细胞膜上平衡型核苷转运体基因表达与阿糖胞苷敏感性的关系

Relationship between gene expressions of equilibrative nucleoside transporter and sensitivity of cytarabine

目的探讨细胞膜上平衡型核苷转运体基因表达与阿糖胞苷(Ara-C)敏感性的关系。方法采用实时荧光定量PCR法检测血液病细胞系中平衡型核苷转运体(hENT)四种亚型基因(HL-60、NB4、U937、MOLT4、JURKAT)的表达,并观察髓系细胞株HL-60和NB4经Ara-C处理后hENT1表达的变化。以未加药处理细胞株作为对照组。结果四类亚型hENT中仅hENT1基因表达与Ara-C的敏感性相关(r=0.939,P=0.018),且hENT1基因在髓系细胞膜上的表达高于它在淋系细胞膜上的表达。经Ara-C作用4 h内,髓系细胞株hENT1基因表达均下调(P<0.05或P<0.01),而8 h后HL-60细胞膜上hENT1的基因表达又上调达对照组水平(P>0.05)。结论介导Ara-C转运的hENT1参与了细胞株对药物的敏感性,其基因表达的变化是Ara-C耐药的重要原因之一。

Objective To investigate the relationship between gene expressions of equilibrative nucleoside transporter and sensitivity of cytarabine（ Ara-C）. Methods Real-time PCR was employed to detect the gene expressions of four subtypes of human equilibrative nucleoside transporter（bENT）in five cell lines （HL-60, NB4, U937, MOLT4 and JURKAT cell lines） , and the changes in gene expression of bENT1 in HL-60 and NB4 cells exposed to Ara-C were observed. Results Among the four subtypes of bENT, only bENT1 gene expression was related to the sensitivity of Ara-C （ r = 0. 939, P = 0.018）. The gene expression of ENT1 in membrane of myeloid cell lines was higher than that in membrane of lymphoid cell lines. After using Ara-C in HL-60 and NB4 cell lines in vitro, the gene expression of ENT1 was down-regulated in the first 4 h（P 〈 0.05 or P 〈0.01 ）, then was up-regulated or even recovered to the baseline level at the point of 8 h（P 〉0.05）. Conclusion hENT1, which mediates the transport of Ara-C, participates in the sensitivity of cell lines to drugs, and the changes in gene expression of hENT1 constitute one of the important factors in the mechanism of drug-resistance for Ara-C.