title: Role of CD44 variant exon 6 in invasion of head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  To determine the correlation between the expression of CD44 variant exon 6 (v6) and the clinicopathological features of head and neck squamous cell carcinomas (HNSCCs), and to study the role of CD44v6 in cell invasion using a human HNSCC cell line (HSC-2).
  
  
  METHODS
  The expression of CD44v6 was evaluated using immunohistochemical analysis in paraffin-embedded tissue specimens from 89 primary lesions. The concentration of CD44v6 protein in 37 cryopreserved tumor specimens was evaluated using the enzyme-linked immunosorbent assay. The HSC-2 cells were treated with 2F10, a monoclonal antibody against CD44v6. The effects of 2F10 on HSC-2 cell proliferation, migration, and invasion potential were evaluated.
  
  
  RESULTS
  The down-regulation of CD44v6 expression or the concentration of cancer tissue significantly correlated with a lower degree of pathohistological differentiation and a higher rate of cervical metastasis. The invasion of HSC-2 cells into type I collagen gel and the expression of CD44v6 were decreased in invading cells released from the upper layer. Furthermore, the treatment of HSC-2 cells with 2F10 significantly enhanced cell invasion. However, 2F10 did not affect either the proliferation or migration properties of HSC-2 cells.
  
  
  CONCLUSIONS
  The down-regulation of CD44v6 expression may be useful as a biological marker for the degree of malignancy in HNSCCs. We assume that the loss or dysfunction of CD44v6 is involved in the acquisition of invasion ability in HSC-2 cells. In addition, the potential existence of a CD44v6-mediated signal transduction pathway may play a role in inhibiting the invasion in HNSCCs.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kanke
authors.forename: M
authors.initials: M
authors.lastname: Fujii
authors.forename: K
authors.initials: K
authors.lastname: Kameyama
authors.forename: J
authors.initials: J
authors.lastname: Kanzaki
authors.forename: Y
authors.initials: Y
authors.lastname: Tokumaru
authors.forename: Y
authors.initials: Y
authors.lastname: Imanishi
authors.forename: T
authors.initials: T
authors.lastname: Tomita
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumura
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology*; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005091:Exons; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000473:pathology*; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics*; D007150:Immunohistochemistry; D009361:Neoplasm Invasiveness / Q000235:genetics*; D014407:Tumor Cells, Cultured
chemical_list: D015415:Biomarkers; D018960:Hyaluronan Receptors