Role of RECK methylation in gastric cancer and its clinical significance

AIM:To investigate the relation between RECK methylation and clinicopathological characteristics of gastric cancer patients and evaluate the role of RECK methylation in peritoneal metastasis of gastric cancer.METHODS:Methylation of RECK gene in 40 paired samples of gastric cancer and its corresponding adjacent normal mucosa,lymph nodes and peritoneal irrigation fluid was detected by methylation-specific polymerase chain reaction.RESULTS:Aberrant methylation of RECK gene was detected in 27.5%(11/40)of the adjacent normal mucosa samples,in 47.5%(19/40)of gastric cancer samples,in 57.1%(12/21)of the lymph node samples,and in 35%(14/40)of peritoneal irrigation fluid samples,respectively,with a significant difference between the adjacent normal mucosa and lymph node samples(P=0.023).Presence of RECK methylation in the primary tumor samples was significantly correlated with tumor invasion(P=0.023).The accuracy of RECK methylation in peritoneal lavage fluid samples for the diagnosis of peritoneal metastasis of gastric cancer was 72.5%(26/40),with a sensitivity of 66.7%(6/9) and a specificity of 74.2%(23/31).CONCLUSION:Aberrant methylation of RECK gene may provide useful information for the early diagnosis and treatment of peritoneal metastasis of gastric cancer.

Promoter Hypermethylation of KiSS-1 Gene in Gastric Cancer

Objective： To investigate the association between KiSS-1 methylation and clinicopathological characteristics of gastric cancer and evaluate the role of peritoneal lavage fluid in detecting peritoneal metastases. Methods： The methylation status of KiSS-1 gene in 40 gastric cancer specimens, the corresponding adjacent normal mucosa, lymph nodes and peritoneal lavage fluid was investigated by methylation-spcific polymerase chain reaction（MS-PCR）. Results： Aberrant methylation of KiSS-1 gene was detected in 55%（22/40） of the adjacent normal mucosa, 82.5% （33/40）of gastric cancer specimens, 80.95%（17/21） of the lymph nodes, and 42.5%（17/40） of peritoneal lavage fluid. Methylation in gastric carcinoma and lymphonode was more frequent than in non-neoplastic gastiric mucosa. Presence of KiSS-1 methylation in peritoneal lavage fluid was significantly correlated with tumor invasion （P=0.043）. The accuracy of KiSS-1 methylation in peritoneal lavage fluid for diagnosing peritoneal metastasis was 70%, with a sensitivity of 77.8% and a specificity of 67.7%. Conclusion： Aberrant methylation of KiSS-1 gene is a common event in the occurrence and progression of gastric carcinoma, which may provide useful information for the early diagnosis of peritoneal metastases and a new therapy for gastric cancer.