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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
PPARgamma
is known to induce apoptosis in malignant tumor cells, but the mechanism of this induction is not well understood. We investigated induction of apoptosis with 15-Deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), a
PPARgamma
ligand, in cholangio cell carcinoma (CCC) cells (RBE,
ETK
-1 or HuCCT-1). Apoptosis was induced in RBE and
ETK
-1 cells with 15d-PGJ2, but not in HuCCT-1 cells, although
PPARgamma
was expressed in all CCC cells. Apoptosis-related proteins were also expressed, including FLIP, bclx, Apaf-1 and XIAP, but expression levels differed among the three cell lines. RBE cells treated with 15d-PGJ2 showed caspase activation, and it appeared that
PPARgamma
-induced apoptosis was dependent on caspase activation. However, neither
ETK
-1 nor HuCCT-1 cells showed significant activation of caspase-8 or -3 with 15d-PGJ2 treatment, raising the possibility of a caspase-independent apoptosis induction pathway. XIAP was down-regulated by 15d-PGJ2 in all three CCC cell lines. Therefore, 15d-PGJ2 induces apoptosis in CCC cells via caspase-dependent or independent pathways. 15d-PGJ2 may also induce down-regulation of XIAP and may promote caspase cascade activation through TNF-family receptor signaling pathways.
...
PMID:The PPARgamma ligand, 15-Deoxy-Delta12,14-PGJ2, regulates apoptosis-related protein expression in cholangio cell carcinoma cells. 1461 59
1,1-Bis(3'-indolyl)-1-(p-trifluoromethylphenyl)methane (DIM-C-pPhCF(3)) and several p-substituted phenyl analogues have been investigated as a new class of
peroxisome proliferator-activated receptor gamma
(
PPARgamma
) agonists. Structure-activity studies in
PPARgamma
-dependent transactivation assays in MCF-7 breast cancer cells show that 5-20 micro M concentrations of compounds containing p-trifluoromethyl, t-butyl, cyano, dimethylamino, and phenyl groups were active, whereas p-methyl, hydrogen, methoxy, hydroxyl, or halogen groups were inactive as
PPARgamma
agonists. Induction of
PPARgamma
-dependent transactivation by 15-deoxy-Delta12,14-prostaglandin J2 (PGJ2) and DIM-C-pPhCF(3) was inhibited in MCF-7 cells cotreated with the
PPARgamma
-specific antagonist N-(4'-aminopyridyl)-2-chloro-5-nitrobenzamide. In mammalian two-hybrid assays, DIM-C-pPhCF(3) and PGJ2 (5-20 micro M) induced interactions of
PPARgamma
with steroid receptor coactivator (SRC) 1,
SRC2
(TIFII), and thyroid hormone receptor-associated protein 220 but not with SRC3 (AIB1). In contrast, DIM-C-pPhCF(3), but not PGJ2, induced interactions of
PPARgamma
with
PPARgamma
coactivator-1. C-substituted diindolylmethanes inhibit carcinogen-induced rat mammary tumor growth, induce differentiation in 3T3-L1 preadipocytes, inhibit MCF-7 cell growth and G(0)/G(1)-S phase progression, induce apoptosis, and down-regulate cyclin D1 protein and estrogen receptor alpha in breast cancer cells. These compounds are a novel class of synthetic
PPARgamma
agonists that induce responses in MCF-7 cells similar to those observed for PGJ2.
...
PMID:A new class of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists that inhibit growth of breast cancer cells: 1,1-Bis(3'-indolyl)-1-(p-substituted phenyl)methanes. 1502 45
The synthesis and bioactivity of the retinoid X receptor (RXR) antagonist 4-[(3'-n-butyl-5',6',7',8'-tetrahydro-5',5',8',8'-tetramethyl-2'-naphthalenyl)(cyclopropylidene)methyl]benzoic acid and several heteroatom-substituted analogues are described. Ligand design was based on the scaffold of the 3'-methyl RXR-selective agonist analogue and reports that 3'-n-propyl and longer n-alkyl groups conferred RXR antagonism. The transcriptional antagonism of the 3'-n-butyl analogue was demonstrated by its blockade of retinoic acid receptor (RAR) beta expression induced by the RXRalpha/peroxisome proliferator-activated receptor (PPAR) gamma heterodimer complexed with an RXRalpha agonist plus the
PPARgamma
agonist ciglitazone and the inhibition of 9-cis-RA-induced coactivator
SRC
-1a recruitment to RXRalpha. Receptor-ligand docking studies using full-atom flexible ligand and flexible receptor suggested that binding of the antagonist to the RXRalpha antagonist conformation was favored because the salt bridge that formed between the retinoid carboxylate and the RXRalpha helix H5 arginine-321 was far stronger than that formed on its binding to the agonist conformation. The antagonist also blocked activation of RAR subtypes alpha and beta by 9-cis-RA but not that of RARgamma.
...
PMID:Determinants of retinoid X receptor transcriptional antagonism. 1531 50
Activation of the nuclear transcription factor
peroxisome proliferator-activated receptor gamma
(
PPARgamma
) inhibits growth and survival of hepatocellular carcinoma (HCC) cell lines. To further investigate the function of
PPARgamma
in HCC,
PPARgamma
expression patterns in primary tumors were examined, and the responses of two HCC cell lines to
PPARgamma
activation and inhibition were compared.
PPARgamma
expression was increased in HCC and benign-appearing peritumoral hepatocytes compared with remote benign hepatocytes. Both compound
PPARgamma
inhibitors and
PPARgamma
small interfering RNAs prevented HCC cell lines from adhering to the extracellular matrix. Loss of adhesion was followed by caspase-dependent apoptosis (anoikis).
PPARgamma
inhibitors had no effect on initial beta1 integrin-mediated adhesion, or on total
focal adhesion kinase
levels but did reduce
focal adhesion kinase
phosphorylation. The
PPARgamma
inhibitor T0070907 was significantly more efficient at causing cancer cell death than the activators troglitazone and rosiglitazone. T0070907 caused cell death by reducing adhesion and inducing anoikis, whereas the activators had no direct effect on adhesion and caused cell death at much higher concentrations. In conclusion,
PPARgamma
overexpression is present in HCC. Inhibition of
PPARgamma
function causes HCC cell death by preventing adhesion and inducing anoikis-mediated apoptosis.
PPARgamma
inhibitors represent a potential novel treatment approach to HCC.
...
PMID:Peroxisome proliferator-activated receptor gamma inhibition prevents adhesion to the extracellular matrix and induces anoikis in hepatocellular carcinoma cells. 1578 38
The present study investigates the molecular details of how arsenic trioxide inhibits preadipocyte differentiation and examines the role of Akt/
PKB
in regulation of differentiation and apoptosis. Continual exposure of arsenic trioxide, at the clinic achievable dosage that does not induce apoptosis, suppressed 3T3-L1 cell differentiation into fat cells by inhibiting the expression of
PPARgamma
and C/EBPalpha and disrupting the interaction between
PPARgamma
and RXRalpha, which determines the programming of the adipogenic genes. Interestingly, if we treated the cells for 12 or 24 h and then withdrew arsenic trioxide, the cells were able to differentiate to the comparable levels of untreated cells as assayed by the activity of GAPDH, the biochemical marker of preadipocyte differentiation. Long term treatment blocked the differentiation and the activity of GAPDH could not recover to the comparable levels of untreated cells. Continual exposure of arsenic trioxide caused accumulation in G2/M phase and the accumulation of p21. We found that arsenic trioxide induced the expression and the phosphorylation of Akt/
PKB
and it inhibited the interaction between Akt/
PKB
and
PPARgamma
. Akt/
PKB
inhibitor appears to block the arsenic trioxide suppression of differentiation. Our results suggested that Akt/
PKB
may play a role in suppression of apoptosis and negatively regulate preadipocyte differentiation.
...
PMID:The role of Akt on arsenic trioxide suppression of 3T3-L1 preadipocyte differentiation. 1591 24
Embryonic stem (ES) cells are genetically normal, pluripotent cells, capable of self-renewal and differentiation into all cell lineages. While leukemia inhibitory factor (LIF) maintains pluripotency in mouse ES cells, retinoic acid and other nuclear hormones induce neuro-glial differentiation in mouse and human ES cells in culture. Peroxisome-proliferator-activated receptors (PPARs) are ligand-dependent nuclear receptor transcription factors that regulate cell growth and differentiation in many cell types. However, the role of PPARs in the regulation of ES cell growth and differentiation is not known. In this study, we show that LIF induces proliferation and self-renewal of mouse D3-ES cells in culture. However, treatment with 15-Deoxy-Delta(12,14)-Prostaglandin J(2) (15d-PGJ2), a natural ligand for
PPARgamma
, or all-trans retinoic acid (ATRA) results in a dose-dependent decrease in proliferation and self-renewal in D3-ES cells. Immunoprecipitation and Western blot analyses showed that LIF induces tyrosine phosphorylation of
JAK1
,
TYK2
and STAT3 in 30 min and treatment with 15d-PGJ2 or ATRA results in a dose-dependent decrease in LIF-induced phosphorylation of
JAK1
and STAT3 in D3-ES cells. However, treatment of D3-ES cells with Ciglitazone or 15d-PGJ2 for 48 h in culture resulted in a dose-dependent increase in
PPARgamma
protein expression. These results suggest that
PPARgamma
agonists regulate LIF signaling through JAK-STAT pathway leading to growth and self-renewal of ES cells.
...
PMID:15-Deoxy-delta12,14-prostaglandin J2 regulates leukemia inhibitory factor signaling through JAK-STAT pathway in mouse embryonic stem cells. 1673 95
PPARgamma
agonists were reported to be implicated in many biological functions in certain kinds of cells, however, little is known about the effects of
PPARgamma
on hepatocarcinoma cell. We explored the effects of rosiglitazone, a
PPARgamma
activator, on human hepatocarcinoma cell line BEL-7404 and its mechanism. After BEL-7404 was exposed to rosiglitazone, its migration was significantly inhibited, which associated with downregulation of the phosphorylation of Akt and
FAK
, while no significant change was detected in the phosphorylation of ERK after rosiglitazone treatment. It is now known that phosphorylated
FAK
is a substrate of PTEN and Akt phosphorylation can be regulated by PTEN via the PIP(3) level. We found rosiglitazone upregulated PTEN expression in a dose- and time-dependent manner, which was mediated by
PPARgamma
. Furthermore, PTEN overexpression resulted in inhibition of cell migration and PTEN knock-down blocked the effect of rosiglitazone on cell migration. It suggested that PTEN was required for rosiglitazone-induced inhibition of BEL-7404 cells migration. In conclusion, our results demonstrated that PTEN played a critical role in rosiglitazone inhibiting cell migration in BEL-7404.
...
PMID:PPARgamma activator rosiglitazone inhibits cell migration via upregulation of PTEN in human hepatocarcinoma cell line BEL-7404. 1677 33
Peroxisome proliferator-activated receptor gamma
(
PPARgamma
) agonists cause cell death in several types of cancer cells. The aim of this study was to examine the effects of two
PPARgamma
agonists, ciglitazone and 15-deoxy-delta(12,14)-prostaglandin J2 (15dPGJ2), on the survival of thyroid carcinoma CGTH W-2 cells. Both ciglitazone and 15dPGJ2 decreased cell viability in a time- and dose-dependent manner. Cell death was mainly due to apoptosis, with a minor contribution from necrosis. Increased levels of active caspase 3, cleaved poly (ADP-ribose) polymerase (PARP), and cytosolic cytochrome-c were noted. In addition, ciglitazone and 15dPGJ2 induced detachment of CGTH W-2 cells from the culture substratum. Both the protein levels and immunostaining signals of focal adhesion (FA) proteins, including vinculin, integrin beta1,
focal adhesion kinase
(
FAK
), and paxillin were decreased after
PPARgamma
agonist treatment. Meanwhile, reduced phosphorylation of
FAK
and paxillin was noted. Furthermore,
PPARgamma
agonists induced expression of protein tyrosine phosphatase-PEST (PTP-PEST), and of phosphatase and tensin homologue deleted on chromosome ten (PTEN). The upregulation of these phosphatases might contribute to the dephosphorylation of
FAK
and paxillin, since pre-treatment with orthovanadate prevented
PPARgamma
agonist-induced dephosphorylation of
FAK
and paxillin. Perturbation of CGTH W-2 cells with anti-integrin beta1 antibodies induced FA disruption and apoptosis in the same cells, thus the downregulation of integrin beta1 by
PPARgamma
agonists resulted in FA disassembly and might induce apoptosis via anoikis. Our results suggested the presence of crosstalk between apoptosis and integrin-FA signaling. Moreover, upregulation and activation of PTEN was correlated with reduced phosphorylation of Akt, and this consequence disfavored cell survival. In conclusion,
PPARgamma
agonists induced apoptosis of thyroid carcinoma cells via the cytochrome-c caspase 3 and PTEN-Akt pathways, and induced necrosis via the PARP pathway.
...
PMID:Effects of PPARgamma agonists on cell survival and focal adhesions in a Chinese thyroid carcinoma cell line. 1679 79
Esophageal cancer is difficult to treat because of its rapid progression, and more effective therapeutic approaches are needed. The
PPARgamma
is a nuclear receptor superfamily member that is expressed in many cancers.
PPARgamma
expression is a feature of esophageal cancer cell lines, and in the present investigation, the
PPARgamma
antagonists T0070907 and GW9662 could induce loss of invasion but could not induce growth reduction or apoptosis at low concentrations (< 10 mM). A high concentration of antagonists (50 microM) inhibited cell growth and induced apoptosis, but these effects did not explain our result at the low concentration. Morphological change, decreased expression of the cell signaling pathway and inhibition of cancer cell invasion were observed in the low concentration. This suggested that
PPARgamma
antagonists inhibited esophageal cancer cell invasion as well as cell adherence, most likely due to alteration in the
FAK
-MAPK pathway, and this was independent of apoptosis. These results suggested that
PPARgamma
plays an important role in cancer cell invasion and that it might be a novel target for therapy of esophageal cancer.
...
PMID:Inhibition of peroxisome proliferator-activated receptor gamma activity in esophageal carcinoma cells results in a drastic decrease of invasive properties. 1680 24
The acute-phase response (APR) leads to alterations in lipid metabolism and type II nuclear hormone receptors, which regulate lipid metabolism, are suppressed, in liver, heart, and kidney. Here, we examine the effect of the APR in adipose tissue. In mice, lipopolysaccharide produces a rapid, marked decrease in mRNA levels of nuclear hormone receptors [
peroxisome proliferator-activated receptor gamma
(
PPARgamma
), liver X receptor alpha (LXRalpha) and LXRbeta, thyroid receptor alpha (TRalpha) and TRbeta, and retinoid X receptor alpha (RXRalpha) and RXRbeta] and receptor coactivators [cAMP response element binding protein, steroid receptor coactivator 1 (SRC1) and
SRC2
, thyroid hormone receptor-associated protein, and
peroxisome proliferator-activated receptor gamma
co-activator 1alpha (PGC1alpha) and PGC1beta] along with decreased expression of target genes (adipocyte P2, phosphoenolpyruvate carboxykinase, glycerol-3-phosphate acyltransferase, ABCA1, apolipoprotein E, sterol-regulatory element binding protein-1c, glucose transport protein 4 (GLUT4), malic enzyme, and Spot14) involved in triglyceride (TG) and carbohydrate metabolism. We show that key TG synthetic enzymes, 1-acyl-sn-glycerol-3-phosphate acyltransferase-2, monoacylglycerol acyltransferase 1, and diacylglycerol acyltransferase 1, are
PPARgamma
-regulated genes and that they also decrease in the APR. In 3T3-L1 adipocytes, tumor necrosis factor-alpha (TNF-alpha) significantly decreases
PPARgamma
, LXRalpha and LXRbeta, RXRalpha and RXRbeta, SRC1 and
SRC2
, and PGC1alpha and PGC1beta mRNA levels, which are associated with a marked reduction in receptor-regulated genes. Moreover, TNF-alpha significantly reduces PPAR and LXR response element-driven transcription. Thus, the APR suppresses the expression of many nuclear hormone receptors and their coactivators in adipose tissue, which could be a mechanism to coordinately downregulate TG biosynthesis and thereby redirect lipids to other critical organs during the APR.
...
PMID:Type II nuclear hormone receptors, coactivator, and target gene repression in adipose tissue in the acute-phase response. 1684 10
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