| First Author | Pett L | Year | 2017 |
| Journal | Biochim Biophys Acta | Volume | 1860 |
| Issue | 5 | Pages | 617-629 |
| PubMed ID | 27750031 | Mgi Jnum | J:251537 |
| Mgi Id | MGI:6105716 | Doi | 10.1016/j.bbagrm.2016.10.005 |
| Citation | Pett L, et al. (2017) Modulation of topoisomerase IIalpha expression and chemosensitivity through targeted inhibition of NF-Y:DNA binding by a diamino p-anisyl-benzimidazole (Hx) polyamide. Biochim Biophys Acta 1860(5):617-629 |
| abstractText | BACKGROUND: Sequence specific polyamide HxIP 1, targeted to the inverted CCAAT Box 2 (ICB2) on the topoisomerase IIalpha (topo IIalpha) 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-Y:ICB2 interaction assessed using EMSAs. Topo IIalpha mRNA (RT-PCR) and protein (Immunoblotting) levels were measured following 18h polyamide treatment of confluent A549 cells. gammaH2AX 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(R). RESULTS: Introduction of the N1-alkyl amino group reduced selectivity for the target sequence 5''-TACGAT-3'' on the topo IIalpha 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 IIalpha. In contrast, inhibition of NF-Y binding by HxIP* 3 stimulated dose-dependent (0.1-2muM) re-induction of topo IIalpha 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 IIalpha expression and chemosensitivity to topo II-targeting agents. GENERAL SIGNIFICANCE: Pharmacological modulation of topo IIalpha 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. |
