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

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: (1) The 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. (2) By 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.