer: we found that RNA expression of ubiquitin-conjugating