氯丙嗪对耐药细胞系K_(562)/AO_2多药耐药逆转作用的研究

Reversal effects of multidrug resistance by chlorpromazine in K_(562)/AO_2 cell line

目的 :研究氯丙嗪对耐药细胞系K562 /AO2 多药耐药逆转作用。方法 :应用免疫组化观察K562 /AO2 细胞系的耐药蛋白表达情况 ,用MTT法测定不同浓度的氯丙嗪对K562 /AO2 细胞系耐药逆转作用 ,用流式细胞术测定不同浓度的氯丙嗪与K562 /AO2 细胞作用后细胞内罗丹明的蓄积情况 ,用半定量RT PCR法测定氯丙嗪对K562 /AO2 细胞多药耐药基因 (mdr 1)mRNA表达的影响。结果 :K562 /AO2 细胞不但P gp表达阳性 ,而且肺耐药相关蛋白 (lungresistanceelatedprotein ,LRP)表达也阳性 ;氯丙嗪能增强多柔比星对K562 /AO2 细胞的杀伤作用 (单用ADM组、氯丙嗪 0 75 μg/mL +ADM组、氯丙嗪 1 5μg/mL +ADM组和氯丙嗪 3 μg/mL +ADM组对K562 /AO2 的抑制率分别为 5 2 %、 2 5 9%、3 9 1%和 74 8% ) ;增加K562 /AO2 细胞内罗丹明的蓄积 (对照组、氯丙嗪 0 75 μg/mL组、氯丙嗪1 5 μg/mL组和氯丙嗪 3μg/mL组细胞内的荧光强度的均值分别为 1 87、 10 2 8、 48 75和65 63 ) ;对K562 /AO2 细胞mdr 1mRNA表达无明显影响 (对照组mdr 1和 β actin的面积比为0 41,氯丙嗪组为 0 42 )。结论 :氯丙嗪对K562 /AO2 细胞的耐药有较强的逆转作用 。

OBJECTIVE:To observe the reverse effects of chlorpromazine in K 562/AO 2 cell line.METHODS:P-gp and LRP were investigated by the immunohistochemistry method;the toxicity of chlorpromazine and/or ADM was assayed by MTT method;intracellular rhodamin123 concentrations were measured by the flow cytometry;Mdr-1 gene expression was assayed by semiquantitative RT-PCR.RESULTS:P-gp and LRP expressions were positive in K 562/AO 2 cell line.The cytotoxicities of ADM to K 562/AO 2 were enhanced by chlorpromazine (the suppression rates to K 562/AO 2 cells were 5.2% in ADM group, 25.9% in chlorpromazine 0.75 μg/mL+ADM group,39.1% in chlorpromazine 1.5 μg/mL+ADM group, 74.8% in chlorpromazine 3 μg/mL+ADM group,respectively).Chlorpromazine increased the intracellular rhodamin 123 accumulation siginificantly (the intracellular intensities of fluorescence were 1.87 in control group,10.28 in chlorpromazine 0.75 μg/mL group,48.75 in chlorpromazine 1.5 μg/mL group, 265.63 in chlorpromazine 3 μg/mL group,respectively).Chlorpromazine did not have effect on Mdr-1 mRNA expression(the ratio of area in control group was 0.41, 0.42 in chlorpromazine group).CONCLUSIONS:Chlorpromazine has significant effect on the reversal of MDR of K 562/AO 2 cell line.The mechanism of reverse effects of chlorpromazine seems to be down-regulated function of P-gp.