Download the full-sized PDF of Synthesis and evaluation of an [18F]-labelled antisense oligonucleotide as an imaging probe to measure cellular response to radiation therapyDownload the full-sized PDF


Download  |  Analytics

Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Faculty of Graduate Studies and Research


This file is not currently in any collections.

Synthesis and evaluation of an [18F]-labelled antisense oligonucleotide as an imaging probe to measure cellular response to radiation therapy Open Access


Other title
Type of item
Degree grantor
University of Alberta
Author or creator
Koslowsky, Ingrid L
Supervisor and department
Mercer, John (Medicine)
Examining committee member and department
Suresh, Mavanur (Pharmacy & Pharmaceutical Sciences)
Lavasanifar, Afsaneh (Pharmacy & Pharmaceutical Sciences)
Mercer, John (Medicine)
Adam, Michael (Chemistry, University of British Columbia)
McQuarrie, Steve (Medicine)
Murray, David (Medicine)
Faculty of Pharmacy and Pharmaceutical Sciences

Date accepted
Graduation date
Doctor of Philosophy
Degree level
Antisense oligodeoxynucleotides (asODNs) show strong binding and high selectivity and can be constructed to recognize specific cellular targets such as gene regulated mRNA. Radiolabelled asODNs have the potential to image gene expression through mRNA targeting and could be a valuable tool in the early assessment of outcome to cancer treatment. We have explored the potential of in vivo imaging of p21 gene expression, using fluorine-18 labelled asODNs ([18F]asODNs) and in vitro techniques, recognizing the relationship between the expression of this gene and resistance of cancer cells to radiation therapy. Radiolabelling of fully phosphorothioated, 20-mer ODNs was performed using the [18F]-labelled prosthetic group, 4-N-[18F]fluorobenzyl-2-bromoacetamide ([18F]FBBA). [18F]FBBA was first synthesized in an automated synthesis unit, resulting in a modest radiochemical yield. Methods to improve the yield were investigated using a metal catalyst-assisted borohydride exchange resin. Alkylation of [18F]FBBA to ODN resulted in radiochemical yields of 40%. Cellular uptake and retention studies were performed in human carcinoma cells expressing p21+/+ (HCT116) and the p21 knock-out cell line, 80S4, using both [18F]-labelled antisense and random sequence ODNs. Nonradioactive FBBA-labelled ODNs were used to evaluate the antisense effectiveness and distribution of the FBBA-modified ODNs. In vitro studies demonstrated that FBBA did not interfere with the antisense effect of ODNs against p21 mRNA; however, the probes required a transfection agent to observe an antisense effect. Cell fractionation studies with [18F]ODNs revealed increasing accumulation of liposome-transfected [18F]asODN in the cytoplasm of HCT116 cells over time. A biocompatible spermine-grafted block copolymer (SP) was subsequently evaluated as a potential vector to improve the delivery of [18F]asODN into cells. SP was shown to direct [F]-labelled ODNs to the cytoplasm, whereas naked [F]ODNs remained sequestered in vesicles, and liposome-transfected [F]ODNs localized mostly in the nucleus. Selective uptake and retention of [18F]asODN was observed in p21+/+ cells only when the probe was transfected with SP. Based on these studies, it can be concluded that [18F]asODNs have the potential to image gene expression, however the focus may need to be directed to find an appropriate vector which can rapidly deliver [18F]-labelled asODNs to the target tissue in vivo.
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 1738748
Last modified: 2015:10:12 19:59:13-06:00
Filename: Koslowsky_Ingrid_Fall 2010.pdf
Original checksum: d47e922f997f5871d7b0437407e27a7b
Well formed: false
Valid: false
Status message: Invalid page tree node offset=491837
Status message: Unexpected error in findFonts java.lang.ClassCastException: edu.harvard.hul.ois.jhove.module.pdf.PdfSimpleObject cannot be cast to edu.harvard.hul.ois.jhove.module.pdf.PdfDictionary offset=3258
Status message: Invalid Annotation list offset=1682002
Status message: Outlines contain recursive references.
File title: Synthesis and evaluation of an [18F]-labelled antisense oligonucleotide as an imaging probe to measure cellular response to ra�������������������������������������������������������������������������������������������������������������������������...
Activity of users you follow
User Activity Date