Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-20988

Winkler, J; Martin-Killias, P; Plückthun, A; Zangemeister-Wittke, U (2009). EpCAM-targeted delivery of nanocomplexed siRNA to tumor cells with designed ankyrin repeat proteins. Molecular Cancer Therapeutics, 8(9):2674-2683.

[img] PDF - Registered users only
1MB

View at publisher

Abstract

Specific delivery to tumors and efficient cellular uptake of nucleic acids remain major challenges for gene-targeted cancer therapies. Here we report the use of a designed ankyrin repeat protein (DARPin) specific for the epithelial cell adhesion molecule (EpCAM) as a carrier for small interfering RNA (siRNA) complementary to the bcl-2 mRNA. For charge complexation of the siRNA, the DARPin was fused to a truncated human protamine-1 sequence. To increase the cell binding affinity and the amount of siRNA delivered into cells, DARPin dimers were generated and used as fusion proteins with protamine. All proteins expressed well in Escherichia coli in soluble form, yet, to remove tightly bound bacterial nucleic acids, they were purified under denaturing conditions by immobilized metal ion affinity chromatography, followed by refolding. The fusion proteins were capable of complexing four to five siRNA molecules per protamine, and fully retained the binding specificity for EpCAM as shown on MCF-7 breast carcinoma cells. In contrast to unspecific LipofectAMINE transfection, down-regulation of antiapoptotic bcl-2 using fusion protein complexed siRNA was strictly dependent on EpCAM binding and internalization. Inhibition of bcl-2 expression facilitated tumor cell apoptosis as shown by increased sensitivity to the anticancer agent doxorubicin.

Citations

26 citations in Web of Science®
33 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

2 downloads since deposited on 29 Sep 2009
0 downloads since 12 months

Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Department of Biochemistry
07 Faculty of Science > Department of Biochemistry
DDC:570 Life sciences; biology
Language:English
Date:2009
Deposited On:29 Sep 2009 15:30
Last Modified:27 Nov 2013 22:30
Publisher:American Association for Cancer Research
ISSN:1535-7163
Publisher DOI:10.1158/1535-7163.MCT-09-0402
PubMed ID:19723880

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page