ABSTRACT
Ubiquitin-conjugating enzyme 9 (Ubc9), the sole conjugating enzyme for sumoylation, regulates protein function and plays an important role in tumorigenesis. Whether Ubc9 is involved in the chemoresistance of breast cancer remains unknown. In this study, we aimed to evaluate the contribution of Ubc9 in the chemoresistance of breast cancer. Immunohistochemistry (IHC) was used to examine the expression level of Ubc9. Chi-square test, Wilcoxon test, and one-way ANOVA were applied to analyze the relationship between Ubc9 expression, clinicopathologic features, and clinical response to neoadjuvant chemotherapy. The significance of variables for survival was analyzed by the Cox proportional hazards model in a multivariate analysis. Kaplan-Meier survival curves were plotted and log-rank test was performed. The proportion of Ubc9-positive cells was higher in invasive ductal carcinoma than in normal breast tissues [(48.48 ± 17.94)% vs. (5.82 ± 2.80)%, P < 0.001]. High Ubc9 expression was associated with poor differentiation (Χ² = 6.538, P = 0.038), larger tumor size (Χ² = 4.701, P = 0.030), advanced clinical stage (Χ² = 4.651, P = 0.031), lymph node metastasis (Χ² = 9.913, P = 0.010), basal-like phenotype (Χ² = 8.660, P = 0.034), and poor clinical response to neoadjuvant chemotherapy (Χ² = 11.09, P = 0.001). The expected 6-year cumulative disease-free survival rate was 87.32% in patients with low Ubc9 expression compared to 68.78% in those with high Ubc9 expression (Χ² = 4.289, P = 0.038). These data indicate that high Ubc9 expression correlates with poor response to chemotherapy and poor clinical prognosis.
Subject(s)
Adult , Female , Humans , Middle Aged , Antineoplastic Combined Chemotherapy Protocols , Therapeutic Uses , Breast Neoplasms , Drug Therapy , Pathology , General Surgery , Carcinoma, Ductal, Breast , Drug Therapy , Pathology , General Surgery , Cyclophosphamide , Therapeutic Uses , Disease Progression , Disease-Free Survival , Drug Resistance, Neoplasm , Epirubicin , Therapeutic Uses , Fluorouracil , Therapeutic Uses , Immunohistochemistry , Kaplan-Meier Estimate , Lymphatic Metastasis , Mastectomy , Methods , Neoadjuvant Therapy , Neoplasm Staging , Proportional Hazards Models , Remission Induction , Tumor Burden , Ubiquitin-Conjugating Enzymes , Metabolism , Up-RegulationABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of vascular endothelial growth factor-C (VEGF-C) and cyclooxygenase-2 (COX-2) proteins, and their relationship with biological behaviors of non-small-cell lung carcinoma (NSCLC).</p><p><b>METHODS</b>Immunohistochemical staining was used to detect the expression of VEGF-C and COX-2 proteins in 77 cases of NSCLC. The relationship was analyzed between the expression of VEGF-C, COX-2 and lymphatic vessel density (LVD), tumor size, histological type, differentiation, lymph node metastasis, clinical recurrence and survival time of the patients.</p><p><b>RESULTS</b>Out of 77 cases of NSCLC, 45 cases and 29 cases showed positive expression of VEGF-C and COX-2 proteins, respectively. The expression rates of VEGF-C and COX-2 protein were 58.4% and 37.7%, respectively. The expression of VEGF-C protein was correlated negatively with the degree of differentiation of NSCLC (P < 0.05). The expression of VEGF-C was positively correlated with lymph node metastasis, LVD and tumor size (P < 0.01). The survival time of the patients was negatively correlated with the expression of VEGF-C (P < 0.01). The expression of COX-2 was positively correlated with LVD (P < 0.01). The survival time of the patients was negatively correlated with the expression of COX-2 (P < 0.05).</p><p><b>CONCLUSION</b>The expression of VEGF-C and COX-2 proteins are closely correlated with the biological behaviors of NSCLC, especially VEGF-C protein. Its high expression suggests probable lymph node metastasis and poor prognosis.</p>