TY  - CONF
AU  - Dahmen, Volker
AU  - Kriehuber, Ralf
TI  - Cytotoxic effects and specific gene expression alterations induced by I-125-labelled Triplex-forming oligonucleotides
M1  - FZJ-2017-08411
PY  - 2011
AB  - 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
T2  - 7th International Symposium on Physical, Molecular, Cellular and Medical Aspects of Auger
CY  - 24 Aug 2011 - 26 Aug 2011, Jülich (Germany)
Y2  - 24 Aug 2011 - 26 Aug 2011
M2  - Jülich, Germany
LB  - PUB:(DE-HGF)24
UR  - https://juser.fz-juelich.de/record/841326
ER  -