2-脱氧葡萄糖通过降低有氧糖酵解增强白血病K562／ADM耐药细胞对阿霉素的敏感性

摘要

Aim To investigate the effect of 2-deoxy-D-glucose(2-DG)on the sensitivity of leukemia multi-drug resistant K562/ADMcells to adriamycin by inhib-iting glycolytic pathway as well as its molecular mecha-nisms.Methods The leukemia drug-resistant K562/ADM cells and parental K562 cells were used as the target cell models.The cell proliferating activity was assessed with an MTT colorimetric assay,and the gly-colysis including glucose consumption,lactate export, and hexokinase activity was determined by glucose, lactic acid and hexokinase (HK)testing kits.The ex-pression and phosphorylation of mammalian target of rapamycin(mTOR)and glucose transporter-4 (GLUT-4)expression were analyzed by western blot.Results K562/ADM drug-resistant cells possessed higher HK activity,GLUT-4 expression level and aerobic glycolic ability than K562 sensitive cells. 2-DG treatment markedly inhibited HK activity,glucose consumption, and lactate export both in K562 cells and K562/ADM cells,and suppressed the proliferation of the two cells in a time-and concentration-dependent manner.Low concentration of 2-DG or adriamycin could increase the expression and phosphorylation of mTOR.However, the co-administration of 2-DG and adriamycin markedly counteracted adriamycin-mediated enhancement of mTOR expression and phosphorylation and down-regu-lated GLUT-4 expression in K562/ADM cells,and 2-DG dramatically improved the sensitivity of K562/ADM cells to cytotoxicity.Conclusion 2-DG inhibits the proliferation of drug-resistant K562/ADM cells and en-hances the sensitivity to adriamycin by blocking aerobic glycolysis pathway through inhibiting hexokinase activi-ty,counteracting adriamycin-stimulated increased ex-pression and phosphorylation of mTOR and downregu-lating GLUT-4 expression.%目的研究2-脱氧葡萄糖（2-deoxy-D-glucose，2-DG）通过抑制糖代谢增强白血病K562／ADM多药耐药细胞对阿霉素（adriamycin，ADM）敏感性的作用及机制。方法以白血病K562／ADM及其亲本K562细胞为靶细胞模型，MTT法检测细胞增殖活性，葡萄糖、乳酸、己糖激酶测试盒分析葡萄糖消耗量、乳酸生成量和己糖激酶（hexokinase，HK）活性。Western blot 法检测哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin，mTOR）表达和磷酸化（p-mTOR）以及葡萄糖转运体-4（glucose transporter-4，GLUT-4）的表达。结果与亲本K562细胞相比，白血病K562／ADM耐药细胞HK活性、GLUT-4表达水平和有氧糖酵解能力增强。2-DG能够明显抑制K562／ADM及K562细胞的HK活性、葡萄糖消耗量和乳酸生成量，呈时间－浓度依赖性地抑制白血病细胞的增殖活性。低剂量2-DG和 ADM可诱导 K562／ADM细胞mTOR高表达及磷酸化水平增高，但2-DG与ADM联合则可有效对抗ADM诱导的K562／ADM细胞mTOR高表达和磷酸化，并可降低GLUT-4的表达，提高K562／ADM细胞对阿霉素的敏感性。结论2-DG通过竞争性抑制HK活性和抵抗ADM诱发的代偿性mTOR活化，降低GLUT-4表达，有效阻断有氧糖酵解途径而降低K562／ADM耐药细胞的增殖活性、增强其对化疗药物的敏感性。