title: Downregulation of human equilibrative nucleoside transporter 1 by RNAi enhances 5-fluorouracil response in pancreatic cancer.
abstract: OBJECTIVE
  Human Equilibrative Nucleoside Transporters 1 (hENT1) gene is involving in mediating nucleosides and nucleoside analog drugs across the plasma membrane, and may affect the chemotherapeutical efficacy. We explored the relationship between hENT1 expression and 5-fluorouracil (5-FU) response in pancreatic cancer cell line.
  
  
  METHODS
  A siRNA expression vector (pSilencer4.1-hENT1-shRNA) was constructed and stably transfected into human pancreatic cancer cell line (Panc-1). The downregulation of hENT1 expression was confirmed by RT-PCR and Western blot. MTT, flow cytometry and 5-FU anti-tumor activity in nude mice were used to evaluate the cells phenotype changes in vitro and in vivo.
  
  
  RESULTS
  We established a stably transfected cell line (pSilence-hENT1-Panc-1) in which the expression of hENT1 gene was downregulated. The shRNA transfection itself did not affect the cells proliferation, cell cycle and tumorigenicity in vivo. However, when the cells were treated with 5-FU, cells viability and IC50 value of 5-FU was significantly reduced in the transfected cells, and cell cycle of pSilence-hENT1-Panc-1 was arrest in G0/G1. Furthermore, the volume of xenograft diminished significantly after 5-FU daily chemotherapy in mice inoculated with transfected cells.
  
  
  CONCLUSIONS
  The hENT1 gene specific downregulation by RNAi enhanced 5-FU chemosensitivity in pancreatic cancer cell line Panc-1.
authors: Department of Vascular Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors: Xiaolei
authors: X
authors: Hu
authors: Wuqiang
authors: W
authors: Chen
authors: Jianmin
authors: J
authors: Xu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D033721:Equilibrative Nucleoside Transporter 1 / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D005472:Fluorouracil / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D010957:Plasmids; D034622:RNA Interference / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D000964:Antimetabolites, Antineoplastic; D033721:Equilibrative Nucleoside Transporter 1; D005472:Fluorouracil