title: Differential expression of the non-receptor tyrosine kinase BRK in oral squamous cell carcinoma and normal oral epithelium.
abstract: BRK is a non-receptor tyrosine kinase whose functional role is poorly understood. Although it is an epithelial specific kinase, its expression appears to be tissue specific. To date, little is known about BRK expression in human oral epithelium. We investigated expression of BRK in human oral squamous cell carcinomas (OSCC) and normal oral epithelium (NOE) using immunohistochemistry, laser confocal microscopy and Western blotting. The subcellular localization of BRK was identified by confocal microscopy and Western blotting of nuclear and cytoplasmic extracts from these cells. The results indicate that NOE express higher levels of BRK compared with OSCC cells. In NOE and moderately differentiated OSCC cells, BRK was localized in the nucleus and cytoplasm. However, in poorly differentiated OSCC cells, BRK was localized in perinuclear regions. These results suggest that BRK expression differs in normal and OSCC which may reflect a possible functional involvement in OSCC.
authors.affiliation: Department of Periodontics, College of Dentistry, M/C 859, University of Illinois at Chicago, 801 S. Paulina Street, Chicago, IL 60612-7212, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Petro
authors.forename: R C
authors.initials: RC
authors.lastname: Tan
authors.forename: A L
authors.initials: AL
authors.lastname: Tyner
authors.forename: M W
authors.initials: MW
authors.lastname: Lingen
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D006801:Humans; D018613:Microscopy, Confocal; D009061:Mouth Mucosa / Q000201:enzymology; D009062:Mouth Neoplasms / Q000201:enzymology*; D009363:Neoplasm Proteins; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D009363:Neoplasm Proteins; D011505:Protein-Tyrosine Kinases; C088375:PTK6 protein, human