Differential transport of cytosine-containing nucleosides by recombinant human concentrative nucleoside transporter protein hCNT1.
The transportability of cytosine-containing nucleosides by recombinant hCNT1 was investigated in transfected mammalian cells. Apparent K(m) values for hCNT1-mediated transport of uridine, cytidine and deoxycytidine were, respectively, 59, 140 and 150 microM. Uridine transport was inhibited 89, 32 and 11%, respectively, by 500 microM gemcitabine, cytarabine and lamivudine, demonstrating that, unlike gemcitabine (a high-affinity hCNT1 permeant), cytarabine and lamivudine are poor hCNT1 permeants.
Graham
K A
KA
Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Canada.
Leithoff
J
J
Coe
I R
IR
Mowles
D
D
Mackey
J R
JR
Young
J D
JD
Cass
C E
CE
D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology; D001692:Biological Transport; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003561:Cytarabine / Q000494:pharmacology; D003562:Cytidine / Q000378:metabolism*; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D000882:Haplorhini; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D019259:Lamivudine / Q000494:pharmacology; D026901:Membrane Transport Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity; D014162:Transfection; D014529:Uridine / Q000378:metabolism*; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D000998:Antiviral Agents; D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D011994:Recombinant Proteins; C065171:cif nucleoside transporter; D003561:Cytarabine; D003841:Deoxycytidine; D019259:Lamivudine; D003562:Cytidine; D014529:Uridine; D000093542:Gemcitabine