[关键词]
[摘要]
为了研究抗MDR1核酶逆转肿瘤细胞中P-gp介导的多重耐药性(MDR)的作用。方法： 首先，我们建立了单纯由P-gp介导的、20倍耐药的人Daudi淋巴瘤细胞的模型 Daudi/MDR20。同时我们将表达不同抗MDR1核酶的逆转录病毒载体（N2A+tRNA i met-196MDR1-Rz，N2A+tRNA i met -196MDR1-sRz 和 N2A+tRNA i met -iMDR1-sRz）转染到GP+envAM12细胞中进行包装，获得了高滴度的病毒［（1.1～2.5）×10 5 cfu/ml］。后者用于感染Daudi/MDR20。结果： 通过一系列分子生物学检测证实,携带3种核酶的逆转录病毒不但整合到DNA中，而且也高水平表达相应的核酶tRNA i met -iMDR1-sRz，tRNA i met -196MDR1-sRz 和tRNA i met -196MDR1-Rz。结果表明,tRNA i met -iMDR1-sRz和tRNAimet-196MDR1-sRz转导的Daudi/MDR20细胞完全逆转了对长春新碱的敏感性，并伴随着MDR1 mRNA和P-gp表达的阻断。结论： 逆转录病毒载体高效介导的抗MDR1核酶的基因转移能够完全逆转肿瘤细胞中P-gp依赖的MDR。
[Key word]
[Abstract]
In order to explore the reversal of the multidrug resistance(MDR) purely related to P-glycoprotein expression by using the anti-MDR1 ribozyme genes. Methods： Daudi human lymphoma cells 20-fold resistant to vincristine (VCR)(Daudi/MDR20) were developed. Three retroviral vectors highly expressing the anti-MDR1 ribozymes: 196MDR1-Rz, 196MDR1-sRz and iMDR1-sRz were also constructed and transfected into GP+envAM12 cells for packaging. The viral supernatants with high titers ［(1.1～2.5)×10 5 cfu/ml］ were used to infected Daudi/MDR20 cells. Results： The tRNAimet-iMDR1-sRz and tRNAimet-196MDR1-sRz-transduced Daudi/MDR20 cells effectively restored chemosensitivity to VCR and were accompanied by blocked expression of MDR1 mRNA and P-glycoprotein as well as overexpression of anti-MDR1-Rzs. Conclusion: The high level expressions of anti-MDR1 ribozymes mediated by retroviral vectors appear to have contributed to the efficinet reversal of P-gp-mediated MDR in tumor cells.
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[基金项目]
* 本课题受国家自然科学基金(39970831)资助
