Orla Howe

Prof. Orla Howe

Technological University Dublin, Dublin, Ireland
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 March 2004 in Human Molecular Genetics
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Journal Article
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NGNuri Gueven
Nuri Gueven
OBOlivier J. Becherel
Olivier J. Becherel
AKAmanda W. Kijas
Amanda W. Kijas
PCPhilip Chen
Philip Chen
Orla HoweOrla Howe
Orla Howe
Martin LavinMartin Lavin
Martin Lavin
Ataxia-oculomotor apraxia (AOA1) is a neurological disorder with symptoms that overlap those of ataxia-telangiectasia, a syndrome characterized by abnormal responses to double-strand DNA breaks and genome instability. The gene mutated in AOA1, APTX, is predicted to code for a protein called aprataxin that contains domains of homology with proteins involved in DNA damage signalling and repair. We demonstrate that aprataxin is a nuclear protein, present in both the nucleoplasm and the nucleolus. Mutations in the APTX gene destabilize the aprataxin protein, and fusion constructs of enhanced green fluorescent protein and aprataxin, representing deletions of putative functional domains, generate highly unstable products. Cells from AOA1 patients are characterized by enhanced sensitivity to agents that cause single-strand breaks in DNA but there is no evidence for a gross defect in single-strand break repair. Sensitivity to hydrogen peroxide and the resulting genome instability are corrected by transfection with full-length aprataxin cDNA. We also demonstrate that aprataxin interacts with the repair proteins XRCC1, PARP-1 and p53 and that it co-localizes with XRCC1 along charged particle tracks on chromatin. These results demonstrate that aprataxin influences the cellular response to genotoxic stress very likely by its capacity to interact with a number of proteins involved in DNA repair.

7 October 2010 in The Analyst
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Journal Article
Closed access
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HNHaq Nawaz
Haq Nawaz
FBFranck Bonnier
Franck Bonnier
PKPeter Knief
Peter Knief
Orla HoweOrla Howe
Orla Howe
Fiona LyngFiona Lyng
Fiona Lyng
Hugh ByrneHugh Byrne
Hugh Byrne
The study of the interaction of anticancer drugs with mammalian cells in vitro is important to elucidate the mechanisms of action of the drug on its biological targets. In this context, Raman spectroscopy is a potential candidate for high throughput, non-invasive analysis. To explore this potential, the interaction of cis-diamminedichloroplatinum(II) (cisplatin) with a human lung adenocarcinoma cell line (A549) was investigated using Raman microspectroscopy. The results were correlated with parallel measurements from the MTT cytotoxicity assay, which yielded an IC50 value of 1.2 ± 0.2 µM. To further confirm the spectral results, Raman spectra were also acquired from DNA extracted from A549 cells exposed to cisplatin and from unexposed controls. Partial least squares (PLS) multivariate regression and PLS Jackknifing were employed to highlight spectral regions which varied in a statistically significant manner with exposure to cisplatin and with the resultant changes in cellular physiology measured by the MTT assay. The results demonstrate the potential of the cellular Raman spectrum to non-invasively elucidate spectral changes that have their origin either in the biochemical interaction of external agents with the cell or its physiological response, allowing the prediction of the cellular response and the identification of the origin of the chemotherapeutic response at a molecular level in the cell.

23 February 2017 in Current Topics in Medicinal Chemistry
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Journal Article
Closed access
LVLivia Viganor
Livia Viganor
Orla HoweOrla Howe
Orla Howe
PMPauraic McCarron
Pauraic McCarron
MMMalachy McCann
Malachy McCann
MDMichael Devereux
Michael Devereux
The “antibiotic era”, characterized by the overuse and misuse of antibiotics, over the last half-century has culminated in the present critical “era of resistance”. The treatment of bacterial infections is challenging because of a decline in the current arsenal of useful antibiotics and the slow rate of new drug development. The discovery of a new gene (mcr-1) in 2015, which enables bacteria to be highly resistant to polymyxins (such as colistin), the last line of antibiotic defence left, heralds a new level of concern as this gene is susceptible to horizontal gene transfer, with alarming potential to be spread between different bacterial populations, suggesting that the progression from “extensive drug resistance” to “pan-drug resistance” may be inevitable. Clearly there is a need for the development of novel classes of anti-bacterial agents capable of killing bacteria through mechanisms that are different to those of the known classes of antibiotics. 1,10-phenanthroline (phen) is a heterocyclic organic compound which exerts in vitro antimicrobial activity against a broad-spectrum of bacteria. The antimicrobial activity of phen can be significantly modulated by modifying its structure. The development of metal-phen complexes offers the medicinal chemist an opportunity to expand such structural diversity by controlling the geometry and varying the oxidation states of the metal centre, with the inclusion of appropriate auxiliary ligands in the structure, offering the opportunity to target different biochemical pathways in bacteria. In this review, we summarize what is currently known about the antibacterial capability of metal-phen complexes and their mechanisms of action.

16 December 2010 in Dalton Transactions
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Journal Article
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AKAndrew Kellett
Andrew Kellett
MOMark O'COnnor
Mark O'COnnor
MMMalachy McCann
Malachy McCann
MMMary McNamara
Mary McNamara
PLPatrick Lynch
Patrick Lynch
MDMichael Devereux
Michael Devereux
Three, structurally characterised, bis-phen Cu(II) complexes of the phthalate isomers display rapid, low micromolar in vitro cytotoxicity against a range of epithelial tumour cells. The complexes induce relaxation of supercoiled plasmid DNA in the absence of external reducing agents and display efficient CT-DNA, Poly[d(A–T)]2 and Poly[d(G–C)]2 binding.

4 February 2016 in British Journal of Cancer
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Journal Article
Open access
GCGillian Conway
Gillian Conway
ACAlan Casey
Alan Casey
VMVladimir Milosavljevic
Vladimir Milosavljevic
YLYupeng Liu
Yupeng Liu
Orla HoweOrla Howe
Orla Howe
JCJames Curtin
James Curtin
The BJC is owned by Cancer Research UK, a charity dedicated to understanding the causes, prevention and treatment of cancer and to making sure that the best new treatments reach patients in the clinic as quickly as possible. The journal reflects these aims. It was founded more than fifty years ago and, from the start, its far-sighted mission was to encourage communication of the very best cancer research from laboratories and clinics in all countries. The breadth of its coverage, its editorial independence and it consistent high standards, have made BJC one of the world's premier general cancer journals. Its increasing popularity is reflected by a steadily rising impact factor.