title: Soft and hard keratin expression in Epstein-Barr-virus-associated gastric carcinoma.
abstract: BACKGROUND
  Epstein-Barr-virus-associated gastric carcinoma (EBVaGC) is a distinct subset of gastric carcinoma (GC). The expressions of cytokeratins (CK)7, 8, 18, 19 and 20 and truncated basic hair keratin 1 (hHb1-deltaN) were investigated in GC to clarify the characteristics of EBVaGC.
  
  
  METHODS
  For immunohistochemical evaluation, 173 GC tissues were examined and 31 GC tissues and 5 GC cell lines were used for quantitative real-time RT-PCR (qrt-RT-PCR) and RT-PCR.
  
  
  RESULTS
  EBVaGC showed significantly lower immunohistochemical positivity of CK7 (-/(+/-)/+/+ +/+ + +; 27/15/4/1/1) compared to EBV-negative GC (12/29/27/44/13), even after stratification by histological types. The qrt-RT-PCR test demonstrated decreased amounts of CK7, 18 and 19 mRNAs in EBVaGC. Two among 5 GC cell lines showed a decrease of CK7 mRNA level after recombinant EBV infection. hHb1-deltaN expression was not specific to EBVaGC.
  
  
  CONCLUSIONS
  Abnormalities of CK7, 18 and 19 expressions, especially a decreased amount of CK7 expression, are characteristics of EBV-associated epithelial malignancies and might be important in carcinogenesis.
authors.affiliation: Department of Human Pathology and Diagnostic Pathology, Graduate School of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan. uozaki-tky@umin.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uozaki
authors.forename: Ja-Mun
authors.initials: JM
authors.lastname: Chong
authors.forename: Eka
authors.initials: E
authors.lastname: Fujimoto
authors.forename: Miho
authors.initials: M
authors.lastname: Itoh
authors.forename: Miyuki
authors.initials: M
authors.lastname: Saito
authors.forename: Kazuya
authors.initials: K
authors.lastname: Sakuma
authors.forename: Makoto
authors.initials: M
authors.lastname: Sudo
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ushiku
authors.forename: Toshiro
authors.initials: T
authors.lastname: Niki
authors.forename: Hideo
authors.initials: H
authors.lastname: Nagai
authors.forename: Kenzo
authors.initials: K
authors.lastname: Takada
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukayama
mesh_terms: D000368:Aged; D045744:Cell Line, Tumor; D020031:Epstein-Barr Virus Infections / Q000378:metabolism* / Q000473:pathology; D005260:Female; D004854:Herpesvirus 4, Human; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000821:virology*
chemical_list: D012333:RNA, Messenger; D007633:Keratins