Cytoplasmic Hu-Antigen R (HuR) Expression is Associated with Poor Survival in Patients with Surgically Resected Cholangiocarcinoma Treated with Adjuvant Gemcitabine-Based Chemotherapy

Hu-antigen R (HuR) is an RNA-binding protein that regulates the stability, translation, and nucleus-to-cytoplasm translocation of messenger RNAs (mRNAs). The aim of this study was to investigate the prognostic significance of HuR in cholangiocarcinoma patients who received adjuvant gemcitabine-based chemotherapy (AGC) after surgical resection. Nuclear and cytoplasmic HuR expression was investigated immunohistochemically in 131 patients with resected cholangiocarcinoma, including 91 patients administered AGC and 40 patients who did not receive adjuvant chemotherapy. The correlation between HuR expression and survival was evaluated by statistical analysis. High nuclear and cytoplasmic HuR expression was observed in 67 (51%) and 45 (34%) patients, respectively. Cytoplasmic HuR expression was significantly associated with lymph node metastasis (p < 0.01), while high cytoplasmic HuR expression was significantly associated with poor disease-free survival [DFS] (p = 0.03) and overall survival [OS] (p = 0.001) in the 91 patients who received AGC, but not in the 40 patients who did not receive AGC (DFS p = 0.17; OS p = 0.07). In the multivariate analysis of patients who received AGC, high cytoplasmic HuR expression was an independent predictor of poor DFS (hazard ratio [HR] 1.77; p = 0.04) and OS (HR 2.09; p = 0.02). Nuclear HuR expression did not affect the survival of enrolled patients. High cytoplasmic HuR expression was closely associated with the efficacy of AGC in patients with cholangiocarcinoma. The current findings warrant further investigations to optimize adjuvant chemotherapy regimens for resectable cholangiocarcinoma.