title: Inhibition of the ERCC1-XPF structure-specific endonuclease to overcome cancer chemoresistance.
abstract: ERCC1-XPF is a structure-specific endonuclease that is required for the repair of DNA lesions, generated by the widely used platinum-containing cancer chemotherapeutics such as cisplatin, through the Nucleotide Excision Repair and Interstrand Crosslink Repair pathways. Based on mouse xenograft experiments, where ERCC1-deficient melanomas were cured by cisplatin therapy, we proposed that inhibition of ERCC1-XPF could enhance the effectiveness of platinum-based chemotherapy. Here we report the identification and properties of inhibitors against two key targets on ERCC1-XPF. By targeting the ERCC1-XPF interaction domain we proposed that inhibition would disrupt the ERCC1-XPF heterodimer resulting in destabilisation of both proteins. Using in silico screening, we identified an inhibitor that bound to ERCC1-XPF in a biophysical assay, reduced the level of ERCC1-XPF complexes in ovarian cancer cells, inhibited Nucleotide Excision Repair and sensitised melanoma cells to cisplatin. We also utilised high throughput and in silico screening to identify the first reported inhibitors of the other key target, the XPF endonuclease domain. We demonstrate that two of these compounds display specificity in vitro for ERCC1-XPF over two other endonucleases, bind to ERCC1-XPF, inhibit Nucleotide Excision Repair in two independent assays and specifically sensitise Nucleotide Excision Repair-proficient, but not Nucleotide Excision Repair-deficient human and mouse cells to cisplatin.
authors.affiliation: MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
authors.forename: Ewan M
authors.initials: EM
authors.lastname: McNeil
authors.affiliation: MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
authors.forename: Katy R
authors.initials: KR
authors.lastname: Astell
authors.affiliation: MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
authors.forename: Ann-Marie
authors.initials: AM
authors.lastname: Ritchie
authors.affiliation: Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
authors.forename: Steven
authors.initials: S
authors.lastname: Shave
authors.affiliation: Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Houston
authors.affiliation: Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
authors.forename: Preeti
authors.initials: P
authors.lastname: Bakrania
authors.affiliation: Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
authors.forename: Hayley M
authors.initials: HM
authors.lastname: Jones
authors.affiliation: Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
authors.forename: Puneet
authors.initials: P
authors.lastname: Khurana
authors.affiliation: Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Wallace
authors.affiliation: Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Chapman
authors.affiliation: Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Wear
authors.affiliation: Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
authors.forename: Malcolm D
authors.initials: MD
authors.lastname: Walkinshaw
authors.affiliation: Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
authors.forename: Barbara
authors.initials: B
authors.lastname: Saxty
authors.affiliation: MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK. Electronic address: David.Melton@ed.ac.uk.
authors.forename: David W
authors.initials: DW
authors.lastname: Melton
mesh_terms: D020134:Catalytic Domain / Q000187:drug effects; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D004260:DNA Repair / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D004720:Endonucleases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D057166:High-Throughput Screening Assays; D006801:Humans; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000235:genetics; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA
chemical_list: D004268:DNA-Binding Proteins; C095888:xeroderma pigmentosum group F protein; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin
keywords: DNA repair inhibitor; ERCC1–XPF; FANCQ; Interstrand Crosslink Repair; Melanoma; Nucleotide Excision Repair; Ovarian cancer