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@INPROCEEDINGS{Dahmen:841326,
author = {Dahmen, Volker and Kriehuber, Ralf},
title = {{C}ytotoxic effects and specific gene expression
alterations induced by {I}-125-labelled {T}riplex-forming
oligonucleotides},
reportid = {FZJ-2017-08411},
year = {2011},
abstract = {Triplex-forming oligonucleotides (TFOs) are able to bind
DNA in a sequence specific manner and are a promising tool
to manipulate genes or gene regulatory units in a cellular
environment. TFOs posses also a potential for radiotherapy
e.g. as a carrier for Alpha- or Auger Electron-Emitter (AEE)
to target specific DNA sequences in tumour cells. We
established a method for the effective labelling of TFOs
with the AEE iodine-125 (I-125) and studied the influence of
labelled TFO with regard to cell survival and appearance of
DNA Double-Strand-Breaks (DSB). Furthermore the ability of
TFOs to alter gene expression of targeted genes was
examined.TFOs specific for the genes BCL2, GAPDH and BRCA1
were designed employing TFO Target Sequence Search (Univ. of
Texas). TFO labelling with I-125 was performed using the
primer extension method. Formation of DNA triplexes was
visualized with MS Imaging Plates employing a FLA-5000
Imaging System (Fujifilm) and electrophoretic mobility shift
assay. Cell survival and DNA DSB frequency in SCL-II cells
after transfection with a I-125-labelled Multi-Binding-Site
(MBS) TFO (~ 7000 binding sites) were analyzed with the
Colony-Forming Assay respectively with the 53BP1-Foci assay.
SCL-II cells transfected with TFOs binding to single DNA
targets in specific genes were analyzed for gene expression
alterations of the targeted genes with qRT-PCR.The MBS
I-125-TFO transfected SCL-II cells showed a reduction of
colony forming ability of ~ 45 $\%$ and the number of
53BP1-Foci was ~ 1.5-times increased when compared to
sham-transfected negative control. The transfection with
single binding site I-125-TFOs lead to a 1.7-times increased
expression for BCL2 and a 0.5-times reduced expression for
GAPDH. No altered gene expression was detected for
BRCA1.I-125-labelled MBS TFOs induce a pronounced cytotoxic
effect in SCL-II cells. Single gene targeting TFOs alter
gene expression in a gene-specific manner.Funded by
Kompetenzverbund Strahlenforschung (KVSF), Bundesministerium
für Bildung und Forschung (BMBF), Project No.: 02NUK005A},
month = {Aug},
date = {2011-08-24},
organization = {7th International Symposium on
Physical, Molecular, Cellular and
Medical Aspects of Auger, Jülich
(Germany), 24 Aug 2011 - 26 Aug 2011},
subtyp = {After Call},
cin = {S-US},
cid = {I:(DE-Juel1)S-US-20090406},
pnm = {899 - ohne Topic (POF3-899)},
pid = {G:(DE-HGF)POF3-899},
typ = {PUB:(DE-HGF)24},
url = {https://juser.fz-juelich.de/record/841326},
}