多药耐药细胞系K562/A02裸小鼠皮下移植瘤模型的建立与鉴定

Establishment and Evaluation of a Model using K562/A02 Multidrug Resistant Tumor Xenografts in Nude Mice

目的:建立一种耐药特性稳定的裸小鼠移植瘤动物模型,为进行体内肿瘤耐药机制研究和逆转药物的筛选提供实验模型和实验基础。方法:将具有典型MDR表型的K562/A02耐药细胞接种于裸小鼠右侧背侧皮下,而亲本K562细胞接种裸小鼠左侧背侧皮下,接种细胞数为1×107细胞/只,观察肿瘤成瘤情况及生长特性,并比较裸小鼠移植瘤细胞和体外培养细胞对化疗药物的敏感性,同时利用RT-PCR和免疫组织化学染色对裸小鼠K562/A02移植瘤基因表型进行鉴定。结果:1)K562/A02裸小鼠移植瘤的成瘤率为100%,大约于第6～9天成瘤(体积>100mm3),敏感肿瘤生长速度与耐药肿瘤无明显差别;2)裸小鼠K562/A02移植瘤肿瘤细胞和体外培养原代细胞对阿霉素的IC50分别为185.24μg/ml和235.25μg/ml,而K562/A02移植瘤肿瘤的IC50分别为3.07μg/ml和3.26μg/ml;阿霉素治疗组能够明显减慢K562敏感移植瘤的生长,而对K562/A02耐药移植瘤的生长几乎无作用;3)K562/A02裸小鼠移植瘤肿瘤细胞具有mdr1/Pgp表达,而K562裸小鼠移植瘤肿瘤细胞则无mdr1/Pgp表达。结论:以K562/A02细胞建立的裸小鼠耐药移植瘤模型,仍保持近似体外的耐药活性和基因表型,为耐药机制和逆转研究提供了良好的体内模型。

Objective： To establish an animal model using nude mice injected with K562/A02, a leukemia cell line with, stable multiple drug resistance （MDR）, in order to study the mechanism of drug resistance of tumors in vivo and to screen for drugs that can reverse this effect. Methods： K562/ A02 cells, classically MDR, were subcutaneously injected in the right flank of nude mice, and the parent K562 cells were subcutaneously injected in the left flank of the mice. Each injection contained 1 107cells. The conditions and growth characteristics of the tumors were observed, and the sensitivity to chemotherapy of the injected tumor cells and in vitro culture cells were compared. Tumors arising from the injected cells were also analyzed using RT-PCR and immunohistochemical staining Results： a） The tumorigenesis rate of K562/A02 cells in nude mice was 100%. In 6 to 9 days, the tumors reached a volume of more than 100 mm3 and there was no apparent difference in the growth rate between the drug resistant and the sensitivetumors; b） For adriamycin, the ICSO for K562/A02 injected cells and the in vitro cultured primary cells was 185.24μg/ml and 235.25μg/ml, respectively. The IC50 for K562/A02 injected cells and the in vitro cultured primary cells was 3.07μg/ml and 3.26μg/ml, respectively. The growth of the sensitive K562. cells was significantly reduced in the mice treated with driamycin, but the drug had little effect on the growth of drug resistant K562/A02 cells injected into the mice; c） The K562/A02 tumor cells in nude mice had mdrl/Pgp expression, yet the K562 tumor cells in nude micehad no such expression. Conclusion： A model for multiple drug resistant tumors in nude mice that maintains the drug resistance seen in vitro has been established using K562/A02 cells. This model has potential for research on the mechanism of drug resistance and its reversal .