Abstract

Background: The incidence of gastric cancer is different in two sexes with ratio 2 to 1 that it is more common in men. The most important biologically reason is sexual hormones between two sexes that lead to sexual dimorphism and in turn can cause a sex bias in incidence of disease between two sexes. Recently, studies have shown that microRNA is involved in sexual dimorphism in gene expression. Given the sexual dimorphism in the incidence of gastric cancer and sex hormones response elements in the regulatory regions of miR-146a and miR-148a genes, in this study, the expression of these two genes in the stomach of healthy men and women at different age groups were compared.

Materials and Methods: Using endoscopy, gastric antrum tissues of 35 healthy women and 35 healthy men were collected. After RNA extraction and synthesis of cDNA, the expression of miR-146a and miR-148a genes were compared between sexes by Real time RT-PCR and data were analyzed using independent sample t and ANOVA tests.

Results: There was no difference between men and women in genes expression of miR-146a and miR-148a. However, expression of miR-146a gene was significantly more in men under 45 years than men over 45 years (p= 0.017, df= 14,  t= 1.47). Also,  expression of miR-148a gene was significantly more in men over 45 years than men under 45 years (p=0.001, df= 12, t= 1.28). But the expression of both genes had no significant difference between women under 45 years and women over 45 years.

Conclusion: Expression of miR-146a and miR-148a genes in the stomach is increased and decreased with aging in men, respectively.