N-糖基化修饰在髓性白血病耐药中的作用

目的研究N-糖基化修饰、糖基因表达调控在髓性白血病耐药中的作用,明确N-糖基化修饰、糖基因与白血病耐药的相关性,从而为预测和诊断髓性白血病耐药性,寻求逆转药物提供新策略和靶点。方法通过修饰白血病耐药细胞株的N-糖基化（衣霉素Tunicamycin和PNGase F处理）,Western Blot检测Pgp、CD147糖蛋白的表达水平;MTT法检测N-糖基化修饰前后髓性白血病耐药细胞株的生长情况及对化疗药物的敏感性,观察上述细胞膜型N-糖基化修饰后对化疗药物耐药性的影响;进一步通过RNA干扰技术干预差异表达的糖基因,MTT法检测干扰前后白血病耐药细胞株的生长情况及对化疗药物的敏感性,观测糖基因的表达调控对髓性白血病耐药的影响。结果 NB4/ADR细胞经N-糖基化修饰后,P-gp、CD147糖蛋白的表达水平发生改变,同时该细胞的药物敏感性也增强（P〈0.05）;当通过RNA干扰技术特异性使NB4/ADR细胞中B3GNT8和ST8SIA4表达下调时,该细胞的药物敏感性增强（P〈0.05）。结论髓性白血病细胞株中N-糖基化修饰、糖基因的改变均与白血病多药耐药具有相关性,为预测和诊断髓性白血病耐药性,寻求逆转药物提供新策略和靶点。

The role of N-glycosylation modification in drug resistance of myeloid leukemia

Objective To investigate and clarify the role of N-glycosylation and glycogene in drug resistance of leu- kemia, further predict and diagnose myelogenous leukemia muhidrug resistance, and provide a new therapeutic strategy and target point of myelogenous leukemia. Methods Modificating the N-glycosylation by Tunieamycin or PNGase F treatment in multidrug resistance cell line of leukemia, Western Blot was used for measuring the expression of P-gp and CD147. The biosynthesis and chemosensitivity were examed by MTT between N-glycosylation modification and its parental cells, analysing the chemosensitivity in membrane phenotype with N-glycosylation modification. Further analysis of the differential expression of glycogenes by RNA interference approach, the biosynthesis and chemosensitivity were examed by MTT between the interferenced and its parental cells, analysing the expression regulation of glycogenesn the muhidrug resistance of myelogenous leukemia. Results The silencing of glycogene B3GNT8 or ST8SIA4 in K562/ADR cells resulted in increased chemosensitivity to anti-tumor drugs （P 〈 0.05 ）. The analysis of the N-glycan regulation by way of tunicamycin application or PNGase F treatment in NBJADR cells showed partial inhibition of biosynthesis and increased sensitivity to chemotherapeutic drugs in vitro. Conclusion The altered expression of glycogenes and modification of N-glycosylation in myelogenous leukemia correlate with muhidrug resistance, and have significant implications for the development of treatment strategies.