转染人肿瘤坏死因子-α、白介素-2基因对肺癌细胞耐药基因MDR1、LRP表达的影响

Effects of huTNF-α and hIL-2 gene transfection on the expression of MDR1 and LRP genes in lung cancer cell lines

目的 研究转染人体肿瘤坏死因子 α(huTNF α)、白介素 2 (hIL 2 )基因对肺癌细胞耐药基因MDR1、LRP表达的影响 ,探讨基因治疗逆转肺癌多药耐药的可行性。方法 通过阳离子脂质体将克隆的huTNF α和hIL 2基因导入肺癌细胞系A5 49、GLC 82、H44 6、H460 ,经筛选阳性单克隆 ,用半定量RT PCR方法检测转染目的基因前后肺癌细胞系MDR1、LRP基因在mRNA水平的表达情况。结果 MDR1在A5 49、GLC 82、H44 6、H460 ,LRP在A5 49、GLC 82、H 460中均呈阳性表达 ;转染huTNF α目的基因后各肺癌细胞系MDR1、LRP基因的表达无影响 ,而转染hIL 2目的基因能够明显抑制A5 49、H44 6、H 460细胞系MDR1的表达。结论 MDR1、LRP基因在肺癌细胞系中的阳性表达与肺癌的固有耐药性有关 ;huTNF α、hIL 2目的基因能够在被转染细胞中获得表达 ,而且转染hIL 2目的基因能够明显抑制MDR1在A5 49、H44 6、H460的表达。该结果不仅为探讨肺癌多药耐药性的病理机制提供了一个新的线索 ,而且为基因治疗逆转肺癌的多药耐药性提供了一个新的实验依据。

Objective To study the effects of huTNF α and hIL 2 gene transfection on the expression of MDR1 and LRP genes in lung cancer cell lines. Methods huTNF α and hIL 2 gene plasmids were constructed and transfected into A549, GLC 82, H446 and H460 cells with lipofectinmin. Positive clones were screened out by G418. The expressions of MDR1 and LRP genes were detected at mRNA level by reverse transcription polymerase chain reaction (RT PCR) in the non transfected cells and the cloned cells.Results MDR1 gene was positive in A549, GLC 82, H446 and H460 cell lines, LRP gene was positive in A549, GLC 82 and H460 cell lines; The transfected cell lines expressed both huTNF α and hIL 2 gene, and the A549, H446 and H460 cell lines transfected with hIL 2 gene had no MDR1 expression at mRNA level compared with the non transfected ones. Conclusion MDR1 and LRP genes are expressed in lung cancer cell lines, which indicates the presence of intrinsic drug resistance before any form of therapy. MDR1 gene is not expressed in hIL 2 transfected cell lines, which demonstrates that hIL 2 gene modulates the MDR1 gene expression at mRNA level, and may reverse the multidrug resistance of lung cancer.