title: Pax-5 expression in nonhematopoietic tissues.
abstract: We evaluated 123 formalin-fixed, paraffin-embedded samples, including neuroendocrine tumors, adult brain, mesonephric tissues, and from various other sites. A pre-B lymphoma cell line, Daudi, and a small cell carcinoma cell line, NCL-H128, were evaluated by Western blot. All tissues were immunostained by mouse monoclonal anti-Pax-5 antibody by using standard, synthetic polymer-based detection methods. Our study describes for the first time distribution of Pax-5 in adult brain tissue, including periaqueductal gray matter of the midbrain, area postrema of the medulla oblongata, and occasional cells of the spinal trigeminal nucleus (caudal nucleus). We confirm that Pax-5 is expressed regularly in poorly differentiated neuroendocrine tumors but never in well-differentiated classic carcinoid tumors. Pax-5 expression also was found readily in benign and malignant mesonephric tissues and focally in müllerian duct-derived tissues and tumors. Expression of Pax-5 in the Daudi and NCL-H128 cell lines was confirmed by Western blot. Together, these results are important for correct interpretation of results in immunophenotyping of undifferentiated tumors, for diagnosis of mesonephric carcinoma, and, potentially, for correct classification of neuroendocrine tumors in small biopsy samples.
authors.affiliation: Department of Laboratory Medicine and Pathology, Royal University Hospital, College of Medicine, University of Saskatchewan, Saskatoon, Canada.
authors.forename: Emina
authors.initials: E
authors.lastname: Torlakovic
authors.forename: Ana
authors.initials: A
authors.lastname: Slipicevic
authors.forename: Chris
authors.initials: C
authors.lastname: Robinson
authors.forename: John F
authors.initials: JF
authors.lastname: DeCoteau
authors.forename: G Cecilie
authors.initials: GC
authors.lastname: Alfsen
authors.forename: Mogens
authors.initials: M
authors.lastname: Vyberg
authors.forename: Richa
authors.initials: R
authors.lastname: Chibbar
authors.forename: Vivi Ann
authors.initials: VA
authors.lastname: Flørenes
mesh_terms: D000328:Adult; D015153:Blotting, Western; D018288:Carcinoma, Small Cell / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D018358:Neuroendocrine Tumors / Q000378:metabolism* / Q000473:pathology; D051757:PAX5 Transcription Factor / Q000096:biosynthesis*; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology; D002583:Uterine Cervical Neoplasms / Q000378:metabolism / Q000473:pathology
chemical_list: D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human