K_（562）和L_（210）耐高三尖杉酯碱细胞系的建立及其耐药机制的初步研究

通过逐渐递增高三尖杉酯碱（ＨＨＴ）剂量的方法，分别克隆筛选出两株耐ＨＨＴ１６．７和１３．４倍的Ｋ５６２和Ｌ１２１０白血病细胞系。各命名为Ｋ５６２ＨＨＴ和Ｌ１２１０ＨＨＴ。二者对阿霉素、长春新碱、柔红霉索和马法兰等抗肿瘸药物均呈不同程度的交叉耐药。斑点杂交的结果表明二者的多药耐药基因（ＭＤＲ－１）表达明显增强，且用ＭＤＲ－１基因表达产物Ｐ１７０糖蛋白特异性的ＪＳＢ－１单克隆抗体检测Ｋ５６２ＨＨＴ细胞，结果呈强阳件反应，而敏感株为阴性。此外，二者的谷胱甘肽－Ｓ－转移酶（ＧＳＴ）α和π基因ｍＲＮＡ水平均有提高，而ＧＳＴμ无明显改变。

Two homoharringtonine resistant leukemic cell lines(K562 HHT and L1210 HHT): establishment, characterization and mechanisms of action

e developed two leukemic cell lines (K562 HHTand L1210 HHT) stably 16.7 fold and 13.4 foldresistant to HHT respectively with which the culturewere treated. Both cell lines were also cross-resistantto DOX, VCR, DNR and Mel. Increased expressionof MDRI gene in the both lines was noted. To furtherevaluate. the imphcations of MDR1 in HHTresistance. We studied the expression of MDR 1 in sen-sitive and HHT-resistant sublines of K562 by ABCwith an monoclonal antibody against P170, JSB-1.K562 HHT cells were positive but sensitive cells werenegative. Additionally, the increased drug resistancewas associated with increased level of expression of aand n class GST gene. but not with increased level ofexpression of p class GST gene.