Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript Ⅱ KDR-TK plasmid by enzymatic digestion with Xho I and Sal I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble, pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP) expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to theprodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively. CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs. Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

Increased serum levels of soluble CD146 and vascular endothelial growth factor receptor 2 in patients with exudative age-related macular degeneration

AIM: To investigate serum levels of soluble CD146(s CD146) and vascular endothelial growth factor receptor 2(VEGFR2) in patients with age-related macular degeneration(AMD). METHODS: Eighty-eight patients with exudative AMD and 45 sex-and age-matched healthy controls were enrolled in this study conducted in China. Serum samples was obtained from the patients with exudative AMD and from the controls. Serum sCD146 and VEGFR2 protein levels were measured using an enzyme-linked immunosorbent assay.RESULTS: We found that serum sCD146 and VEGFR2 protein levels were significantly higher in the patients with exudative AMD group than in the controls(t=3.859, P<0.001 and t=3.829, P<0.001, respectively). Serum sCD146 levels were significantly higher in patients with classic choroidal neovascularization(CNV) than in those with occult CNV(t=9.899, P<0.001). There was a significant difference in the trend for exudative AMD in the highest versus lowest quartile of circulating sCD146 levels(χ2=10.29, P=0.001). The receiver operating characteristic curve analysis showed that the area under the curve was 0.696 for s CD146(95%CI: 0.601-0.791) with an optimum diagnostic cut-off value of 157.16 ng/mL, a sensitivity of 55.7%, and a specificity of 82.2%.CONCLUSION: The serum sCD146 level increases and may be a biomarker for exudative AMD.

Serum vascular endothelial growth factor receptor-2 and adropin levels in age-related macular degeneration

AIM： To investigate the serum levels of vascular endothelial growth factor receptor-2（VEGFR-2） and adropin in age-related macular degeneration（AMD）patients.·METHODS： Ninety-eight AMD patients were included in the study. Seventy-eight age- and sex-matched healthy volunteers were recruited as the control group.Fundus florescein angiography and optical coherence tomography were performed to assess the posterior segment details. Serum VEGFR-2 and adropin levels were measured using enzyme-linked immunosorbent assays and compared between the study groups.· RESULTS： AMD group had significantly increased foveal retinal thickness, serum LDL and HDL levels and significantly decreased subfoveal choroidal thickness（P =0.01, 0.047, 0.025 and 〈0.001, respectively）. Serum VEGFR-2level revealed a significant decrease in AMD patients compared to controls（26.48 ±6.44 vs 30.42 ±7.92 ng/m L,P 〈0.001）. There was an insignificant increase in serum adropin level in AMD patients（6.17±3.19 vs 5.79±2.71 ng/m L,P =0.4）. Serum level of VEGFR-2 in AMD patients had a significant negative correlation with foveal retinal thickness（r =-0.226, P =0.025） and a significant positive correlation with subfoveal choroidal thickness（r=0.2, P=0.048）.·CONCLUSION： The current study demonstrated that the decreased serum VEGFR-2 level may be considered in the development of AMD. Adropin does not seem to play a role in the pathogenesis of AMD.

Overexpression of vascular endothelial growth factor enhances the neuroprotective effects of bone marrow mesenchymal stem cell transplantation in ischemic stroke

Although bone marrow mesenchymal stem cells(BMSCs)might have therapeutic potency in ischemic stroke,the benefits are limited.The current study investigated the effects of BMSCs engineered to overexpress vascular endothelial growth factor(VEGF)on behavioral defects in a rat model of transient cerebral ischemia,which was induced by middle cerebral artery occlusion.VEGF-BMSCs or control grafts were injected into the left striatum of the infarcted hemisphere 24 hours after stroke.We found that compared with the stroke-only group and the vehicle-and BMSCs-control groups,the VEGF-BMSCs treated animals displayed the largest benefits,as evidenced by attenuated behavioral defects and smaller infarct volume 7 days after stroke.Additionally,VEGF-BMSCs greatly inhibited destruction of the blood-brain barrier,increased the regeneration of blood vessels in the region of ischemic penumbra,and reducedneuronal degeneration surrounding the infarct core.Further mechanistic studies showed that among all transplant groups,VEGF-BMSCs transplantation induced the highest level of brain-derived neurotrophic factor.These results suggest that BMSCs transplantation with vascular endothelial growth factor has the potential to treat ischemic stroke with better results than are currently available.

VEGFR2、miR-21、UCP1及UCP3在非小细胞肺癌组织中表达及与其预后的相关性分析

目的分析血管内皮细胞生长因子受体2(VEGFR2)、微小RNA-21(miR-21)、解偶联蛋白1(UCP1)、解偶联蛋白3(UCP3)在非小细胞肺癌(NSCLC)组织内的表达及与其预后的相关性。方法选取98例NSCLC患者,术中取其癌组织与癌旁正常组织,检测VEGFR2、miR-21、UCP1及UCP3表达;分析VEGFR2、miR-21、UCP1及UCP3表达与其临床病理特征的关系;随访1年,分析VEGFR2、miR-21、UCP1及UCP3表达与患者生存率的关系。结果癌组织内的VEGFR2、UCP1阳性表达率及miR-21相对表达量高于癌旁正常组织,UCP3阳性表达率低于癌旁正常组织,差异有统计学意义(P<0.05);VEGFR2、miR-21、UCP1及UCP3表达与淋巴结转移、临床分期、分化程度有关(P<0.05);VEGFR2、UCP1阳性表达及miR-21高表达患者的1年生存率分别低于VEGFR2、UCP1阴性表达及miR-21低表达患者,UCP3阳性表达患者的1年生存率高于UCP3阴性表达者,差异有统计学意义(P<0.05)。结论VEGFR2、miR-21、UCP1及UCP3在NSCLC癌组织内呈异常表达,与患者的预后具有紧密联系。

Expression of angiopoietins, Tie2 and vascular endothelial growth factor in angiogenesis and progression of hepatocellular carcinoma

AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically resected specimens of HCC and noncancerous liver （NCL） tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 （Ang-1）, angiopoietin-2 （Ang-2）, Tie2, and VEGF messenger RNA （mRNA） was examined by real-time quantitative reverse transcription-polymerase chain reaction （RT-PCR）. Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes＇ expression level and its relationship with tumor＇s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density （MVD） and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC. RESULTS： Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue （P 〈 0.05）, whereas the Ang-1 and Tie2 mRNAs showed no statistical significance （P 〉 0.05）, though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/ Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/Ang-1 ratio, Ang-2 and VEGF were all associated with tumor＇s clinicopathological parameters （P 〈 0.05） except for histological grades （P 〉 0.05）. Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different （P 〉 0.05）. CONCLUSION： Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.

Effects of endostatin on expression of vascular endothelial growth factor and its receptors and neovascularization in colonic carcinoma implanted in nude mice

AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.

The Effect of Simvastatin on mRNA Expression of Transforming Growth Factor-β1,Bone Morphogenetic Protein-2 and Vascular Endothelial Growth Factor in Tooth Extraction Socket

Aim To determine the effect of local simvastatin application on the mRNA expression level of transforming growth factor-β1 （TGF-β1）, bone morphogenetic protein-2 （BMP-2） and vascular endothelial growth factor （VEGF） in the tooth sockets of rat. Methodology Forty-eight male Wistar rats were randomly divided into experimental and control groups （n=24）. Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The expression of TGF-β1, BMP-2 and VEGF mRNA was determined by in situ hybridization in the tooth extraction socket at five days, one week, two weeks and four weeks after implantation. Results The fusiform stroma cells in the tooth extraction socket began to express TGF-β1, BMP-2 and VEGF mRNA in both experimental and control groups from one week after tooth extraction until the end of experiment. The expression of TGF-131 and BMP-2 mRNA in the experimental group was significantly up-regulated after one, two and four weeks, and expression of VEGF mRNA was significantly increased after one and two weeks compared with that in the control group. Conclusion The findings indicate that local administration of simvastatin can influence alveolar bone remodeling by regulating the expression of a school of growth factors which are crucial to osteogenesis in the tooth extraction socket.

Molecular Modeling Studies of Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitors Combining Molecular Docking and 3D-QSAR Methods

The vascular endothelial growth factor （VEGF） and its receptor tyrosine kinases VEGFR-2 or kinase insertdomain receptor （KDR） have emerged as attractive targets for the design of novel anticancer agents. In the present work, molecular docking method combined with three dimensional quantitative structure-activity relationships （comparative molecular field analysis （CoMFA） and comparative molecular similarity indice analysis （CoMSIA）） to analyze the possible interactions between KDR and those derivatives which acted as selective inhibitors. The CoMFA and CoMSIA models gave a cross-validated coefficient Q2 of 0.713 and 0.549, non-cross-validated R2 values of 0.974 and 0.878, and predicted R2 values of 0.966 and 0.823, respectively. The 3D contour maps generated by the CoMFA and CoMSIA models were used to identify the key structural requirements responsible for the biological activity. The information obtained from 3D-QSAR and docking studies were very helpful to design novel selective inhibitors of KDR with desired activity and good chemical property.

Role of serum β2-microglobulin, glycosylated hemoglobin, and vascular endothelial growth factor levels in diabetic nephropathy

BACKGROUND Diabetic nephropathy(DN)is a common complication of type 1 and type 2 diabetes that can lead to kidney damage and high blood pressure.Increasing evidence support the important roles of microproteins and cytokines,such asβ2-microglobulin(β2-MG),glycosylated hemoglobin(HbA1c),and vascular endothelial growth factor(VEGF),in the pathogenesis of this disease.In this study,we identified novel therapeutic options for this disease.AIM To analyze the guiding significance ofβ2-MG,HbA1c,and VEGF levels in patients with DN.METHODS A total of 107 patients with type 2 diabetes mellitus complicated with nephropathy and treated in our hospital from May 2018 to February 2021 were included in the study.Additionally,107 healthy individuals and 107 patients with simple diabetes mellitus were selected as the control groups.Changes inβ2-MG,HbA1c,and VEGF levels in the three groups as well as the different proteinuria exhibited by the three groups were examined.RESULTS Changes inβ2-MG,HbA1c,and VEGF levels in the disease,healthy,and simple diabetes groups were significantly different(P<0.05).The expression of these factors from high to low were evaluated in different groups by pairwise comparison.In the disease group,high to low changes inβ2-MG,HbA1c,and VEGF levels were noted in the massive proteinuria,microproteinuria,and normal urinary protein groups,respectively.Changes in these factors were positively correlated with disease progression.CONCLUSION The expression of serumβ2-MG,HbA1c,and VEGF was closely correlated with DN progression,and disease progression could be evaluated by these factors.

Effect of c-fos antisense probe on prostaglandin E_2-induced upregulation of vascular endothelial growth factor mRNA in human liver cancer cells

AIM: To examine the effect of prostaglandin E2 (PGE2) on the expression of vascular endothelial growth factor (VEGF) mRNA in the human hepatocellular carcinoma (HCC) HepG2 cells and the possible involvement of c-fos protein in this process.METHODS: Human HCC HepG2 cells were divided into three groups treated respectively with PGE2, a combination of PGE2 and c-fos antisense oligodeoxynucleotide (ASO),and PGE2 plus c-fos sense oligodeoxynudeotide (SO). The expression of VEGF mRNA in HepG2 cells after different treatments was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). The relative expression level of VEGF mRNA in HepG2 cells in each group was measured.RESULTS: Administration of PGE2 resulted in an increased expression of c-fosand VEGF mRNA in HepG2 cells. The relative expression level of c-fos mRNA reached the peak at 3 h (68.4±4.7%) after PGE2 treatment, which was significantly higher than that at 0 h (20.6±1.7%, P＜0.01).Whereas, the highest expression level of VEGF mRNA was observed at 6 h (100.5±6.1%) after PGE2 treatment, which was significantly higher than that at 0 h (33.2±2.4%,P＜0.01). C-fos ASO significantly reduced PGE2-induced VEGF mRNA expression in HepG2 cells.CONCLUSION: PGE2 increases the expression and secretion of VEGF in HCC cells by activating the transcription factor c-fos, promotes the angiogenesis of HCC and plays an important role in the pathogenesis of liver cancer.

Inhibitory effect of interferon-α-2b on expression of cyclooxygenase-2 and vascular endothelial growth factor in human hepatocellular carcinoma inoculated in nude mice

AIM： To evaluate the effects of interferon-α-2b （IFN- α-2b） on expression of cyclooxygenase-2 （COX-2） and vascular endothelial growth factor （VEGF） in human hepatocellular carcinoma （HCC） inoculated in nude mice and to study the underlying mechanism of IFN-α- 2b against HCC growth. METHODS： Thirb/-two nude mice bearing human HCC were randomly divided into four groups （n = 8）. On the 10th day after implantation of HCC cells, the mice in test groups （groups A, B and C） received IFN-α- 2b at a serial dose （10000 IU for group A, 20000 IU for group B, 40000 IU for group C sc daily） for 35 d. The mice in control group received normal saline （NS）. The growth conditions of transplanted tumors were observed. Both genes and proteins of COX-2 and VEGF were detected by RT-PCR and Western blot. Apoptosis of tumor cells in nude mice was detected by TUNEL assay after treatment with IFN-α-2b. RESULTS： Tumors were significantly smaller and had a lower weight in the IFN-α-2b treatment groups than those in the control group （P 〈 0.01）, and the tumor growth inhibition rate in groups A, B and C was 27.78%, 65.22% and 49.64%, respectively. The expression levels of both genes and proteins of COX-2 and VEGF were much lower in the IFN-α-2b treatment groups than in the control group （P 〈 0.01）. The apoptosis index （AI） of tumor cells in the IFN-α-2b treatment groups was markedly higher than that in the control group （P 〈 0.01）. Group B had a higher inhibition rate of tumor growth, a lower expression level of COX-2 and VEGF and a higher AI than groups A and C （P 〈 0.05）, but there was no significant difference between groups A and C. CONCLUSION： The inhibitory effects of IFN-α-2b on implanted tumor growth and apoptosis may be associated with the down-regulation of COX-2 and VEGF expression. There is a dose-effect relationship. The medium dose of IFN-α-2b for inhibiting tumor growth is 20 000 IU/d.

GENISTEIN INHIBITS EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN HER-2/NEU TRANSFECTED HUMAN BREAST CANCER MCF-7 CELLS

Objective： our previous studies have demonstrated that HER-2/neu gene expression in human breast cancer MCF-7 cells promotes angiogenesis in MCF-7 cells xenograft tumors, and genistein inhibits angiogenesis in MCF-7 cells with HER-2/neu expression xenograft tumors. Here, the effects of genistein on the expression of vascular endothelial growth factor （VEGF） in MCR-7 cells with HER-2/neu expression were further studied for exploring the molecular mechanism of anti-angiogenesis in HER-2/neu-overexpressing breast cancer by genistein. Methods： HER-2/neu-overexpressing MCF-7 cells （MCF-7/HER-2） were established by transfecting HEg-2/neu gene into HER-2/neu negative expression breast cancer MCF-7 cells. Immunocytochemical staining, western blot and reverse transcription-polymerase chain reaction （RT-PCR） were adopted to measure the expression of VEGF in MCF-7/HER-2 cells treated by genistein for 24, 48 and 72h. Results： HER-2/neu expression up-regulated VEGF mRNA and protein in MCF-7 cells, genistein decreased VEGF mRNA and protein level in MCF-7/HER-2 cells in a time-dependent manner. Conclusion： These results suggest that VEGF plays an important role in HER-2/neu gene expression promoted antiogenesis in breast cancer and genistein induced down-regulation of the expression of VEGF may be one of the molecular mechanisms of its anti-angiogenesis in HER-2/neu-overexpressing breast cancer.

Three-dimensional-arterial spin labeling perfusion correlation with diabetes-associated cognitive dysfunction and vascular endothelial growth factor in type 2 diabetes mellitus rat

BACKGROUND Type 2 diabetes mellitus(T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia.The mechanisms of diabetes-associated cognitive dysfunction(DACD) have not been fully elucidated to date.Some studies proved lower cerebral blood flow(CBF) in the hippocampus was associated with poor executive function and memory in T2DM.Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor(VEGF) expression and CBF changes in humans and animal models.In this study,we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional(3D) arterial spin labeling(3D-ASL) and VEGF expression in the hippocampus.AIM To assess the correlation between CBF(measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM.METHODS Forty Sprague-Dawley male rats were divided into control and T2DM groups.The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM.Cognitive function was assessed using the Morris water maze experiment.The CBF changes were measured by 3D-ASL magnetic resonance imaging.VEGF expression was determined using immunofluorescence.RESULTS The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group.The total distance traveled was longer in the T2DM group;also,the platform was crossed fewer times.The percentage of distance in the target zone significantly decreased.CBF decreased in the bilateral hippocampus in the T2DM group.No difference was found between the right CBF value and the left CBF value in the T2DM group.The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value.The escape latency negatively correlated with the CBF value.The number of rats crossing the platform positively correlated with the CBF value.CONCLUSION Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD.CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.

Vascular Endothelial Growth Factorl65-regulated Nasopharyngeal Carcinoma Cell Lines Invasion and Migration Involve Expression and Activation of Matrix Metalloproteinase-2

The effect of vascular endothelial growth factor （VEGF） overexpression on matrix metalloproteinase-2 （MMP-2） in nasopharyngeal carcinoma （NPC） cells in vitro and the possible mechanism involved were investigated, and the correlation between the expression of VEGF and MMP-2 in NPC evaluated. The NPC cells were transfected with PAd-trackVEGF165 plasmid. The expression levels of VEGF and MMP-2 mRNA and protein in NPC cells were detected by semi-quantitative RT-PCR and Western blot respectively. It was found that the expression of VEGF and MMP-2 mRNA and protein was significantly increased in NPC cells after transfection of VEGF 165. It was concluded that the expression of VEGF was correlated to the in vitro invasion of NPC cells, and the induction of MMP-2 by VEGF was a key process of NPC cell invasion.

Effects of Meloxicam on Vascular Endothelial Growth Factor and Angiopoietin-2 Expression in Colon Carcinoma Cell Line HT-29

To investigate the effect of meloxicam, a selected NSAIDs, on cell growth, expression of VEGF and angiopointin-2 （Ang-2） protein in HT-29 cell line, cultured HT-29 cells were treated with meloxicam of various concentrations for various lengths of time. The proliferation of HT-29 was detected by cell counting kit-8 （CCK-8）, the cell cycle was determined by flow cytometer and the levels of VEGF and Ang-2 protein in supernatants were examined by enzyme linked immunosorbent assay （ELISA）. The mRNA expressions of VEGF and Ang-2 in cultured HT-29 were determined by real-time quantitative reverse-transcription polymerase chain reaction. Our results showed that treatment of meloxicam of different concentrations and for various lengths of time had a cytotoxicic effect on the cell proliferation of HT-29 cells in a concentration-dependant and time-dependant manner. Cell cycle analysis showed that the cells were mainly blocked in G0/G1 phase. The VEGF and Ang-2 protein levels in supernatants of the culture medium were decreased gradually in a concentration-dependent or time-dependent fashion. The mRNA expression of cox-2, VEGF and Ang-2 showed a gradual and concentration-dependent reduction. It is concluded that meloxicam can reduce the expression of VEGF and Ang-2 at the protein and mRNA level in colon carcinoma cell line.

Vascular endothelial growth factor B inhibits insulin secretion in MIN6 cells and reduces Ca2+ and cyclic adenosine monophosphate levels through PI3K/AKT pathway

BACKGROUND Type 2 diabetes(T2 D) is characterized by insufficient insulin secretion caused by defective pancreatic β-cell function or insulin resistance,resulting in an increase in blood glucose.However,the mechanism involved in this lack of insulin secretion is unclear.The level of vascular endothelial growth factor B(VEGF-B) is significantly increased in T2 D patients.The inactivation of VEGF-B could restore insulin sensitivity in db/db mice by reducing fatty acid accumulation.It is speculated that VEGF-B is related to pancreatic β-cell dysfunction and is an important factor affecting β-cell secretion of insulin.As an in vitro model of normal pancreatic β-cells,the MIN6 cell line can be used to analyze the mechanism of insulin secretion and related biological effects.AIM To study the role of VEGF-B in the insulin secretion signaling pathway in MIN6 cells and explore the effect of VEGF-B on blood glucose regulation.METHODS The MIN6 mouse pancreatic islet β-cell line was used as the model system.By administering exogenous VEGF-B protein or knocking down VEGF-B expression in MIN6 cells,we examined the effects of VEGF-B on insulin secretion,Ca2+ and cyclic adenosine monophosphate(cAMP) levels,and the insulin secretion signaling pathway.RESULTS Exogenous VEGF-B inhibited the secretion of insulin and simultaneously reduced the levels of Ca2+ and cAMP in MIN6 cells.Exogenous VEGF-B also reduced the expression of phospholipase C gamma 1(PLCγ1),phosphatidylinositol 3-kinase(PI3 K),serine/threonine kinase(AKT),and other proteins in the insulin secretion pathway.Upon knockdown of VEGF-B,MIN6 cells exhibited increased insulin secretion and Ca2+ and cAMP levels and upregulated expression of PLCγ1,PI3 K,AKT,and other proteins.CONCLUSION VEGF-B can regulate insulin secretion by modulating the levels of Ca2+ and cAMP.VEGF-B involvement in insulin secretion is related to the expression of PLCγ1,PI3 K,AKT,and other signaling proteins.These results provide theoretical support and an experimental basis for the study of VEGF-B in the pathogenesis of T2 D.

联合多期增强CT纹理分析及血液学指标术前预测胃癌VEGFR2表达状态

目的探讨多期动态增强CT纹理分析参数联合血液学指标术前预测胃癌血管内皮生长因子受体2(vascu‐lar endothelial growth factor receptor2,VEGFR2)表达状态的价值。方法选取本院148例胃癌患者资料,获得术前血液学指标和三期增强CT纹理分析参数。基于组内相关系数和差异性检验对参数进行特征筛选。基于二元Logistic回归构建血液学模型、CT纹理分析模型及综合模型来预测VEGFR2表达状态。通过受试者工作特征曲线评估三个模型的诊断效能,并通过列线图来可视化地预测胃癌患者VEGFR2的表达状态。结果基于血液学指标构建的血液学模型曲线下面积(area under the curve,AUC)为0.687。由静脉期纹理分析参数构建的CT纹理分析模型的AUC值为0.624。联合血液学模型和CT纹理分析模型构建的综合模型AUC值为0.723。结论联合多期动态增强CT纹理分析参数及血液学指标有助于术前预测胃癌VEGFR2表达状态。

Expression of Vascular Endothelial Growth Factor-C and Vascular Endothelial Growth Factor Receptor-3 in Ovarian Epithelial Tumors

Objective： To explore the role of vascular endothelial growth factor-C （VEGF-C） in the process of angiogenesis, lymphangiogenesis and lymphatic metastasis in epithelial ovarian tumors. Methods： In situ hybridization and immunohistochemical staining for VEGF-C were performed in 30 epithelial ovarian carcinomas, 9 borderline tumors and 26 benign tumors. Endothelial cells were immunostained with anti-VEGFR-3 pAb and anti-CD31 mAb, and VEGFR-3 positive vessels and microvessel density （MVD） were assessed by image analysis. Results： VEGF-C mRNA and protein expression were detected in cytoplasm of carcinoma cells. VEGF-C mRNA and protein expression in ovarian epithelial carcinomas were significantly higher than those in borderline tumors and benign tumors （P〈0.05 or P〈0.01）. In ovarian epithelial carcinomas, VEGF-C protein expression, VEGFR-3 positive vessels and MVD were significantly higher in the cases of clinical stage Ⅲ-Ⅳ and with lymph node metastasis than those of clinical stage Ⅰ-Ⅱ and without lymph node metastasis respectively （P〈0.05 or P〈0.01）. VEGFR-3 positive vessels and MVD were significantly higher in VEGF-C protein positive tumors than negative tumors （P〈0.05）. VEGFR-3 positive vessels was significantly correlated with MVD（P〈0.01）. Conclusion： VEGF-C might play a role in lymphatic metastasis via lymphangiogenesis and angiogenesis in epithelial ovarian tumors, and VBEGF-C could be used as a biologic marker of metastasis in ovarian epithelial tumors.

EXPRESSION OF MATRIX METALLOPROTEINASE-2 AND VASCULAR ENDOTHELIAL GROWTH FACTOR IN HUMAN GLIOMA AND THEIR RELATION TO THE INVASION OF THE TUMOR

Objective To study the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) in different grade human glioma. To investigate their relation to the pathological grade and invasion of the tumor. Methods The expression of MMP-2 and VEGF were determined by immunohistochemical technique in 48 cases of human glioma and 10 specimens of normal brain tissue. Results The expression levels of MMP-2 and VEGF in human glioma were positively related to tumor grades (P<0.01), and their expressions in the glioma of grade Ⅲ and Ⅳ were significantly different from those in the glioma of grade Ⅰ-Ⅱand normal brain tissue (P<0.01). The expression of MMP-2 was positively correlated to that of VEGF (P<0.01). Conclusion MMP-2 and VEGF were highly expression in human glioma and were positively related to the tumor grades. The synergic interaction of MMP-2 and VEGF promoted the angiogenesis and invasion of human glioma.