title: Expression of laminin 5-γ2 chain in cutaneous squamous cell carcinoma and its role in tumour invasion.
abstract: BACKGROUND
  Laminin-5 (Ln5), a heterotrimer composed of three chains (α3, β3, and γ2), is a major component of the basement membrane in most adult tissues. One of the chains, Ln5-γ2, is a marker of invasive tumours because it is frequently expressed as a monomer in malignant tumours. Recent studies from our laboratories detected higher levels of Ln5-γ2 expression in basal cell carcinoma (BCC) than in trichoblastoma. Furthermore, Ln5-γ2 overexpression tended to correlate with aggressiveness in BCC.
  
  
  METHODS
  In this study, we compared the expression of Ln5-γ2 in invasive squamous cell carcinoma (SCC, n = 62) of the skin to that in preinvasive Bowen's disease (BD, n = 51), followed by analysis of the role of Ln5-γ2 in cancer invasion in vitro.
  
  
  RESULTS
  Immunohistochemically, the proportion of SCC cases (86%) strongly positive for Ln5-γ2 expression was higher than that of BD (16%). Real-time RT-PCR showed Ln5-γ2 overexpression in SCC cell line, A431, compared with normal keratinocyte cell line, HaCaT. Ln5-γ2 monomer and proteolytically cleaved, biologically active fragments of Ln5-γ2 were identified in SCC tumour extracts. In in vitro raft cultures, which simulate in vivo conditions, Ln5-γ2 siRNA significantly suppressed epidermal growth factor (EGF)-stimulated A431 cell invasion.
  
  
  CONCLUSIONS
  Our results indicate that Ln5-γ2 has a role in cutaneous SCC invasion.
authors.affiliation: Department of Pathology, Fukuoka University Hospital, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hamasaki
authors.forename: K
authors.initials: K
authors.lastname: Koga
authors.forename: M
authors.initials: M
authors.lastname: Aoki
authors.forename: M
authors.initials: M
authors.lastname: Hamasaki
authors.forename: N
authors.initials: N
authors.lastname: Koshikawa
authors.forename: M
authors.initials: M
authors.lastname: Seiki
authors.forename: H
authors.initials: H
authors.lastname: Iwasaki
authors.forename: J
authors.initials: J
authors.lastname: Nakayama
authors.forename: K
authors.initials: K
authors.lastname: Nabeshima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001913:Bowen's Disease / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007797:Laminin / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: C400567:LAMC2 protein, human; D007797:Laminin