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Query: EC:3.4.21.73 (
urokinase-type plasminogen activator
)
10,685
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We immunohistochemically examined 186 lung adenocarcinomas for the presence of prognostic indicators of local growth of tumor, invasiveness and metastasis. Of the examined tumors, 67% showed a high expression of
transforming growth factor alpha
(TGF alpha); 50% for epidermal growth factor (EGF), 45% for EGF receptor (EGFR), and 30% for
urokinase
type plasminogen activator (uPA). In the EGFR-high cases, the 5-year survival rates of patients with high TGF alpha and low TGF alpha were 36% and 85%, respectively. In the EGFR-low cases, there was no statistical difference between the two groups. These findings suggested the presence of autocrine growth mechanisms. On the other hand, the high expression of uPA was modulated by TGF alpha and/or EGF. The 5-year survival rates of patients with high uPA and low uPA were 20% and 51%, respectively. The tumors with high expression of uPA showed degradation of the matrix components, including laminin and fibronectin. These findings suggested that uPA played a role to break through the surrounding basement membrane of blood and lymphatic vessels, and connective tissue for their growth and metastasis. We wish to emphasize the usefulness of the immunohistochemical evidences, such as autocrine growth mechanism and breakdown of extracellular matrix, as a possible parameters of tumor development, invasiveness and metastasis.
...
PMID:[Immunohistochemical evidences of prognostic parameters associated with tumor development of pulmonary adenocarcinoma]. 194 64
A single topical treatment of mouse skin with the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) results in transient inductions of a variety of genes. Based on the time courses of their inductions, these genes can be classified into two main groups: "early" response genes whose mRNA expression reaches a maximum 0.5-2 h after TPA treatment and "secondary" response genes whose mRNA expression is maximal 4 h or more after treatment. The nuclear oncogenes c-fos, c-myc, and c-jun belong to the early response group, whereas the metallothionein, osteopontin, and
urokinase
genes belong to the secondary response group. The steady-state expressions of these early and secondary response genes are all very low in normal skin, except that of c-jun, which is relatively high. Steady-state levels of expression and inducibility of these genes by TPA were not altered in initiated skin or in apparently normal skin during tumor promotion. We examined the expressions of these genes in papillomas and carcinomas produced by two-stage (initiator-promoter) and three-stage (initiator-promoter-initiator) protocols in mouse skin. Steady-state expression of the early responding nuclear oncogenes in papillomas and carcinomas was found to remain at the same low level as in normal skin. However, all the secondary responding genes were found to be expressed constitutively at high levels in these tumors. Elevated expressions of the genes for
transforming growth factor alpha
and beta were also observed in papillomas and to varying extents in carcinomas. These observations suggest that the regulatory machinery for transcription by the protein kinase C-mediated pathway through nuclear oncogenes is altered during the processes of tumor promotion and progression. The genes whose expression is elevated may be associated directly or indirectly with tumor promotion and progression.
...
PMID:Elevated expression of secondary, but not early, responding genes to phorbol ester tumor promoters in papillomas and carcinomas of mouse skin. 212 8
The effect of two growth factors ellicited in response to surgical woundings (
transforming growth factor alpha
[TGF alpha] and beta 1) on the regulation of
cellular plasminogen activator
activity (PAA) in human transitional carcinoma cell lines, with differing baseline PAA (253J--high; 647V--low), was studied. mRNA transcript levels of PA regulatory proteins in both cell lines were responsive to TGF alpha and TGF beta 1. However, both the magnitude and nature of the response differed markedly between the two lines. TGF alpha increased
uPA
transcript levels in both cell lines in a dose-dependent fashion. In the case of
uPA
receptor, exogenous TGF alpha concentrations which increased receptor levels over fivefold in the 253J line had no effect on this transcript in the 647V line. This differential responsiveness was even more pronounced for TGF beta 1. TGF beta 1 appeared to increase
uPA
transcript in the 253J line in a dose dependent manner while decreasing transcript levels in the 647V line. uPAr mRNA in 253J cells increased over a 19-fold range in response to TGF beta 1 while this same transcript was decreased 14-fold in 647V cells. The most pronounced effect of TGF beta 1 was seen on PAI1 transcript levels in the 253J line. This transcript increased in a concentration dependent fashion from non-detectable levels. These findings demonstrate that growth factors ellicited by surgical wounding may alter the biology of neoplastic cells. Both the growth factor milieu, and intrinsic cellular regulatory mechanism, appear important in determing net PAA in transitional carcinoma cell lines.
...
PMID:Regulation of plasminogen activator activity in transitional carcinoma cell lines by wound site growth factors. 795 2
Keratinocyte growth factor (KGF), a member of the fibroblast growth factor (FGF) family (and alternatively designated FGF-7), is a paracrine growth factor produced by mesenchymal cells and mitogenic specifically for epithelial cells. The potential effect of KGF on wound healing was assessed in vitro by measuring randomized migration and plasminogen activator (PA) activity of keratinocytes in response to the growth factor. Incubation of normal human keratinocytes with KGF in modified MCDB 153 medium significantly stimulated cell migration and PA activity compared with control (p < 0.001 and p < 0.01, respectively). When tested in these assays on an equimolar basis, 1 nM KGF was at least as potent as
transforming growth factor alpha
and more active than basic FGF. None of these effects were observed when KGF was administered to fibroblasts or endothelial cells. Stimulation of keratinocyte migration by KGF was dose dependent, and a neutralizing monoclonal antibody against KGF reduced KGF-stimulated migration and cell growth. Zymographic analyses of cell extracts and conditioned medium from KGF-treated keratinocytes revealed increased PA activity, which was mainly attributable to an elevated level of
urokinase
-type PA. These in vitro results suggest that KGF may have an important role in stimulating reepithelialization during the process of wound repair.
...
PMID:Keratinocyte growth factor (FGF-7) stimulates migration and plasminogen activator activity of normal human keratinocytes. 833 Dec 96
Serum-free rat hepatocyte cultures can be stimulated to divide by the inactive, single-chain form of hepatocyte growth factor (scHGF), suggesting that hepatocytes contain a protein that can cleave scHGF to its biologically active, two-chain (tcHGF) form. We added radiolabeled scHGF to serum-free cultures and confirmed that tcHGF was being generated. Because scHGF can be cleaved to tcHGF by plasminogen activators (PAs), we next tested the cultures for active PA. Although little PA activity was initially present, the majority was of the
urokinase
type (
u-PA
) as determined by neutralization studies using either a polyclonal antibody against
u-PA
or, since
u-PA
functions in the context of its receptor (u-PAR), a monoclonal antibody against u-PAR. Considerable PA activity developed within 24 h, which was also neutralizable with antibody. To test whether the active, receptor-bound
u-PA
from the cell cultures was cleaving scHGF, iodinated scHGF was added to intact cells in the presence of the antibody against u-PAR. Comparison to control cultures determined that the antibody prevented scHGF cleavage. Analysis of cultures treated with HGF, epidermal growth factor, and
transforming growth factor alpha
(
TGF-alpha
) alpha showed these growth factors increased the hepatocyte PA activity in parallel with the mRNA for
u-PA
. TGF-beta had the opposite effect, and when TGF-beta was added to the culture system, conversion of scHGF to tcHGF was prevented in concert with the production of the type 1 PA inhibitor. When liver remnants from hepatectomized animals were assayed for active TGF-beta, elevated protein was found just prior to the appearance of PA inhibitor 1 message and protein. Collectively, our data show that in culture, active
u-PA
is present and cleaves scHGF to tcHGF in the context of its receptor. It also suggests that modulation of
u-PA
activity by various growth factors is relevant for regulating cleavage of scHGF to tcHGF both in vitro and in vivo.
...
PMID:Presence of urokinase in serum-free primary rat hepatocyte cultures and its role in activating hepatocyte growth factor. 866 23
The aim of the present study was to examine the regulatory role of
transforming growth factor alpha
(TGF alpha) on
urokinase plasminogen activator
(
uPA
) gene expression and protein levels in hen granulosa cells from different stages of ovarian follicular development in vitro. Granulosa cells from the first (F1), the second and third (F2-3), and the fourth, fifth, and sixth (F4-6) largest preovulatory follicles were cultured for 21 h in the absence and presence of TGF alpha (10 ng/ml). The
uPA
mRNA abundance and protein content were determined by Northern and Western blot analysis, respectively. Cell-associated and secreted PA activity was measured by a fibrinolysis assay and characterized by zymography. Hen granulosa cells produce a
uPA
with a molecular mass of about 35 kDa and a transcript size of approximately 2.5 kb. Basal
uPA
mRNA abundance, protein content, and activity were highest in granulosa cells from F4-6 follicles and decreased with follicular maturation. Granulosa cell
uPA
mRNA levels, protein content, and activity were increased in the presence of TGF alpha, reaching maximal levels in granulosa cells from less mature follicles, although the percentage of stimulation was higher in cells from late stages of follicular development. These findings clearly demonstrate specific expression of
uPA
in proliferatively active granulosa cells and responsiveness of
uPA
to TGF alpha at both transcriptional and translational levels. They support the concept that PA of the
urokinase
type plays an important role in extracellular matrix remodeling during TGF alpha-induced granulosa cell proliferation and ovarian follicular growth.
...
PMID:Up-regulation of urokinase plasminogen activator messenger ribonucleic acid and protein in hen granulosa cells by transforming growth factor alpha in vitro during follicular development. 916 Jul 33