四氢异喹啉类化合物HZ08逆转白血病K562/DOX细胞多药耐药性的试验研究

目的:探讨四氢异喹啉类化合物HZ08对人白血病多药耐药K562/DOX细胞的逆转作用及其可能的机制。方法:采用MTT法检测HZ08的体外细胞毒性及其对阿霉素(DOX)的增敏作用,采用逆转倍数(RF)值评价其逆转效果;应用流式细胞仪分析细胞内罗丹明123(Rh123)潴留量的变化和DOX浓度,评价P糖蛋白(P-gp)的功能;采用Western blot法及免疫细胞化学法测定mdr1基因产物P-gp的表达;同时以人白血病敏感细胞株K562/S细胞为对照进行比较试验。结果:与K562/S细胞比较,HZ08可明显增强DOX对K562/DOX的细胞毒性,RF值增加;HZ08能浓度相关性地增加K562/DOX细胞对Rh123的摄取以及细胞内Rh123的潴留,明显抑制P-gp介导的Rh123外排;K562/DOX细胞膜上P-gp呈强阳性表达,但HZ08对K562/DOX细胞P-gp表达水平无明显影响;HZ08可显著增加K562/DOX细胞内DOX浓度。结论:HZ08可通过抑制K562/DOX细胞P-gp的功能、增加耐药细胞内DOX的浓度而增强K562/DOX细胞对DOX的敏感性,其可能成为有效的多药耐药逆转剂的候选药物。

Reversal Effect of Tetrahydroisoquinolines Compound HZ08 on Multi-drug Resistance of Human Leukemia Cell Line K562/DOX

OBJECTIVE：To investigate the reversal effect and its mechanism of tetrahydroisoquinolines compound HZ08 on multi-drug resistance（MDR） of human leukemia cell line K562/DOX.METHODS：The effect of HZ08 on enhancing doxorubicin（DOX） cytotoxicity was tested by MTT assay,reversal effect of HZ08 was evaluated by the reversal fold（RF）.Flow cytometry（FCM） was used to investigate the amount of rhodamine 123（Rh123） retention and the intracellular concentration of DOX,and estimate the function of P-glycoprotein（P-gp）.The expressions of P-gp were analyzed by Western blot and immunohistochemistry（IHC）method.RESULTS：Compared with human leukemia sensitive cell line K562/S,the cytotoxicity of DOX to K562/DOX cells was significantly enhanced by HZ08 and the value of PF increased.HZ08 increased the uptake and retention of of Rh123 in K562/DOX cells in a concentration-related manner and inhibited the excretion of Rh123 induced by P-gp.The expression of P-gp in K562/DOX cells was obviously positive.HZ08 had no obvious effect on the expression of P-gp in K562/DOX cells.The concentration of DOX in K562/DOX cells was increased significantly by HZ08.CONCLUSION：HZ08 can enhance the drug sensitivity of K562/DOX cells to DOX by inhibiting the function of P-gp and increasing intracellular concentration of DOX.HZ08 could be a promising candidate for MDR reversing agents in cancer chemotherapy.