• Molecules and Cells
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• 제28권1호
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• pp.1-5
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• 2009

Vascular endothelial growth factor (VEGF) is essential for many angiogenic processes both in normal and pathological conditions. However, the signaling pathways involved in VEGF-induced angiogenesis are incompletely understood. The protein kinase D1 (PKD1), a newly described calcium/calmodulin-dependent serine/threonine kinase, has been implicated in cell migration, proliferation and membrane trafficking. Increasing evidence suggests critical roles for PKD1-mediated signaling pathways in endothelial cells, particularly in the regulation of VEGF-induced angiogenesis. Recent studies show that class IIa histone deacetylases (HDACs) are PKD1 substrates and VEGF signal-responsive repressors of myocyte enhancer factor-2 (MEF2) transcriptional activation in endothelial cells. This review provides a guide to PKD1 signaling pathways and the direct downstream targets of PKD1 in VEGF signaling, and suggests important functions of PKD1 in angiogenesis.

• BMB Reports
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• 제41권12호
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• pp.833-839
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• 2008

Angiogenesis in tumors is driven by multiple growth factors that activate receptor tyrosine kinases. An important driving force of angiogenesis in solid tumors is signaling through vascular endothelial growth factor (VEGF) and its receptors (VEGFRs). Angiogenesis inhibitors that target this signaling pathway are now in widespread use for the treatment of cancer. However, when used alone, inhibitors of VEGF/VEGFR signaling do not destroy all blood vessels in tumors and do not slow the growth of most human cancers. VEGF/VEGFR signaling inhibitors are, therefore, used in combination with chemotherapeutic agents or radiation therapy. Additional targets for inhibiting angiogenesis would be useful for more efficacious treatment of cancer. One promising target is the signaling pathway of hepatocyte growth factor (HGF) and its receptor (HGFR, also known as c-Met), which plays important roles in angiogenesis and tumor growth. Inhibitors of this signaling pathway have been shown to inhibit angiogenesis in multiple in vitro and in vivo models. The HGF/c-Met signaling pathway is now recognized as a promising target in cancer by inhibiting angiogenesis, tumor growth, invasion, and metastasis.

• The Korean Journal of Physiology and Pharmacology
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• 제24권5호
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• pp.423-431
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• 2020

This study aimed to evaluate the effect of curcumin on brain hypoxic-ischemic (HI) damage in neonatal rats and whether the phosphoinositide 3-kinase (PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved. Brain HI damage models were established in neonatal rats, which received the following treatments: curcumin by intraperitoneal injection before injury, insulin-like growth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricular injection after injury. This was followed by neurological evaluation, hemodynamic measurements, histopathological assessment, TUNEL assay, flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt, Akt, and VEGF. Compared with rats that underwent sham operation, rats with brain HI damage showed remarkably increased neurological deficits, reduced right blood flow volume, elevated blood viscosity and haematocrit, and aggravated cell damage and apoptosis; these injuries were significantly improved by curcumin pretreatment. Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF, while curcumin pretreatment inhibited the expression of these proteins. In addition, IGF-1 treatment rescued the curcumin-induced down-regulated expression of p-PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effect of curcumin on brain HI damage. Overall, pretreatment with curcumin protected against brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway in neonatal rats.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권1호
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• pp.1-8
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• 2010

Background and Purpose: Vascular endothelial growth factor (VEGF)-C and VEGF receptor (VEGFR)-3 are involved in tumor lymphangiogenesis. Oral mucosal squamous cell carcinoma (OMSCC) preferentially metastasizes to cervical lymph nodes, so we investigated the expression and distribution of VEGFR-3 signaling proteins in OMSCC. Materials and Methods: Tissue samples of 18 OMSCC, 10 oral mucosal leukoplakia, and 3 normal oral mucosa were evaluated for expression of VEGF-C, VEGF-D, and VEGFR-3 by immunohistochemical staining. The presence of lymphatic vessels was determined using D2-40 staining, by which we also measured lymphatic vessel density (LVD). Results: 72% (13/18) and 56% (10/18) of tissue samples showed VEGF-C and VEGF-D immunopositivity in tumor cells and tumor-associated endothelial cells. VEGFR-3 was also expressed in most of OMSCC, which was up-regulated when compared with normal mucosa or with leukoplakia. Furthermore, LVD was higher in OMSCC than in leukoplakia. Conclusion: Taken together, our results suggest that autocrine activation of lymphatic endothelial cell via VEGFR-3 by VEGF-C and/or VEGF-D could be involved in progression of OMSCC. Therefore, VEGF-C/VEGFR-3 signaling pathway can be a molecular target for anti-metastatic therapy in OMSCC.

• BMB Reports
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• 제49권3호
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• pp.191-196
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• 2016

Vascular endothelial growth factor (VEGF) is a key mediator of angiogenesis and critical for normal embryonic development and repair of pathophysiological conditions in adults. Although phospholipase D (PLD) activity has been implicated in angiogenic processes, its role in VEGF signaling during angiogenesis in mammals is unclear. Here, we found that silencing of PLD2 by siRNA blocked VEGF-mediated signaling in immortalized human umbilical vein endothelial cells (iHUVECs). Also, VEGF-induced endothelial cell survival, proliferation, migration, and tube formation were inhibited by PLD2 silencing. Furthermore, while Pld2-knockout mice exhibited normal development, loss of PLD2 inhibited VEGF-mediated ex vivo angiogenesis. These findings suggest that PLD2 functions as a key mediator in the VEGF-mediated angiogenic functions of endothelial cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.530-543
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• 2006

Adeonoid cystic carcinoma (ACC) is one of the most common malignant tumors of salivary glands. It is characterized by a relentless regrowth especially around nerve tissues and a high rate of hematogenous distant metastasis. Clinically most deaths from salivary ACC are caused by delayed lung metastases that are resistant to conventional chemotherapy. So, knowledge of cellular and molecular properties that influence the dissemination of metastatic tumor cells, is important for new treatment strategies of metastatic lesions. We determined expressions of angiogenic signaling molecules microvessel density (MVD) using surgical specimens of human salivary ACC. Protein expressions of vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-2, activated VEGFR-2, and human CD31 were assessed in 20 cases of salivary ACC by immunohistochemical staining. Most of the tumors, especially ACC with a tubulocribriform pattern, were positive for antibodies of VEGF, VEGFR-2, and activated VEGFR-2. The overall percentages of the 20 specimens expressing VEGF, VEGFR-2, activated VEGFR-2 were 90, 95, and 95%, respectively. Immunoreactivities of the biomarkers in salivary ACC were higher than those in normal salivary gland. Furthermore, immune-related cells as well as tumor cells expressed VEGF/VEGFR-2. Microvessel density of salivary ACC was higher than that of normal salivary gland (P<0.05). Taken together, angiogenic signaling molecules are actively expressed in salivary ACC. And we suggest that these molecules may have critical role in the hematogenous spread of salivay ACC, which has a propensity for delayed lung metastasis. Therefore, these biomarkers can be molecular targets for therapy of metastasis of salivary ACC.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권3호
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• pp.201-206
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• 2004

Vascular endothelial growth factor (VEGF), plays a key role in angiogenesis. Many endogenous factors can affect angiogenesis in endothelial cells. VEGF is known to be a strong migration, sprouting, survival, and proliferation factor for endothelial cells during angiogenesis in endothelial cells. Searching for novel genes involved in VEGF signaling during angiogenesis, we carried out differential display polymerase chain reaction on RNA from VEGF-stimulated human umbilical vein endothelial cells (HUVECs). In this study, follistatin (FS) differentially expressed in VEGF-treated HUVECs, compared with controls. Addition of VEGF (10ng/L) produced an approximately 11.8-fold increase of FS mRNA. F5 or VEGF produced approximately 1.8- or 2.9-fold increases, respectively, in matrix metalloproteinase-2 (MMP-2) secretion for 12h, compared to the addition of a control buffer. We suggest that VEGF may affect the angiogenic effect of HUVECs, through a combination of the direct effects of VEGF itself, and the indirect effects mediated via induction of FS in vitro.

• 생명과학회지
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• 제34권2호
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• pp.128-137
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• 2024

이 리뷰 논문에서는 혈관 투과성, 내피세포 모집, 종양관련 혈관 및 림프관의 유지 등에서 핵심적인 과정인 angiogenesis와 lymphangiogenesis에 있어서 vascular endothelial growth factors (VEGF)가 이행하는 중요한 역할에 대해 재조명하고자 한다. VEGF는 tyrosine-kinase receptor인 VEGFR-1, VEGFR-2, VEGFR-3를 통해 그 역할을 이행하며, 이러한 VEGF-VEGFR 시스템은 암에서뿐만 아니라 비정상적인 혈관 및 림프관 형성으로 인해 야기되는 다른 질병들에 있어서도 핵심적인 요소로 각광받고 있다. 암의 측면에서 보았을 때, VEGF와 그 수용체는 종양관련 혈관 및 림프관을 형성하는 과정에서 필수적이라는 점에서 치료적인 타겟으로 이목을 끌고 있다. 때문에 암세포의 성장을 방해하기 위한 항VEGF 항체, 수용체 길항체, 수용체 기능 억제제 등과 같은 여러 가지 시도들이 있었지만, 아직까지 그 임상효과가 불확실하며 더 많은 연구들이 필요한 실정이다. 이 논문에서는 VEGF의 생리적 역할을 VEGF-A, VEGF-B, VEGF-C, VEGF-D, PLGF에 따라 나누어 설명하면서 VEGF/VEGFR 시스템의 중요성을 강조한다. VEGFR-1과 VEGFR-3은 각각 angiogenesis와 lymphangiogenesis에 핵심적인 인자이며, VEGFR-2의 경우 두 가지 모두를 일으킨다. 전반적으로 이 리뷰는 현재까지 밝혀진 암을 포함한 다양한 질병에서의 VEGF와 VEGFR의 역할에 대해 상세히 설명하고자 하였다. 이를 통해 치료 표적으로서 VEGF와 VEGFR의 활용이 더욱 촉진될 것으로 기대된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.991-994
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• 2012

Objective: VEGF-C has recently been identified as a key molecule which is involved in tumor lymphangiogenesis. The aim of this research was to investigate the role of PARP-1 inhibition in the regulation of VEGF-C expression in CT26 cells. Methods: CT26 cells were treated with or without the PARP-1 inhibitor 5-aminoisoquinolinone (5-AIQ). The expression of PARP-1, NF-kB, and VEGF-C proteins in CT26 cells was measured by Western blot analysis and the VEGF-C mRNA level was determined by reverse transcription polymerase chain reaction (RT-PCR). CT26-secreted VEGF-C was detected by enzyme-linked immunosorbent assay (ELISA). Results: The results of Western blot analysis showed that the expression levels of PARP-1, NF-kB, and VEGF-C were reduced in 5-AIQ treated CT26 cells and the levels of VEGF-C mRNA in 5-AIQ treated CT26 were significantly lower than t in 5-AIQ-untreated cells (P<0.05). The concentrations of CT26-secreted VEGF-C were also dramatically decreased (P<0.05). Conclusion: Here, we provide evidence for the first time that PARP-1 inhibition dramatically reduces VEGF-C expression via the nuclear factor NF-kB signaling pathway. We therefore propose that PARP-1 inhibition has an anti-lymphangiogenic effect and may contribute to the prevention of metastatic dissemination via the lymphatic system.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.543-551
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• 2001

The vascular endothelial growth factor (VEGF), or VEGF-A, is intimately involved in both physiological and pathological forms of angiogenesis. VEGF-A is now recognized as the founding member of a family of growth factors that has expanded to include VEGF-B, VEGF-C, VEGF-D, VEGF-E, and placental growth factor (PIGF). This family of cytokines binds differentially to at least three receptor tyrosine kinases, however, the extent to which family members other than VEGF-A contribute to physiological and pathological angiogenesis remains unclear. Issues that are of relevance include uncertainty regarding the consequences of signaling through VEGF - RI in particular, and the ability of some family members to heterodimerize, leading to the possibility ofheterodimeric receptor complexes. Structural characterization is one approach that can be used to address these issues, however, the vast majority of previous structure-function studies have only focused on VEGF-A. While these studies may provide some clues regarding the structural basis of the interaction of other family members with their receptors, studies using the ligands themselves are clearly required if highly specific interactions are to be revealed. With the recent progress toward refolding and purifying substantial' quantities of other VEGF family members, such structural studies are now possible. Here, these ~ssues are addressed with a particular emphasis on VEGF-B and its receptors.