川芎嗪联合三氧化二砷逆转K562/ADM细胞多药耐药的实验研究

目的探讨川芎嗪与三氧化二砷联合逆转耐药人红白血病细胞株K562/ADM多药耐药的效果。方法采用WST-8法测定细胞的药敏性及抗药性逆转,应用流式细胞术检测细胞凋亡、细胞内ADM浓度、P-gp蛋白的表达,采用免疫细胞化学二步法检测细胞GST-π表达。结果非细胞毒性浓度的TMP（20μg/ml）及As2O3（0.5μmol/L）可降低ADM对K562/ADM细胞的IC50（P〈0.05）,2种药物联合应用对ADM的逆转倍数明显高于两者单独应用（P〈0.05）,而且也高于两者单独应用之和;两者以非细胞毒性浓度联合应用提高K562/ADM细胞内ADM浓度和细胞凋亡百分率,作用大于两药单独应用,并且明显下调细胞P-gp和GST-π表达（P〈0.05,P〈0.01）。结论非细胞毒性剂量的TMP和As2O3,均可部分逆转有多药耐药表型的细胞株K562/ADM对阿霉素的耐药性,两者联合应用效果优于单独应用,具有协同作用,其机制可能与下调P-gp和GST-π表达有关。

The Experimental Studies of Tetramethylpyrazine in Combination with Arsenic Trioxide on the Reversal of Multidrug Resistance in K562/ADM Cell Line

Objective To evaluate the effect of tetramethylpyrazine in combination with arsenic trioxide on the reversal of muhidrug resistance in K562/ADM cell line. Methods The sensitivity of cell lines and the reversal of drug resistance were determined with WST - 8 method. The cell apoptosis and the concentration of intracellular ADM and P - gp expression were measured with flow cytometry（FCM） , and the expression of GST-πin cells was assessed by immunohistochemical methods. Results TMP（20 μg/ml）and As2 03 （0. 5 μmol/L）at the non -cytotoxic dose could markedly decrease the IC50 value of K562/ADM cell line to adriamycin（ADM） （P 〈 0.05 ）. TMP combined with As203 at the non -cytotoxic dose strongly improved drug resistance reversal effect, which was larger than the single application of TMP or As2 03 respectively and their summation （P 〈 0.05 ）. TMP combined with As2O3 at the non - cytotoxic dose strongly increase intracellular ADM concentration and apoptosis percentage of K562/ADM cell line, which was larger than the single application of TMP or As2O3 respectively. TMP combined with As2O3 at the non - cytotoxic dose down - regulate strongly both of P - gp and GST -πexpression （ P 〈0. 05, P 〈 0.01 ）. Conclusion TMP and As2O3 al the non-cytotoxic dose could partly reverse the MDR of K562/ADM. The effect of combination of two agents were superior to that of single agent due to their synergism, which may be related to down - regulating of P - gp and GST - πexpression.