Immunoreactivity of CD99 in stomach cancer.
CD99 is characteristically expressed in Ewing's sarcoma/primitive neuroectodermal tumor. Recently its immunoreactivity has also been reported in other tumors. However, the significance of CD99 isoforms expressed in these tumors has not been elucidated. In this study, we evaluated the expression of CD99 isoforms and its relationship with histopathologic parameters in gastric adenocarcinomas. Paraffin sections of 46 gastric adenocarcinomas were stained with an anti-CD99 monoclonal antibody, YG32. Twelve (26.1%) cases of 46 gastric adenocarcinomas showed immunoreactivity to YG32. The CD99 expression was also seen both in non-neoplastic foveolar epithelial cells and infiltrating lymphocytes. In addition, Western blot and RT-PCR analyses revealed that the type I is the predominant isoform of CD99 in non-neoplastic and neoplastic gastric tissues. The CD99 expression was usually seen in the intestinal type adenocarcinoma, while rarely in the diffuse type. The CD99 immunoreactivity decreased in MMP-2-overexpressing adenocarcinomas (p=0.028). Our results suggest that the type I is the major isoform of CD99 expressed in non-neoplastic gastric mucosa and gastric adenocarcinomas and its downregulation in gastric adenocarcinoma may be associated with cellular dedifferentiation and/or MMP-2 overexpression.
Jung
Kyeong Cheon
KC
Department of Pathology, College of Medicine, Hallym University, Chunchon, Korea. jungkc@hallym.ac.kr
Park
Weon Seo
WS
Bae
Young Mee
YM
Hahn
Jang-Hee
JH
Hahn
Kyuhyoung
K
Lee
Hansoo
H
Lee
Hae Wan
HW
Koo
Hyung-Jin
HJ
Shin
Hai-Jeong
HJ
Shin
Hyung Sik
HS
Park
Young Euy
YE
Park
Seong Hoe
SH
D000071443:12E7 Antigen; D000230:Adenocarcinoma / Q000276:immunology* / Q000473:pathology; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis* / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000235:genetics; D005260:Female; D005753:Gastric Mucosa / Q000166:cytology / Q000276:immunology; D006801:Humans; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008875:Middle Aged; D020033:Protein Isoforms / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000276:immunology* / Q000473:pathology
D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D020033:Protein Isoforms; D012333:RNA, Messenger; D020782:Matrix Metalloproteinases