L Sadeghi-Amiri - Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
N Nikbakhsh-Zati - Department of Surgery, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran.
A Barzegar - Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
P Mehraban - Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.

Introduction and aim: Gastric cancer is the fourth common malignancies and the second leading cause of cancer related death worldwide. DNA methylation of some genes has been considered as one of the most important changes which control organization and function of a cell. Recent studies have revealed discrete methylation pattern of P450 CYP1A1 genes which is xenobiotics detoxification enzyme in tumeric versus its neighboring normal tissue. Method: Tissues were dissected from patients who were undergone surgery. Genomic DNA extracted using phenol-chloroform method was subjected to bisulfate treatment by Qiagene kit. Desired region located in CYP1A1 gene promoter were PCR-amplified and were sequenced in both directions in Bioneer company. Statistical analysis was conducted by mann-whitney method. Results: Results showed that the methylation rates of some CpG dinucleotides are different in normal versus turmeric tissues. Statistical analysis revealed that there are significant differences between methylation rates of turmeric and normal tissues ((P<0.05%). Conclusion: Increasing the methylation rates of CpG dinucleotides present in CYP1A1 gene promoter is significantly associated with stomach cancer incidence in. Regarding to the importance of respective region in CYP1A1 gene promoter as xenobiotic and transcription factors response elements, different methylation rate in turmeric versus normal tissues would change transcription rates which might lead to cancer incidence. Screening methylation pattern of this region may be useful as tumor marker to evaluate susceptibility to stomach cancer.

CYP1A1, DNA methylation, Gastric cancer, Northern Iran.