Soft and hard keratin expression in Epstein-Barr-virus-associated gastric carcinoma.
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.
Uozaki
Hiroshi
H
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
Chong
Ja-Mun
JM
Fujimoto
Eka
E
Itoh
Miho
M
Saito
Miyuki
M
Sakuma
Kazuya
K
Sudo
Makoto
M
Ushiku
Tetsuo
T
Niki
Toshiro
T
Nagai
Hideo
H
Takada
Kenzo
K
Fukayama
Masashi
M
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*
D012333:RNA, Messenger; D007633:Keratins