Background: Gain-of-function of fibroblast growth factor receptor 3 (FGFR3) is involved in the pathogenesis of
many tumors. More and more studies have focused on the potential usage of therapeutic single-chain Fv
(ScFv) antibodies against FGFR3. RNA interference (RNAi) has been considered as a promising therapeutic
method against cancer. A tool which can deliver small interference RNAs (siRNAs) into FGFR3 positive cancer
cells is very promising for anti-tumor therapy.
Results: In this study, a novel fusion protein R3P, which consists of FGFR3-ScFv and protamine, was generated in
Escherichia coli
by inclusion body expression strategy and Ni-NTA chromatography. Its yield reached 10 mg per
liter of bacterial culture and its purity was shown to be higher than 95%. 1 μg of R3P could efficiently bind to
about 2.5 pmol siRNAs and deliver siRNAs into FGFR3 positive RT112 and K562 cells. Annexin V staining
results showed that R3P can deliver the amplified breast cancer 1 (AIB1) siRNAs to induce RT112 cell apoptosis.
Conclusion: These results indicated that R3P was a promising carrier tool to deliver siRNAs into FGFR3 positive
cancer cells and to exert anti-tumor effect.