title: Overexpression of peroxiredoxins I, II, III, V, and VI in malignant mesothelioma.
abstract: Peroxiredoxins (Prxs) are a recently characterized group of thiol-containing proteins with efficient antioxidant capacity, capable of consuming hydrogen peroxide in living cells. Altogether six distinct Prxs have been characterized in mammalian tissues. Their expression was investigated in histological samples of mesothelioma and in cell lines established from the tumours of mesothelioma patients. Four cases with histopathologically healthy pleura from non-smokers were used as controls. Healthy pleural mesothelium was negative or very weakly positive for all Prxs. In mesothelioma, the most prominent reactivity was observed with Prxs I, II, V, and VI. Prx I was highly or moderately expressed in 25/36 cases, the corresponding figures for Prxs II-VI being 27/36 (Prx II), 13/36 (Prx III), 2/36 (Prx IV), 24/36 (Prx V), and 30/36 (Prx VI). Positive staining was observed both in the cytosolic and the nuclear compartment, with the exception of Prx III, which showed no nuclear reactivity. The staining pattern of Prxs III and V was granular. Immunoelectron microscopic localization of Prxs was in accordance with the immunohistochemical findings, showing diffuse cytoplasmic localization for Prxs I, II, IV, and VI and distinct mitochondrial labelling for Prxs III and V. There was no significant association between the extent of staining and different Prxs. It appeared that Prxs may not have prognostic significance, but being prominently expressed in most mesotheliomas these proteins, at least in theory, may play a role in the primary drug resistance of this disease.
authors.affiliation: Department of Internal Medicine, Pulmonary Division, University of Oulu and Oulu University Hospital, Kajaanintie 50A, 90220 Oulu, Finland. vuokko.kinnula@oulu.fi
authors.forename: Vuokko L
authors.initials: VL
authors.lastname: Kinnula
authors.forename: S
authors.initials: S
authors.lastname: Lehtonen
authors.forename: R
authors.initials: R
authors.lastname: Sormunen
authors.forename: R
authors.initials: R
authors.lastname: Kaarteenaho-Wiik
authors.forename: S W
authors.initials: SW
authors.lastname: Kang
authors.forename: S G
authors.initials: SG
authors.lastname: Rhee
authors.forename: Y
authors.initials: Y
authors.lastname: Soini
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D017209:Apoptosis; D016022:Case-Control Studies; D002467:Cell Nucleus / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008654:Mesothelioma / Q000378:metabolism* / Q000473:pathology; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D008928:Mitochondria / Q000737:chemistry; D010544:Peroxidases / Q000032:analysis / Q000378:metabolism*; D054465:Peroxiredoxin VI; D054464:Peroxiredoxins; D010994:Pleura / Q000473:pathology; D010997:Pleural Neoplasms / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: D000975:Antioxidants; D010544:Peroxidases; D054465:Peroxiredoxin VI; D054464:Peroxiredoxins