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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
There is increasing evidence suggesting that chondrocyte death may contribute to the progression of osteoarthritis (OA). This study focused on the characterization of signaling cascade during NO-induced cell death in human OA chondrocytes. The NO generator, sodium nitroprusside (SNP), promoted chondrocyte death in association with DNA fragmentation,
caspase-3
activation, and down-regulation of Bcl-2. Both
caspase-3
inhibitor Z-Asp(OCH3)-Glu(OCH3)-Val-Asp(OCH3)-CH2F and caspase-9 inhibitor Z-Leu-Glu(OCH3)-His-Asp(OCH3)-CH2F prevented the chondrocyte death. Blocking the mitogen-activated protein kinase pathway by the mitogen-activated protein kinase kinase 1/2 inhibitor PD98059 or p38 kinase inhibitor SB202190 also inhibited the SNP-mediated cell death, suggesting possible requirements of both extracellular signal-related protein kinase 1/2 and p38 kinase for the NO-induced cell death. Furthermore, the selective inhibition of cyclooxygenase (COX)-2 by NS-398 or the inhibition of COX-1/
COX-2
by indomethacin blocked the SNP-induced cell death. The chondrocyte death induced by SNP was associated with an overexpression of
COX-2
protein (as determined by Western blotting) and an increase in PGE2 release. PD98059 and SB202190, but neither Z-DEVD FMK nor Z-LEHD FMK completely inhibited the SNP-mediated PGE2 production. Analysis of interactions between PGE2 and the cell death showed that PGE2 enhanced the SNP-mediated cell death, whereas PGE2 alone did not induce the chondrocyte death. These data indicate that NO-induced chondrocyte death signaling includes PGE2 production via
COX-2
induction and suggest that both extracellular signal-related protein kinase 1/2 and p38 kinase pathways are upstream signaling of the PGE2 production. The results also demonstrate that exogenous PGE2 may sensitize human OA chondrocytes to the cell death induced by NO.
...
PMID:The induction of cell death in human osteoarthritis chondrocytes by nitric oxide is related to the production of prostaglandin E2 via the induction of cyclooxygenase-2. 1097 59
Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit colorectal carcinogenesis and prevent or revert the growth of premalignant colonic polyps. They inhibit cyclooxygenase (COX) but recent data indicate that this is not the only or even the most important mechanism of inhibition in colorectal tumor cells. We have used colonic carcinoma and adenoma cell lines to study the effects of the NSAID sulindac sulfide, its COX-inactive metabolite, sulindac sulfone, and the isoenzyme-specific inhibitors SC58125, SC236 and SC58560 on tumor cell growth in relation to
COX-2
expression and prostaglandin production. To establish the role of
COX-2
in NSAID action, we constructed clones expressing different levels of
COX-2
from SW480 cells. All five compounds inhibited DNA synthesis and/or induced apoptosis, each with a characteristic pattern. ID(50)s were very similar in all the cell lines and were independent of COX expression, except for the COX-1 inhibitor SC58560, which was least effective in HT29/HI1, the cell line expressing the highest level of COX-1 (ID(50) 70 microM; in other cells lines the ID(50) was 15 microM). For all other compounds ID(50) concentrations varied less than two-fold: 25-40, 40-90 and 150 microM for SC236, sulindac sulfide and sulindac sulfone, respectively. SC58125 was the weakest inhibitor, never causing >50% cell loss. All compounds modulated expression of Bcl-2 and Bak and activated
caspase 3
. Overexpression of
COX-2
in SW480 cells protected them against induction of apoptosis by sulindac sulfide. The effect was restricted to clones producing high levels of prostaglandin E(2). In summary, our data indicate that both COX-dependent and COX-independent mechanisms are involved in NSAID-induced growth in colorectal tumor cells. The concentrations necessary to inhibit growth were higher than serum concentrations that can be obtained in vivo, indicating that the therapeutic effect of NSAIDs cannot be explained by a direct effect of NSAIDs on the epithelial cells alone. For therapeutic purposes, compounds using different targets could be used to minimize side effects while optimizing therapeutic effect.
...
PMID:Growth inhibition and induction of apoptosis in colorectal tumor cells by cyclooxygenase inhibitors. 1115 36
Recent evidence suggests that the degradation of cartilage in osteoarthritis is characterized by chondrocyte apoptosis, but little is known about the molecular mechanisms involved or potential protective measures. In the present study, we used an immortalized chondrocyte cell line to explore the mechanisms of apoptotic chondrocyte cell death. We found that staurosporine-mediated chondrocyte death depended on the concentration and time of incubation, and coincided with increased Bax:Bcl-X mRNA expression, cytochrome C release, and activation of
caspase-3
. Pre-treatment of the cultures with nimesulide, a preferential cyclooxygenase (COX)-2 inhibitor, or with ibuprofen, a non-selective COX-1/
COX-2
inhibitor, protected the chondrocytes against the staurosporine-mediated nuclear damage and cell death in a concentration-dependent manner (10(-12) to 10(-6) M). Cell protection coincided with inhibition of the staurosporine-mediated induction of
caspase-3
activation. Notably, the selective
COX-2
inhibitor NS-398 (10(-6) M, 24 hr pre-treatment) did not protect the cells against staurosporine-mediated apoptotic death. The data suggest that nimesulide and ibuprofen, in addition to their anti-inflammatory and analgesic benefits, may also have a protective effect in osteoarthritis through the inhibition of apoptosis in chondrocytes.
...
PMID:Non-steroidal anti-inflammatory drugs protect against chondrocyte apoptotic death. 1129 47
Reactive oxygen species (ROS) are well-established modulators of luteal cell apoptosis in the estrous cycle. The objective of this study was to clarify the molecular mechanisms of luteolysis by characterizing the levels and regions of mRNAs involved in ROS-induced luteal cell apoptosis. Stimulation of bovine luteal cells by H2O2 resulted in the induction of apoptotic nuclear condensation and
Caspase-3
activation. In addition, a marker for oxidative stress-damaged DNA, 8-hydroxy-2'-deoxyguanosine, was highly accumulated in the large luteal cells prepared from the late estrous stage. Reverse transcription polymerase chain reaction and Northern blot analysis demonstrated that mRNAs of cyclooxygenase (COX)-2, p53, and Bax were highly accumulated in the H2O2-treated cells. In situ hybridization revealed that these mRNAs were most abundantly expressed in the large luteal cells. These findings suggest that enhancement of ROS in the bovine corpus luteum induces expression of
COX-2
, p53, and Bax mRNAs, resulting in activation of the signaling pathway for luteal-cell apoptosis.
...
PMID:Reactive oxygen species up-regulates cyclooxygenase-2, p53, and Bax mRNA expression in bovine luteal cells. 1137 91
Non-steroidal anti-inflammatory drugs (NSAIDs) can induce tumor cells to undergo apoptosis in vitro. They have also shown cancer-preventive activity in vivo. The mechanism of their effects is, however, not well defined. We investigated the mechanism by which a new NSAID, NS398, induces apoptosis in esophageal cancer cell lines. NS398 decreased cell viability in 2 cyclo-oxygenase-2-positive (
COX-2
(+)) esophageal cancer cell lines but not in a
COX-2
(-) cell line. DNA fragmentation and TUNEL assays demonstrated that NS398 induced the 2
COX-2
(+) cancer cell lines to undergo apoptosis. The percentage of apoptosis induced by NS398 was associated with the level of
COX-2
expression. Further investigation showed that the cytochrome c pathway was responsible for NS398-induced apoptosis; i.e., cytochrome c was released from mitochondria, caspase-9 and
caspase-3
were activated and finally poly(ADP-ribose)polymerase (PARP) was cleaved. Furthermore, the effect of NS398 was inhibited by the caspase inhibitor Z-DEVD-FMK and prostaglandin E(2). In contrast, bcl-2, bax, c-myc, Fas and Fas-ligand showed minor changes. Altogether, our data suggest that induction of apoptosis by NS398 is associated with
COX-2
expression and occurs through the cytochrome c-dependent pathway, which sequentially activates caspase-9 and
caspase-3
and cleaves PARP.
...
PMID:Induction of apoptosis by cyclo-oxygenase-2 inhibitor NS398 through a cytochrome C-dependent pathway in esophageal cancer cells. 1141 Aug 69
Epidemiologic studies have documented a 40-50% reduction in incidence of colorectal cancer in individuals taking nonsteroidal antiinflammatory drugs (NSAIDs). Since NSAIDs are known to inhibit cyclooxygenases (COX-1,
COX-2
), the basic mechanism of their antitumor effects is conceivably the altered metabolism of arachidonic acid and, subsequently, prostaglandins (PGs). Although
COX-2
, the inducible isoform, is regularly expressed at low levels in colonic mucosa, its activity increases dramatically following mutation of the APC (adenomatous polyposis coli) gene suggesting that beta-catenin/T-cell factor mediated Wnt-signaling activity may regulate
COX-2
gene expression. In addition, hypoxic conditions and sodium butyrate exposure may also contribute to
COX-2
gene transcription in human cancers. The development of selective
COX-2
inhibitors has made it possible to further evaluate the role of
COX-2
activity in colorectal carcinogenesis. To date, at least five mechanisms by which
COX-2
contributes to tumorigenesis and the malignant phenotype of tumor cells have been identified, including: (1) inhibition of apoptosis; (2) increased angiogenesis; (3) increased invasiveness; (4) modulation of inflammation/immuno-suppression; and (5) conversion of procarcinogens to carcinogens. A clear positive correlation between
COX-2
expression and inhibition of apoptosis has been established, associated with increased PGE2 levels resulting in modulation of pro- and anti-apoptotic factors (e.g., bcl-2, MAKs/ras,
caspase-3
, Par-4). In terms of angiogenesis and invasiveness,
COX-2
activity was found to increase the expression of growth factors (e.g., VDEG, PDGF, bFGF) and matrix metalloproteinases (MMPs). Since
COX-2
inhibitors have been demonstrated to interfere with tumorigenesis and apoptosis,
COX-2
and its gene product may be attractive targets for therapeutic and chemoprotective strategies in colorectal cancer patients. This may lead to new perspectives that by controlling the cancer phenotype, rather than attempting to eradicate all affected cells, may provide significant benefits to the cancer patient.
...
PMID:Cyclooxygenase-2: a novel target for cancer chemotherapy? 1146 77
Cyclooxygenases (COXs) catalyze the synthesis of prostaglandins (PGs) from arachidonic acid. Overexpression of
COX-2
is frequently found in human cancers and is suggested to play an important role in tumorigenesis. Recent studies indicated that
COX-2
inhibitors exert potent anti-cancer effects on a number of cancers. Interestingly, some
COX-2
inhibitors potently induce apoptosis, while other
COX-2
inhibitors primarily induce growth inhibition. Therefore, there is a variability in the effects that different
COX-2
inhibitors have on cancer cells. In this study, we demonstrated that induction of apoptosis of high
COX-2
-expressing A549 lung cancer cells by a specific
COX-2
inhibitor NS398 was observed in cells cultured under serum-free condition. However, this drug induced G1 growth arrest rather than apoptosis in A549 cells maintained in 10% serum medium. Conversely, low
COX-2
-expressing H226 lung cancer cells were resistant to NS398-induced apoptosis under both serum-free and serum-containing conditions. Moreover, our results showed that NS398-induced apoptosis is associated with activation of
caspase-3
, a cysteine protease that plays a crucial role in the execution phase of apoptosis. These results suggest that the cytotoxic effect of
COX-2
inhibitors on cancer cells may be influenced by extracellular environments and the anti-cancer action of these inhibitors in vivo needs careful evaluation. Additionally, a correlation between the level of
COX-2
expression and the extent of apoptosis induced by
COX-2
inhibitors was found.
...
PMID:Cyclooxygenase-2 level and culture conditions influence NS398-induced apoptosis and caspase activation in lung cancer cells. 1160 58
Apoptosis plays a central role in tumor development and it has been hypothesized that lack/failure of apoptosis leads to the development of tumors, including colon tumors. Thus, induction of apoptosis in tumor cells is an effective approach to the regulation of tumor growth. It has been shown by us and other investigators that various chemopreventive agents induce apoptosis and inhibit tumor growth. Identification of agents or combinations of agents that induce tumor cell apoptosis guides the development of novel agents for colon cancer treatment. Experiments were designed to assess the effectiveness of lovastatin, a 3-hydroxy-3-methyl glutaryl-CoA reductase inhibitor, and celecoxib a cyclooxygenase-2 inhibitor, individually or in combination on the induction of apoptosis in human HT-29 colon cancer cells. In addition, we studied the modulatory effect of lovastatin and celecoxib on lamin B levels,
caspase-3
activity and expression in relationship to apoptosis in colon cancer cell lines. HT-29 cells exposed to various subtoxic levels of lovastatin or celecoxib or a combination of both were analyzed for apoptosis (by DAPI method),
caspase-3
expression (immunoblot analysis) and
caspase-3
activity (fluorimetric method). We found that: i) pretreatment with lovastatin (5-30 microM) induces apoptosis in HT-29 cells significantly only at high concentrations (> or = 20 microM) but not at low dose levels; ii) similarly, pretreatment with celecoxib produced apoptosis in colon cancer cells at high concentrations only (> or = 75 microM); iii)
caspase-3
protein expression was moderately altered by the treatment with lovastatin or celecoxib at lower concentrations; however, a significant increase (1.6 to 4-fold) in
caspase-3
expression and activity was found in HT-29 cells exposed with 20-25 microM lovastatin and/or 5-125 microM celecoxib and iv) importantly, in tumor cells exposed to low doses of (5 or 10 microM) lovastatin, combined with 25-75 microM of celecoxib, apoptosis induction rose 2.5 to 10-fold,
caspase-3
expression was 2.3 to 8-fold higher, and enzyme activities were 1.5 to 5.5-fold elevated. This effect was highly synergistic and dose-dependent. Lamin B levels were significantly increased in a dose-dependent manner in cells treated with lovastatin but no such effect was observed with celecoxib. These results indicate that agents with different modes of action when applied in combinations will induce apoptosis synergistically by enhancing
caspase-3
activities. These findings further support the hypothesis that HMGCo-R and
COX-2
activities play important roles in apoptosis and regulation of apoptosis by selective agents such as lovastatin and celecoxib would provide effective strategies for the prevention of colon cancer.
...
PMID:Lamin B, caspase-3 activity, and apoptosis induction by a combination of HMG-CoA reductase inhibitor and COX-2 inhibitors: a novel approach in developing effective chemopreventive regimens. 1189 21
Prior studies have shown that cyclooxygenase (COX)-2, an enzyme involved in inflammatory mechanisms as well as neuronal activities, is up-regulated in the Alzheimer's disease (AD) brain and may represent a therapeutic target for anti-inflammatory treatments. We report the effect of neuronal overexpression of human (h)
COX-2
in a murine model of AD neuropathology. Transgenic mice expressing both the human amyloid precursor protein mutation (APPswe) and the human presenilin (PS1-A246E) mutation, with resultant AD plaque pathology, were crossed with transgenic mice expressing human (h)
COX-2
in neurons. At 12 months of age, the APPswe/PS1-A246E/hCOX-2 triple-transgenic mice showed an elevation in the number of phosphorylated retinoblastoma (pRb) tumor suppressor protein and active
caspase-3
immunopositive neurons, compared to double APPswe/PS1-A246E or single hCOX-2 transgenic controls. No detectable influence of neuronal hCOX-2 on AD neuropathology was found in the brain of APPswe/PS1-A246E/hCOX-2 triple-transgenic mice, compared to double APPswe/PS1-A246E. In vitro studies revealed that hCOX-2 overexpression in primary cortico-hippocampal neurons derived from the hCOX-2 transgenics accelerates beta-amyloid (Abeta)(1-42)-mediated apoptotic damage which was prevented by the cell cycle dependent (CDK) inhibitor, flavoperidol. The data indicates that
COX-2
overexpression causes alteration of neuronal cell cycle in a murine model of AD neuropathology, and provides a rational basis for targeting neuronal
COX-2
in therapeutic research aimed at slowing the clinical progression of AD.
...
PMID:Cyclooxygenase (COX)-2 and cell cycle activity in a transgenic mouse model of Alzheimer's disease neuropathology. 1195 94
Evidence is accumulating that bile acids induce apoptosis in colonic cells. Therefore, it becomes important to study the underlying molecular mechanisms and the role of this phenomenon in tumor promotion. Minutes after exposure of HCT 116 and HT-29 cells to deoxycholate (DCA), DNA damage, measured using the COMET assay, was evident.
Caspase-3
was rapidly activated in HCT 116 cells exposed to DCA, whereas in HT-29 cells,
caspase-3
activation was delayed. Using transient transfections with reporter constructs, we showed that the transcription factors activator protein-1 (AP-1) and NF-kB were increased in HCT 116 cells, in a dose-dependent fashion, by DCA
COX-2
promoter activity was also induced by DCA and using mutant
COX-2
promoter plasmids, we showed that the ability of DCA to induce promoter activity was partly dependent upon a functional NF-kB and C/EBP site, and completely dependent on a functional c-AMP response element site. DNA damage thus appears to be the initiating event in DCA-induced apoptosis. In conclusion, the bile acid, DCA, has a major impact on apoptotic mechanisms in colonic cells and this may be contributing to its effect as a tumor promoter.
...
PMID:Deoxycholic acid causes DNA damage in colonic cells with subsequent induction of caspases, COX-2 promoter activity and the transcription factors NF-kB and AP-1. 1201 58
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