Efficient Nanoparticle Mediated Gene Silencing in Human Colon Cancer Cells

MicroRNA (miRNA) triggered gene silencing provided a new therapeutic approach to overcome various diseases, but the major obstacle of such an approach is how to ensure minimal toxicity and effective delivery of miRNA to target cells. In the present study, we formulated anti-miR-222 loaded poly(D, L-lactide-co-glycolic acid) (PLGA) nanoparticles, which raised intracellular gene silencing against p27 and triggered apoptosis in human colon cancer cells (HCT-116 cells). We compared PLGA nanoparticle based transfections with commercially available transfection reagents (X-treme) mediated transfection, and found that nanoparticle based transfection efficiency is very high (similar to 85%) and is comparable to commercial reagents mediated transfections in HCT-116 cells. Our findings also show that the anti-miR-222 loaded PLGA nanoparticles had minimal toxicity with almost 87% of cells being viable 24 h post-transfection, while X-treme based transfections resulted in only 71% viable cells. Furthermore, PLGA nanoparticles obviously accumulated in tumor cell surfaces after transfection, indicating that the PLGA nanopartilcles contribute to cellular uptake of miRNA and significantly enhance the treatment effect of miR-222 by inducing apoptosis. Therefore, PLGA nanoparticle based transfection could be used for efficient anti-miR-222 transfection to cancer cells. The results demonstrated that PLGA nanoparticles could be promising non-viral vectors for gene delivery.