Background and purpose: At present

gastric cancer is considered to be both genetic and epigenetic disease

and epigenetic alterations play a significant role in the development of gastric cancer. DNA methylation is the most well studied and most in-depth epigenetic modifications in human-beings. The silencing of tumor-related genes by DNA methylation is reversible. ERCC1 is a kind of DNA repair gene. The present study was aimed to detect the CpG island methylation status of ERCC1 gene promoter in gastric cancer tissues and corresponding peripheral blood

and to explore the relationship between methylation of ERCC1 gene in peripheral blood and in gastric cancer tissues. Methods: Methylation specific PCR was performed to detect the methylation status of ERCC1 gene in the tumor tissues and the paired peripheral blood from 30 gastric cancer patients. Results: The positive rate of methylation of ERCC1 gene promoter CpG island was 76.7% (23/30) in the tumor tissues and 63.3% (19/30) in serum of gastric cancer patients

and the difference had no statistical significance. Conclusion: Our studies suggest that ERCC1 gene promoter CpG island methylation can be detected in a high proportion of the serum consisting with that in tumor tissues of gastric cancer patients

and the detection of methylation status of ERCC1 gene in peripheral blood provides a more simple

fast and reliable way for the medical treatment of gastric cancer and also provides the possible theoretical basis for the CpG island methylation of ERCC1 gene promoter as a target for the treatment of gastric cancer.