Gene/Protein
Disease
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Enzyme
Compound
Pivot Concepts:
Gene/Protein
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Target Concepts:
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Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Vasoactive intestinal peptide (VIP) upregulates the expression of vascular endothelial cell growth factor (
VEGF
(189),
VEGF
(165) and
VEGF
(121)) mRNAs in human prostate cancer LNCaP cells, as shown by reverse transcriptase-polymerase chain reaction (RT-PCR). Real-time RT-PCR indicated that the effect was maximal by 1-2 h and must be accounted for increased transcription since VIP decreased
VEGF
(165) mRNA stability. VIP stimulated
VEGF
(165) protein synthesis as measured by ELISA. VIP regulation of
VEGF
expression was mediated by VPAC(1) receptor and was cAMP/
protein kinase A
(
PKA
) dependent. Phosphoinositide 3-kinase (PI3-K) and mitogen-activated protein kinase MEK1/2 systems may also be involved as shown with specific kinase inhibitors. These actions together with the observation of VIP-induced neuroendocrine differentiation in LNCaP cells suggest a proangiogenic potential of VIP in prostate cancer.
...
PMID:Vasoactive intestinal peptide increases vascular endothelial growth factor expression and neuroendocrine differentiation in human prostate cancer LNCaP cells. 1509 99
Activated protein C (APC), a natural anticoagulant, has recently been demonstrated to activate the mitogen-activated protein kinase (MAPK) pathway in endothelial cells in vitro. Because the MAPK pathway is implicated in endothelial cell proliferation, it is possible that APC induces endothelial cell proliferation, thereby causing angiogenesis. We examined this possibility in the present study. APC activated the MAPK pathway, increased DNA synthesis, and induced proliferation in cultured human umbilical vein endothelial cells dependent on its serine protease activity. Antibody against the endothelial protein C receptor (EPCR) inhibited these events. Early activation of the MAPK pathway was inhibited by an antibody against protease-activated receptor-1, whereas neither late and complete activation of the MAPK pathway nor endothelial cell proliferation were inhibited by this antibody. APC activated endothelial nitric oxide synthase (eNOS) via phosphatidylinositol 3-kinase-dependent phosphorylation, followed by activation of
protein kinase
G, suggesting that APC bound to EPCR might activate the endothelial MAPK pathway by a mechanism similar to that of
VEGF
. APC induced morphogenetic changes resembling tube-like structures of endothelial cells, whereas DIP-APC did not. When applied topically to the mouse cornea, APC clearly induced angiogenesis in wild-type mice, but not in eNOS knockout mice. These in vitro events induced by APC might at least partly explain the angiogenic activity in vivo. This angiogenic activity of APC might contribute to maintain proper microcirculation in addition to its antithrombotic activity.
...
PMID:Activated protein C induces endothelial cell proliferation by mitogen-activated protein kinase activation in vitro and angiogenesis in vivo. 1516 95
Prostaglandins are ubiquitous metabolites of arachidonic acid, and cyclooxygenase inhibitors prevent their production and secretion. Animals with loss of cyclooxygenase-2 function have reduced reparative bone formation, but the role of prostaglandins during endochondral bone formation is not defined. The role of PGE2 as a regulator of chondrocyte differentiation in chick growth plate chondrocytes (GPCs) was examined. While PGE2, PGD2, PGF2alpha, and PGJ2 all inhibited colX expression, approximately 80% at 10(-6) M, PGE2 was the most potent activator of cAMP response element (CRE)-mediated transcription. PGE2 dose-dependently inhibited the expression of the differentiation-related genes, colX,
VEGF
, MMP-13, and alkaline phosphatase gene, and enzyme activity with significant effects at concentrations as low as 10(-10) M. PGE2 induced cyclic AMP response element binding protein (CREB) phosphorylation and increased c-Fos protein levels by 5 min, and activated transcription at CRE-Luc, AP-1-Luc, and c-Fos promoter constructs. The
protein kinase A
(
PKA
) inhibitor, H-89, completely blocked PGE2-mediated induction of CRE-Luc and c-Fos promoter-Luc promoters, and partially inhibited induction of AP-1-Luc, while the protein kinase C (PKC) inhibitor Go-6976 partially inhibited all three promoters, demonstrating substantial cross-talk between these signaling pathways. PGE2 inhibition of colX gene expression was dependent upon both
PKA
and PKC signaling. These observations demonstrate potent prostaglandin regulatory effects on chondrocyte maturation and show a role for both
PKA
and PKC signaling in PGE2 regulatory events.
...
PMID:PGE2 inhibits chondrocyte differentiation through PKA and PKC signaling. 1538 23
Resveratrol, trans-3,5,4'-trihydroxystilbene, was first isolated in 1940 as a constituent of the roots of white hellebore (Veratrum grandiflorum O. Loes), but has since been found in various plants, including grapes, berries and peanuts. Besides cardioprotective effects, resveratrol exhibits anticancer properties, as suggested by its ability to suppress proliferation of a wide variety of tumor cells, including lymphoid and myeloid cancers; multiple myeloma; cancers of the breast, prostate, stomach, colon, pancreas, and thyroid; melanoma; head and neck squamous cell carcinoma; ovarian carcinoma; and cervical carcinoma. The growth-inhibitory effects of resveratrol are mediated through cell-cycle arrest; upregulation of p21Cip1/WAF1, p53 and Bax; down-regulation of survivin, cyclin D1, cyclin E, Bcl-2, Bcl-xL and clAPs; and activation of caspases. Resveratrol has been shown to suppress the activation of several transcription factors, including NF-kappaB, AP-1 and Egr-1; to inhibit protein kinases including IkappaBalpha kinase, JNK, MAPK, Akt, PKC, PKD and
casein kinase II
; and to down-regulate products of genes such as COX-2, 5-LOX,
VEGF
, IL-1, IL-6, IL-8, AR and PSA. These activities account for the suppression of angiogenesis by this stilbene. Resveratrol also has been shown to potentiate the apoptotic effects of cytokines (e.g., TRAIL), chemotherapeutic agents and gamma-radiation. Phamacokinetic studies revealed that the target organs of resveratrol are liver and kidney, where it is concentrated after absorption and is mainly converted to a sulfated form and a glucuronide conjugate. In vivo, resveratrol blocks the multistep process of carcinogenesis at various stages: it blocks carcinogen activation by inhibiting aryl hydrocarbon-induced CYP1A1 expression and activity, and suppresses tumor initiation, promotion and progression. Besides chemopreventive effects, resveratrol appears to exhibit therapeutic effects against cancer. Limited data in humans have revealed that resveratrol is pharmacologically quite safe. Currently, structural analogues of resveratrol with improved bioavailability are being pursued as potential therapeutic agents for cancer.
...
PMID:Role of resveratrol in prevention and therapy of cancer: preclinical and clinical studies. 1551 85
In the present study, we report that staurosporine, a known PKC inhibitor, enhanced in vitro angiogenesis. Endothelial cells plated in a three-dimensional matrix formed cords and enclosed structures within 4-6 hours. The cells in cord structures became elongated during the subsequent incubation. Tube formation was confirmed by confocal microscopy. Addition of
VEGF
enhanced the early responses of endothelial cells, leading to enhanced formation of cords. Staurosporine unexpectedly also enhanced the early endothelial responses, leading to faster alignment of cells and assembly into tube-like structures. At concentrations inhibitory to endothelial cell PKC activity, staurosporine produced 91% and 203% increases in the number of cords and the enclosed structures, respectively, as compared to the controls. Other selective inhibitors of PKC did not stimulate in vitro angiogenesis in the absence or presence of
VEGF
. Further investigation showed that inhibition of PI-3 kinase and
Raf-1
significantly reduced the effects of staurosporine. Staurosporine-induced in vitro angiogenesis required integrins alpha2 and alphavbeta3 and was associated with significantly enhanced FAK phosphorylation. These data indicate that staurosporine enhances in vitro angiogenesis by a means unrelated to its PKC inhibition. The data suggest that enhancement of in vitro angiogenesis by staurosporine involves integrin-mediated signaling, including the stimulation of FAK phosphorylation.
...
PMID:Staurosporine promotes endothelial cell assembly and FAK phosphorylation during in vitro angiogenesis. 1561 75
Tumor angiogenesis plays an important role in the malignancy of solid tumors. A number of recent studies including our own have suggested that
Raf-1
is involved in this process, and may be critical in regulating gene activation of several angiogenesis factors. To further define
Raf-1
function in angiogenesis and to explore novel approaches to modulate angiogenesis, we employed the small interference RNA technique to knock-down gene expression of
Raf-1
in gastric cancer cell line SGC7901 that expresses a high level of
Raf-1
. The protein level of
Raf-1
in the SGC7901cells was decreased dramatically after transfection with a
Raf-1
specific siRNA vector. Further study proved that,
VEGF
and HIF-1alpha, two angiogenesis promoting factors, were found to be downregulated. And we also find that Vector-based RNA interference for
Raf-1
increases transfected gastric cell apoptosis and inhibits cellular proliferation. Our results suggest that
Raf-1
may be involved in angiogenesis by controlling the expression of angiogenesis-related factors and provide a possible strategy for the treatment of tumor angiogenesis by targeting
Raf-1
.
...
PMID:Inhibition of gastric cancer angiogenesis by vector-based RNA interference for Raf-1. 1566 29
Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription factor that plays a major role in cellular adaptation to hypoxia. The mechanisms regulating HIF-1 activity occurs at multiple levels in vivo. The HIF-1alpha subunit is highly sensible to oxygen and is rapidly degraded by the proteasome 26S in normoxia. Activation in hypoxia occurs through a multistep process including inhibition of HIF-1alpha degradation, but also increase in the transactivation activity of HIF-1. Several data indicate that phosphorylation could play a role in this regulation. In this report, we investigated the role of
casein kinase 2
(
CK2
), an ubiquitous serine/threonine kinase, in the regulation of HIF-1 activity. Hypoxia was capable of increasing the expression of the beta subunit of
CK2
, of inducing a relocalization of this subunit at the plasma membrane, of inducing nuclear translocation of the alpha subunit and of increasing
CK2
activity. Three inhibitors of this kinase, DRB (5,6-dichloro-1-beta-D-ribofuranosyl-benzimidazole), TBB (4,5,6,7-tetrabromotriazole) and apigenin, as well as overexpression of a partial dominant negative mutant of CK2alpha, were shown to inhibit HIF-1 activity as measured by a reporter assay and through hypoxia-induced
VEGF
and aldolase expression. This does not occur at the stabilization process since they did not affect HIF-1alpha protein level. DNA-binding activity was also not inhibited. We conclude that
CK2
is an important regulator of HIF-1 transcriptional activity but the mechanism of this regulation remains to be determined. Since HIF-1 plays a major role in tumor angiogenesis and since
CK2
has been described to be overexpressed in tumor cells, this new pathway of regulation can be one more way for tumor cells to survive.
...
PMID:Role for casein kinase 2 in the regulation of HIF-1 activity. 1595 68
There is much evidence that direct inhibition of the kinase activity of vascular endothelial growth factor receptor-2 (VEGFR-2) will result in the reduction of angiogenesis and the suppression of tumor growth. Palladium-catalyzed C-C bond, C-N bond formation reactions were used to assemble various pyrazine-pyridine biheteroaryls as potent VEGFR-2 inhibitors. Among them, 4-{5-[6-(3-chloro-phenylamino)-pyrazin-2-yl]-pyridin-3-ylamino}-butan-1-ol (39) and N-{5-[6-(3-chloro-phenylamino)-pyrazin-2-yl]-pyridin-3-yl}-N',N'-dimethyl-ethane-1,2-diamine (41) exhibited the highest kinase selectivity against fibroblast growth factor receptor kinase, platelet-derived growth factor receptor kinase, and
glycogen synthase kinase
-3. All of these compounds showed good cellular potency to inhibit
VEGF
-stimulated proliferation of human umbilical vein endothelial cells (HUVEC) but with modest effects on the unstimulated growth of HUVEC. The low inhibition of these compounds to the growth of tumor cell lines, such as HeLa, HCT-116, and A375 further confirms that these VEGFR-2 inhibitors are not cytotoxic agents. The in vivo antitumor activity of 39 and 41 were demonstrated in the A375 human melanoma xenograft nude mice model. Molecular modeling (QSAR analysis) was conducted in an attempt to rationalize the observed structure-activity relationship.
...
PMID:Synthesis and structure-activity relationships of pyrazine-pyridine biheteroaryls as novel, potent, and selective vascular endothelial growth factor receptor-2 inhibitors. 1603 69
Thrombospondin-1 (TSP-1), a natural inhibitor of angiogenesis, acts directly on endothelial cells (EC) via CD36 to inhibit their migration and morphogenesis induced by basic fibroblast growth factor. Here we show that CD36 triggered by TSP-1 inhibits in vitro angiogenesis stimulated by vascular endothelial growth factor-A (VEGF-A). To demonstrate that the TSP-1 inhibitory signal was mediated by CD36, we transduced CD36 in CD36-deficient endothelial cells. Both TSP-1 and the agonist anti-CD36 mAb SMO, which mimics TSP-1 activity, reduced the
VEGF
-A165-induced migration and sprouting of CD36-ECs. To address the mechanisms by which CD36 may exert its angiostatic function, we investigated the functional components of the C-terminal cytoplasmic tail by site-directed mutagenesis. Our results indicate that C464, R467, and K469 of CD36 are required for the inhibitory activity of TSP-1. In contrast, point mutation of C466 did not alter TSP-1 ability to inhibit EC migration and sprouting. Moreover, we show that activation of CD36 by TSP-1 down-modulates the
VEGF
receptor-2 (VEGFR-2) and p38 mitogen-associated
protein kinase
phosphorylation induced by
VEGF
-A165, and this effect was specifically abolished by point mutation at C464. These results identify specific amino acids of the C-terminal cytoplasmic tail of CD36 crucial for the in vitro angiostatic activity of TSP-1 and extend our knowledge of regulation of VEGFR-2-mediated biological activities on ECs.
...
PMID:Identification of CD36 molecular features required for its in vitro angiostatic activity. 1603 98
Syndecans are transmembrane proteoglycans expressed on adherent cells. They are a family of four proteins, which participate in cell-matrix adhesion, the regulation of growth factors (FGFs,
VEGF
, HGF) binding and signaling. The extracellular domain of syndecans contains heparan sulfate and chondroitin sulfate glycosaminoglycan chains. Syndecans have transmembrane region and a short cytoplasmic domain. The cytoplasmic domain attaches activated
protein kinase
Calpha, phosphatidyl-inositol-4,5-bisphosphate, syntenin, beta-catenin and many others molecules. Syndecans bind numerous ligands, which are present in extracellular matrix: growth factors, enzymes, extracellular matrix molecules (fibronectin, laminin). They form connections with actin cytoskeleton. The changes in syndecan expression influence on cell adhesion and migration, structure of focal contacts and cytoskeleton. Syndecans participate in cell differentiation and tissue regeneration.
...
PMID:[Syndecans in cell adhesion and differentiation]. 1620 42
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