Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transforming growth factor-beta (TGF-beta) is a potent mediator of cell proliferation and extracellular matrix formation, depending on the cell type and the physiological conditions. TGF-beta is usually secreted in a "latent" complex that needs activation before it can exert its effects. Several observations correlate increased expression of TGF-beta 1 with tumorigenesis. To evaluate the physiological relevance of increased TGF-beta 1 synthesis in tumor cells we established cell clones overexpressing TGF-beta 1 and observed the resulting physiological changes in TGF-beta overproducing cells in vitro and in vivo. As a model system we used the human E1A-transformed 293 tumor cells, which are insensitive to the direct growth modulatory effects of TGF-beta. The selection of this cell line allows an assessment of physiological alterations independent of TGF-beta induced proliferative changes. The use of two TGF-beta 1 expression vectors containing either the natural or a modified TGF-beta 1 precursor cDNA permitted the establishment of separate 293 cell lines overexpressing latent or active TGF-beta. Comparison of the resulting changes in glycolytic rate, adhesiveness and integrin and plasminogen activator expression established that, in vitro, both types of clones behaved similarly, indicating that expression of latent TGF-beta induces autocrine changes in the tumor cells and thus suggesting that some level of cell-associated activation occurs. TGF-beta overexpression resulted in an increased metabolic rate due to enhanced glycolysis, a property long associated with tumor cells. This increased glycolysis was not associated with altered proliferation. Cells overexpressing TGF-beta also displayed enhanced fibronectin mRNA and plasminogen activator synthesis and increased adhesiveness in vitro. They showed enhanced survival when plated sparsely on plastic in the absence of serum, and attached more readily to laminin. In addition, synthesis of several beta 1 integrins, in particular the alpha 1/beta 1, alpha 2/beta 1, and alpha 3/beta 1, all of which recognize laminin, were enhanced. Finally, cells overexpressing active TGF-beta, but not latent TGF-beta, also showed increased tumorigenicity in nude mice. Thus, an increase in endogenous TGF-beta synthesis confers several proliferation-independent phenotypic changes which may be of significance for the survival of the tumor cell inoculum or its subsequent growth, and for tumor formation and development. In the case of cells expressing active TGF-beta, the release of active TGF-beta into the vicinity of the tumor cells may also result in a more hospitable environment for tumor growth.
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PMID:Altered metabolic and adhesive properties and increased tumorigenesis associated with increased expression of transforming growth factor beta 1. 163 53

Noradrenaline (NA) plasma levels were examined in 18 healthy volunteers on 2 consecutive days after a single treatment with either lormetazepam (0.06 mg/kg) (LMZ group), flunitrazepam (0.03 mg/kg) (FNZ group) or placebo (PLA group) in combination with the benzodiazepine (BZ) antagonist Ro 15-1788 (0.1 mg/kg). Behavioural responses (mood changes, anxiety) were also investigated in parallel. Both BZ decreased NA plasma levels to 50% of the basal values 10 min after the injection; administration of Ro 15-1788 15 min later reinstated NA plasma levels to basal values. A second administration of Ro 15-1788 (0.1 mg/kg) 24 h after BZ or PLA treatment increased NA plasma levels, estimated 10 min after the injection in both the LMZ- and the FNZ groups, but not in the PLA group. Behavioural responses measured under the same treatment also indicated minor anxiety responses followed by mood impairment. These data suggest that a stressful situation may be precipitated by the antagonist Ro 15-1788 24 h after a single BZ treatment, which resembles a withdrawal response, and increases NA plasma levels.
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PMID:Changes in noradrenaline plasma levels and behavioural responses induced by benzodiazepine agonists with the benzodiazepine antagonist Ro 15-1788. 287 61

Ro 15-1788, a selective benzodiazepine (BZD) antagonist, is known to precipitate withdrawal reactions in BZD-pretreated animals. We examined whether a high dose of Ro 15-1788 can precipitate withdrawal reactions relating to behavior and changes in the stress-hormone plasma levels after acute BZD treatment in man. On two consecutive days, 15 min and 24 h respectively after a single treatment with either lormetazepam (0.06 mg/kg: LMZ group), flunitrazepam (0.03 mg/kg: FNZ group) or placebo (PLA group), 18 healthy volunteers received two injections of Ro 15-1788 (0.01 mg/kg). Behavioral responses (mood changes, anxiety), cortisol and prolactin plasma levels, and physiological parameters were examined. In all groups there were only slight changes in the circulation parameters. Minor anxiety reactions were seen after Ro 15-1788, which occurred the 1st day in the PLA group and the 2nd day in the BZD groups. Depression was noted especially in the FNZ group after both injections of Ro 15-1788. The physiological morning decrease in cortisol plasma level was influenced on the 1st day in the LMZ group (2 volunteers showed high plasma levels) and the 2nd day in the FNZ group: a slight increase of cortisol plasma level was measured after the 2nd injection of Ro 15-1788. Prolactin plasma levels arose immediately after LMZ injection and continued to increase after Ro 15-1788 injection. No increase in prolactin plasma levels was found in the other groups or in the LMZ group after the 2nd challenge by Ro 15-1788.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Benzodiazepine antagonism by RO 15-1788: psychometric, hormonal and biophysical parameters]. 290 13

Transforming growth factor-beta (TGF-beta) mediates the production of extracellular matrix proteins, proteases and protease inhibitors in epithelial cells. Both TGF-beta and phorbol-12-myristate-13-acetate (PMA) exert both positive and negative effects on mitogenesis in these as well as other cell types. Phorbol esters act through stimulation of protein kinase C (PKC) and are among the most potent tumor promoters known. The present study was conducted to determine whether the effect of TGF-beta in human non-small cell lung cancer (NSCLC) and normal human bronchial epithelial (NHBE) cells parallels that of the phorbol esters and whether this effect of TGF-beta involves PKC. TGF-beta 1 and PMA increased expression of TGF-beta 1 mRNA 24 hr after their addition to both NSCLC and NHBE cells. The effects of these agents on expression of the mRNAs for TGF-beta 2 and TGF-beta 3 were more complex; while TGF-beta 2 and TGF-beta 3 mRNAs increased transiently in response to TGF-beta 1 in NHBE cells and TGF-beta 3 mRNA increased transiently in some NSCLC cells, expression of these mRNAs decreased in most of these cells in response to PMA with the exception of the carcinoid NCI-H727 where TGF-beta 2 mRNA increased dramatically, TGF-beta 1 and PMA both caused a persistent increase in expression of the mRNAs for both plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator (PA) up to 24 hr in most NSCLC cells, with the increase in PAI-1 mRNA beginning several hours before that of PA mRNA. In contrast, while TGF-beta 1 also increased expression of PAI-1 mRNA in NHBE cells, the expression of PA mRNA decreased simultaneously. The effect of PMA on PAI-1 and PA mRNAs was opposite of TGF-beta 1 in these cells, with expression of PAI-1 mRNA decreasing and PA mRNA increasing after addition of PMA. These data show that there is parallel regulation of the genes for TGF-beta 1, PAI-1 and PA by TGF-beta 1 and PMA in NSCLC, but differential regulation of the genes for PAI-1 and PA by these agents in NHBE cells. The responses of the mRNAs and proteins of TGF-beta 1, PAI-1 and PA to TGF-beta 1 and PMA were inhibited by the serine/ threonine kinase inhibitor H7 in NSCLC cells. Treatment of NSCLC cells with TGF-beta 1 and PMA resulted in a persistent increase in the expression of fibronectin mRNA and protein. This response was blocked by the addition of H7. Inhibition of these effects by H7 in NSCLC cells suggests that H7 blocks TGF-beta responses by inhibiting a protein serine/threonine kinase(s). Because the effects of TGF-beta and PMA on the different TGF-beta isoforms, PA, PAI and fibronectin in NHBE and NSCLC cells are complex, our data suggest that there are distinct mechanisms for controlling the different TGF-beta isoforms, PA, PAI and extracellular matrix proteins in normal lung and lung cancer cells.
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PMID:Effects of transforming growth factor-beta 1 and phorbol ester on PAI-1 and PA genes in human lung cells. 925 8

In addition to autoregulating its own expression, transforming growth factor-beta 1 (TGF-beta1) also regulates the production of proteases, protease inhibitors and extracellular matrix proteins. To investigate the relationship between plasminogen activator (PA), plasminogen activator inhibitor-1 (PAI-1) and the extracellular matrix in malignant and normal lung epithelial cells and to determine whether malignant lung epithelial cells may be more invasive than normal lung epithelial cells because of differences in expression of these proteins in response to TGF-beta, the regulation of PA, PAI-1, fibronectin, laminin and thrombospondin by TGF-beta1 in human non-small cell lung cancer (NSCLC) cells was examined and compared with normal human bronchial epithelial (NHBE) cells. TGF-beta1 caused a persistent increase in expression of the mRNAs for both PA and PAI-1 in NSCLC cells, with the increase in PAI-1 mRNA beginning several hours before that of PA mRNA. By immunoprecipitation analysis, it was shown that TGF-beta1 also induced a corresponding increase in the amount of PAI-1 protein in these NSCLC cells as well. In contrast, while TGF-beta1 also increased expression of PAI-1 mRNA in NHBE cells, expression of PA mRNA decreased simultaneously. Treatment of NSCLC cells with TGF-beta1 resulted in a persistent increase in expression of the mRNAs for fibronectin, laminin and thrombospondin; expression of fibronectin protein also increased after treatment with TGF-beta1 in these cells. When NHBE cells were similarly cultured in the presence of TGF-beta1, expression of fibronectin mRNA also increased in a persistent manner; however, only an early transient increase in the level of the mRNAs for laminin and thrombospondin was detected in these cells. These data show that there is differential regulation of the genes for PA and PAI-1 and the extracellular matrix protein fibronectin in response to TGF-beta1 not only when NSCLC and NHBE cells are compared, but also when different NSCLC cells are compared with each other.
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PMID:Differential regulation of protease and extracellular matrix protein expression by transforming growth factor-beta 1 in non-small cell lung cancer cells and normal human bronchial epithelial cells. 929 10