RESUMEN
Objective:To investigate the effect of miR-503 targeting CBX2 on drug resistance of breast cancer MDA-MB-231 cells and its potential mechanism.Methods:miR-con group, miR-503 group, si-con group, two groups of si-chromosome homologues (CBX), anti-miR-con group, anti-miR-503 group, miR-503+pcDNA group, miR-503+pcDNA-CBx2 group were set up. Real-time quantitative fluorescence polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-503 and CBX2 mRNA. Western blot was used to detect protein expression. Cell activity was detected by MTT assay. The targeted regulatory relationship was detected by double luciferase assay.Results:Compared with normal breast cells HBL-100 (1.02±0.09), the expression level of miR-503 in breast cancer cells MCF-7 (0.41±0.05), MDA-MB-231 (0.25±0.03) and BT474 (0.35±0.04) was significantly decreased. The expression levels of CBX2 mRNA in MCF-7, MDA-MB-231 and BT474 cells were (4.02±0.35), (4.62±0.36) and (3.47±0.33), respectively. The expression levels of CBX2 protein in MCF-7, MDA-MB-231 and BT474 cells were (0.64±0.07), (0.74±0.05) and (0.68±0.06), respectively. The mRNA and protein contents of CBX2 in normal breast cells HPL-100 were (1.01±0.08) and (0.40±0.04), respectively, and the expression of CBX2 in breast cancer cells was significantly higher than that in normal breast cells ( P<0.05). Overexpression of miR-503 (3.64± 0.30) and silting of CBX2 inhibited proliferation, migration and invasion of MDA-MB-231 cells, and inhibited CBX2 (0.26±0.03), cyclin-dependent kinases, CDK) 4 (0.32± 0.03), Cyclin (CCN) D1 (0.58±0.03), matrix metalloproteinases (matrix metalloproteinases), MMP-2 (0.32±0.03) and MMP-9 (0.32±0.04) ( P<0.05). miR-503 targeted the expression of CBX2, and overexpression of CBX2 (0.75±0.03) could reverse the proliferation and drug resistance of miR-503 to MDA-MB-231 breast cancer cells. Conclusion:miR-503 may inhibit the proliferation, migration and invasion of breast cancer cells by down-regulating the expression of CBX2.
RESUMEN
Cranial magnetic resonance imaging (MRI) examinations were performed in 419 patients with type 2 diabetes mellitus (T2DM) from June to December 2016.The brain white matter lesions were defined by white matter hyperintensity (WMH) in MRI,which was detected in 380 cases (WMH group) and not detected in 39 cases (non-WMH group).The Montreal Cognitive Assessment (MoCA) was used to evaluate the cognitive function.The study showed that there were significant differences in the duration of diabetes,the proportion of hypertension,total cholesterol (TC) and MoCA scores between the two groups (all P＜0.05).The age,duration of diabetes,hypertension and glyclated hemoglobin (HbA1c) were significantly correlated with white matter lesions(OR=1.157,1.116,5.184,1.128;P＜0.05);and the white matter lesions,age,and body mass index (BMI) were significantly correlated with cognitive dysfunction in diabetic patients (OR=2.137,1.175,1.247;P＜0.05).The study result indicates that control of white matter lesions may prevent and improve cognitive dysfunction in T2DM patients.