Modulation of topoisomerase IIα expression and chemosensitivity through targeted inhibition of NF-Y:DNA binding by a diamino p-anisyl-benzimidazole (Hx) polyamide.
Biochim Biophys Acta Gene Regul Mech
; 1860(5): 617-629, 2017 May.
Article
en En
| MEDLINE
| ID: mdl-27750031
ABSTRACT
BACKGROUND:
Sequence 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.METHODS:
DNase I footprinting was used to evaluate DNA binding of the diamino Hx-polyamides, and their ability to disrupt the NF-YICB2 interaction assessed using EMSAs. Topo IIα mRNA (RT-PCR) and protein (Immunoblotting) levels were measured following 18h 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®.RESULTS:
Introduction of the N1-alkyl amino group reduced selectivity for the target sequence 5'-TACGAT-3' 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-YICB2 interaction and showed no effect against the downregulation of topo IIα. In contrast, inhibition of NF-Y binding by HxIP* 3 stimulated dose-dependent (0.1-2µM) re-induction of topo IIα and potentiated cytotoxicity of topo II poisons by enhancing DNA damage.CONCLUSIONS:
Polyamide 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. GENERALSIGNIFICANCE:
Pharmacological 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.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Daño del ADN
/
Regulación Enzimológica de la Expresión Génica
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Regiones Promotoras Genéticas
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ADN-Topoisomerasas de Tipo II
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Factor de Unión a CCAAT
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Proteínas de Unión al ADN
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Antígenos de Neoplasias
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Nylons
Límite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta Gene Regul Mech
Año:
2017
Tipo del documento:
Article
País de afiliación:
Reino Unido