[Magnetic liposome mediated shRNA specifically suppresses the growth of non-small cell lung cancer in vitro and in vivo].

OBJECTIVE

To evaluate the inhibition of shRNA mediated by magnetic liposome in the growth of non-small cell lung cancer (NSCLC) under the interference of magnetic field in vitro and in vivo and explore the effects of magnetic field on the efficiency of magnetofection.

METHODS

The plasmid of pGFPshIGF-1R was constructed for expressing GFP and shRNA against IGF-1R. CombiMAG as superparamagnetic iron oxide nanoparticles (SPIONs) and Lipofectamine2000 as cationic liposome comprised the magnetic liposome. pGFPshIGF-1R was transferred into A549 cells by magnetofection under a series of interaction durations and intensity of external magnetic fields. pGFPshIGF-1R was delivered into A549 cells in vitro and injected intravenously into the tumor-bearing mice every 48 h for four doses in vivo by way of lipofection or magnetofection. The magnetofection efficiency was analyzed by cytometry and the potency of IGF-1R knockdown by Western blot. At Week 3 after the 4th injection, the mice were sacrificed and the tumors removed and weighed. The tumor inhibition rate was calculated.

RESULTS

The interaction durations and intensity of magnetic field could influence the magnetofection efficiency. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1% ± 6.0% and by liposomal magnetofection by 85.1% ± 3.0%. In vivo, pGFPshIGF-1R delivered by both lipofection and magnetofection significantly inhibited the tumor growth by 41.3% (P < 0.01) and 65.2% (P < 0.01).

CONCLUSIONS

Based on magnetic liposome as gene vectors, magnetofection may become a promising targeted therapy for lung cancer. And the transfection efficiency is influenced by magnetic field.