Expression of human equilibrative nucleoside transporter 1 (hENT1) and its correlation with gemcitabine uptake and cytotoxicity in mantle cell lymphoma.
OBJECTIVE
Nucleoside transporters might play a relevant role in the intracellular targeting of many nucleoside analogs used in anticancer therapy. Two gene families (SLC28 and SLC29) encode the two types of human nucleoside transporters, concentrative nucleoside transporter (CNT) and equilibrative nucleoside transporter (ENT) proteins. Chronic lymphocytic leukemia (CLL) cells express both SLC28- and SLC29-related mRNA, although transport function seems to be mostly related to ENT-type transporters. Here we have analyzed the role of nucleoside transporters in nucleoside-derived drug bioavailability and action in mantle cell lymphoma (MCL) cells.


METHODS
The relative amounts of hENT1 and hENT2-related mRNA and protein were analyzed in five MCL cell lines and 20 primary MCL tumors by real-time quantitative reverse transcriptase polymerase chain reaction and western blots. Cell viability, measured by annexin V-FITC staining, and nucleoside-derived drug transport were also studied.


RESULTS
MCL cells express higher levels of hENT1 protein than do CLL cells, and a good correlation was found between protein and mRNA levels of hENT1, thus indirectly suggesting that hENT1 might be transcriptionally regulated in MCL cells. More importantly, a significant correlation between these two parameters, drug uptake and sensitivity to gemcitabine, was also observed.


CONCLUSIONS
These results further support the concept that nucleoside transporters are implicated in the therapeutic response to nucleoside analogs, and suggest a particular and novel role for hENT1 in the genotoxic response to selected nucleoside analogs, such as gemcitabine, in MCL cells.
Marcé
Silvia
S
Unitat d'Hematopatologia, Hospital Cliníc, IDIBAPS, Villarroel 170, 08036 Barcelona, Spain.
Molina-Arcas
Míriam
M
Villamor
Neus
N
Casado
F Javier
FJ
Campo
Elias
E
Pastor-Anglada
Marçal
M
Colomer
Dolors
D
D045744:Cell Line, Tumor; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D033721:Equilibrative Nucleoside Transporter 1 / Q000032:analysis* / Q000235:genetics; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000188:drug therapy* / Q000473:pathology; D009705:Nucleosides / Q000493:pharmacokinetics; D012333:RNA, Messenger / Q000032:analysis; D000093542:Gemcitabine
D033721:Equilibrative Nucleoside Transporter 1; D009705:Nucleosides; D012333:RNA, Messenger; C438649:SLC29A1 protein, human; D003841:Deoxycytidine; D000093542:Gemcitabine