大蒜素联合红霉素逆转K562／A02细胞多药耐药机理的研究

本研究比较大蒜素、红霉素单用及两药联用逆转K562/A02细胞多药耐药的效果并探讨相关机制,为临床采用低剂量药物联合逆转多药耐药提供实验依据。采用MTT法比较非细胞毒剂量大蒜素、红霉素单用及两药联用对K562/A02细胞多药耐药的逆转效果差异及毒性叠加情况,RT-PCR检测K562/A02细胞mdr1基因表达情况,免疫组织化学法检测P-gp表达情况,流式细胞仪检测细胞内阿霉素平均荧光强度。结果表明:大蒜素1、4、8 mg/L对K562/A02细胞的逆转倍数分别为1.80、2.26、2.82,呈浓度依赖性。红霉素60 mg/L的逆转倍数为2.20,大蒜素与红霉素联用的逆转倍数为4.94,无毒性叠加作用。大蒜素与红霉素单独作用均可下调耐药株mdr1、P-gp的表达,增加胞内阿霉素浓度,而两药联合作用时上述作用明显增强。结论非细胞毒剂量的大蒜素和红霉素联合应用逆转K562/A02细胞多药耐药效果明显强于单用,且无毒性叠加作用。联合用药在下调mdr1/P-gp表达、增加细胞内化疗药物浓度方面具有协同作用。

Mechanism Reversing MDR of K562/A02 by Garlicin Combined with Erythromycin

This study was purposed to investigate the reversal effect of garlicin,erythromycin alone or combination of garlicin with erythromycin on K562/A02 and its possible mechanisms,so as to provide experimental evidence for combination reversal strategies.Cytotoxicity and the reversal effect of garlicin and erythromycin alone and combination of this two drugs were detected by MTT assay.The expression of mdr1 gene of K562/A02 was detected by RT-PCR.The P-gp expression was observed by immunohistochemical technique.Flow cytometry was used to detect intracellular drug concentration.The results showed that the sensitivity of K562/A02 to ADM increased somewhat in the presence of 1,4,8 mg/L garlicin,the reversal multiples at 1,4,8 mg/L garlicin were 1.80,2.26 and 2.82 respectively in dose-dependent manner.The reversal multiple of erythromycin 60 mg/L was 2.20.The combination of two drugs could increase the reversal multiple to 4.94,and had no more cytotoxin.Both of garlicin and erythromycin alone could down-regulate the expression of mdr1 and P-gp of K562/A02 and elevate the intracellular concentrations of ADM in K562/A02 cells.Meanwhile,the effects described above were enhanced when garlicin was combined with erythromycin.It is concluded that the garlicin and erythromycin alone under cytotoxic dose both can reverse the MDR of K562/A02 cells effectively.Moreover,the combination of two drugs is more effective than that in use alone.Combination of these two drugs shows synergistic actions in re-gulating the expression of mdr1/P-gp and increasing the intracellular concentrations of ADM in K562/A02 cell.