转染血管内皮细胞生长因子受体基因的K562细胞在裸鼠体内生长的实验研究

The experimental study of transfected sFlt-Ig gene on K562 leukemia cell growth in nude mice

目的 观察人白血病细胞转染可溶性内皮细胞生长因子受体基因 (sFlt 1)后 ,对其在裸鼠体内生长的影响。方法 ①将内皮细胞生长因子受体 1(Flt 1)的配体结合区基因片断与免疫球蛋白重链的恒定区基因片断重组成Flt Ig融合基因 ,插入到pcDNA3质粒 ;②采用电穿孔方法转染K5 6 2细胞 ,经过筛选、克隆 ,用RT PCR检测Flt 1mRNA的表达 ;③将表达Flt Ig基因的细胞和转染对照载体的细胞分别给裸鼠移植 ,动态观察肿瘤的生长。结果 Flt Ig融合基因转染K5 6 2细胞后 ,获得 5株Flt IgmRNA表达阳性的细胞株 ,取一株扩增后移植给 6只裸鼠 ,移植后第 14,2 1和 2 8天实验组肿瘤的体积约为对照组的 1/2 ,明显小于对照组。结论 转染Flt Ig融合基因的K5 6 2细胞 ,在裸鼠体内生长受到明显抑制 ,这可能与转染后的肿瘤细胞表达可溶性Flt Ig蛋白 ,中和了肿瘤细胞分泌的内皮细胞生长因子 。

Objective To observe the influence of transfected soluble vascular endothelial growth factor (VEGF) receptor (sFlt 1) gene on K562 leukemia cell growth in vivo. Methods ①The binding region of VEGF receptor (Flt 1) ligand was combined with fragment of IgH stable region to construct Flt Ig fusion gene and insert into pcDNA3 vector. ②By using electroporation, the pcDNA3/Flt Ig was transfected into K562 leukemia cells, and selected by G418. Flt Ig mRNA expression was detected by RT PCR. ③ The transfected pcDNA3 /Flt Ig and pcDNA3 Ig K562 cells were respectively transplanted into nude mice and the tumor volume was dynamically measured. Results Five subclones of K562 cells with high expression of Flt Ig gene have been established, one of them was transplanted into 6 nude mice. The tumor volume of experimental mice was obviously smaller than that of control mice, about one half of the control group (P<0.05). Conclusion The growth of transfected pcDNA3/Flt Ig K562 cells was significantly inhibited. It is possible that soluble Flt Ig protein secreted from K562/Flt Ig cells neutralized VEGF produced from tumor cells, therefore inhibited the tumor angiogenesis.