  A Trojan-horse strategy for cancer therapy employing tumor-tropic mesenchymal
stem cells transfected with a non-viral nanovector is here presented. In this
sense, ultrasound-responsive mesoporous silica nanoparticles were coated with a
polycation (using two different molecular weights), providing them with gene
transfection capabilities that were evaluated using two different plasmids.
First, the expression of Green Fluorescent Protein was analyzed in
Decidua-derived Mesenchymal Stem Cells after incubation with the silica
nanoparticles. The most successful nanoparticle was then employed to induce the
expression of two suicide genes: cytosine deaminase and uracil phosphoribosyl
transferase, which allow the cells to convert a non-toxic pro-drug
(5-fluorocytosine) into a toxic drug (5-Fluorouridine monophosphate). The
effect of the production of the toxic final product was also evaluated in a
cancer cell line (NMU cells) co-cultured with the transfected vehicle cells,
Decidua-derived Mesenchymal Stem Cells.
