BSO逆转人肺腺癌细胞株多药耐药性的实验研究

目的研究谷胱甘肽(GSH)合成酶抑制剂——BSO对人肺腺癌多药耐药细胞株A549DDP细胞内GSH含量影响;探讨BSO逆转多药耐药(MDR)作用机制及逆转效果。方法GSH还原酶循环法测定BSO对细胞内GSH含量的影响。MTT比色法测定经BSO预处理后顺氯氨铂(DDP)、阿霉素(ADM)对细胞50%抑制浓度(IC50)的影响。流式细胞仪检测BSO对MDR细胞内柔红霉素(DNR)荧光强度的影响。结果耐药细胞A549DDP细胞内GSH含量较人肺腺癌A549细胞内GSH含量明显增高。BSO在一定浓度范围内(50～200μmol·L-1)对A549细胞和耐药细胞A549DDP无明显细胞毒性作用(抑制率均小于10%)。BSO呈剂量依赖性非线性抑制细胞内GSH的合成,其对MDR细胞内GSH合成影响较为显著,而对A549细胞内GSH合成影响较小。BSO在一定浓度范围内能降低DDP、ADM对A549DDP细胞的IC50,而对A549细胞的IC50无明显影响。A549DDP细胞内DNR荧光强度较A549细胞显著降低,能不同程度提高A549DDP细胞内柔红霉素荧光强度,均较未处理组显著提高;与未经BSO处理的A549细胞比较,细胞内荧光强度轻度增高,但统计学上无显著性差异。结论BSO能有效逆转A549DDP细胞的MDR,其机制与降低MDR细胞内GSH含量有关。

Study on the reversion of multi - drug resistance in human lung adenocarcinoma cell line with BSO

Objective To investigate the effects of BSO (buthionine sulfoximine,a glutathione synthase inhibitor),on the modulation of intracellular glutathione (GSH),and on the multidrug resistance reversion in human lung adenocarcinoma cell line A_~549 /DDP.Methods DDP-resistant A_~549 (A_~549 /DDP) cells were treated with BSO in different acceptable concentrations in vitro.The intracellular GSH content was measured by glutathione reductase recycling assay;the cytotoxicity of DDP and ADM in A_~549 /DDP cells was determined by MTT assay;flow cyctometry assay was performed to study the changes of fluorescent intensity of DNR accumulation in A_~549 /DDP cells after pretreatment with BSO.Results The content of GSH in A_~549 /DDP cells was significantly higher than that in A_~549 cells; the synthesis of GSH in A_~549 /DDP could be potently inhibited by BSO treatment. The IC_~50 of DDP and ADM in A_~549 /DDP cells were decreased after pretreatment with BSO in a dose-dependent fashion and non-linear manner, but BSO had no such effects on A_~549 cells.The fluorescent intensity of DNR accumulation in the A_~549 /DDP cells, obviously lower than in A_~549 cells,was remarkably increased after pretreatment with BSO.Conclusion BSO is an effective MDR reversion agent in vitro.Its reversal mechanism is associated with the decrease of intracellular GSH content,which might help increase the intracellular accumulation of anticancer drugs,as DNR for example.