title: CD9 expression on lymphatic vessels in head and neck mucosa.
abstract: CD9, a member of the transmembrane 4 superfamily, is involved in cell adhesion, migration, and tumor metastasis. Little is known about its vascular expression pattern. In this study, we investigated CD9 expression on endothelial cells in the mucosa of the head and neck and compared it with vascular tumors. Using immunohistochemistry, expression of CD9 was studied in 17 samples of head and neck mucosa and skin (laryngeal mucosa: n = 2, oral: n = 6, and epidermis: n = 9) and a variety of vascular tumors (lymphangiomas: n = 9, juvenile nasopharyngeal angiofibromas: n = 4, hemangiomas: n = 7, angiosarcomas: n = 5, and Kaposi's sarcomas: n = 7) and compared with the expression of CD34 and PAL-E (blood vessel markers) and the lymphatic marker podoplanin. Regular lymphatic endothelium and lymphangiomas were strongly positive for CD9 and podoplanin but were mostly negative for PAL-E and CD34. By contrast, blood vessel endothelium and hemangiomas were strongly positive for PAL-E and CD34 but were mostly negative for CD9 and podoplanin. Weak to moderate CD9 reactivity was also observed on EC of juvenile nasopharyngeal angiofibromas, angiosarcomas, and Kaposi's sarcomas. Expression of CD9 by lymphatic EC was confirmed by reverse-transcriptase PCR and Western blot analyses. CD9 may be useful as a marker for lymphatic EC. It could promote the adherence of inflammatory and tumor cells to lymphatic EC and participate in the growth and maintenance of the lymphatic capillary net.
authors.affiliation: Department of Head and Neck Surgery, University of Vienna Medical School, Vienna, Austria.
authors.forename: Boban M
authors.initials: BM
authors.lastname: Erovic
authors.forename: Csilla
authors.initials: C
authors.lastname: Neuchrist
authors.forename: Sandra
authors.initials: S
authors.lastname: Kandutsch
authors.forename: Markus
authors.initials: M
authors.lastname: Woegerbauer
authors.forename: Johannes
authors.initials: J
authors.lastname: Pammer
mesh_terms: D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D018952:Antigens, CD34 / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D002478:Cells, Cultured; D004729:Endothelium, Lymphatic / Q000166:cytology / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D006257:Head / Q000098:blood supply*; D006801:Humans; D042601:Lymphatic Vessels / Q000166:cytology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009061:Mouth Mucosa / Q000098:blood supply / Q000378:metabolism*; D009333:Neck / Q000098:blood supply*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D060245:Tetraspanin 29; D019043:Vascular Neoplasms / Q000098:blood supply / Q000473:pathology; D000098853:Podoplanin
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018952:Antigens, CD34; D015415:Biomarkers; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D060245:Tetraspanin 29; C554869:CD9 protein, human; C117468:PDPN protein, human; D000098853:Podoplanin