[Correlation of E-cadherin hypermethylation to tumorigenesis and development of gastric cancer].
OBJECTIVE
CpG island hypermethylation in promoter region of E-cadherin (E-cad) gene plays an important role in tumorigenesis of many tumors. This study was to explore the correlation of E-cadherin hypermethylation to tumorigenesis and development of gastric cancer.


METHODS
Methylation-specific polymerase chain reaction (MSP) was used to detect the methylation of E-cad gene in 41 specimens of gastric cancer, 40 specimens of premalignant gastric lesions and 38 specimens of normal gastric tissues. The expression of E-cad protein was detected by SP immunohistochemistry.


RESULTS
The positive rate of E-cad gene methylation was significantly higher in gastric cancer than in premalignant lesions and normal tissues (19.5% vs. 2.5% and 0.0%, P<0.05). The positive rate of E-cad protein was significantly lower in gastric cancer tissues than in premalignant lesions and normal tissues (70.7% vs. 97.5% and 100.0%, P<0.05). The positive rate of E-cad gene methylation was significantly higher in poorly differentiated cancer tissues than in well differentiated cancer tissues (43.8% vs. 4.0%, P<0.05), significantly higher in gastric cancer tissues with lymph node metastasis than in those without lymph node metastasis (33.3% vs. 5.0%, P<0.05), and significantly higher in gastric cancer tissues with serosa invasion than in those without serosa invasion (35.0% vs. 4.8%, P<0.05). The positive rate of E-cad protein was significantly lower in gastric cancer tissues with E-cad gene methylation than in those without E-cad gene methylation (0.0% vs. 87.9%, P<0.05).


CONCLUSIONS
CpG island hypermethylation of E-cad gene exists in gastric cancer, which down-regulates E-cad expression and might be involved in tumorigenesis and development of gastric cancer.
Liu
Wen-Tian
WT
Department of Gastroenterology, General Hospital, Tianjin Medical University, Tianjin, 300052, PR China. lwentian@sohu.com
Jiao
Huan-Li
HL
Yang
Yu-Long
YL
Wang
Dong
D
Zhang
Wei-Ming
WM
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000231:Adenocarcinoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D018279:Carcinoma, Signet Ring Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018899:CpG Islands; D019175:DNA Methylation; D015536:Down-Regulation; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
D015820:Cadherins