title: Differences in C/EBPs in normal tissue and papillomas of the larynx.
abstract: Transcription factors belonging to the family of CAAT enhancer binding proteins (C/EBPs) programme differentiation in a wide variety of cells. We asked about the expression of C/EBPs in squamous epithelium. Using immunohistochemistry, C/EBPalpha and C/EBPbeta were easily detected in tissue sections from normal larynx or laryngeal papillomas, benign tumours with a papillomavirus aetiology and characterized by abnormal differentiation. A temporal expression of these C/EBPs occured as keratinocytes differentiated. In both tissues, C/EBPbeta appeared to be exclusively nuclear. In normal tissue, the greatest amount of C/EBPbeta was present in the spinous layer, and much less occurred in the granular layer. The basal layer of the laryngeal papillomas contained the most C/EBPbeta. Less was present in the spinous layer. Little C/EBPbeta was in the granular layer. Much C/EBPalpha was in the cytoplasm in both tissues. In normal tissue, nuclear C/EBPalpha staining was virtually absent in the basal layer, and became present in the spinous layer. Nuclear C/EBPalpha was randomly distributed in all layers in papillomas. Using immunoblots and Southwestern blots, we detected abundant truncated isoforms of C/EBPalpha in the papillomas. Since differentiation of many tissues is determined by the relative amounts of different C/EBPs, our data supports a role for C/EBPs in the differentiation of squamous epithelium.
authors.affiliation: Department of Otolaryngology, Long Island Jewish Medical Center, The Long Island Campus of Albert Einstein College of Medicine, New York, USA.
authors.forename: L
authors.initials: L
authors.lastname: Jin
authors.forename: G Y
authors.initials: GY
authors.lastname: Yang
authors.forename: K
authors.initials: K
authors.lastname: Auborn
mesh_terms: D015153:Blotting, Western; D022762:CCAAT-Enhancer-Binding Proteins; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000032:analysis*; D019281:Dimerization; D004847:Epithelial Cells / Q000737:chemistry; D005629:Frozen Sections; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D007822:Laryngeal Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000821:virology; D007830:Larynx / Q000737:chemistry*; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000032:analysis*; D010212:Papilloma / Q000737:chemistry* / Q000473:pathology / Q000821:virology; D027383:Papillomaviridae; D020033:Protein Isoforms / Q000032:analysis*; D020218:Response Elements / Q000235:genetics
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D020033:Protein Isoforms