Quantitative measurement of delivery and gene silencing activities of siRNA polyplexes containing pyridylthiourea-grafted polyethylenimines.
Fiche publication
Date publication
mai 2014
Auteurs
Membres identifiés du Cancéropôle Est :
Dr DONTENWILL Monique, Dr FRISCH Benoit, Dr PINEL Sophie, Dr ZUBER Guy, Dr KICHLER Antoine
Tous les auteurs :
Pinel S, Aman E, Erblang F, Dietrich J, Frisch B, Sirman J, Kichler A, Sibler AP, Dontenwill M, Schaffner F, Zuber G
Lien Pubmed
Résumé
The activity of synthetic interfering nucleic acids (siRNAs) relies on the capacity of delivery systems to efficiently transport nucleic acids into the cytosol of target cells. The pyridylthiourea-grafted 25KDa polyethylenimine (piPEI) is an excellent carrier for siRNA delivery into cells and it was extensively investigated in this report. Quantification of the siRNA-mediated gene silencing efficiency indicated that the piPEI specific delivery activity at the cell level may be measured and appears relatively constant in various cell lines. Delivery experiments assaying inhibitors of various entry pathways or concanamycin A, an inhibitor of the H(+)/ATPase vacuolar pump showed that the piPEI/siRNA polyplexes did not require any specific entry mode but strongly relied on vacuolar acidification for functional siRNA delivery. Next, piPEI polyplexes containing a siRNA targeting the transcription factor HIF-1alpha, known to be involved in tumor progression, were locally injected into mice xenografted with a human glioblastoma. A 55% reduction of the level of the target mRNA was observed at doses comparable to those used in vitro when the piPEI delivery activity was calculated per cell. Altogether, our study underscores the usefulness of "simple"/rough cationic polymers for siRNA delivery despite their intrinsic limitations. The study underscores as well as that bottom-up strategies make sense. The in vitro experiments can precede in vivo administration and be of high value for selection of the carrier with enhanced specific delivery activity and parallel other research aiming at improving synthetic delivery systems for resilience in the blood and for enhanced tissue-targeting capacity.
Référence
J Control Release. 2014 May 28;182:1-12