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VEGF Expression (vegf + expression)
Selected AbstractsEffects of Cytokines on VEGF Expression and Secretion by Human First Trimester Trophoblast Cell LineAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2002SUN JU CHOI PROBLEM:,The mechanism through which vascular endothelial growth factor (VEGF) regulation occurs at the feto-maternal interface is poorly understood. The aim of this study was to investigate the effects of various cytokines on VEGF expression and secretion by trophoblast cells. METHOD OF STUDY:,We investigated the effects of cytokines on VEGF expression in human first trimester trophoblast cell line by analyzing VEGF messenger RNA (mRNA) by reverse transcription-polymerase chain reaction and VEGF protein secretion by enzyme linked immunosorbent assay. RESULTS:,The trophoblast cells expressed VEGF mRNA constitutively and the main subtypes were identified as VEGF121 and VEGF165. When cultured in the presence of interferon (IFN)-,, interleukin (IL)-1,, tumor necrosis factor (TNF)-,, IL-2, or IL-10, VEGF mRNA expression was found to be significantly increased by IL-1,, IFN-, and TNF-, but to be unaffected by IL-2 and IL-10. Moreover, VEGF secretion was most significantly increased by IFN-, treatment. CONCLUSION:,These results suggest that IL-1,, IFN-,, and TNF-, may regulate the production of VEGF in early gestational trophoblasts. [source] Signalling pathways involved in retinal endothelial cell proliferation induced by advanced glycation end products: inhibitory effect of gliclazideDIABETES OBESITY & METABOLISM, Issue 2 2004J.-C. Mamputu Aim:, We have previously demonstrated that advanced glycation end products (AGEs) stimulate bovine retinal endothelial cell (BREC) proliferation through induction of vascular endothelial growth factor (VEGF) production by these cells. We have also shown that gliclazide, a sulfonylurea which decreases oxidative stress, inhibits this effect. The aim of the present study was to characterize the signalling pathways involved in AGE-induced BREC proliferation and VEGF production and mediating the inhibitory effect of gliclazide on these biological events. Methods:, BRECs were treated or not treated with AGEs in the presence or absence of gliclazide, antioxidants, protein kinase C (PKC), mitogen-activated protein kinase (MAPK) or nuclear factor-,B (NF-,B) inhibitors. BREC proliferation was assessed by measuring [3H]-thymidine incorporation into DNA. Activation of PKC, MAPK and NF-,B signal transduction pathways and determination of VEGF expression were assessed by Western blot analysis using specific antibodies. MAPK activity was also determined by an in vitro kinase assay. Results:, Treatment of BRECs with AGEs significantly increased cell proliferation and VEGF expression. AGEs induced PKC-, translocation, extracellular signal-regulated protein kinase 1/2 and NF-,B activation in these cells. Pharmacological inhibition of these signalling pathways abolished AGE effects on cell proliferation and VEGF expression. Exposure of BRECs to gliclazide or antioxidants such as vitamin E or N -acetyl- l -cysteine resulted in a significant decrease in AGE-induced activation of PKC-, MAPK- and NF-,B-signalling pathways. Conclusions:, Our results demonstrate the involvement of PKC, MAPK and NF-,B in AGE-induced BREC proliferation and VEGF expression. Gliclazide inhibits BREC proliferation by interfering with these intracellular signal transduction pathways. [source] Vascular endothelial growth factor and diabetic retinopathy: pathophysiological mechanisms and treatment perspectivesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2003Ruth B. Caldwell Abstract Retinal neovascularization and macular edema are central features of diabetic retinopathy, the major cause of blindness in the developed world. Current treatments are limited in their efficacy and are associated with significant adverse effects. Characterization of the molecular and cellular processes involved in vascular growth and permeability has led to the recognition that the angiogenic growth factor and vascular permeability factor vascular endothelial growth factor (VEGF) plays a pivotal role in the retinal microvascular complications of diabetes. Therefore, VEGF represents an exciting target for therapeutic intervention in diabetic retinopathy. This review highlights the current understanding of the mechanisms that regulate VEGF gene expression and mediate its biological effects and how these processes may become altered during diabetes. The cellular and molecular alterations that characterize experimental models of diabetes are considered in relation to the influence of high glucose-mediated oxidative stress on VEGF expression and on the mechanisms of VEGF's actions under hyperglycemic induction. Finally, potential therapeutic strategies for preventing VEGF overexpression or blocking its pathological effects in the diabetic retina are considered. Copyright © 2003 John Wiley & Sons, Ltd. [source] Parathyroid hormone stimulates the endothelial expression of vascular endothelial growth factorEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2008G. Rashid ABSTRACT Background, We showed previously that parathyroid hormone (PTH) may stimulate the endothelial expression of pro-atherosclerotic and pro-inflammatory markers. Considering the impact of PTH on vasculature, we decided to evaluate its effect on mRNA and intra-cellular protein expressions of endothelial vascular endothelial growth factor (VEGF) taking into account that VEGF may play a role in the pathogenesis of endothelial dysfunctions. Materials and methods, Human umbilical vein cords endothelial cells (HUVEC) were stimulated for 24 h with 10,12,10,10 mol L,1 PTH. The VEGF-165 mRNA expression (critical in stimulating endothelial cell proliferation) was evaluated by RT/PCR and the intra-cellular VEGF protein expression by flow cytometry. The pathways by which PTH may have an effect on VEGF expression were also evaluated. Results, PTH (10,10 mol L,1) significantly increased VEGF-165 mRNA expression (P < 0·05). The addition of 50 nmol L,1 protein kinase C (PKC) and 10 µmol L,1 protein kinase A (PKA) inhibitors significantly reduced the VEGF-165 mRNA expression (P = 0·01). We also examined whether nitric oxide (NO) may be involved in the PTH-induced stimulation of VEGF-165 expression. Pre-treatment of the cells with 200 µmol L-nitro arginine methyl ester (L-NAME, NO synthase inhibitor) was found to inhibit VEGF-165 mRNA expression (P = 0·006). VEGF protein could not be detected in the medium of HUVEC but it was present in the cell cytoplasm. PTH had no significant effect on cytoplasmatic VEGF protein expression. Conclusion, The stimulatory effect of PTH on endothelial VEGF-165 mRNA expression is partly through PKC and PKA pathways and is also NO dependent. [source] Tenascin-C regulates angiogenesis in tumor through the regulation of vascular endothelial growth factor expressionINTERNATIONAL JOURNAL OF CANCER, Issue 1 2004Keiichiro Tanaka Abstract In order to verify whether tenascin-C (TN-C) is involved in angiogenesis as an extracellular signal molecule during tumorigenesis, cancerous cell transplantation experiments and coculture experiments were carried out, focusing on the regulation of vascular endothelial growth factor (VEGF). The A375 human melanoma cells introduced the GFP gene (A375-GFP), implanted subcutaneously into BALB/cA nude (WT) and TN-C knockout BALB/cA nude (TNKO) congenic mice. Furthermore, coculture experiments between A375-GFP and embryonic mesenchyme, which was prepared from both genotypes, were carried out to investigate the molecular mechanism in the cell-cell interactions. Both the content of TN-C and that of VEGF in the tumor and the conditioned medium were analyzed by the sandwich ELISA method. Seven days after transplantation of the A375-GFP, capillary nets became far more abundant in the tumors grown in WT mice than those in TNKO mice. Interestingly, VEGF and TN-C expressions showed antithetical expression patterns between the tumors in WT mice and those in TNKO mice. This peculiar phenomenon seems to be caused by a time lag prior to the onset of the mesenchymal regulation for the TN-C expression of A375-GFP. The coculture experiments revealed that WT mesenchyme had a much stronger effect than TNKO mesenchyme on both TN-C and VEGF expression. However, the defects of TNKO mesenchyme were restored in all cases by additional TN-C. These results clearly indicated that the expressions of both TN-C and VEGF depend on the surrounding mesenchyme, and that the function of mesenchyme is regulated by its own mesenchymal TN-C. In conclusion, the present data suggest that the matrix microenvironment organized by the host mesenchyme is very important for angiogenesis in tumor development. © 2003 Wiley-Liss, Inc. [source] Vascular endothelial growth factor (VEGF), VEGF receptors expression and microvascular density in benign and malignant thyroid diseasesINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2007Ala'eddin Jebreel Summary Angiogenesis is critical for the growth and metastatic spread of tumours. Vascular endothelial growth factor (VEGF) is the most potent inducer of neovasculature, and its increased expression has been related to a worse clinical outcome in many diseases. The purpose of this study was to evaluate the relation between VEGF, its receptors (VEGFR-1 and VEGFR-2) and microvessel density (MVD) in thyroid diseases. Immunostaining for VEGF and VEGF receptors was performed in 66 specimens of thyroid tissue, comprising 17 multinodular goitre (MNG), 14 Graves' disease, 10 follicular adenoma, 8 Hashimoto's thyroiditis, 7 papillary carcinoma and 10 normal thyroid specimens. Thyrocyte positivity for VEGF and VEGF receptors was scored 0,3. Immunohistochemistry for CD31, and CD34 on the same sections was performed to evaluate MVD. Immunohistochemical staining of VEGF in thyrocytes was positive in 92% of all the thyroid tissues studied. Using an immunostaining intensity cut off of 2, increased thyrocyte staining was seen in follicular adenoma specimens, MNG and normal thyroids compared with Hashimoto's thyroiditis and Graves' disease (P < 0.05). Similarly, VEGF thyrocyte expression in Graves' disease was less than other pathologies (P < 0.05). VEGFR-1 expression and the average MVD score did not differ between the different thyroid pathologies. VEGF expression was lower in autoimmune pathologies compared to autonomous growth processes. Conversely, both VEGFR-1 and VEGFR-2 were widely expressed in benign and neoplastic thyroid disease, suggesting that the up-regulation of VEGF and not its receptors occurs as tissue becomes autonomous. There was no clear relationship between MVD measurement and thyroid pathology. [source] miR-20b modulates VEGF expression by targeting HIF-1, and STAT3 in MCF-7 breast cancer cells,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2010Sandra Cascio MicroRNAs (miRNAs) are small non-coding RNAs that regulate the expression of different genes, including genes involved in cancer progression. A functional link between hypoxia, a key feature of the tumor microenvironment, and miRNA expression has been documented. We investigated whether and how miR-20b can regulate the expression of vascular endothelial growth factor (VEGF) in MCF-7 breast cancer cells under normoxic and hypoxia-mimicking conditions (CoCl2 exposure). Using immunoblotting, ELISA, and quantitative real-time PCR, we demonstrated that miR-20b decreased VEGF protein levels at 4 and 24,h following CoCl2 treatment, and VEGF mRNA at 4,h of treatment. In addition, miR-20b reduced VEGF protein expression in untreated cells. Next, we investigated the molecular mechanism by which pre-miR-20b can affect VEGF transcription, focusing on hypoxia inducible factor 1 (HIF-1) and signal transducer and activator of transcription 3 (STAT3), transcriptional inducers of VEGF and putative targets of miR-20b. Downregulation of VEGF mRNA by miR-20b under a 4,h of CoCl2 treatment was associated with reduced levels of nuclear HIF-1, subunit and STAT3. Chromatin immunoprecipitation (ChIP) assays revealed that HIF-1,, but not STAT3, was recruited to the VEGF promoter following the 4,h of CoCl2 treatment. This effect was inhibited by transfection of cells with pre-miR-20b. In addition, using siRNA knockdown, we demonstrated that the presence of STAT3 is necessary for CoCl2 -mediated HIF-1, nuclear accumulation and recruitment on VEGF promoter. In summary, this report demonstrates, for the first time, that the VEGF expression in breast cancer cells is mediated by HIF-1 and STAT3 in a miR-20b-dependent manner. J. Cell. Physiol. 224:242,249, 2010 © 2010 Wiley-Liss, Inc. [source] Involvement of vascular endothelial growth factor, CD44 and CD133 in periodontal disease and diabetes: an immunohistochemical studyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2009Guendalina Lucarini Abstract Aim: The aim of this study was to investigate the relationship between expression of angiogenic and regeneration markers and periodontal disease in subjects with/without diabetes mellitus. Material and Methods: Immunohistochemical detection of vascular endothelial growth factor (VEGF), CD44 and CD133 was performed in 16 samples each of (1) healthy gingiva from non-diabetic subjects (controls), (2) gingiva from non-diabetic subjects with periodontitis, (3) gingiva from subjects with type 1 diabetes and periodontitis, (4) gingiva from subjects with type 2 diabetes and periodontitis. Results: Diseased gingivae from patients with diabetes and periodontitis had greater clinical measures of periodontal disease than those with periodontitis only. VEGF expression was significantly enhanced in epithelial and endothelial cells from patients with periodontitis compared with controls (p<0.05). Epithelial CD44 expression was strong in all groups, while CD44 was significantly enhanced (p<0.05) in connective tissue cells from both diabetic groups. Epithelial and endothelial CD133 expression was comparable in all patients except those with type 2 diabetes and periodontitis, where it was not detected. Stromal CD133 expression was significantly lower in patients with type 2 diabetes and periodontitis and was increased in periodontitis patients (p<0.05). Conclusions: The involvement and high expression of VEGF, CD44 and CD133 in periodontal disease may predict a greater regeneration capacity of gingival tissue. [source] Suppression of growth of pancreatic cancer cell and expression of vascular endothelial growth factor by gene silencing with RNA interferenceJOURNAL OF DIGESTIVE DISEASES, Issue 4 2008Jian WANG OBJECTIVE: To explore the anti-angiogenesis and tumor cell growth suppressive effects resulted from gene silencing by RNAi in BxPC-3 human pancreatic cancer cells. METHODS: The designation and transfection of vascular endothelial growth factor (VEGF)-siRNA lentivirus was carried out in vitro. Real-time PCR and western blot were conducted to measure the expression levels of VEGF mRNA and protein. Flow cytometry was employed to evaluate cell apoptosis and cell death. A lactate dehydrogenase (LDH) assay was used to assess the cytotoxicity of VEGF-siRNA. A 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to picture the cellular growth. For the in vivo study, BxPC-3 cells were injected subcutaneously into nude mice to form xenografts. The mice were divided into three groups according to the intervention used. The control group, the negative control group and the knockdown group of mice were injected with saline, an empty lentivirus vehicle and lentivirus carrying VEGF-siRNA, respectively. None of the mice died during the study. When these mice were killed, the xenografts were collected and the tumor sizes of the different groups were compared. Finally, immunohistochemistry was used to assess the VEGF expression level and microvascular density. RESULTS: After the transfection of VEGF-siRNA lentivirus, the cellular expression of VEGF mRNA decreased to 50% of the control and the VEGF protein in the BxPC-3 cells decreased to 30% of the control. Apoptosis and cell death increased after transfection of the VEGF-siRNA lentivirus. The LDH assay showed high cytotoxicity induced by VEGF-siRNA lentivirus transfection. The MTT assay showed slower cellular growth in the knockdown cells. Tumor growth suppression was observed in nude mice that had received the VEGF-siRNA lentivirus transfection, and the tumor sizes of the xenografts in this group were clearly smaller than those in other two groups. VEGF expression and microvascular density were significantly decreased. CONCLUSION: Vascular endothelial growth factor gene silencing via VEGF-siRNA can effectively inhibit the production of VEGF and exert an anti-angiogenesis and tumor cell growth suppressive effect both in vitro and in vivo. [source] Vascular endothelial growth factor secretion from mesenteric adipose tissue and from creeping fat in Crohn's diseaseJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2006Andreas Schäffler Abstract Background:, Creeping fat represents a characteristic feature of Crohn's disease (CD), and adipose tissue secretes adipocytokines and chemokines/growth factors such as vascular endothelial growth factor (VEGF). Because VEGF serum levels and mucosal VEGF expression is elevated in CD patients, the aim of the present paper was to investigate creeping fat-derived VEGF secretion in CD. Material and Methods:, Adipose tissue was obtained from creeping fat of 10 patients with CD. Mesenteric adipose tissue was resected from 13 patients with colon cancer (CC) and from seven patients with diverticulitis (DIV). Three fat tissue specimens per well, and several wells (6,8) per patient were incubated ex vivo for 24 h. The release of VEGF into the supernatant was measured by ELISA. Results:, There was stable VEGF secretion from mesenteric adipose tissue of patients with CC or DIV and from creeping fat of patients with CD. Whereas the VEGF secretion rate was not different between patients with CD (465 ± 98 pg/g fat per 24 h) and CC (399 ± 48 pg/g fat per 24 h), VEGF secretion was significantly reduced in patients suffering from DIV (115 ± 41 pg/g fat per 24 h; P < 0.0001 and P = 0.001, respectively). The CD patients treated with steroids had significantly lower VEGF secretion rates (294 ± 42 pg/g fat per 24 h) than CD patients not receiving steroids (607 ± 105 pg/g fat per 24 h; P = 0.001). Conclusions:, Creeping fat is an important source of VEGF secretion. The characteristics of the inflammatory changes in CD might be due to the lack of VEGF downregulation that is seen in DIV. [source] Vascular endothelial growth factor protects hepatoma cells against oxidative stress-induced cell deathJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2006Shinji Osada Abstract Background:, The aim of the present study was to examine coordination of the vascular endothelial growth factor (VEGF) and VEGF receptor (Flk-1) system and to study control of VEGF expression by oxidative stress, which is considered a model for chronic liver disease. Methods:, Cell viability was determined by test method with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-dephenyl tetrazolium bromide (MTT). Expressions of cellular proteins were evaluated by western blot analysis. Results:, The c-Met tyrosine phosphorylation in PLC/PRF/5 hepatoma cells was increased by treatment with 20 ng/mL hepatocyte growth factor (HGF), and extracellular signal-regulated kinase (ERK) was also activated. Although Flk-1 was phosphorylated in response to VEGF (>50 ng/mL), phosphorylated ERK was not detected at these concentrations. A total of 5.0 and 10 µmol/L hydrogen peroxide (H2O2) caused cell death in a dose-dependent manner after 24 h. On western blot analysis at 1 h with H2O2, rapid phosphorylation of both ERK1/2 and c-Jun NH2 -terminal kinase (JNK) was observed. In the first 6 h, H2O2 induced cell death for 58.4 ± 6.8%, whereas the presence of 100 ng/mL VEGF improved the survival rate to 77.2 ± 4.2%. The VEGF significantly decreased H2O2 -induced cell death after 12 h, whereas HGF (20 ng/mL) did not have a similar effect. When cells were incubated with 5 µmol/L H2O2, expression of VEGF protein was detected. Furthermore, H2O2 -induced phosphorylation of ERK and JNK was also reduced by VEGF (100 ng/mL). In contrast, HGF did not induce phosphorylation of ERK and JNK. Conclusion:, Hepatoma cells might be able to survive under continuous oxidative stress through expression of VEGF. [source] Vascular endothelial growth factor enhances migration of astroglial cells in subventricular zone neurosphere culturesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2010Nina Mani Abstract Vascular endothelial growth factor (VEGF) is an endothelial and neuronal survival factor and a mitogen for endothelial cells and astrocytes in both explant and in vivo injury models. In the CNS, interplay between the vasculature and neural stem progenitor (NSP) cells is required for the maintenance of angiogenic/neurogenic coordination in the germinal niche in the subventricular zone (SVZ) of the lateral ventricle. Using an in vitro SVZ neurosphere (NS) model, this study aimed to understand the direct effects of VEGF and its receptor signaling on neonatal NSP cell growth and migration. Our data indicate that VEGF administration, compared with untreated or brain-derived neurotrophic factor-treated NS, significantly increased growth and migratory capacity of glial fibrillary acidic protein (GFAP)+ and nestin+ NSP cells and in secondary cultures induced a stellate astrocyte morphology. Blockade of both VEGF, which is normally expressed in some NS cells, and its flt-1 receptor signaling by neutralizing antibodies caused morphological changes specifically in GFAP+ cells and disrupted sphere formation and outward migration. These cells did not appear as conventional polygonal astrocytes; their process growth was severely restricted, and overall migration was reduced by up to 76% of control cultures. Blockade of VEGF's flk-1 receptor reduced VEGF expression and caused a lesser, though significant, decrease (29%) in NSP (GFAP+) cell migration. The results show that both VEGF and, in particular, flt-1 receptor signaling are critical to the proper configuration of the NS and its subsequent development. VEGF is also an important growth and migratory factor particularly for GFAP+ cells developing in SVZ-derived NS in culture. © 2009 Wiley-Liss, Inc. [source] Estrogen administration during superovulation increases oocyte quality and expressions of vascular endothelial growth factor and nitric oxide synthase in the ovaryJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2010Choong-Sik Ha Abstract Aims:, This study investigated whether estrogen administration during superovulation enhances oocyte quality using a mice model. We also investigated whether this estrogen treatment regulates the expressions of angiogenic factors, such as vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS), in the ovary. Method:, Female mice were co-injected with various doses of estrogen (1 µM, 10 µM and 100 µM) and pregnant mare serum gonadotrophin during superovulation, followed by human chorionic gonadotrophin injection 48 hours later. Then they were mated with individual males. After 18 hours, zygotes were flushed and cultured to blastocyst. The expression of VEGF and eNOS in the ovary was examined using Western blot and immunohistochemistry. The control group was superovulated without estrogen. Results:, Both numbers of ovulated zygotes and the rate of embryo development to blastocyst were significantly increased in the 1-µM estrogen dose compared to the control group. VEGF and eNOS expressions were stimulated by estrogen treatment. In particular, VEGF expression was significantly increased at 1-µM estrogen concentration, whereas, eNOS expression was significantly increased in all estrogen concentrations compared to controls. Conclusions:, The study showed that estrogen co-injection during superovulation increased the ovarian response, embryo developmental competence and expressions of VEGF and eNOS in the ovary. [source] Odontogenic keratocyst expresses vascular endothelial growth factor: an immunohistochemical studyJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 5 2009G. K. Mitrou Background:, Vascular endothelial growth factor (VEGF) expression may act as a sensitive measure of the angiogenic potential of a lesion. Furthermore, VEGF has been implicated in the pathogenesis of cystic tumors and inflammatory odontogenic cysts. Thus, we studied the expression of VEGF in the epithelium of odontogenic keratocyst (OK) in association with cell proliferation and apoptosis. Methods:, Forty-two cases of OK, 26 cases of dentigerous cyst (DC), and 15 cases of residual cyst (RC) were retrospectively examined by immunohistochemistry for VEGF, Ki67/Mib-1 and anti-caspase-3. For VEGF and caspase-3, the intensity of immunostaining was qualitatively assessed, while for the evaluation of Ki67 the average number of positively stained nuclei in 10 high-power microscopic fields (×400) was calculated. Results:, The VEGF expression was stronger in OK when compared with DC (P < 0.007). The rate of nuclear Ki67 expression in OK was significantly higher than that in DC (P < 0.001) and RC (P < 0.001). Cytoplasmic caspase-3 expression was statistically more intense in RC than in OK (P = 0.001) or DC (P < 0.001). A statistically significant correlation was seen in OK for Ki67 (P < 0.001) and VEGF (P = 0.023), but not for caspase-3. Multiple regression analysis revealed a linear relationship between VEGF and Ki67. Conclusions:, The VEGF was expressed in the epithelium of OK, DC, and RC with a variable intensity, and in OK VEGF expression was related to Ki67. It is suggested that VEGF expression by the odontogenic epithelium is not induced solely by inflammation. [source] Vascular endothelial growth factor (VEGF) expression in oral tissues: possible relevance to angiogenesis, tumour progression and field cancerisationJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 8 2001J. Carlile Abstract: The aim of this study was to assess whether vascular endothelial growth factor (VEGF) expression in oral tissues is associated with angiogenesis, disease progression or field cancerisation. Vascularity and VEGF immunoreactivity were quantified in 68 archival specimens including normal oral mucosa (NOM), dysplasia (DYS) and squamous cell carcinoma (SCC). Vascularity increased significantly with disease progression; it was also higher in NOM adjacent to SCC than in NOM from healthy tissue, suggesting an association with field cancerisation. VEGF expression in epithelial cells was evaluated using two antibodies and three indices. VEGF indices and vascularity were not directly correlated. The expression of VEGF was similar in all DYS and NOM specimens, whether or not adjacent to a concurrent lesion. A comparison of SCC with NOM or DYS led to opposite results, depending on the VEGF antibody and index used. We conclude that VEGF expression in the oral mucosa may play a physiological role, but does not appear to be associated with angiogenesis, field cancerisation or transition to dysplasia. Further studies concerned with tumour development require examining specific VEGF isoforms and standardisation of the methodology. [source] TNF-,,induced NF-,B signaling reverses age-related declines in VEGF induction and angiogenic activity in intervertebral disc tissuesJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009Tetsuro Ohba Abstract We previously demonstrated that VEGF and its receptors were expressed in human herniated discs (HD). TNF-, induced VEGF, resulting in neovascularization of disc tissues in a model of HD. The goal of the current research was to investigate the precise role of TNF-,,induced VEGF and the mechanism of angiogenesis in disc tissues. We performed ELISAs, Western blots, and immunohistological examinations to assess the role of TNF-,,induced VEGF using organ disc cultures with wild type, TNF receptor 1-null (TNF-RInull), or TNF receptor 2-null (TNF-RIInull) mice. VEGF induction was inhibited when we used TNF-RInull -derived disc tissues. NF-,B pathway inhibitors also strongly suppressed VEGF induction. Thus, TNF-, induced VEGF expression in disc cells primarily through the NF-,B pathway. In addition, VEGF immunoreactivity was detected predominantly in annulus fibrosus cells and increased after TNF-, stimulation. TNF-, treatment also resulted in CD31 expression on endothelial cells and formation of an anastomosing network. In contrast, angiogenic activity was strongly inhibited in the presence of NF-,B inhibitors or anti-VEGF antibody. Our data show angiogenesis activity in disc tissues is regulated by VEGF and the NF-,B pathway, both of which are induced by TNF-,. The level of angiogenic activity in disc tissues was closely related to aging. Because neovascularization of HD is indispensable for HD resorption, the prognosis of HD and the rate of the resorption process in patients may vary as a function of the patient's age. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:229,235, 2009 [source] Effect of ketoprofen in topical formulation on vascular endothelial growth factor expression and tumor growth in nude mice with osteosarcomaJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2004Kenshi Sakayama Abstract OST cells, a low metastatic cell line established from human osteosarcoma, were inoculated under the periosteum of the ossa cranii of nude mice. Four weeks later, tumors were percutaneously treated for an additional 4 weeks with a patch containing either placebo or ketoprofen (KP). In the placebo group, OST cells formed osteoid and invaded the cranial bone. Tumor mass weighed 3.54 g. Approximately 85% of cells within the tumor expressed proliferating cell nuclear antigen (PCNA), indicating that they were proliferating with a high mitotic activity. Many feeder vessels were located within the tumor. The majority of tumor cells expressed intensely vascular endothelial growth factor (VEGF). In the KP group, invasion of OST cells into the cranial bone was suppressed and the tumor mass was 47% of that of the placebo group. Approximately 65% of cells within the tumor were PCNA-negative, indicating that their growth was arrested. There were considerably fewer feeder vessels within the tumor in the KP group than in the placebo group. Only a small number of cells expressed VEGF. Based on these findings, we concluded that topical administration of KP to nude mice with osteosarcoma inhibited VEGF expression, reduced the development of feeder vessels for supply of nutrients and oxygen, and suppressed tumor growth. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Enhanced expression of vascular endothelial growth factor by periodontal pathogens in gingival fibroblastsJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2003Kanyarat Suthin Vascular endothelial growth factor (VEGF) has recently attracted attention as a potent inducer of vascular permeability and angiogenesis. Aberrant angiogenesis is often associated with lesion formation in chronic periodontitis. The aim of the present study was to investigate the properties of VEGF expression in human gingival fibroblasts (HGF) culture. HGF were stimulated with lipopolysaccharide (LPS), vesicle (Ve) and outer membrane protein (OMP) from Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. HGF constitutively produced VEGF and levels were significantly enhanced (P < 0.01) by stimulation with Ve and OMP from A. actinomycetemcomitans and P. gingivalis at concentrations of 10 µg/ml or higher. On the other hand, VEGF levels were not increased by LPS stimulation. VEGF mRNA expression was also observed in Ve- and OMP-stimulated HGF. A vascular permeability enhancement (VPE) assay was performed using guinea pigs to ascertain whether supernatant from cultures of Ve- and OMP-stimulated HGF enhance vascular permeability in vivo. Supernatant from cultures of Ve- and OMP-stimulated HGF strongly induced VPE. This was markedly suppressed upon simultaneous injection of anti-VEGF polyclonal antibodies with the supernatant. Heating and protease treatment of the stimulants reduced the VEGF enhancing levels in Ve and OMP in vitro. These results suggest that Ve and OMP may be crucial heat-labile and protease-sensitive components of periodontal pathogens that enhance VEGF expression. In addition, VEGF might be associated with the etiology of periodontitis in its early stages according to neovascularization stimulated by periodontal pathogens causing swelling and edema. [source] Melatonin suppresses tumor angiogenesis by inhibiting HIF-1, stabilization under hypoxiaJOURNAL OF PINEAL RESEARCH, Issue 2 2010Shi-Young Park Abstract:, Angiogenesis is an important mediator of tumor progression. As tumors expand, diffusion distances from the existing vascular supply increases, resulting in hypoxia in the cancer cells. Sustained expansion of a tumor mass requires new blood vessel formation to provide rapidly proliferating tumor cells with an adequate supply of oxygen and nutrients. The key regulator of hypoxia-induced angiogenesis is the transcription factor known as hypoxia-inducible factor (HIF)-1. HIF-1, is stabilized by hypoxia-induced reactive oxygen species (ROS) and enhances the expression of several types of hypoxic genes, including that of the angiogenic activator known as vascular endothelial cell growth factor (VEGF). In this study, we found that melatonin, a small lipophilic molecule secreted primarily by the pineal gland, destabilizes hypoxia-induced HIF-1, protein levels in the HCT116 human colon cancer cell line. This destabilization of HIF-1, resulted from the antioxidant activity of melatonin against ROS induced by hypoxia. Moreover, under hypoxia, melatonin suppressed HIF-1 transcriptional activity, leading to a decrease in VEGF expression. Melatonin also blocked in vitro tube formation and invasion and migration of human umbilical vein endothelial cells induced by hypoxia-stimulated conditioned media of HCT116 cells. These findings suggest that melatonin could play a pivotal role in tumor suppression via inhibition of HIF-1-mediated angiogenesis. [source] Melatonin modulates the expression of VEGF and HIF-1, induced by CoCl2 in cultured cancer cellsJOURNAL OF PINEAL RESEARCH, Issue 2 2008Min Dai Abstract:, Melatonin is an important natural oncostatic agent. At present there are no data available as to its possible influence on tumor angiogenesis, which is a major biological mechanism responsible for tumor growth and dissemination. It is well known that vascular endothelial growth factor (VEGF) is crucial to a solid tumor's higher vascularization and development. To investigate the possible influence of melatonin on angiogenesis, we studied the effect of melatonin on endogenous VEGF expression in three human cancer cell lines (PANC-1, HeLa and A549 cells). In this study, we report that physiologic concentrations of melatonin have no obvious impact on the VEGF expression, whereas pharmacologic concentrations of melatonin suppress the VEGF mRNA and protein levels induced by hypoxia mimetic cobalt chloride (CoCl2). Melatonin also decreases hypoxia-inducible factor (HIF)-1, protein levels, suggesting a role for transcription factor HIF-1 in the suppression of VEGF expression. The effect of pharmacologic concentrations of melatonin on VEGF and HIF-1, under normoxia is uncertain, which indicates that the regulatory mechanisms of VEGF in the absence or presence of CoCl2 are different and other or additional transcription factors may be involved. Taken together, our data show that melatonin in high concentrations markedly reduces the expression of endogenous VEGF and HIF-1, induced by CoCl2 in cultured cancer cells. [source] Age-dependent vascular endothelial growth factor expression and angiogenic capability of bladder smooth muscle cells: implications for cell-seeded technology in bladder tissue engineeringJOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 8 2009Joseph Azzarello Abstract Cell seeding technology is commonly used in the field of tissue engineering to enhance the performance of bioscaffolds and promote tissue regeneration. The age of cells used for ex vivo seeding to achieve maximal tissue regeneration has not been defined. Since rapid angiogenesis is the most critical step for tissue graft survival and success, we evaluated passage-dependent vascular endothelial growth factor (VEGF) expression in cultured smooth muscle cells (SMCs) obtained from urinary bladder and endothelial cell response to bladder SMCs. Levels of various VEGF isoforms mRNA expression and total VEGF secretion were determined by a semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) and an enzyme-linked immunosorbent assay (ELISA) analysis, respectively. In vitro endothelial cell migration in Transwell® and capillary-like tube formation in MatrigelÔ were used to predict the ability of bladder SMCs to promote angiogenesis. VEGF produced by cultured bladder SMCs increased from passages 4 to 7, and decreased from passages 7 to 12 at both mRNA and protein levels. Endothelial cell migration as well as capillary-like tube formation correlated with levels of VEGF expression by bladder SMCs. Pre-incubation of endothelial cells with a VEGF receptor 1/2 inhibitor, SU5416, significantly reduced the number of capillary-like tubes in SMC-endothelial cell MatrigelÔ co-culture, and confirmed the involvement of VEGF in endothelial cell tube formation. Our results demonstrate that cell passage number is related to levels of VEGF production, which may translate to angiogenesis in engineered tissues. Copyright © 2009 John Wiley & Sons, Ltd. [source] Effects of long-term cyclo-oxygenase 2 selective and acid inhibition on Barrett's oesophagusALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2007A. LANAS Summary Background There is an overexpression of cyclo-oxygenase 2 (COX-2) in Barrett's oesophagus (BO). Aim To determine the long-term effect of a COX-2 inhibitor on cellular mechanisms involved in BO. Methods A randomized controlled trial was conducted in BO patients allocated to continue the usual proton pump inhibitor (PPI) alone treatment, or PPI combined with rofecoxib (25 mg/day) for 6 months. Cell proliferation index and COX-2 expression in BO glands was determined in biopsy specimens at baseline and after treatment. Cell apoptosis, cyclin D1, p53 and vascular endothelial growth factor (VEGF) expression was also explored in a subset of patients. Student- t test and the U-Mann,Whitney test were used for quantitative and ordinal variables. Results Of 62 patients, 58 completed the study. A higher proportion of patients on rofecoxib + PPI exhibited a decrease in COX-2 expression compared to those treated with PPI alone, but cell proliferation index was not affected. Unlike PPI alone, rofecoxib + PPI was associated with an increase in the apoptotic cell index, a decrease in p53 cell staining and VEGF expression in mucosal vessels. No effect on low-grade dysplasia or cyclin D1 was observed. Conclusions The addition of rofecoxib to PPI therapy does not affect cell proliferation index in BO cells after 6 months of therapy, but does reduce COX-2 and VEGF expression and increases cell apoptosis. [source] Vascular endothelial growth factor expression in oligodendrogliomas: a correlative study withSainte-Anne malignancy grade, growth fractionand patient survivalNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 4 2000P. Varlet Microangiogenesis is a delayed but crucial event in the malignant progression of oligodendrogliomas. Accord-ingly, in the new Sainte-Anne grading system of oligodendrogliomas, endothelial hyperplasia and contrast enhancement, both being indicators of microangiogenesis, are key criteria for the distinction of grade A from grade B tumours. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor: a strong correlation between VEGF expression, Sainte-Anne malignancy grade and patient outcome might thus be expected. In order to assess this hypothesis, VEGF immunostaining was performed in a series of 34 oligodendrogliomas that included 11 grade B and 23 grade A, of which nine became grade B during the study period (mean clinical and imaging follow-up: 41 months). VEGF expression correlated strongly with Sainte-Anne tumour grade (P < 0.001), and inversely with patient survival (P < 0.001) and recurrence-free survival (P = 0.002). One hundred per cent of grade B but only 17% of grade A were VEGF-positive. By contrast, the MIB-1 labelling index did not correlate with VEGF expression, total survival or recurrence-free survival. In accordance with the grading system, this study showed that, in oligodendrogliomas, VEGF expression and microangiogenesis are progression-related phenomena that confer on these tumours a growth advantage by presumably reducing hypoxia-induced apoptotic cell death. These findings might have important implications in the future for the indication and timing of anti-angiogenic therapies. [source] VEGF expression as a prognostic marker in osteosarcomaPEDIATRIC BLOOD & CANCER, Issue 6 2009Jyoti Bajpai MD Abstract Background The vascular endothelial growth factor (VEGF) pathway is the key regulator of angiogenesis. In osteosarcoma baseline VEGF is of proven prognostic value but prognostic potential of post-NACT VEGF expression is largely unexplored. Procedure Treatment naive patients with osteosarcoma were subjected to initial staging workup followed by three cycles of neoadjuvant chemotherapy (NACT) and surgery; resected tumors were assessed for histological necrosis by Huvos grading. Initial biopsy and resected tumor specimens post-NACT were examined for VEGF expression by immunohistochemistry. Positive VEGF expression was considered when intensive positive staining was observed in >10% of the tumor cells. VEGF expression at baseline was compared with grade of tumor; pre-NACT and post-NACT VEGF expression were compared with histological necrosis. Receiver operating characteristic curves were generated to assess best threshold and predictability. Results A total of 31 patients were recruited with median age of 17 years (range 5,66 years); male/female ratio was 25:6; 23 patients (74%) were non-metastatic. At baseline, there was 90% concordance between positive VEGF expression and higher histological grade (28/31); baseline VEGF expression did not correlate well with stage and histological necrosis. Twenty-one (67%) were poor and 10 (33%) were good histologic responders; post-NACT VEGF expression as well as VEGF change following NACT significantly correlated with histological necrosis. Conclusion Positive VEGF expression in surviving tumor cells post-NACT in resected tumors appears to be an important negative prognostic factor in osteosarcoma which may help future therapies to be identified according to the angiogenic potential of the disease. Pediatr Blood Cancer 2009;53:1035,1039. © 2009 Wiley-Liss, Inc. [source] Epithelial,mesenchymal interactions in keloid pathogenesis modulate vascular endothelial growth factor expression and secretion,THE JOURNAL OF PATHOLOGY, Issue 1 2007CT Ong Abstract Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis during the wound healing process. As epithelial,mesenchymal interactions have been shown to regulate a plethora of genes in wound healing, we hypothesized that these interactions might have a role in modulating VEGF expression and angiogenesis. A two chamber co-culture model was used, wherein normal and keloid keratinocytes and fibroblasts were physically separated by membrane inserts while allowing cytokine diffusion. Cell lysates obtained from keratinocytes co-cultured with fibroblasts demonstrated increased expression of VEGF. An enzyme-linked immunosorbent assay (ELISA) showed significant increase in VEGF expression in co-culture conditioned media compared with controls. Additionally, the conditioned medium from keloid keratinocyte and fibroblast co-cultures increased proliferation and formation of complex three-dimensional capillary-like structures in human umbilical vein endothelial cells, emphasising the importance of epithelial,mesenchymal interactions in the angiogenic process. Immunostaining of keloid tissue localized VEGF in the basal layer of the epidermis and also demonstrated higher blood vessel density than normal skin. Keloid tissue extract also demonstrated increased expression of VEGF compared with normal skin. It is likely that epidermal VEGF exerts significant paracrine control over the dynamics and expression profile of underlying dermal fibroblasts. Addition of the inhibitors WP631, mitoxantrone, and Rapamycin to keloid keratinocyte and fibroblast co-cultures, downregulated secreted VEGF expression in a dose-dependent manner, suggesting therapeutic potential for these compounds in the treatment of keloid scars. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Effects of Cytokines on VEGF Expression and Secretion by Human First Trimester Trophoblast Cell LineAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2002SUN JU CHOI PROBLEM:,The mechanism through which vascular endothelial growth factor (VEGF) regulation occurs at the feto-maternal interface is poorly understood. The aim of this study was to investigate the effects of various cytokines on VEGF expression and secretion by trophoblast cells. METHOD OF STUDY:,We investigated the effects of cytokines on VEGF expression in human first trimester trophoblast cell line by analyzing VEGF messenger RNA (mRNA) by reverse transcription-polymerase chain reaction and VEGF protein secretion by enzyme linked immunosorbent assay. RESULTS:,The trophoblast cells expressed VEGF mRNA constitutively and the main subtypes were identified as VEGF121 and VEGF165. When cultured in the presence of interferon (IFN)-,, interleukin (IL)-1,, tumor necrosis factor (TNF)-,, IL-2, or IL-10, VEGF mRNA expression was found to be significantly increased by IL-1,, IFN-, and TNF-, but to be unaffected by IL-2 and IL-10. Moreover, VEGF secretion was most significantly increased by IFN-, treatment. CONCLUSION:,These results suggest that IL-1,, IFN-,, and TNF-, may regulate the production of VEGF in early gestational trophoblasts. [source] Beneficial Effects of Desferrioxamine on Encapsulated Human Islets,In Vitro and In Vivo StudyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2010V. Vaithilingam As many as 2000 IEQs (islet equivalent) of encapsulated human islets are required to normalize glucose levels in diabetic mice. To reduce this number, encapsulated islets were exposed to 100 ,M desferrioxamine (DFO) prior to transplantation. Cell viability, glucose-induced insulin secretion, VEGF (Vascular endothelial growth factor), HIF-1, (Hypoxia inducible factor-1 alpha), caspase-3 and caspase-8 levels were assessed after exposure to DFO for 12, 24 or 72 h. Subsequently, 1000, 750 or 500 encapsulated IEQs were infused into peritoneal cavity of diabetic mice after 24 h exposure to DFO. Neither viability nor function in vitro was affected by DFO, and levels of caspase-3 and caspase-8 were unchanged. DFO significantly enhanced VEGF secretion by 1.6- and 2.5-fold at 24 and 72 h, respectively, with a concomitant increase in HIF-1, levels. Euglycemia was achieved in 100% mice receiving 1000 preconditioned IEQs, as compared to only 36% receiving unconditioned IEQs (p < 0.001). Similarly, with 750 IEQ, euglycemia was achieved in 50% mice receiving preconditioned islets as compared to 10% receiving unconditioned islets (p = 0.049). Mice receiving preconditioned islets had lower glucose levels than those receiving unconditioned islets. In summary, DFO treatment enhances HIF-1, and VEGF expression in encapsulated human islets and improves their ability to function when transplanted. [source] Reduction of human prostate tumor vascularity by the ,1-adrenoceptor antagonist terazosinTHE PROSTATE, Issue 2 2001Kaspar Keledjian Abstract BACKGROUND We previously demonstrated that the quinazoline-derived a1-adrenoceptor antagonists doxazosin and terazosin suppress prostate cancer growth via apoptosis induction. The aim of this study was to determine the potential effect of a1-adrenoceptor antagonists on tumor vascularity of the human prostate. METHODS A total of 34 men with benign prostatic hyperplasia (BPH) who have been on terazosin treatment (for the obstructive symptoms) were pathologically diagnosed with prostate cancer following surgery. These patients were stratified according to the length of treatment periods with terazosin into two groups, 1 week,6 months, and 6,17 months. The control group consisted of prostatectomy specimens from 25 untreated prostate cancer patients undergoing surgery for localized disease. Formalin-fixed, paraffin-embedded prostate specimens were analyzed for apoptosis (TUNEL assay), cell proliferation (Ki-67), microvessel density (MVD) (von Willebrand factor/Factor VIII), vascular endothelial growth factor (VEGF) expression, and prostate specific antigen (PSA) immunoreactivity. RESULTS A significant induction of apoptosis was observed among cancerous prostatic epithelial cells in the terazosin-treated, as compared to the untreated prostate cancer specimens, while there was no significant change in the proliferative index of the same tumor cell populations after treatment. Furthermore, terazosin resulted in a significant decrease in prostate tissue MVD compared with the untreated group (P,<,0.01), that correlated with the increased apoptotic index of the cancerous areas. Tissue PSA expression in the prostatic tumor foci was also markedly reduced after terazosin treatment, while no significant changes in VEGF expression were detected. CONCLUSIONS These findings provide the first evidence that terazosin, a quinazoline-based a1-blocker decreases prostate tumor vascularity. Our study has significant clinical implications in identifying selected ,1-adrenoceptor antagonists as potential anti-tumor agents with apoptotic and anti-angiogenic effects in the human prostate that can be exploited for the treatment of advanced prostate cancer. Prostate 48:71,78, 2001. © 2001 Wiley-Liss, Inc. [source] Regulation of tumor dormancy as a function of tumor-mediated paracrine regulation of stromal Tsp-1 and VEGF expression,APMIS, Issue 7-8 2008SOO-YOUNG KANG Tumor dormancy is a critical yet poorly understood phenomenon affecting both the diagnosis and treatment of human cancers. This is due in large part to the lack of model systems available to study dormant tumor cells and the length of time needed to adequately examine the models that do exist. It has been demonstrated in several types of human cancer that tumor dormancy is a function of an impairment in angiogenesis. The intracellular signaling pathways regulating the expression of several pro- and anti-angiogenic proteins have been well characterized in human cancer cells. The intercellular signaling that takes place between tumor cells and the surrounding tumor-associated stroma has not been as extensively studied with regard to the regulation of angiogenesis, and as a result dormancy. In this review we define the key players in the regulation of angiogenesis and examine how their expression is regulated in the tumor-associated stroma. The resulting analysis is often seemingly paradoxical, underscoring the complexity of intercellular signaling within tumors and the need to better understand the environmental context underlying these signaling mechanisms. [source] Hypoxia-inducible factor-1, expression in experimental cirrhosis: correlation with vascular endothelial growth factor expression and angiogenesis,APMIS, Issue 7 2007SEVGI BOZOVA Angiogenesis progresses together with fibrogenesis during chronic liver injury. Hypoxia-inducible factor-1, (HIF-1,), a master regulator of homeostasis, plays a pivotal role in hypoxia-induced angiogenesis through its regulation of vascular endothelial growth factor (VEGF). The association between hypoxia, angiogenesis and VEGF expression has been demonstrated in experimental cirrhosis. However, expression of HIF-1, has yet to be reported. The aim of this study was to investigate the significance of HIF-1, expression during experimental liver fibrosis and the relationships between HIF-1, expression, VEGF expression and angiogenesis. Cirrhosis was induced in male Wistar rats by intraperitoneal administration of diethyl nitrosamine (DEN) (100 mg/kg, once a week). The serial sections from liver tissues were stained with anti-HIF-1,, anti-VEGF and anti-CD34 antibodies before being measured by light microscopy. Our results showed that HIF-1, expression gradually increases according to the severity of fibrosis (p<0.01). Moreover, its expression was found to be correlated with angiogenesis (r=0.916) and VEGF expression (r=0.969). The present study demonstrates that HIF-1, might have a role in the development of angiogenesis via regulation of VEGF during experimental liver fibrogenesis and suggests that this factor could be a potential target in the manipulation of angiogenesis in chronic inflammatory diseases of the liver. [source] | ||||||||||||||||||||||||||||||||||