Study of regulatory promoter polymorphism [-248 G>A] of Bax gene in patients with gastric cancer in the northern provinces of Iran

Aim: The aim of this study is to evaluate the polymorphism in Bax gene and its association with some clinical pathology traits in gastric cancer

Background: Gastric cancer is considered as the fourth most common cancer in the north and northwest of Iran. Bcl2 family has a key role in regulation of apoptosis, and any changes in the expression of Bcl2 lead to cancer

Patients and methods: Blood samples were collected from 100 cases and 89 controls in the northern provinces of Iran to evaluate promoter polymorphism [-248G

Results: The result of this study demonstrated the existence of polymorphism in the above-mentioned region of Bax gene. Sixty-nine patients [%69] with genotype GG and 31 patients [%31] with genotype AG were observed in the case group. No mutant genotype was found among cases. Sixty-seven individuals [%75/28] with genotype GG, 21 individuals [%23/59] with genotype AG and only one mutant genotype [AA] were demonstrated in the control group. The bioinformatics analysis showed that this polymorphism removed the probable Sp1 motifs, which may affect its expression in the cells

Conclusion: Allele G was the most frequent between both patient and control samples. Polymorphism may be effective on Bax expression, but it requires further investigation. Our results showed significant effects between genotypes and features of gender and age, whereas no significant relation were observed between the genotypes and grade, stage as well as smoking traits

[Tyrosine kinase domain gene polymorphism of epidermal growth factor receptor in gastric cancer in northern Iran]

Gastric cancer is one of the most common diseases of digestive system with a low 5-year survival rate and metastasis is the main cause of death. Multi-factors, such as changes in molecular pathways and deregulation of cells are involved in the disease development. Epidermal growth factor receptor pathway [EGFR] which is associated with cell proliferation and survival can influence cancer development. EGFR function is governed by its genetic polymorphism; thus, we aimed to study the tyrosine kinase domain gene mutations of the receptor in patients with gastric cancer. In this experimental study, 123 subjects [83 patients with gastric cancer and 40 normal subjects] were investigated in north of Iran for EGFR gene polymorphisms during 1 year. Genomic DNA was extracted by DNA extraction kit according to the manufacture's protocol. Polymerase chain reaction single-stranded conformation polymorphism [PCR-SSCP] and silver staining were performed for investigating EGFR gene polymorphisms. The participants included 72 men and 44 women. Gene polymorphism in exon 18 was present in 10% of the study population but SSCP pattern in exon 19 did not show different migrate bands neither in patients nor in normal subjects. It seems that screening for tyrosine kinas gene polymorphism of epidermal growth factor receptor in patients with gastric cancer and use of tyrosine kinas inhibitors could be useful in the prevention of disease progress and improvement of treatment process for a better quality of life in these patients