三氧化二砷对肺腺癌耐药细胞A549/R耐药性的影响

Effect of arsenic trioxide on drug resistance in drug-resistance human lung adenocarcinoma cell line A549/R

目的探讨三氧化二砷(As2O3)对肺腺癌耐药细胞株(A549/R)耐药性的影响及调节机制。方法采用四甲基偶氮唑蓝(MTT)法及荧光分光光度计分别检测As2O3的细胞毒性、A549/R细胞的药敏性及As2O3作用前后细胞内药浓的变化;采用生物化学方法检测A549/R细胞谷胱甘肽-S-转移酶(GSTs)活性,观察非细胞毒性剂量(0.150μmol/L)和低毒剂量(0.375μmol/L)的As2O3对肺腺癌A549/R耐药细胞内GSTs活性的影响;以逆转录-聚合酶链反应(RT-PCR)方法同步检测GST-π、多药耐药性相关蛋白(MRP)mRNA表达水平及变化。结果As2O3在非细胞毒剂量下可显著降低耐药细胞对ADM的IC50值;As2O3作用后A549/R细胞内ADM积聚增加,其逆转倍数为2.3倍;A549/R细胞中GSTs活性增高,GST-π及MRP mRNA呈过表达状态;不同浓度的As2O3可降低GSTs活性;同时可下调GST-π、MRP mRNA的表达水平。结论As2O3可通过下调GST-π、MRP mRNA的表达而部分逆转A549/R细胞对ADM耐药。

Objective To investigate the effect of arsenic trioxide （As2O3） on drug resistance in drug-resistance human lung adenocarcinoma cell line A549/R and its possible mechanism. Methods Cytotoxicity of As2O3 and the sensibility to adriamycin （ADM） in A549/R cell line were studied by using MTT assay. The concentration of intracellular ADM was detected by spectrofluorometry. After A549/R cells were treated with As2O3 at the concentration of 0.15 and 0. 375μmol/L in combination with ADM, the glutathione-s-transferase （GSTs） activity was measured by biochemical methods. The expression of GST-π mRNA, MDR related protein （MRP） mRNA was assessed by reverse transcription-polymerase chain reaction （RT-PCR） at the same time. Results The noncytotoxic dose of As2O3 could obviously reduce the medium inhibition concentration （ IC50 ） of ADM in A549/R cell. After treatment with As2O3, the intracellular accumulation of ADM in A549/R cell line was significantly increased with the reversal ratio of 2.3 as compared to its parental cell line. The GSTs activities in A549/R cell line were higher than in parental cell line A549/S. A549/R cell line had overexpression of GST-π mRNA and MRP mRNA as compared to its parental cell line. The different doses of As2O3 could obviously reduce the GSTs activity and significantly down-regulate the expression of GST-π mRNA and MRP mRNA in A549/R cells. Conclrsion As2O3 could partly reverse the ADM resistance of A549/R cell line by down-regulation of GST-π and MRP mRNA.