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Objective To investigate the role of Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3) signaling pathway in the pathogenesis of type 2 diabetic macroangiopathy. Methods The human umbilical vein endothelial cells (HUVECs) were incubated for 24 h with the serum of healthy volunteers, simple type 2 diabetic patients and patients with type 2 diabetic macroangiopathy. JAK2 specific inhibitor AG490 was used to block the JAK2/STAT3 signaling pathway. According to different treatments, the cells were divided into normal control group (NC group, n=30), simple diabetes mellitus group (DM group, n=30), type 2 diabetic macroangiopathy group (DV group, n=30), DM+AG490 group (DM+AG490 group, n=30) and DV+AG490 group (DV+AG490 group, n=30). Real-time quantitative PCR technique was used to detect the mRNA expression of JAK2, STAT3, vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (FLT1) in each group. Western blotting analysis was used to detect the protein expression of JAK2, STAT3 and phosphorylated STAT3(p-STAT3). Results Compared with the NC group, the expression of JAK2, STAT3 mRNA and JAK2, and p-STAT3 protein were significantly up-regulated in DM and DV groups (P<0.05), and the expression of JAK2, STAT3 mRNA and JAK2, p-STAT3 protein in DV groups were significantly higher than those in DM group (P< 0.05). The expression of JAK2, STAT3 mRNA and JAK2, p-STAT3 protein in DM+AG490 group and DV+AG490 group were significantly lower than those in the DM group and DV group (P< 0.05). Compared with the NC and DM group, the expression of VEGF, FLT1 mRNA was significantly up-regulated in DV group(P<0.05). Compared with the DV group, the expression of VEGF and FLT1mRNA were significantly reduced in DV+AG490 group (P< 0.05). Conclusion JAK2/STAT3 signaling pathway may play a role in the pathogenesis of type 2 diabetic macroangiopathy.
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Objective To investigate the effects of metformin on cell proliferation in differentiation degree of endometrial carcinoma cells and related mechanisms. Methods The endometrial cancer cell lines Ishikawa and AN3CA were used. Cell proliferation was assessed after exposure to metformin with or without epithelial growth factor receptor (EGFR) inhibitor AG1478 by cell counting kit-8 (CCK-8) method. EGFR mRNA was determined by reverse transcription (RT)-PCR. The expression of phosphorylation EGFR (p-EGFR) and total EGFR (t-EGFR) and phosphorylation extracellular signal-regulated kinase 1/2 (p-ERK1/2) and total ERK1/2 (t-ERK1/2) were examined by western blot. Results (1)CCK-8 experiment showed that metformin could inhibit the proliferation of endometrial cancer cells in a time-dependent manner and a dose-dependent manner (P0.05). But the expression levels of p-EGFR and p-ERK1/2 protein were significantly lower between two groups (P<0.01), which showed a time-dependent manner(P<0.01). Conclusion Metformin could inhibit the proliferation of endometrial cancer cells, the inhibition is associated with the differentiation degree of cancer cells. Metformin could enhance the EGFR signaling pathway inhibitor AG1478 inhibition of endometrial cancer cells, which may inhibit EGFR expression of phosphorylated proteins to inhibit the phosphorylation of ERK1/2 proteins and then inhibit proliferation of endometrial cancer cells.
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Phosphatase of regenerating liver-3 (PRL-3) is a novel small molecule protein-tyrosine-phosphatase,which plays an important role in the oncogenesis and deveopment of tumors.Studies show that PRL-3 regulates neoplasm progress through participating in multiple signal pathways.Its high expression can significantly promote neoplasm metastasis in cancer tissue.However,there is no expression of PRL-3 in most normal tissue.PRL-3 is expected to be a potential tumor maker of diagnosis and a new target for the therapy of cancer.
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Objective To expore the mechanism of low-dose interfone-γ(IFN-γ) influences on differentiation of oligodendrocyte precursor cell. Methods The cerebral cortex samples were obtained from one day old SD rats to form mixed single cell suspensions. After culturing in full medium for 7 to 10 days, succession and differential velocity adherent technique were performed to acquire oligodendrocyte precursor cell and cultured in serum-free medium. IFN-γ, AG490 and Fludarabine were added during the culture of oligodendrocyte precursor cell and reverse transcription-polymerase chain reaction, Western blot and flow cytometry were performed to evaluate the expression of intracellular P27kip1 and its influence on the differentiation of oligodendrocyte precursor cell. Results (1)The expression of P27kip1 mRNA and protein was lower in IFN-γ group than in control group (t=85. 535, P<0. 05;t= 12. 481, P<0. 05), while the expression of P27kip1 mRNA and protein in IFN-γ+AG490 group and IFN-γ+Fludarabine group were both higher than those in IFN-γ group (P<0. 05). (2) The phosphorylation levels of JAK2/STAT1 in INF-γ group were higher than that in the other three groups (P<0. 05). (3) The percentage of myelin basic protein positive cells was (68. 42 ± 2. 53)% in IFN-γ group, lower than that in control group [(88.21 ± 1.97)%](t=10.682, P < 0.05). Myelin basic protein positive cells in IFN-γ + AG490 group were (57. 63 ±2. 75) %, lower than those in the IFN-γ group. The same figure in IFN-γ+Fludarabine group were (79. 53±4. 15)% , higher than those in IFN-γ group (t = 3.957, P<0.05). Conclusions Low-dose IFN-γ can regulate the expression of intracellular P27kip1 through JAK2/STAT1 signal transduction pathway and Fludarabine may participate in this process and improve the differentiation and maturation of oligodendrocyte precursor cell.