Reduced oxygen level (hypoxia) induces endothelial dysfunction and release of the endogenous nucleoside adenosine. Human umbilical vein endothelium (HUVEC) function in an environment with 3% to 5% O2 and exhibit efficient adenosine membrane transport via human equilibrative nucleoside transporters 1 (hENT1). We studied whether adenosine transport and hENT1 expression are altered by hypoxia in H...

BACKGROUND Glucose-6-phosphate dehydrogenase (G6PD) deficiency is associated with erythrocyte sensitivity to oxidative damage and hemolytic crises. In β-thalassemia major, where hemoglobin instability imposes oxidative stress, erythrocytes show reduced hENT1 nucleoside transporter expression and decreased nucleoside uptake. This study investigated hENT1 expression and nucleoside transport in G6...

PURPOSE Gemcitabine is a promising adjuvant treatment for patients with resected pancreatic adenocarcinoma and its use in combination with radiotherapy is under exploration. Human equilibrative nucleoside transporter 1 (hENT1) and human concentrative nucleoside transporter (hCNT) 1 and 3 are the major transporters responsible for 2',2'-difluoro-2-deoxycytidine (gemcitabine) uptake into cells. T...

Human equilibrative nucleoside transporter 1 (hENT1) is a prototypical nucleoside transporter protein ubiquitously expressed on the cell surface of almost all human tissue. Given the role of hENT1 in the transport of nucleoside drugs, an important class of therapeutics in the treatment of various cancers and viral infections, efforts have been made to better understand the mechanisms by which h...

The human equilibrative nucleoside transporter 1 (hENT1) is an important modulator of the physiological action of adenosine. We identified amino acid residues involved in adenosine transport using a yeast-based assay to rapidly screen and identify randomly generated hENT1 mutants that exhibited decreased sensitivity to inhibition of adenosine transport by various hENT1 competitive inhibitors. W...

245 words (Max 250 words) Total: 8233 words Page 1 of 41 Articles in PresS. Am J Physiol Regul Integr Comp Physiol (August 29, 2007). doi:10.1152/ajpregu.00293.2007 Copyright © 2007 by the American Physiological Society. 2 Abstract To better understand the role of human equilibrative (hENTs) and concentrative (hCNTs) nucleoside transporters in physiology and pharmacology, we investigated the re...

3'-Deoxy-3'-fluorothymidine (FLT) is a positron emission tomography (PET) tracer used to identify proliferating tumor cells. The purpose of this study was to characterize FLT transport by human nucleoside transporters (hNTs) and to determine the role of hNTs for FLT uptake in various human cancer cell lines. FLT binding to hNTs was monitored by the inhibitory effects of FLT on [(3)H]uridine upt...

Pancreatic cancer is one of the most lethal cancers, where curative surgical resections are rare and less than 5% of patients experience long-term survival. Despite numerous clinical trials, improvements in the systemic treatment of this disease have been limited. Gemcitabine, a nucleoside analogue, is still considered the standard of care chemotherapy for most patients in the advanced disease ...

The human equilibrative nucleoside transporters hENT1 and hENT2 (each with 456 residues) are 40% identical in amino acid sequence and contain 11 putative transmembrane helices. Both transport purine and pyrimidine nucleosides and are distinguished functionally by a difference in sensitivity to inhibition by nanomolar concentrations of nitrobenzylmercaptopurine ribonucleoside (NBMPR), hENT1 bein...

Expression of human equilibrative nucleoside transporter 1 (hENT1) in pancreatic ductal adenocarcinoma (PDAC) has been postulated to be a marker of sensitivity to gemcitabine. However, heterogeneity in the studies attempting to quantify hENT1 expression in patients with PDAC treated with gemcitabine has yielded inconclusive results that impede the adoption of hENT1 expression as a predictive bi...