Comparison of CDH1 Gene Hypermethylation Status in Blood and Serum among Gastric Cancer Patients

[摘要] Hypermethylation is epigenetic alteration, well known for gene silencing. CHD1 gene is known as invasion and tumor suppressor gene, decreased expression due to hypermethylation could promote tumor cell invasion and metastasis. Present study designed to investigate the CDH1 gene promoter hypermethylation status by methylation specific polymerase chain reaction in 100 newly diagnosed gastric cancer patients. 53% of hypermethylation was observed in DNA extracted from blood in Gastric cancer patients while 66% was observed in serum based DNA. Significant differences in CDH1gene promoter hypermethylation was observed in serum based DNA extracted from Gastric cancer patients. Patients in early stage (I & II) vs advanced stage (III & IV), distant organ metastases vs no metastases had 60% vs 7% and 42% 24% of CDH1 promoter hypermethylation in serum DNA (p = 0.006, 0.001) respectively. Patients who were with lymph node invasion, loss of appetite, loss of weight had 55%, 47%, 61% CDH1 gene promoter hypermethylation compare to who were not with lymph node invasion, loss of appetite, loss of weight had 11%, 19%, 5% of hypermethylation and these differences was found to be significant. Strong association was observed with overall median survival of patients (p < 0.0001). Patients who had CDH1 gene promoter hypermethylation in serum based DNA showed poor overall median survival (14.3 months) and unmethylated patients had better overall median survival (33.2 months). CDH1 hypermethylation status was found to be associated with advancement of disease, distant organ metastases and lymph node invasion in Gastric cancer patients.

[关键词] Gastric cancer;Hypermethylation;CDH1 gene;Prognosis