Aim: To investigate the relationship between methylation of Syk (spleen tyrosine kinase) gene in promoter region and oncogenesis, metastasis of gastric carcinoma. The relation between silencing of the Syk gene and methylation of Syk promoter region was also studied.
Methods: By using methylation-specific PCR (MSP) technique, the methylation of Syk promoter region in specimens from 61 gastric cancer patients (tumor tissues and adjacent normal tissues) was detected. Meanwhile, RT-PCR was used to analyse syk expression exclusively.
Results: The expression of the Syk gene was detected in all normal gastric tissues. Syk expression in gastric carcinoma was lower in 14 out of 61 gastric cancer samples than in adjacent normal tissues (chi(2)=72.3, P<0.05). No methylation of Syk promoter was found in adjacent normal tissues. hypermethylation of Syk gene in promoter was detected 21 cases in 61 gastric carcinoma patients. The rate of methylation of Syk promoter in gastric carcinoma was higher than that in adjacent normal tissues (chi(2)=25.1, P<0.05). In 31 patients with lymph node metastasis, 17 were found with Syk promoter methylation. A significant difference was noted between two groups (chi(2)=11.4,P<0.05).
Conclusion: Hypermethylation leads to silencing of the Syk gene in human gastric carcinoma. Methylation of Syk promoter is correlated to oncogenesis and metastasis of gastric carcinoma. Syk is considered to be a potential tumor suppressor and anti-metastasis gene in human gastric cancer.