Negin Naderi - Department of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran
Saber Zahri - Department of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran
Saeid Latifi Navid - Department of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran
Abbas Yazdanbod - Department of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran

Gastric cancer is the fifth most common cancer in the world and almost two-thirds of all cases of gastric cancer occur in Asia. This malignancy is a multi-step process that loss of function of P53 plays a crucial role. The human P53 gene expresses 12 different isoforms. Since Δ133p53 isoforms is a dominant negative toward full-length P53 (FL-P53), and its expression regulated via alternative promoter in intron 4 of the gene, hence mutations in intron 4 can change the internal promoter activity, and lead to the tumorigenesis process. The aim of the present study is the evaluation of alteration of intron 4 of p53 gene in gastric cancer. In this case-control study tumor and control tissues isolated via endoscopy from 48 patients with gastric cancer who had referred to Ara’s clinic of Imam Khomeini hospital in Ardabil and they had no family history of stomach cancer. Genomic DNA of tissues was extracted and the sequence of intron 4 of the p53 gene was amplified and sequenced. Finally, the effect of possible mutations and its frequency were analyzed. In this study, rs1794287 polymorphism in the position of 475 of intron 4 was observed in 31.58% of the tumor samples. The most common type of tumor in this study was intestinal adenocarcinoma. The mean patient age obtained 67.3 years. The result showed that the intron 4 of the gene polymorphism is probably a genetic predisposing factor for gastric cancer, and this polymorphism is better to be considered as a molecular marker in the genetic study of patients with gastric cancer.

gastric cancer, p53 gene, intron 4