Purpose To investigate the correlation of Dock180 and miR-31 expression in breast cancer cells,and to observe the effect of miR-31 on the invasion of breast cancer cells by Dock180.Methods MiR-31 was transfected into breast cancer cells by liposome transfection technique.The actual binding site of miR-31 to the 3'-untranslated region of Dock180 was confirmed through luciferase assay.Western blot was performed to detect the expression of Dockl80 and other related proteins.Real-time PCR was used to measure the expression of Dock180.Matrigel invasion were performed to detect the invasion of breast cancer cell lines with miR-31 increased.Resuits The protein levels of Dock180 in breast cancer cell lines negatively correlated with miR-31 expression,and Dock180 was directly targeted by miR-31.Dock180 downregulation and miR-31 overexpression reduced breast cancer cells invasion.Conclusion Dock180 modulated by miR-31 plays an important function in breast cancer cell lines invasion.

AIM:To investigate the mechanism of chronic stress-induced myocardial injury in atherosclerotic(AS)mice.METHODS:Eight-week-old SPF-grade male ApoE-/-mice and C57BL/6J mice used in this study.The mice received dietary intervention for 10 weeks followed by pathological examination to test the successful AS modeling.After AS establishment,the mice were exposed to chronic unpredictable mild stress(CUMS)for 6 weeks and then divided into five groups:control,CUMS,AS-regular diet(AS-r)+CUMS,AS-high-fat diet(AS-h),and AS-h+CUMS.During CUMS,open-field test and sucrose preference test were performed on mice in all groups.Blood lipids were characterized using an automatic biochemical analyzer.Hematoxylin-eosin(HE)and oil red O staining were performed to evaluate pathological changes in the aortic root.Cardiac function was assessed using echocardiography.The serum concentration of myocardial injury markers and ATP content was detected by ELISA.Transmission electron microscopy was employed to observe the ul-trastructure of myocardial mitochondria.Myocardial mitochondrial oxygen consumption rate was determined using the Oxy-graph-2k high-resolution respiratory energy metabolism analyzer.Western blot was conducted to quantify the expression of B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),and cleaved caspase-3.RESULTS:compared with the Control group,the total distance traveled,the number of entries into the central area,and the sucrose preference rate were significantly decreased in all CUMS groups(P<0.05).All AS groups exhibited varying levels of lipid deposition and endo-thelial damage in the aortic root,along with a significant reduction in cardiac function(P<0.05)and varying degrees of myocardial injury(P<0.05).In the AS-h+CUMS and AS-r+CUMS groups,myocardial mitochondrial structure was signifi-cantly disrupted.ATP content was significantly reduced(P<0.05),and the rates of oxygen consumption associated with mitochondrial respiratory chain complex I,mitochondrial respiratory chain complexes I+II,and the maximum respiratory capacity of the electron transport system were all significantly decreased(P<0.05).Moreover,the protein levels of Bax and cleaved caspase-3 were significantly increased(P<0.05),while that of Bcl-2 protein was significantly decreased(P<0.05).CONCLUSION:Chronic stress triggers mitochondrial non-steady-state load by disrupting myocardial structure and energy metabolism in AS mice,promoting myocardial cell apoptosis and myocardial injury.