人脑胶质瘤细胞多药耐药性的形成及其耐药特性的研究

目的探讨人脑胶质瘤细胞多药耐药性（ＭＤＲ）的形成规律及其耐药特性。方法采用长春新碱（ＶＣＲ）在体外对人脑胶质瘤ＢＴ３２５细胞持续诱导获得了表现为ＭＤＲ特征的人脑胶质瘤细胞模型．以ＭＴＴ法测定胶质瘤细胞增殖，透射电镜行超微结构研究，通过流式细胞仪，检测培养的胶质瘤细胞与３２例术后胶质瘤新鲜组织标本中Ｐ－糖蛋白的表达。结果耐药的胶质瘤细胞ＢＴ３２５／ＶＣＲ对长春新碱的耐受程度为其亲本细胞的２４倍，对阿霉素、威猛交叉耐药，对５－氟脲嘧啶敏感。透射电镜下见ＢＴ３２５／ＶＣＲ细胞常染色质明显，线粒体丰富，粗面内质网增多。研究表明ＢＴ３２５／ＶＣＲ表现为Ｐ－糖蛋白介导的典型ＭＤＲ。胶质瘤新鲜组织标本中，Ｐ－糖蛋白表达阳性率为３７５％（１２／３２），同肿瘤的恶性程度呈正相关（Ｐ＜０．０１）。结论长春新碱能够诱导人脑胶质瘤细胞产生Ｐ－糖蛋白介导的典型ＭＤＲ。胶质瘤中多药耐药基因产物Ｐ－糖蛋白表达的阳性率同肿瘤的恶性程度呈正相关。应用流式细胞仅能早期发现耐药细胞，具有临床推广价值。

Establishment and charaterization of multidurg resistance in human glioma cell line and surgical glioma specimens

Objective To try to explain the machanims and characteristics of multidrug resistance in humanglioma and to investigate the clinical significance of predicting the responsiveness of individual glioma cells to chemotherapeutic agents. Methods Multidrug resistant glioma subline was isolated from BT325 human glioma cell line under selection pressure of vincristine. The human glioma cells growth was measured by MTT assay in vitro. Electronictransmission microscope was used to examine the fine structure of cultured human glioma cells. The expression of glycoprotein in cultured human glioma cell line and 32 surgical glioma specimens was tested by flow cytometer with Pglycoprotein monoclonal antibody JSB1. Results The multidrug resistant glioma suhline-BT325/VCR was resisted tovincristine. 24 times as high as that of BT325 human glioma cell line. and also significantly resisted to adriamycin andteniposide. but sensitived to fluracil. Under electronic transmission microscope,the BT325/VCR subline wasdocumented to be rich in mitochrodria, rough endoplasmic reticulum and euchromatin. The BT25/VCR cell lineshowed a overexpression of P-glycoprotein and P-glycoprotein medicated typical multidrug resistance phenotype. In 32surgical glioma specimens, there was no evidence of complete absense of P-glycoprotein, with a definifion of morethan 37.5% (12/32) of P-glycoprotein as positive. Significant positive correlation between the positive rate of P-glycoprotein expression and the degree of tumour malignancy were also found. Conclusions Vincristine could induce P-glycoprotein mediated typical multidrug resistance. Multidrug resistance naturally occurred in many human gliomas,and well correlated between the positive expression rate and the malignancy in glioma. The flow cytometer assay for Pglycoprotein detection might be preferable to determinations of multidrug resistant glioma cells. thereby be beneficialfor the design of treatment protocols.