The role of human nucleoside transporters in cellular uptake of 4′-thio-β-D-arabinofuranosylcytosine and β-D-arabinosylcytosine
The role of human nucleoside transporters in cellular uptake of 4′-thio-β-D-arabinofuranosylcytosine and β-D-arabinosylcytosine
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DOI：
10.1124/mol.105.021543
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发表时间：
2006-07-01
影响因子：
3.6
通讯作者：
Cass, Carol E.
中科院分区：
文献类型：
--
作者：
Clarke, Marilyn L.;Damaraju, Vijaya L.;Cass, Carol E.
4 '-硫代-β-D-阿拉伯呋喃糖基胞嘧啶（TaraC）正处于治疗癌症的I期开发阶段。在含人平衡型核苷转运蛋白（hENT）1的CEM细胞中，（10 μ M;[H-3] TaraC和[H-3]1-β-D-阿拉伯呋喃糖基胞嘧啶（araC）的浓度（每微升细胞水每秒皮摩尔）较低（分别为0.007 +/- 003和0.034 +/- 0.003）与[H-3]尿苷（0.317 +/- 0.048）（一种高活性hENT 1渗透物）相比。在含有hENT 1和hENT 2的HeLa细胞中，（10 μ M;[H-3] TaraC、[H-3] araC和[H-3]脱氧胞苷的浓度较低（分别为0.30 +/- 0.003、0.42 +/- 0.03和0.51 +/- 0.11）并且主要由hENT 1介导（分别类似于74、类似于65和类似于61%）。在含有重组人浓缩核苷转运蛋白（hCNT）1或hCNT 3的HeLa细胞中，未检测到10 μ M [H-3] TaraC和[H-3] araC的转运。重组转运蛋白（在酵母中产生）对一组含胞嘧啶核苷的表观亲和力产生的结果与观察到的TaraC和araC对hENT 1/2的低渗透活性和对hCNT 1/2/3的可忽略的渗透活性一致。在长期的药物暴露的CEM细胞与hENT 1活性，araC比TaraC的细胞毒性，而与硝基苄硫代肌苷的共同曝光（以阻止hENT 1）产生相同的细胞毒性araC和TaraC。通过基因转移将hENT 2和hCNT 1活性分别导入核苷转运缺陷的CEM细胞中，可中度和轻度增加对两种药物的敏感性。这些结果表明，核苷转运能力（主要通过hENT 1，在较小程度上通过hENT 2，可能通过hCNT 1）是两种药物药理活性的决定因素。
4'-Thio-beta-D-arabinofuranosyl cytosine (TaraC) is in phase I development for treatment of cancer. In human equilibrative nucleoside transporter (hENT) 1-containing CEM cells, initial rates of uptake (10 mu M; picomoles per microliter of cell water per second) of [H-3] TaraC and [H-3]1-beta-D-arabinofuranosyl cytosine ( araC) were low (0.007 +/- 003 and 0.034 +/- 0.003, respectively) compared with that of [H-3] uridine (0.317 +/- 0.048), a high-activity hENT1 permeant. In hENT1- and hENT2-containing HeLa cells, initial rates of uptake ( 10 mu M; picomoles per cell per second) of [H-3] TaraC, [H-3] araC, and [H-3] deoxycytidine were low (0.30 +/- 0.003, 0.42 +/- 0.03, and 0.51 +/- 0.11, respectively) and mediated primarily by hENT1 (similar to 74, similar to 65, and similar to 61%, respectively). In HeLa cells with recombinant human concentrative nucleoside transporter (hCNT) 1 or hCNT3 and pharmacologically blocked hENT1 and hENT2, transport of 10 mu M [H-3] TaraC and [H-3] araC was not detected. The apparent affinities of recombinant transporters ( produced in yeast) for a panel of cytosine-containing nucleosides yielded results that were consistent with the observed low-permeant activities of TaraC and araC for hENT1/2 and negligible permeant activities for hCNT1/2/3. During prolonged drug exposures of CEM cells with hENT1 activity, araC was more cytotoxic than TaraC, whereas coexposures with nitrobenzylthioinosine ( to pharmacologically block hENT1) yielded identical cytotoxicities for araC and TaraC. The introduction by gene transfer of hENT2 and hCNT1 activities, respectively, into nucleoside transport-defective CEM cells increased sensitivity to both drugs moderately and slightly. These results demonstrated that nucleoside transport capacity ( primarily via hENT1, to a lesser extent by hENT2 and possibly by hCNT1) is a determinant of pharmacological activity of both drugs.