摘要
采用递增顺铂（ＤＤＰ）浓度的方法，体外连续培养建成一株耐ＤＤＰ的人肺腺癌细胞系Ａ（５４９）ＤＤＰ，耐ＤＤＰ为亲代Ａ（５４９）的２４．４倍。在无ＤＤＰ的培养基中培养５月余，其耐药性仍稳定。Ａ（５４９）ＤＤＰ细胞内谷胱甘肽（ＧＳＨ）水平显著高于亲代细胞（Ｐ＜０．０１）。ＢＳＯ耗竭细胞内ＧＳＨ后，Ａ（５４９）ＤＤＰ细胞对ＤＤＰ敏感性增加５倍，ＢＳＯ对亲代Ａ（５４９）细胞无增敏作用，Ａ（５４９）ＤＤＰ细胞ＧＳＴ酶同功酶ＧＳＴ—π含量较Ａ（５４９）高１．６倍，却无ＧＳＴ基因扩增，表明ＧＳＨ／ＧＳＴ解毒系统参与Ａ（５４９）ＤＤＰ耐药性的产生。实验结果亦示Ａ（５４９）ＤＤＰ与卡铂及氨甲喋呤间存在交叉耐药，而与易产生ＭＤＲ或ａｔＭＤＲ之ＡＤＭ、ＶＣＲ、ＶＰ－１６、ＶＭ－２６无交叉耐药，Ａ（５４９）细胞无Ｐ－糖蛋白（Ｐ－ｇｐ）表达，Ｓｏｕｔｈｅｒｎｂｌｏｔ研究Ａ（５４９）ＤＤＰ无ｍｄｒｌＴｏｐｏⅡ基因扩增，提示Ａ（４５９）ＤＤＰ细胞系与ＭＤＲ及ａｔ－ＭＤＲ无交叉耐药。
In order to study the mechanisms of resistance to cisplatin (DDP) and to look for a way of overcoming the resistance, we developed a human lung adenocarcinoma cell line (A(549)DDP) by continuously exposing cells to gradually increasing dose of DDP for a duration of 8 months. The resistant phenotype of the A(549)DDP cell line was stable for more than 5 months in the absence of drug. The A(549)DDP cell line is 24. 4-fold resistant to DDP than it's parent cell line (A(54)) as tested at IC(50) with MTT assay. Cellular glutathione (GSH) content increased significantly in the A(549)DDP cell line (P<0. 01). D. L-buthionine-S R-sulphoximine (BSO) was used to analyse the role of GSH in the mechanism of resistance to DDP. Pretreatment with BSO (50μm,48h, GSH exhausted and not being detectable) increased the DDP-induced cytotoxiCity 5-fold in A(549)DDP but no similar change was noted in A(549). Measuring glutathione-S-transferase π(GSH-π) content by cell ELISA we found that it was approximately 1. 6-fold higher in the resistant cell with no evidence of GST gene amplificantion. The A(549)DDP Cell line Was remarkably cross-resistant to carboplatin and MTX, but not to ADM, VP-16, and VM-26, etc. The results failed to show evidence of mdrl,TopeⅡ gene amplification nor P-glycoprotein overexpression. It is suggested that the GSH/GST detoxifying systems may play an important role in the resistant phenotype of A(549)DDP and that the mechanisms of DDP-resistance were not related with mdr in A(549)DDP cell line.
出处
《中国肿瘤临床》
CAS
CSCD
北大核心
1995年第8期582-587,共6页
Chinese Journal of Clinical Oncology
基金
国家自然科学基金
