Study of small GTPase other than RAS (Rab25, Rab31) and the microRNAs that regulate these protein translation (miR-let-7d, miR-185, miR-196a, miR-140) in breast cancer patients

Abstract

Background: Breast cancer (BC) is one of the most common leading causes of cancer related death in the world, thus its early detection might be a critical strategy to improve patients’ prognosis and survival. The aim of this study was to investigate the association of Rab25, Rab31 and microRNAs that control these Rabs (Let-7d, miR-185, miR-196a, miR-140) and their correlations with clinicopathologic characteristics in BC patients. Methods: Both mRNA and protein expression levels were measured by Real−time PCR, immunohistochemistry (IHC) and western blot respectively, in clinical tissues of 68 BC patients compared to margin tissues (MT). Results: Our results showed that expression levels of Rab25, Rab31 and Snail were markedly higher in both mRNA and protein levels (p < 0.01), in BC tissues compare to MT tissues (p < 0.05). Positive correlation between Rab25 and Snail protein levels in both BC tissues (r = 0.517, P = 0.001) and MT tissues (r = 0.226, P = 0.064) were observed, while correlation between Rab31 and Snail was weakly positive in both BC tissues (r = 0. 170, P = 0.165) and MT tissues (r = 0.088, P = 0.475). While expression levels of Let-7d, miR-185 and miR-140 were markedly lower in mRNA levels in BC tissues, miR-196a expression level was significantly higher in these samples (p < 0.001). Significant correlation between Rab25 levels with Let-7d and miR-185 (r = -0.717, P = 0.001 and r = -0.552, P = 0.015, respectively), and Rab31 with miR-140 And miR-196a (r = -0.530, P = 0.011 and r = 0.683, P = 0.005, respectively) were observed. Conclusion: The present study reported significant changes in the expression of Rab25 and Rab31 and their controlling microRNAs in BC patients compared to control samples, which may be clinically relevant for understanding the characteristics of BC.