کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5507806 | 1400350 | 2017 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Modulation of topoisomerase IIα expression and chemosensitivity through targeted inhibition of NF-Y:DNA binding by a diamino p-anisyl-benzimidazole (Hx) polyamide Modulation of topoisomerase IIα expression and chemosensitivity through targeted inhibition of NF-Y:DNA binding by a diamino p-anisyl-benzimidazole (Hx) polyamide](/preview/png/5507806.png)
- Polyamide N1 functionalisation offers a strategy to improve drug-like properties.
- Diamino Hx-polyamides contain an N1-alkyl amino group on the heterocyclic rings.
- Incorporating an additional cationic group enhances solubility and cellular uptake.
- Targeted inhibition of NF-Y:DNA binding by HxIP* re-stimulated topo IIα expression.
- Pharmacological modulation of topo IIα increases chemosensitivity to topo II poisons.
BackgroundSequence specific polyamide HxIP 1, targeted to the inverted CCAAT Box 2 (ICB2) on the topoisomerase IIα (topo IIα) promoter can inhibit NF-Y binding, re-induce gene expression and increase sensitivity to etoposide. To enhance biological activity, diamino-containing derivatives (HxI*P 2 and HxIP* 3) were synthesised incorporating an alkyl amino group at the N1-heterocyclic position of the imidazole/pyrrole.MethodsDNase I footprinting was used to evaluate DNA binding of the diamino Hx-polyamides, and their ability to disrupt the NF-Y:ICB2 interaction assessed using EMSAs. Topo IIα mRNA (RT-PCR) and protein (Immunoblotting) levels were measured following 18 h polyamide treatment of confluent A549 cells. γH2AX was used as a marker for etoposide-induced DNA damage after pre-treatment with HxIP* 3 and cell viability was measured using Cell-Titer Glo®.ResultsIntroduction of the N1-alkyl amino group reduced selectivity for the target sequence 5â²-TACGAT-3â² on the topo IIα promoter, but increased DNA binding affinity. Confocal microscopy revealed both fluorescent diamino polyamides localised in the nucleus, yet HxI*P 2 was unable to disrupt the NF-Y:ICB2 interaction and showed no effect against the downregulation of topo IIα. In contrast, inhibition of NF-Y binding by HxIP* 3 stimulated dose-dependent (0.1-2 μM) re-induction of topo IIα and potentiated cytotoxicity of topo II poisons by enhancing DNA damage.ConclusionsPolyamide functionalisation at the N1-position offers a design strategy to improve drug-like properties. Dicationic HxIP* 3 increased topo IIα expression and chemosensitivity to topo II-targeting agents.General significancePharmacological modulation of topo IIα expression has the potential to enhance cellular sensitivity to clinically-used anticancer therapeutics. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.
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Journal: Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms - Volume 1860, Issue 5, May 2017, Pages 617-629