两种人骨肉瘤U20S细胞阿霉素耐药株的比较

Comparison of Characteristics of Two Adriamycin Resistant Human Osteosarcoma U20S Cell Lines

目的研究不同方式建立的人骨肉瘤U20S细胞阿霉素耐药株的生物学特性及其耐药机制。方法采用大剂量间隙作用、浓度梯度递增间隙作用建立U20S阿霉素耐药株U20S／ADM1，U20S／ADM2，光镜及透射电镜下观察细胞形态变化；MTT法测定其耐药指数、药物敏感性，绘制生长曲线计算倍增时间；罗丹明外排实验检测P-糖蛋白（P-gP）泵功能；RT-PCR检测多药耐药基因1（MDR1）mRNA、多药耐药相关蛋白1（MRP1）mR-NA的表达。结果U20S／ADMl，U20S／ADM2的耐药指数分别为79．63和91．06，对紫杉醇、顺铂有交叉耐药；细胞倍增时间延长（P〈0．01）；耐药株细胞线粒体丰富，粗面内质网及游离核糖体增多；细胞内罗丹明蓄积量低于亲本细胞（P〈0．01），两种耐药株之间无明显差异（P〉0．05）；MDR1mRNA，MRP1mRNA表达均高于亲本细胞（P〈0．05），MDRlmRNA表达两种耐药株问无明显差异（P〉0．05），U20S／ADM1的MRP1mRNA表达低于U20S／ADM2（P〈0．05）。结论两种耐药株均可产生MDR，耐药机制可能与MDR1，MRP1过表达有关；不同建立方式存在一定差异，浓度梯度递增间隙作用方式更容易产生耐药。

Objective To conlpare muhidrug-resistant characteristics anti mechanisms of two human osieosarcoma cell lines se- lected/induced by different methods. Methods Two resistant cell lines U2OS/ADM1 and U2OS/ADM2 were established by impacting with high dose of adfiamycin for a short time and gradually increasing concentration of a（lriamyein from the parent cell line U2OS in vitro,observed their morphoh）gical features by optical microscope and transmission electron microscope,checked their resistance index（R1） and drug sensi- tivity by MTr assay, gathered their growth curve and calculated their doubling time. The accumulation of Rh123 was evaluated by flow cytome- try. Expression of MDRImRNA and MRP1 mRNA was compared with that in parent cells by RT-PCR. Results The RI of U2OS/ADM1 and U2OS/ADM2 cells were 79.63 an（t 91.06 to adriamycin. They also demonstrated cross resistance to paclitaxel and eisplatin. Both resistant cell lines grew slowly and exhibited changes in morphology. They were rich in mitochondria and increased in rough endoplasmic reticulum and free ribosomes. The accumulation of Rh123 was lower in two resistant cell fines than in the parent cells. The expression of MDRI mRNA and MRPlmRNA was enhanced in both resistant cell lines. The accumulatitm of Rh123 and expression of MDR1mRNA had no significant differ- ence between two resista,lt cell lines. MBPImRNA was higher in U2OS/ADM2 cells than in U2OS/ADMI cells. Conclusion U2OS/ADM1 cells and U2OS/ADM2 cells were typical MDR cell lines. The drug-resistance mechanisms nmybe related to overexpression of MDRI mRNA and MRPlmRNA. The resistant ability of U2OS/ADM2 cells was higher than U2OS/ADM1 ceils.