EpCAM is overexpressed in gastric cancer and its downregulation suppresses proliferation of gastric cancer.
OBJECTIVE
To identify the role of epithelial cellular adhesion molecule (EpCAM) in gastric cancer growth and explore the potential value of EpCAM monoclonal antibody as new therapeutic strategy for gastric cancer.


METHODS
The expression of EpCAM was determined by immunohistochemistry staining in gastric cancer tissues, RT-PCR and Western blot in cell lines. EpCAM expression in cell lines was downregulated by small interfering RNA. Then the effects of EpCAM on gastric cancer cell growth in vivo and in vitro were determined by MTT, FCM analysis, clone formation assay and tumor formation assay. Additionally, western blot was used to detect the effect of EpCAM on cell cycle-relevant factor cyclin D1.


RESULTS
EpCAM was found to be overexpressed in gastric cancer tissues and cell lines. Downregulation of EpCAM resulted in a decrease of cell proliferation and cell cycle arrest in AGS and SGC7901 cells, which had high endogenous EpCAM expression. EpCAM downregulation also suppressed tumor formation in nude mice. Moreover, EpCAM repression in gastric cancer cells could downregulate cyclin D1.


CONCLUSIONS
EpCAM was a potential oncogene and contributed to the growth of gastric cancer. Our data first provided compelling evidence of potential value of EpCAM in the therapy of gastric cancer in clinic.
Wenqi
Du
D
State Key Laboratory of Cancer Biology, Digestive Diseases of Xijing Hospital, Fourth Military Medical University, 710032 Xi'an, Shaanxi Province, People's Republic of China. dwq0307@fmmu.edu.cn
Li
Wang
W
Shanshan
Cao
C
Bei
Chen
C
Yafei
Zhang
Z
Feihu
Bai
B
Jie
Liu
L
Daiming
Fan
F
D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000378:metabolism*; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D000071858:Epithelial Cell Adhesion Molecule; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*
D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D012333:RNA, Messenger