[Down-regulation of caveolin-1 in gastric carcinoma and its clinical biological significance].
OBJECTIVE
Caveolin-1, a candidate tumor suppressor gene, aberrantly expressed in many kinds of carcinomas. This research was designed to check the expression of Caveolin-1 in non-cancerous gastric mucosa, intestinal metaplasia, atypical hyperplasia, gastric cancer tissues, and gastric cancer cell lines MGC803 and BGC823, and to analyze its clinical biological significance in stepwise gastric carcinogenesis.


METHODS
Frozen gastric tissue array-based immunohistochemistry (IHC) was used to examine the expression of Caveolin-1 in 56 specimens of gastric cancer, 29 specimens of non-cancerous mucosa, 11 specimens of intestinal metaplasia, and 7 specimens of atypical hyperplasia. Correlations of Caveolin-1 expression to clinical stage, lymph node metastasis, Lauren's type, and histological type were analyzed. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect mRNA and protein levels of Caveolin-1 in 56 specimens of gastric cancer and relevant adjuvant non-cancerous tissue, and cell lines MGC803 and BGC823.


RESULTS
Positive rate of Caveolin-1 was significantly lower in gastric cancer than in non-cancerous mucosa, intestinal metaplasia, and atypical hyperplasia (17.9% vs. 84.8%, 81.8%, and 57.1%, P<0.05). Positive rate of Caveolin-1 was lower in advanced gastric cancers than in gastric cancer of early stage (16.0% vs. 33.3%), but the difference was not significant (P>0.05). Positive rate of Caveolin-1 was significantly lower in diffuse gastric cancer than in gastric cancer of intestinal type (7.0% vs. 26.9%, P<0.05), significantly lower in the cases with lymph node metastases than in the cases without lymph node metastases (9.7% vs. 31.8%, P<0.05). Protein and mRNA levels of Caveolin-1 in gastric cancer and relevant adjuvant non-cancerous tissues have no significant difference, but its expression was low in MGC803 and BGC823 cells.


CONCLUSIONS
Progressive down-regulation of Caveolin-1 in gastric epithelial cells is correlated to gastric carcinogenesis.
Gao
Xue
X
Cancer Institute/Liaoning Provincial Key Lab of Cancer Genomics, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, 116027, P.R.China.
Sun
Yuan
Y
Huang
Lei
L
Chen
Xiao-Yan
XY
Zhang
Kai-Li
KL
Kong
Qing-You
QY
Liu
Jia
J
Li
Hong
H
D051242:Caveolin 1 / Q000096:biosynthesis* / Q000235:genetics; D045744:Cell Line, Tumor; D018450:Disease Progression; D015536:Down-Regulation; D005753:Gastric Mucosa / Q000378:metabolism* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008679:Metaplasia; D009367:Neoplasm Staging; D011230:Precancerous Conditions / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology
D051242:Caveolin 1; D012333:RNA, Messenger