• Natural Product Sciences
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• v.13 no.2
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• pp.128-131
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• 2007

Tumor angiogenesis is a critical step f3r the growth and metastasis of solid tumors. Vascular endothelial growth factor (VEGF) is the most important angiogenic molecule associated with tumor-induced neovascularization. VEGF exerts its activity through binding to its receptor tyrosine kinase, KDR/Flk-1, expressed on the surface of endothelial cells. This study was carried out to investigate inhibitory effect of extracts from root cortex of Paeonia suffruticosa Andrews on VEGF binding to VEGF receptor. The MeOH extract from P. suffrutiocosa Andr. inhibited the binding of KDR/Flk-1-Fc to immobilized VEGF$_{165}$ more than 45% at the concentration of 100 ${\mu}$g/mL. The MeOH extract was further fractionated into n-hexane, ethyl acetate, n-BuOH, and aqueous fractions. Among the four fractions, the ethyl acetate fraction from the root cortex of P. suffruticosa Andr. exhibited highly effective inhibition (${\approx}$ 79% inhibition) and then n-BuOH fraction (${\approx}$ 45% inhibition) on the binding of KDR/Flk-1-Fc to immobilized VEGF$_{165}$ at the concentration of 100 ${\mu}$g/mL. The ethyl acetate fraction from the root cortex of P. suffruticosa Andr. more efficiently blocked VEGF-induced human umbilical vein endothelial cell proliferation, than the growth of HT1080 human fibrosarcoma. Our results suggest that P. suffruticosa Andr. may be used as a candidate fur developing anti-angiogenic agent.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.121-136
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• 2001

This study was performed to analyse the expression of VEGF and it's receptor(VEGFR) in the tension side of the periodontal ligament following orthodontic tooth movement. Upper first molars of Sprague-Dawley rats were moved medially using closed coil spring for 1, 2, 24 hours and 3, 7, 14 days. H&E staining, immunohistochemical staining and in situ hybridization methods were used to analyse the change of the expression of VEGF and VEGFR. The results from this study were as follows : 1. Following tensional force, periodontal ligament showed elongation of fibers, compression and congestion of vessels and regional hemorrhage. These tissue changes were recovered within 3 days of force application. New bone formation was seen after 3 days of force application and continued for the remaining experimental periods. 2. Following tensional force, VEGF and VEGF mRNA expression was increased in the periodontal ligament cells, osteoblasts and cementoblasts. This change was followed by increased vasculature in the periodontal ligament. 3. After 3 days of tensional force, VEGF and VEGF mRNA expression was confined mainly to the osteopaths and the periodontal ligament cells adjacent to the alveolar bone. After 2 weeks of force application, VEGF and VEGF mRNA expression was reduced to the level of control sample. 4. VEGFRs(Flt-1, Flk-1) showed similar expression pattern and it's expression was mainly seen in the endothelial cells and osteoblasts. Following tensional force VEGFR expression was increased in the endothelial cells and osteoblasts. In conclusion, in the tension side of the penodontal ligament, ligament cells, osteoblast and cementoblast showed increased expression of VEGF & VEGF mRNA. It preceded the increase of vasculature and new bone formation. The increased expression of VEGF mRNA in cementoblast may induce periodontal vessels, which distribute mainly the bone side half of periodontal ligament, grow in the direction of tensional force. Increased expression of VEGFR & VEGFR mRNA not only in endothelial cell but in osteoblast, osteocyte and periodontal cells showed VEGF acts not only in paracrine manner but in autocrine one.

• Biomolecules & Therapeutics
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• v.22 no.1
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• pp.1-9
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• 2014

Vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) system has been shown to play central roles not only in physiological angiogenesis, but also in pathological angiogenesis in diseases such as cancer. Based on these findings, a variety of anti-angiogenic drugs, including anti-VEGF antibodies and VEGFR/multi-receptor kinase inhibitors have been developed and approved for the clinical use. While the clinical efficacy of these drugs has been clearly demonstrated in cancer patients, they have not been shown to be effective in curing cancer, suggesting that further improvement in their design is necessary. Abnormal expression of an endogenous VEGF-inhibitor sFlt-1 has been shown to be involved in a variety of diseases, such as preeclampsia and aged macular degeneration. In addition, various factors modulating angiogenic processes have been recently isolated. Given this complexity then, extensive studies on the interrelationship between VEGF signals and other angiogenesis-regulatory systems will be important for developing future strategies to suppress diseases with an angiogenic component.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.871-877
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• 2008

Heme oxygenase-1 (HO-1), an inducible heme-degrading enzyme, is expressed by macrophages and endothelial cells in response to various stresses and mediators of inflammation. HO-1 has been recently implicated in regulation of angiogenesis via expression of VEGF. The purpose of this study was to determine the effects of HO-1 modulation on the collagen-induced arthritis (CIA) model and on angiogenesis via up- regulation of VEGF expression in human synovial fibroblast. DBA/1J mice were treated with an inhibitor of HO-1, tin protoporphyrin IX (SnPP), or with an inducer of HO-1, cobalt protoporphyrin IX (CoPP), from day 1 to day 35 after CIA induction. The clinical evolution of disease was monitored visually. At the end of the experiment, histopathologic changes were examined on the joints. VEGF expression in paws were measured by immunohistochemical stain. mRNA expression of HO-1 and VEGF stimulated with various concentration of $TNF-{\alpha}$, CoPP accessed on human synovial fibroblast by RT-PCR. Effects of pretreatment with SnPP on mRNA expression of HO-1 and VEGF in the presence of CoPP and $TNF-{\alpha}$ in synovial fibroblast was accessed by Real-time RT-PCR. Administration of cobalt protoporphyrin IX significantly induced the inflammatory response, with increased arthritis index and expression of VEGF in the paws of the arthritis models. Treatment with SnPP significantly reduced the severity of CIA through inhibition of joint inflammation and cartilage destruction. The expression of VEGF were also significantly reduced by SnPP treatment in the paw. CoPPIX as inducer of HO-1, increased HO-1 and VEGF expression dose dependently in synovial fibroblast. In contrast, inhibition of HO-1 activity by SnPPIX abrogated CoPPIX-induced HO-1 and VEGF production in synovial fibroblast. Stimulation with $TNF-{\alpha}$ increased HO-1 and VEGF expression itself and showed additive effect on HO-1 and VEGF expression when it treated with CoPP. When SnPP was treated with CoPP and $TNF-{\alpha}$, it abrogated the CoPP induced HO-1 and VEGF expression and also abrogated $TNF-{\alpha}$ induced HO-1 and VEGF expression in synovial fibroblast. The effects of HO-1 induction in rheumatoid arthritis results in aggravation of arthritis via up-regulation of VEGF. I concluded that inhibition of the expression or activity of HO-1 could be a therapeutic target of rheumatoid arthritis.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.495-499
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• 2006

In our previous studies, we demonstrated that Vascular Endothelial Growth Factor (VEGF) enhances bovine oocyte maturation and early embryonic development in serum supplemented media. In this experiment, to determine the synergistic effect of VEGF with serum components on early embryonic development in vitro in cattle, 1 mg/ml polyvinyl-alcohol (PVA) was replaced with foetal bovine serum (FBS) in maturation and culture media. Bovine oocytes were matured in Synthetic Oviduct Fluid (SOF) supplemented with PVA, PVA+5 ng/ml of VEGF, FBS, or FBS+VEGF. Fertilized oocytes were cultured in the same conditions for 8 days. The development of embryos was examined at 48 h post- insemination and on days 6, 7 and 8. The results were analyzed using repeated measures two- factor ANOVA, in which the effects of VEGF and serum were assigned as two factors. The development rate to 4- to 8-cell embryos at 48 h was significantly higher in the PVA+VEGF group than in the PVA group (44.7% and 31.5%, respectively). However, the highest development rate to 4- to 8-cell embryos was obtained from the FBS+VEGF group (58.8%). On day 8, the blastocyst rates were higher in the PVA+VEGF (22.8%), FBS (32.1%, p<0.05) and FBS+VEGF (42.1%, p<0.05) groups than in the PVA group (17.1%). Two- factor ANOVA of the development rates indicates that VEGF had a significant effect, but had no synergistic effect with serum components on early embryonic development. The results of the present study demonstrate that VEGF improves the in vitro developmental competence of bovine oocytes and/or embryos independent of the effect of serum components.

• Journal of Gastric Cancer
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• v.1 no.1
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• pp.10-16
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• 2001

Purpose: The p53 protein is a tumor supressor gene, and its mutation is associated with biologic aggressiveness. CD44v6, one of the CD44 family, is a cell surface glycoprotein that plays a role in cancer invasion and metastasis. Vascular endothelial growth factor (VEGF) is another recently identified growth factor with significant angiogenic properties. The purpose of this study was to investigate p53, CD44v6, and VEGF expressions to determine whether degree of expression was related to pathological parameters such as Lauren's classification, depth of invasion, and lymph node metastasis. Materials and Methods: Immunohistochemical stains of p53, CD44v6, and VEGF in formalin-fixed paraffin-embedded tissue sections of 125 gastric adenocarcinomas were done. Results: The overall expression rates of p53, CD44v6, and VEGF were $54.4\%$ (68/125), $36.8\%$ (46/125), and $48.0\%$ (60/125), respectively. The p53, not CD44v6 and VEGF was higher in intestinal-type gastric carcinomas by Lauren's classification. The expressions of p53, CD44v6, and VEGF were statistically correlated with depth of tumor invasion. The expression of CD44v6 was higher in the lymph node metastatic group than in the negative group. The p53 expression was significantly associated with VEGF expression. Conclusions: These data suggest that the expressions of p53, CD44v6, and VEGF are biologically related to malignancy. The p53 and CD44v6 expressions are independent; however, p53 gene mutation is one of the contributing factors to VEGF expression in gastric adenocarcinoma.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1270-1274
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• 2005

The vascular endothelial growth factor (VEGF) plays a key role in angiogenesis, which is a process where new blood vessels develop from the endothelium of a pre-existing vasculature. VEGF exerts its activity by binding to its receptor tyrosine kinase, KDR/Flk-1, which is expressed on the surface of endothelial cells. A methanol extract and organic solvent (n-hexane, ethyl acetate, n-butanol, aqueous) fractions from Rubus coreanus were examined for their inhibitory effects on VEGF binding to the VEGF receptor. The methanol extract from the crude drug were found to significantly inhibit VEGF binding to the VEGF receptor ($IC_{50}$$\thickapprox$27 $\mu$g/mL). Among the fractions examined, the aqueous fraction from the medicinal plant showed potent inhibitory effects against the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ in a dose­dependent manner ($IC_{50}$$\thickapprox$11 $\mu$g/mL). Sanguiin H-6 was isolated as an active principle from the aqueous fraction, and inhibited the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ in a dose­dependent manner ($IC_{50}$$\thickapprox$0.3 $\mu$g/mL). In addition, sanguiin H-6 efficiently blocked the VEGF­induced HUVEC proliferation in a dose-dependent manner ($IC_{50}$$\thickapprox$7.4 $\mu$g/mL) but had no effect on the growth of HT1080 human fibrosarcoma cells. This suggests that sanguiin H-6 might be a potential anti-angiogenic agent.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.368-375
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• 2011

Background: Recent clinical observation reported that there was a significant correlation between change in circulating vascular endothelial growth factor (VEGF) levels and the occurrence of severe acute graft-versus-host disease (GVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the action mechanisms of VEGF in GVHD have not been demonstrated. Methods: This study investigated whether or not blockade of VEGF has an effect on acute GVHD in a lethally irradiated murine allo-HSCT model of $B6\;(H-2^b)\;{\rightarrow}B6D2F1\;(H-2^{b/d})$. Syngeneic or allogeneic recipient mice were injected subcutaneously with anti-VEGF peptides, dRK6 ($50{\mu}g/dose$) or control diluent every other day for 2 weeks (total 7 doses). Results: Administration of the dRK6 peptide after allo-HSCT significantly reduced survival with greaterclinical GVHD scores and body weight loss. Allogeneic recipients injected with the dRK6 peptide exhibited significantly increased circulating levels of VEGF and expansion of donor $CD3^+$ T cells on day +7 compared to control treated animals. The donor $CD4^+$ and $CD8^+$ T-cell subsets have differential expansion caused by the dRK6 injection. The circulating VEGF levels were reduced on day +14 regardless of blockade of VEGF. Conclusion: Together these findings demonstrate that the allo-reactive responses after allo-HSCT are exaggerated by the blockade of VEGF. VEGF seems to be consumed during the progression of acute GVHD in this murine allo-HSCT model.

• Tuberculosis and Respiratory Diseases
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• v.50 no.6
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• pp.676-685
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• 2001

Background : Angiogenesis is an essential component of tumor growth and metastasis, and the vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors. Several solid tumors produce substantial amounts of VEGF, which stimulates proliferation and the migration of endothelial cells, thereby inducing neovasculization by a paracrine mechanism. To evaluate the prognostic roles of angiogenesis and VEGF expression in patients with non-small cell lung cancer, the relationship between VEGF expression in tumor tissues, the clinicopathologic features and the overall survival rate were analysed. Methods : Sixty-nine resected primary non-small cell lung cancer specimens were evaluated. The paraffin-embedded tumor tissues were stained by anti-VEGF polyclonal antibodies using an immunohistochemical method to assess VEGF expression. Results : In Forty-one patients (59%), the VEGF antigen was expressed weakly in their tumor tissue, whereas in twenty-eight patients (41%) the VEGF antigen was expressed strongly. The median survival time of the weak VEGF expression group was 24 months, and that of the strong VEGF expression group was 19 months. The three year-survival rates were 35%, 33%, respectively. The survival difference between both groups was not statistically significant. Conclusion : Although results were not statistically significant, the strong expression group tended to poorer prognosis than the weak expression group.

• Journal of Gastric Cancer
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• v.9 no.3
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• pp.96-103
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• 2009

Purpose: Lymph node metastasis is an important factor in determining prognosis and therapeutic options for early gastric cancer (EGC) patients. Vascular endothelial growth factor (VEGF)-C and D are known as lymphangiogenic factors, and cyclooxygenase (COX)-2 is thought to play a role in lymph node metastasis in gastric carcinoma. This study was designed to determine whether the expression of VEGF-C, VEGF-D, and COX-2 is associated with clinicopathologic factors, especially lymph node metastasis in EGCs invading the submucosa. Materials and Methods: Tissue samples were obtained from 85 Patients undergoing standard gastrectomy with lymph node dissection between 1991 and 2007 in the Department of Surgery of Daejeon St. Mary's Hospital in Daejeon, Korea. All patients were diagnosed with gastric cancers and submucosal invasion. We examined the expression of VEGF-C, VEGF-D, and COX-2 using immunohistochemical methods. Results: Of the 85 patients, 16 (18.8%) had lymph node metastasis. VEGF-C, VEGF-D, and COX-2 were positively expressed in 34.1% (29/85), 22.3% (19/85), and 37.6% (32/85) of the patients. VEGF-C and COX-2 expression was significantly correlated with lymph node metastasis (P<0.05). A positive correlation existed between VEGF-C and COX-2 expression (P< 0.001). Conclusion: VEGF-C and COX-2 expression is associated with lymph node metastasis in gastric cancer with submucosal invasion. VEGF-C and COX-2 may thus be predictive markers for lymph node metastasis in EGC patients with submucosal invasion.