Altered expression of miR-146a and miR-148a as new biomarkers in healthy Stomach tissues to distinguish the susceptibility of Men and women to gastric cancer

Background: The incidence of gastric cancer is more common in men than women with ratio 2 to 1 in the Globe. One of the most important biological reasons is sexual hormonesbetween two genders which in turn cause sexual dimorphism, leading a sex bias in incidence of disease between two sexes. MicroRNAs are involved in sexual dimorphism in genes expression. In this study, given the sex hormones response elements in the regulatory regions of miR-148a and miR-146a and sexual dimorphism in incidence of gastric cancer, for finding new biomarkers for prognosis and diagnosis, the expression of these two microRNAs in the stomach of healthy women and men at different age groups were compared.Materials and Methods: In this study, healthy tissues gained from gastric antrum of 35 healthy men and 35 healthy women. RNA contents were extracted and cDNA synthesised, the expression of miR-148a and miR-146a were compared between sexes by Real time RTPCR technique and data were analyzed by using ANOVA and independent sample T tests.Results: The expression of miR-148a and miR-146a did not show significant differences in two sexes. However, expression of miR-148a was more in men over 45 years than men under 45 years (p value< 0.05). Also, the expression of miR-146a was significantly high in men under 45 years than men over 45 years (p< 0.05). But, there was no significant difference between women over 45 years and women under 45 years.Conclusion: The expression of miR-148a and miR-146a with aging in men in the stomach increased and decreased respectively which suggest new biomarkers for prognosis and diagnosis of Gastric cancer.