ABCB1（1199G/A）基因多态性对甲磺酸伊马替尼转运的分子机制

摘 要 目的：探讨P 糖蛋白（P-gp）活性和所介导的甲磺酸伊马替尼胞内累积量及药物跨膜渗透性的影响。 方法: 将构建的ABCB1 1199G/wt和1199A/mut重组质粒分别转染HEK293细胞，利用RT-PCR法考察细胞中P-gp的mRNA表达水平。CCK-8法检测药物对细胞的毒性，高效液相色谱法（HPLC）检测细胞中药物浓度和胞内累积量，跨膜电阻实验考察药物跨膜渗透率，评价P-gp活性对药物转运的作用。结果: 细胞毒性实验表明，转染细胞内的药物浓度均低于对照组，证明P-gp具有介导药物转出胞外的作用。HPLC和跨膜电阻实验表明，与野生型ABCB1(1199G)细胞相比，突变型ABCB1(1199A)细胞抗甲磺酸伊马替尼的作用更强，P-gp对介导甲磺酸伊马替尼外排转运的作用较强且药物的跨膜渗透性也相应较强。结论:实验表明ABCB1（1199G/A）位点突变导致其编码蛋白P-gp活性改变，该位点多态性会导致甲磺酸伊马替尼清除率增加，抑制了药物在靶细胞中有效药物浓度，因此临床上应对ABCB1基因进行分型，指导甲磺酸伊马替尼的个体化用药。

Molecular Mechanism of the Effects of ABCB1 (1199G/A) Gene polymorphisms on Transportation of Imatinib Mesylate

ABSTRACT Objective: To explore the effect of P glycoprotein (P-gp) activity on its mediated imatinib mesylate accumulation and intracellular drug membrane permeability.Methods: 1199G/wt ABCB1 and 1199A/mut recombinant plasmids were transferred into HEK293 cells, respectively, and the expression levels of mRNA in different cell models were investigated by RT-PCR. Cell Counting Kit 8(CCK-8) assay was used to detect the drug toxicity in different cell models, HPLC was applied to determine the drug concentration in different cell models and evaluate the intracellular accumulation, and transmembrane resistance experiment was employed to detect the transmembrane permeability and evaluate the effect of P-gp activity on drug transportation.Results:Cytotoxicity test showed that the drug concentration in the transferred cells was lower than that in the control group, which proved that P-gp had the function of mediating drug out of cells. HPLC and transepithelial electrical resistance experiment showed that compared with the wild type of ABCB1 (1199G) cells, mutation of ABCB1 1199A cells had stronger effect on P-gp mediated mesylate imatinib accumulation and drug membrane permeability. Conclusion:The experiment manifested that ABCB1 (1199G/A) site mutation can change the coding protein P-gp activity and the polymorphisms will lead to the increase of mesylate imatinib clearance rate and the decrease of effective drug concentration in target cells. Meanwhile, the clarification of ABCB1 genetic types in clinics can guide the individualized medication of imatinib mesylate.