title: Different detectability of cyclooxygenase-2 (COX-2) protein in standard paraffin sections and tissue microarrays of human melanomas and naevi - comparative study.
abstract: Cyclooxygenase-2 (COX-2), overexpressed in many types of human cancer, may be a valuable marker for human melanoma. However, there are discrepancies between expression levels detected by different groups. The majority of the studies were carried out using standard paraffin sections. Tissue microarrays (TMAs) might enable analysis of COX-2 expression in numerous lesions. Our study assesses to what extent reprocessing of tissue samples used for preparing TMAs may influence reproducibility of data obtained for standard sections. The study included TMAs and standard histopathologic sections. COX-2 was detected by immunohistochemistry with two primary antibodies targeting different epitopes. COX-2 expression levels detected with both antibodies in standard sections were similar as in our previous study. Surprisingly, results obtained in TMAs were significantly different. While one of the antibodies yielded for TMAs results similar to standard sections, COX-2 expression levels found with the second antibody were very low and expression patterns strikingly different from those observed for standard sections and for both TMAs studied with the first antibody. Good performance of the antibodies found in standard sections of human skin and melanocytic lesions does not guarantee similar results in TMAs. The finding discloses a new aspect of immunohistochemical assays involving TMAs.
authors.affiliation: Department of Medical Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Toruń, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Kuźbicki
authors.affiliation: Department of Medical Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Toruń, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Urban
authors.affiliation: Department of Medical Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Toruń, Poland. Electronic address: chwirot@biol.uni.torun.pl.
authors.forename: Barbara W
authors.initials: BW
authors.lastname: Chwirot
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D051546:Cyclooxygenase 2 / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000737:chemistry* / Q000473:pathology; D009506:Nevus / Q000737:chemistry* / Q000473:pathology; D016612:Paraffin Embedding; D015203:Reproducibility of Results; D012878:Skin Neoplasms / Q000737:chemistry* / Q000473:pathology; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2
keywords: Cyclooxygenase-2 (COX-2); Immunohistochemistry; Marker; Melanoma; Tissue microarrays (TMAs)