Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.2.3.23 (GAS)
 957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding of urokinase plasminogen activator (uPA) to its specific receptor (uPAR) facilitates migration of vascular smooth muscle cells (VSMC). However, the signaling cascade utilized by the urokinase receptor is only incompletely understood. We investigated intracellular uPA/uPAR signaling in human aortic VSMC from the cell membrane to the nucleus. uPA binding to VSMC induced a rapid and pronounced increase in tyrosine phosphorylation of several proteins with molecular masses of 53-60, 85-90, and 130-140 kDa. By using co-immunoprecipitation techniques and in vitro kinase assays, the uPAR-associated proteins were identified as Janus (Jak) and Src non-receptor protein-tyrosine kinases (PTK) Jak1, Tyk2, and p59(fyn), p53/56(lyn), p53/59(hck), and p55(fgr). Furthermore, uPA induced a time-dependent reversible translocation of the Stat1 (signal transducer and activator of transcription) protein to the VSMC nuclei, as shown by confocal microscopy studies. Using an electrophoretic mobility shift assay, we then demonstrated that Stat1 is rapidly activated in response to stimulation with uPA and specifically binds to the DNA regulatory elements GAS (interferon-gamma activation site) and ISRE (interferon-stimulated response element). Mobility supershift experiments confirmed DNA-protein complexes containing Stat1 protein. Migration experiments with double immunofluorescence staining revealed polarization of uPAR, and colocalization with Jak1 and Tyk2 to the leading edge of the migrating cells. Under the same conditions, Jak2, Jak3, and the Src-PTKs remained randomly distributed over the entire body of the cells. Our studies therefore suggest that, in VSMC, the uPAR-signaling complex utilizes at least two different mechanisms, a direct signaling pathway utilizing the Jak/Stat cascade and a second signal transduction mechanism via Src-like protein-tyrosine kinases. uPA-induced signaling via Jak/Stat is most likely involved in the regulation of cell migration, while the functional purpose of the uPA-associated Src-PTK activation remains to be elucidated.
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PMID:The Jak/Stat pathway and urokinase receptor signaling in human aortic vascular smooth muscle cells. 941 82

Urokinase-type plasminogen activator (uPA) and its specific receptor (uPAR) act in concert to stimulate cytoplasmic signaling machinery and transcription factors responsible for cell migration and proliferation. Recently we demonstrated that uPA activates the Janus kinase/signal transducers and activators of transcription (Stat1) signaling in human vascular smooth muscle and endothelial cells. However, the important question whether other transcription factors of the Stat family, in addition to Stat1, are involved in the uPAR-related signaling has not been addressed. In this study, we demonstrate that Stat4 and Stat2, but not Stat3, Stat5, or Stat6, are rapidly activated in response to uPA. We demonstrate further that Stat4 and Stat2 rapidly and transiently translocate to the cell nucleus where they bind specifically to the regulatory DNA elements. Analysis of Stat complexes formed in response to uPA revealed a Stat2-Stat1 heterodimer, which lacks p48, a DNA-binding protein known to combine with Stat1-Stat2. This new uPA-induced Stat2-Stat1 heterodimer binds to GAS (the interferon-gamma activation site) distinct from the interferon-stimulated response element to which the p48 protein containing complexes generally bind. We conclude that uPA activates a specific and unusual subset of latent cytoplasmic transcription factors in human vascular smooth muscle cells that suggests a critical role of uPA in these cells.
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PMID:Urokinase induces activation and formation of Stat4 and Stat1-Stat2 complexes in human vascular smooth muscle cells. 1044 76

Cell motility involves metastasis suppressors and other regulators that play an important role in tumor invasion and metastasis. Phenethyl isothiocyanate (PEITC), found in dietary cruciferous vegetables, has been found to exhibit antitumor properties and therefore is of special interest for the development of chemopreventive and chemotherapeutic agent for human cancers. Here, we report that in addition to its function as an anticancer agent, and PEITC can inhibit migration and invasion through the extracellular signal-regulated kinases 1/2 (ERK1/2), protein kinase C (PKC) and nuclear factor-kappaB (NF-kappaB) signaling pathways in human gastric cells. The results from wound healing and Boyden chamber assays (migration and invasion) assay indicated that PEITC exhibited an inhibitory effect on the migration and invasion of AGS cells. Results from Western blotting examination demonstrated that PEITC exerted an inhibitory effect on the ERK1/2, mitogen-activated protein kinase kinase 7 (MKK7), MAP kinase kinase kinase 3 (MEKK3), son of sevenless 1 (SOS1), PKC, Ras homolog gene family, member A (Rho A) and urokinase-type plasminogen activator (uPA), causing the inhibition of matrix metallopeptidase-2 (MMP-2) and -9 then followed by the inhibition of invasion and migration of GAS cells in vitro. PEITC also inhibited Ras, growth factor receptor-bound protein 2 (GRB2), vascular endothelial growth factor (VEGF), focal adhesion kinase (FAK), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), causing inhibition of cell proliferation of AGS cells. Results from real-time PCR showed that PEITC inhibited the gene expressions of MMP-2, -7 and -9, FAK and RhoA after PEITC treatment for 24 and 48 h of AGS cells. Taken together, these findings may provide insight into a new mechanisms and functions of PEITC in migration and invasion of human gastric cancer AGS cells. Our data imply that molecular targeting of PKC leading to the inhibition of MMP-2 and -9 might be a useful strategy for the inhibition of migration and invasion of human gastric cancer.
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PMID:Phenethyl isothiocyanate inhibits migration and invasion of human gastric cancer AGS cells through suppressing MAPK and NF-kappaB signal pathways. 2065 62

Breast cancer is the leading cause of cancer death in women worldwide which is closely related to metastasis. But the exact molecular mechanism of metastasis is still not fully understood. We now report that both MRTF-A and STAT3 play important roles in migration of MDA-MB-231 breast cancer cells. Moreover, MRTF-A and STAT3 synergistically increased MDA-MB-231 cell migration by promoting the expression of migration markers urokinase-type plasminogen activator (uPA) and osteopontin (OPN) and inhibiting the expression of breast cancer metastasis suppressor 1 (BRMS1). Luciferase reporter assays demonstrated that MRTF-A and STAT3 do not affect transcription of the BRMS1 promoter. Instead, we identified a newly molecular mechanism by which MRTF-A and STAT3 synergistically controlled MDA-MB-231 cell migration by recruiting DNMT1 to hypermethylate the promoter of BRMS1 and thus affect the expression of BRMS1. Interestingly, physical interaction between MRTF-A and STAT3 synergistically promotes the transactivity of DNMT1 by binding to the GAS element within the DNMT1 promoter. Our data thus provide important and novel insights into the roles of MRTF-A and STAT3 in regulating MDA-MB-231 cell migration.
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PMID:MRTF-A and STAT3 promote MDA-MB-231 cell migration via hypermethylating BRSM1. 2585 63