MiR-296-5p suppresses papillary thyroid carcinoma cell growth via targeting PLK1.

OBJECTIVE: Our study aimed to explore the effects of miRNA-296-5p on the biological behaviors of papillary thyroid carcinoma (PTC) cells and its potential mechanism. PATIENTS AND METHODS: Twenty-eight PTC tissues and the corresponding non-cancerous tissues were collected. Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) analysis was performed to detect the expression levels of miR-296-5p in PTC tissues and the adjacent non-cancerous tissues. Besides, the different endogenous expression levels of miR-296-5p in PTC cell line (K1) and normal thyroid gland cell line (Nthy-ori3-1) were also detected by RT-qPCR. Bioinformatics analysis, Western blot and Dual-Luciferase reporter gene assay were performed to demonstrate whether polo-like kinase 1 (PLK-1) was a downstream target of miR-296-5p. Subsequently, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, flow cytometry analysis, colony formation assay and TUNEL assay were performed to estimate whether PLK1 down-regulation could attenuate the malignant behaviors of PTC cells in vitro. RESULTS: RT-qPCR results showed that the expression level of miR-296-5p was significantly down-regulated in PTC tissues and cells, indicating that miR-296-5p may participate in PTC development. We predicted target genes of miR-296-5p by bioinformatics and identified PLK1 as a target gene of miR-296-5p. By Western blot and Dual-Luciferase reporter gene assay, we confirmed that miR-296-5p was partially complement to PLKl mRNA 3'UTR sequence and inhibited PLK1 expression at the post-transcriptional level. In vitro experiments suggested that the transfection of miR-296-5p mimics into K1 cells suppressed cell proliferation, inhibited cell clone formation, arrest the cell cycle in G2/M phase and induced apoptosis. Importantly, PLK1 reversed the inhibitory effects of miR-296-5p on biological behaviors of PTC. CONCLUSIONS: MiR-296-5p influences the biological behaviors of PTC by regulating PLK1. These findings provide a new perspective for the molecular mechanism of PTC pathogenesis and also contribute to developing new targets and methods for PTC treatment.

Pravastatin and C reactive protein modulate protease- activated receptor-1 expression in vitro blood platelets.

Protease-activated receptor-1 (PAR-1) plays an important role in mediating activation of human platelets by thrombin. However, mechanism of statin in ADP-induced platelet PAR-1 expression is also unknown. Aggregometry, flow cytometry, immunoblotting and ELISA were used to determine role of pravastatin participating in ADP-induced platelet activation and PAR-1 expression. ADP stimulation significantly increased PAR-1 expression on platelets. PAR-1 antagonist SCH-79797 inhibited platelet aggregation as well as decreased platelet P-selectin expression induced by ADP. CRP inhibited PAR-1 expression induced by ADP in a concentration-dependent manner. Pravastatin treatment reduced PAR-1 expression in a concentration-dependent manner. Combination treatment of CRP and Pravastatin significantly reduced platelet PAR-1 expression induced by ADP. By western-blot analysis, pravastatin treatment did not influence total PAR-1 after ADP treatment. CRP decreased platelet total PAR-1 expression induced by ADP. Pravastatin and CRP reduced TXB2 formation by ADP significantly. CRP decreased thrombin fragment F1+2 level with ADP treatment. Pravastatin, in contrast, did not influence F1+2 level. Upon treatment with Pravastatin reduced platelet LOX-1 expression induced by ADP. In conclusion, PAR-1 served as a critical mechanism to relay platelet activation process induced by ADP. CRP and pravastatin reduce PAR-1 expression in platelet by ADP pathway.

Glucometabolic state of in-hospital patients with primary hypertension in sub-population of partial regions in China.

Abnormal glucose metabolism (AGM) is common but underestimated in patients with coronary heart disease (CHD). Here, we reported 898 in-hospital patients with primary hypertension (PH) at the university hospitals in developed regions of China. Oral glucose tolerance test (OGTT) was performed in those without known type-2 diabetes mellitus (2-DM). A total of 158 patients had known 2-DM and 32 were newly diagnosed as 2-DM by fasting blood glucose (FBG). OGTT revealed that 83 had 2-DM and 296 had impaired glucose tolerance (IGT). The proportion of 2-DM and AGM increased from 21.2 to 30.4% and from 57.5 to 68.7% upon OGTT. Prevalence of AGM and 2-DM increased with the increase of age, and incidence of AGM and 2-DM was significant higher in patients with risk factors (including CHD, overweight, hyperlipidaemia, proteinuria) than those without risk factors mentioned above. Glucose was not sufficiently controlled in 55.1% of the patients with 2-DM upon treatment, well controlled in 35.4% and not controlled in 9.5%. So AGM is also prevalent in PH patients especially the elders and those with risk factors, which was underestimated in most cases. Moreover, much lower awareness, treatment and control of 2-DM occurred in some regions of China, thus strengthening health education for patients and heightening consciousness of doctor are very important and eminent. Except for FBG, more attention should be paid to postprandial blood glucose ignored before, and OGTT should be a routine procedure in PH patients, especially in older patients and those with the factors mentioned above.