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.

Molecular biomarkers for the detection of metastatic colorectal cancer cells

Approximately half of all patients with colorectal cancer develop local recurrence or distant metastasis during the course of their illness. Recently, the molecular detection of metastatic cancer cells in various types of clinical samples, such as lymph nodes, bone marrow, peripheral blood, and peritoneal lavage fluid, has been investigated as a potential prognostic marker. The prognostic value of molecular tumor cell detection was independent of the type of detection method used. As assays become more sensitive and quantitative, a more thorough assessment of the cancer status of patients will be based on molecular markers alone. At present, it is difficult to conclude that one specific molecular marker is superior to others. Comparative analyses are recommended to assess the prognostic impact of molecular analyses in the same patient and determine the biomarkers that provide the most accurate prognostic information.