title: Measuring ERCC1 protein expression in cancer specimens: validation of a novel antibody.
abstract: Platinum chemotherapy remains part of standard therapies in the management of a variety of cancers. Severe side effects and a high degree of resistance to platinum drugs have led numerous researchers to search for predictive biomarkers, which could aid in identifying patients that are the most likely to respond to therapy. The ERCC1-ERCC4 endonuclease plays a critical role in the repair of platinum-DNA damage and has widely been studied in relation to sensitivity to platinum chemotherapy. The standard method to evaluate ERCC1 protein expression is through the use of immunohistochemistry with monoclonal antibody 8F1, an antibody that was recently found to bind an unrelated protein. The present study determines the specificity of a novel antibody, monoclonal antibody 4F9, and presents a method to evaluate ERCC1 expression in colorectal tumor specimens. Using relevant cell lines as controls, the specificity of antibody 4F9 was tested by immunoblotting, immunohistochemistry and immunofluorescence. Scoring guidelines to aid in the evaluation of ERCC1 tumor expression were developed and evaluated in archival formalin-fixed paraffin embedded colorectal cancer specimens. Antibody 4F9 was found to be specific by all methods applied and it was possible to evaluate the ERCC1 expression in the majority (85%) of colorectal cancer tumor specimens.
authors.affiliation: 1] R&D, Dako A/S, Produktionsvej 42, DK-2600 Glostrup, Denmark [2] Section for Molecular Disease Biology, Institute of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Strandboulevarden 49, DK-2100 Copenhagen Ø, Denmark.
authors.forename: David Hersi
authors.initials: DH
authors.lastname: Smith
authors.affiliation: Department of Pathology, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Anne-Marie Kanstrup
authors.initials: AM
authors.lastname: Fiehn
authors.affiliation: Section for Molecular Disease Biology, Institute of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Strandboulevarden 49, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Louise
authors.initials: L
authors.lastname: Fogh
authors.affiliation: Finsen Laboratory, Rigshospitalet and Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen Biocenter, Ole Maaloevs Vej 5, building 3, 3rd floor, DK-2200 Copenhagen N, Denmark.
authors.forename: Ib Jarle
authors.initials: IJ
authors.lastname: Christensen
authors.affiliation: Department of Pathology, Odense University Hospital, Winslowparken 15, DK-5000 Odense C, Denmark.
authors.forename: Tine Plato
authors.initials: TP
authors.lastname: Hansen
authors.affiliation: Section for Molecular Disease Biology, Institute of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Strandboulevarden 49, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Jan
authors.initials: J
authors.lastname: Stenvang
authors.affiliation: 1] Department of Surgical Gastroenterology 360, Hvidovre Hospital, Kettegård Allé 30, DK-2650 Hvidovre, Denmark [2] Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark.
authors.forename: Hans Jørgen
authors.initials: HJ
authors.lastname: Nielsen
authors.affiliation: 1] R&D, Dako A/S, Produktionsvej 42, DK-2600 Glostrup, Denmark [2].
authors.forename: Kirsten Vang
authors.initials: KV
authors.lastname: Nielsen
authors.affiliation: Department of Pathology, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Jane Preuss
authors.initials: JP
authors.lastname: Hasselby
authors.affiliation: Section for Molecular Disease Biology, Institute of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Strandboulevarden 49, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Nils
authors.initials: N
authors.lastname: Brünner
authors.affiliation: R&D, Dako A/S, Produktionsvej 42, DK-2600 Glostrup, Denmark.
authors.forename: Sussie Steen
authors.initials: SS
authors.lastname: Jensen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies; D000918:Antibody Specificity / Q000276:immunology; D045744:Cell Line, Tumor; D015331:Cohort Studies; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004720:Endonucleases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009369:Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*
chemical_list: D000906:Antibodies; D004268:DNA-Binding Proteins; C071447:ERCC1 protein, human; D004720:Endonucleases