ABSTRACT
Human equilibrative nucleoside transporter 1 (hENT-1) is a membrane nucleoside transporter mediating the intracellular uptake of nucleosides and their analogues. hENT-1 was recently reported to have a predictive role in intrahepatic cholangiocarcinoma (iCC) patients receiving adjuvant gemcitabine-based chemotherapy, but its biological and clinical significance in iCC remains unsettled. This study investigated the role of hENT-1 in regulating tumour growth and predicting the survival of 40 resected iCC patients not receiving adjuvant treatments. hENT-1 expression was found to be significantly higher in iCC than in the matched non-tumoural liver. Patients harbouring hENT-1 localised on the tumour cell membrane had a worse overall survival than membrane hENT-1-negative patients (median 21.2 months vs 30.3 months, p = 0.031), with an adjusted hazard ratio of 2.8 (95% confidence interval 1.01-7.76). Moreover, membrane hENT-1-positive patients had a higher percentage of Ki67-positive cells in tumour tissue than membrane hENT-1-negative patients (median 23% vs 5%, p < 0.0001). Functional analyses in iCC cell lines revealed that hENT-1 silencing inhibited cell proliferation and induced apoptosis in HUH-28 cells expressing hENT-1 on the cell membrane, but not in SNU-1079 cells expressing the transporter only in the cytoplasm. Overall, these findings suggest that membrane hENT-1 is involved in iCC proliferation and associated with worse survival in resected iCC patients. Further prospective studies on larger cohorts are required to confirm these results and better define the potential prognostic role of membrane hENT-1 in this setting of patients.
Subject(s)
Bile Duct Neoplasms/surgery , Biomarkers, Tumor/metabolism , Cell Membrane/metabolism , Cell Proliferation , Cholangiocarcinoma/surgery , Equilibrative Nucleoside Transporter 1/metabolism , Hepatectomy , Adult , Aged , Bile Duct Neoplasms/metabolism , Bile Duct Neoplasms/mortality , Bile Duct Neoplasms/pathology , Biomarkers, Tumor/genetics , Cell Line, Tumor , Cell Membrane/pathology , Cholangiocarcinoma/metabolism , Cholangiocarcinoma/mortality , Cholangiocarcinoma/pathology , Equilibrative Nucleoside Transporter 1/genetics , Female , Gene Expression Regulation, Neoplastic , Hepatectomy/adverse effects , Hepatectomy/mortality , Humans , Male , Middle Aged , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome , Up-RegulationABSTRACT
BACKGROUND: The role of second-line chemotherapy (CT) is not established in advanced biliary tract cancer (aBTC). We investigated the outcome of aBTC patients treated with second-line CT and devised a prognostic model. METHODS: Baseline clinical and laboratory data of 300 consecutive aBTC patients were collected and association with overall survival (OS) was investigated by multivariable Cox models. RESULTS: The following parameters resulted independently associated with longer OS: Eastern Cooperative Oncology Group performance status of 0 (P<0.001; hazard ratio (HR), 0.348; 95% confidence interval (CI) 0.215-0.562), CA19.9 lower than median (P=0.013; HR, 0.574; 95% CI 0.370-0.891), progression-free survival after first-line CT ≥ 6 months (P=0.027; HR, 0.633; 95% CI 0.422-0.949) and previous surgery on primary tumour (P=0.027; HR, 0.609; 95% CI 0.392-0.945). We grouped the 249 patients with complete data available into three categories according to the number of fulfilled risk factors: median OS times for good-risk (zero to one factors), intermediate-risk (two factors) and poor-risk (three to four factors) groups were 13.1, 6.6 and 3.7 months, respectively (P<0.001). CONCLUSIONS: Easily available clinical and laboratory factors predict prognosis of aBTC patients undergoing second-line CT. This model allows individual patient-risk stratification and may help in treatment decision and trial design.
