Nuclear Localization and Gene Expression Modulation by a Fluorescent Sequence-Selective p-Anisyl-benzimidazolecarboxamido Imidazole-Pyrrole Polyamide. Issue 7 (23rd July 2015)

• Record Type: Journal Article
• Authors: Kiakos, Konstantinos; Pett, Luke; Satam, Vijay; Patil, Pravin; Hochhauser, Daniel; Lee, Moses; Hartley, John A.
• Is Part Of: Chemistry & biology. Volume 22:Issue 7(2015)
• Page Start: 862
• Page End: 875
• Publication Date: 2015-07-23
• Subjects: Biochemistry -- Periodicals; 540
• DOI: 10.1016/j.chembiol.2015.06.005
• Languages: English
• ISSNs: 1074-5521

Abstract

Summary: Synthetic pyrrole (P)-imidazole (I) containing polyamides can target predetermined DNA sequences and modulate gene expression by interfering with transcription factor binding. We have previously shown that rationally designed polyamides targeting the inverted CCAAT box 2 (ICB2) of the topoisomerase IIα ( topo IIα ) promoter can inhibit binding of transcription factor NF-Y, re-inducing expression of the enzyme in confluent cells. Here, the A/T recognizing fluorophore, p -anisylbenzimidazolecarboxamido (Hx) was incorporated into the hybrid polyamide HxIP, which fluoresces upon binding to DNA, providing an intrinsic probe to monitor cellular uptake. HxIP targets the 5′-TACGAT-3′ sequence of the 5′ flank of ICB2 with high affinity and sequence specificity, eliciting an ICB2-selective inhibition/displacement of NF-Y. HxIP is readily taken up by NIH3T3 and A549 cells, and detected in the nucleus within minutes. Exposure to the polyamide at confluence resulted in a dose-dependent upregulation of topo IIα expression and enhanced formation of etoposide-induced DNA strand breaks. Graphical Abstract: Highlights: HxIP targets the ICB2 in the topo IIα promoter and displaces/inhibits NF-Y binding HxIP re-induces topo IIα expression in confluent NIH3T3 and A549 cells HxIP fluoresces upon binding to DNA and can be detected in the nucleus De-repression of the topo IIα promoter enhances etoposide-induced DNA damage Abstract : Kiakos et al. present a fluorescent hybrid polyamide, HxIP, which targets the NF-Y/ICB2 interface, re-induces topo IIα expression at confluence, and enhances the DNA-damaging effects of etoposide. HxIP fluoresces upon binding allowing for direct monitoring of its nuclear localization.