title: Incomplete epithelial-mesenchymal transition in p16-positive squamous cell carcinoma cells correlates with β-catenin expression.
abstract: BACKGROUND
  The epithelial-mesenchymal transition (EMT) is suggested to be a crucial factor for the development of an invasive and metastatic cell phenotype, which is characterized by down-regulation of epithelial adhesive proteins (e.g. E-cadherin) and induction of mesenchymal proteins (e.g. vimentin). Therefore, there is a great clinical interest to specify this phenotype. Different growth factors induce EMT, such as epithelial growth factor (EGF) and transforming growth factor beta 1 (TGFβ1). The role of EMT in human papilloma virus (HPV)-positive squamous cell carcinoma (SCC) is still not understood. The aim of this study was to investigate the expression pattern in p16-positive and -negative SCC cells of vimentin, β-catenin and E-cadherin after stimulation with growth factors.
  
  
  METHODS
  We incubated the p16-positive CERV196 and p16-negative HNSCC22B SCC cell lines with EGF and EGF/TGFβ1 (10 ng/ml) and detected E-cadherin, vimentin and β-catenin by immunocytochemistry and enzyme-linked immunosorbent assay after 5, 24 and 96 h.
  
  
  RESULTS
  We found a low expression of vimentin in all studied tumor cell lines. The negative control of HNSCC22B cells showed a higher intrinsic level of membranous E-cadherin and β-catenin. We found statistically significant EGF/TGFβ1-induced expression of vimentin dependent on incubation time in p16-negative HNSCC22B cells. Particularly in the presence of EGF, we detected an increase of β-catenin and vimentin expression in p16-positive SCC tumor cell lines in addition to induced cell scattering and unexpected expression of E-cadherin.
  
  
  CONCLUSIONS
  In conclusion, E-cadherin, β-catenin and vimentin expression are important features to characterize EMT-like events. We were able to show incomplete EGF-induced EMT with β-catenin expression in p16-positive SCC. Extended studies are required to investigate the mechanistic role of EMT markers, especially in p16-positive SCC, in order to develop new anti-SCC therapies to block EMT progression.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany claudia.umbreit@umm.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Umbreit
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Flanjak
authors.affiliation: Institute of Medical Statistics and Biometry, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.affiliation: Department of Urology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Erben
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Aderhold
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Faber
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Stern-Straeter
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Hoermann
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Johannes David
authors.initials: JD
authors.lastname: Schultz
mesh_terms: D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D015820:Cadherins / Q000096:biosynthesis; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002448:Cell Adhesion / Q000235:genetics; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000494:pharmacology; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D000077195:Squamous Cell Carcinoma of Head and Neck; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D014746:Vimentin / Q000096:biosynthesis; D051176:beta Catenin / Q000096:biosynthesis*
chemical_list: D014408:Biomarkers, Tumor; C000614131:CDKN2A protein, human; D015820:Cadherins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D009363:Neoplasm Proteins; D053773:Transforming Growth Factor beta1; D014746:Vimentin; D051176:beta Catenin; D004815:Epidermal Growth Factor
keywords: E-cadherin; ECM; EGF; EMT; Epithelial growth factor; HNSCC; HPV; SCC; TGFβ1; epithelial–mesenchymal transition; extracellular matrix; head and neck squamous cell carcinoma; human papillomavirus; p16-positive SCC; squamous cell cancer; transforming growth factor β1; vimentin; β-catenin