Journal of Biomedicine and Biotechnology
Volume 2006 (2006), Article ID 71659, 15 pages
doi:10.1155/JBB/2006/71659
Abstract
RNA interference (RNAi) is a powerful method for specific gene
silencing which may also lead to promising novel therapeutic
strategies. It is mediated through small interfering RNAs (siRNAs)
which sequence-specifically trigger the cleavage and subsequent
degradation of their target mRNA. One critical factor is the
ability to deliver intact siRNAs into target cells/organs in vivo.
This review highlights the mechanism of RNAi and the guidelines
for the design of optimal siRNAs. It gives an overview of studies
based on the systemic or local application of naked siRNAs or the
use of various nonviral siRNA delivery systems. One promising
avenue is the the complexation of siRNAs with the polyethylenimine
(PEI), which efficiently stabilizes siRNAs and, upon systemic
administration, leads to the delivery of the intact siRNAs into
different organs. The antitumorigenic effects of
PEI/siRNA-mediated in vivo gene-targeting of tumor-relevant
proteins like in mouse tumor
xenograft models are described.