Inhibition of VEGF expression in A431 and MDA-MB-231 tumour cells by cationic lipid-mediated siRNA delivery

Abstract

In order to promote siRNA transfer in tumour cells, we used an original cationic lipid, synthesized in our laboratory, dimethyl-hydroxyethyl-aminopropane-carbamoyl-cholesterol (DMHAPC-Chol). Liposomes were prepared from this lipid and dioleoylphosphatidylethanolamine (DOPE) in equimolar proportion. Its transfecting capacity was evaluated using ELISA, cell cytometry, and RT-PCR in estimating the silencing effect of VEGF siRNA. This liposome efficiently delivered VEGF siRNA in two human cancer cell lines abundantly secreting VEGF, A431 and MDA-MB-231. Results showed that 50 nM of VEGF siRNA carried by DMHAPC-Chol/DOPE liposomes already silenced more than 90% of VEGF in these cells. A comparative study with two commercial carriers indicated that the inhibition induced by VEGF siRNA transported by cationic DMHAPC-Chol/DOPE liposomes was comparable to that induced by INTERFERin and better than lipofectamine 2000. Moreover, a transfection by a GFP plasmid followed by a GFP siRNA showed that DMHAPC-Chol/DOPE liposomes compared to lipofectamine were less efficient for plasmid but better for siRNA transport. Following one of our previous works concerning cell delivery of plasmid (), the main interest of results presented here resides in the double potential of DMHAPC-Chol/DOPE liposomes to deliver little-sized siRNA as well as large nucleic acids in cells.

Keywords::

• DMHAPC-Chol cationic liposomes
• small interfering RNA
• vascular endothelial growth factor
• cancer cells

Acknowledgements

We would like to thank Dr Vanessa Castejon for the reading of the manuscript, Angèle Travadel for the figure processing and Stéphane Chambris for technical assistance in cell culture.

Declaration of interest

This work was supported by a ‘‘Bonus pour la Qualité de Recherche’’ of the Université Paris 13 and a grant of the Ligue Contre le Cancer to whom the authors are grateful.