Abstract: MDR1 express product P-glycoprotein was detected by immunocytochemical method and flowcytometry. The cytotoxicity and multidrug resistance reversion effect of tea polyphenol was examined by MTT assay in MCF-7 and MCF-7/Adr carcinoma cell lines, and compared with Pgp inhibitor quinidine. The Pgp expression of MCF-7/Adr was strongly positive, the positive rate was 15%; the Pgp expression of MCF-7 was negative, the positive rate was 1.8%. IC50 of tea polyphenol to MCF-7 and MCF-7/Adr is 115.2μg/mL and 207.6μg/mL respectively. IC50 of quinidine to MCF-7 and MCF-7/Adr is 129.8μmol/L(42.1μg/mL)and 94.1μmol/L(30.5μg/mL)respectively. Tea polyphenol and quinidine changed little toxicity of adriamycin to MCF-7, but tea polyphenol and quinidine improved the sensitivity of MCF-7Adr to adriamycin significantly. Immunocytochemistry and flow cytometry can detect P-glycoprotein expression level qualitatively and quantitatively. Tea polyphenol is not only an anti-tumor agent, but also a multidrug resistant modulator similar as quinidine. Tea polyphenol is advantageous for its little toxicity in tumor treatment.

Key words: immunocytochemistry, flowcytometry, tea polyphenol, quinidine, MTT, P-glycoprotein

摘要： 用免疫组化法和流式细胞仪对肿瘤细胞系MCF-7和MCF-7/Adr的P-糖蛋白表达水平进行定性定量研究。用噻唑蓝比色法(MTT)研究茶多酚的细胞毒性及其对耐药性的逆转作用，并与Pgp抑制剂——奎尼定进行了比较。免疫组化法检测P-糖蛋白表达水平，MCF-7/Adr呈强阳性，而MCF-7呈阴性；流式细胞仪定量检测结果MCF-7/Adr细胞系细胞阳性率为15%，MCF-7细胞系细胞阳性率为1.8%。MCF-7/Adr细胞系存在Pgp的过度表达。噻唑蓝比色法(MTT)检测结果茶多酚、奎尼定的加入对阿霉素对MCF-7的细胞毒性几乎没有影响。而茶多酚、奎尼定的加入明显增加了MCF-7/Adr对阿霉素的敏感性。免疫组化与流式细胞技术结合，可用于肿瘤细胞系P-糖蛋白表达水平的定性定量检测。茶多酚不仅具有一定的抗癌活性，还与奎尼定一样具有多药耐药性逆转作用。

关键词: 免疫组化, 流式细胞仪, 茶多酚, 奎尼定, 噻唑蓝比色法, P-糖蛋白