MCF-7细胞瞬时基因表达转染模式的建立

THE CONSTRUCTION OF TRANSIENT GENE EXPRESSION TRANSFECTION SYSTEM IN MCF-7 CELLS

目的 建立一种高效、简便、低毒、价廉的瞬时基因表达细胞转染模式。 方法 选择人乳腺癌细胞 系MCF 7,采用Polyethylenimine(PEI)作为转染剂,对细胞密度、载体DNA量、PEI氮与DNA磷的比率(PEI N∶DNA P) 以及PEI DNA混合物与细胞共存的无血清培养时间等对转染效率的影响进行了比较分析。 结果 转染时的24 孔板每孔接种的细胞以2×105为宜,PEI N∶DNA P的最优比率不是固定的,它与转染时DNA的量有关,每孔转染1 μgDNA时其最优PEI N∶DNA P比率为33∶1左右,而每孔转染4μgDNA时其最优PEI N∶DNA P比率为9∶1左右。 另外,PEI DNA混合物与细胞共存的无血清培养时间至少需要3h,最佳时间为5～7h。 结论 利用转染剂PEI, 控制合适的细胞密度、DNA质量、PEI N∶DNA P比率和无血清培养的时间,可成为一种高效、简便、低毒、价廉的瞬时 基因表达的细胞转染模式。

Objective To establish an efficient, simple, low cytotoxicity and cheap transfaction system. Methods We have used the cationic polymer polyethylenimine(PEI) to study transient transfection in MCF-7 cells by testing different conditions, including cell concentrations, DNA concentrations, the ratio of PEI nitrogen to DNA phosphate(PEI-N∶DNA-P) and the time of cells grown in serum-free culture together with PEI-DNA complex. Results The optimized cell concentrations were 2×10 5 cells seeded per well in 24-well dishes 18-24?h before transfection. The DNA concentrations and ratio of PEI-N∶DNA-P are very important for optimal transfection and they affect each other. For 1?μg DNA per well, the optimal PEI-N∶DNA-P is about 33∶1, however, as for 4?μg DNA, it is 9∶1. The best time of cells grown in serum-free culture together with PEI-DNA complex is about 5-7?h.Conclusion With optimized conditions, we can establish an efficient, simple, low cytotoxicity and cheap transfection system by using PEI.