STI571耐药白血病细胞系的建立及其生物学特性初步研究

Establishment of K562 Cell Lines Resistant to STI571 and a Preliminary Biological Study

为了探讨STI5 71耐药机制和体外诱导建立甲磺酸伊马替尼 (imatinibmesylate ,又称STI5 71)耐药的白血病细胞系 ,采用STI5 71递增给药的方法诱导裸鼠高致瘤性人慢粒红白血病变细胞系K5 6 2 n和多药耐药细胞系K5 6 2 n VCR对STI5 71耐药 ,比较它们与各自亲本细胞系间基本生物学特性的异同。结果显示 ,建立多药耐药基础上对STI5 71耐药的白血病细胞亚系K5 6 2 n VCR STI,对STI5 71耐药倍数为 2 3.4 1,对长春新碱 (VCR)耐药倍数为 6 6 2 .2 6 ,对高三尖杉酯碱 (HHT)具有交叉耐药性。K5 6 2 n经STI5 71诱导后对多种药物耐受性有所提高 ,命名为K5 6 2 n STI。K5 6 2 n STI和K5 6 2 n VCR STI细胞内DNR积聚量分别为 33.2 4和 18.76 ,低于各自亲本细胞系。K5 6 2 n STI与K5 6 2 n VCR STI均检测到mdr 1基因的mRNA转录。K5 6 2 n STI和K5 6 2 n VCR STI与亲本细胞系相比 ,倍增时间延长 ,增殖指数增高。结论 :体外小剂量STI5 71递增给药的方法能够提高K5 6 2 n细胞系对STI5 71的耐受性 ,同时mdr 1基因表达阳性 ,表现一定程度的多药耐受 ,提示STI5 71耐药机制与多药耐药机制之间可能存在相关性。由于K5 6 2 n为裸鼠高致瘤的人白血病细胞系 ,K5 6 2 n STI和K5 6 2 n VCR STI5

To produce leukemic STI571-resistant cell lines and to explore the mole cular mechanism of STI571-resistance, cell lines K562-n and K562-n/VCR were induced by exposing cells to gradually increasing STI571 concentration of culture medium to have STI571-resistance and major biological characteristics between th ese subclones and the parent cells were compared. The results showed that a STI5 71-resistant cell line based on multidrug-resistance was established,which exhibited 23.41-fold re sistance to STI571, 662.26-fold resistance to VCR and cross-resistance to HHT. K 562-n/STI was generated from K562-n and had some characteristics of MDR. The i nt racellular accumulation of DNR in K562-n/STI and K562-n/VCR/STI were 33.24 and 1 8.76 respectively. Transcription of mdr-1 gene in both K562-n/STI and K562-n/ V CR/STI was positive. Cell doubling time of K562-n/STI and K562-n/VCR/STI was s ignif icantly longer than that in their parent cells (P<0.05). And proliferation i ndex was also highe r than that in parent cells (P<0.05). It is conclusion that the tolerance of K562-n cells to STI571 can be augmented by adding low-dose of STI571 into t he culture medium repeatedly. K562-n/STIs expressed MDR at som e extent, and transcription of mdr-1 gene in K562-n/STIs was positive. As K562-n is a cell line used to develope human leukemia in nude mice, K562-n/ ST I and K562-n/VCR/STI 571 will contribute to the study of mechanism of STI571-r esistance as in vitro and in vivo exprimental models.