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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Lung cancer is one of the most common causes of cancer death worldwide. Although recent advances in chemotherapy and radiation therapy have yielded modest improvements in patient outcomes, overall survival remains poor. Therefore, new therapeutic targets are needed. Phosphoinositide-dependent kinase-1 (PDK1) is one potential target. The aim of the present studies was to investigate the potential of a celecoxib-derived PDK1 inhibitor (OSU03013), that does not inhibit
cyclooxygenase-2
, to kill lung cancer cells in vitro. Using human non-small-cell lung cancer A549 cells, OSU03013 dose-dependently induced apoptosis. After 6 h of treatment with 7.5 microM OSU03013, 26% of the cells were apoptotic, compared to 4% of the control cells as determined by measuring the sub-G1 peak of propidium iodide stained cells with flow cytometry. A similar increase in apoptosis was evident using the Cell Death ELISA assay. OSU03013-induced apoptosis was accompanied by a reduction in the mitochondrial membrane potential, the release of cytochrome c and the cleavage of
caspase-3
. Surprisingly, the phosphorylation of Akt at serine 473 was increased in A549 cells treated with 7.5 microM OSU03013. However, the toxicity of OSU03013 was reduced in A549 cells expressing a constitutively active form of Akt. These data demonstrate that OSU03013 induces apoptosis in A549 cells via the mitochondrial pathway. Inhibition of the Akt pathway appears uninvolved in this toxicity, although Akt can provide protection. These results also suggest the potential of celecoxib-derived agents to treat some forms of lung cancer.
...
PMID:Cytotoxicity of a non-cyclooxygenase-2 inhibitory derivative of celecoxib in non-small-cell lung cancer A549 cells. 1649 9
Cyclooxygenase-2
(
COX-2
) induction and prostaglandin E(2) (PGE(2)) elevation have been reported to occur after cerebral ischemic insult. PGE(2) induces apoptosis through the PGE(2) EP2 receptor by a cAMP-dependent pathway. Glycogen synthase kinase-3 (GSK-3) affects many fundamental cellular functions. We examined whether GSK-3 is involved in PGE(2)-induced cell death by using GSK-3 inhibitors in rat cultured cortical neurons. Cells treated with 12.5 microM PGE(2) for 2 days shrank. The injured cells underwent chromatin condensation and nuclear fragmentation detected by staining with Hoechst33258, indicating apoptotic cell death. We assayed the effects of selective GSK-3 inhibitors SB216763 and alsteropaullone on PGE(2)-induced apoptosis. These inhibitors completely protected the cells from apoptosis induced by PGE(2). Moreover, dibutyryl cAMP (a cell permeable cAMP)-induced apoptosis was also prevented by alsteropaullone. In addition, GSK-3 inhibitors inhibited
caspase-3
activation accompanied by PGE(2)-induced apoptosis. We showed in this report that PGE(2)-induced apoptosis is prevented by GSK-3 inhibitors, suggesting that PGE(2) induces caspase-dependent apoptosis mediated through GSK-3 activation in rat cultured cortical neurons.
...
PMID:Prevention of rat cortical neurons from prostaglandin E2-induced apoptosis by glycogen synthase kinase-3 inhibitors. 1650 98
Direct delivery of chemotherapeutic agents to the lung can increase both the drug concentration and exposure period to lung tumours. The objective of this study was to formulate docetaxel (DOC) into a metered dose inhaler (MDI), assess its aerodynamic characteristics and to evaluate the effect of celecoxib (CXB), a
cyclooxygenase-2
(
COX-2
) inhibitor, on the in-vitro cytotoxicity and apoptotic response of aerosolized DOC against human lung adenocarcinoma cell line A549. A stable solution-type MDI formulation was developed with 0.25% DOC and 15% w/w ethyl alcohol using HFA 134a propellant. The formulation was evaluated for medication delivery, mass median aerodynamic diameter (MMAD), geometric standard deviation (GSD), percent throat deposition, respirable mass and respirable fraction. A six-stage viable impactor was used to assess the in-vitro cytotoxicity of DOC-MDI alone or in combination with CXB. Induction of apoptosis in A549 cells by DOC (non-aerosolized and aerosolized) in combination with CXB was evaluated by established techniques, such as
caspase-3
estimation and terminal deoxynucleotidyl transferase-mediated nick end labelling (TUNEL) staining. The influence of different treatments on the expression of
COX-2
and peroxisome proliferator-activated receptor-gamma(PPAR-gamma) in A549 cells was studied by RT-PCR. The DOC-MDI formulation had a MMAD of 1.58 microm, (GSD = 3.2) and a medication delivery of 80 microg/shot. DOC-MDI (one shot) in combination with CXB (10 microg mL(-1)) had a cell kill of more than 80% as determined by in-vitro cytotoxicity assay. The specific
caspase-3
activity in A549 cells treated with DOC (0.01 microg mL(-1)) and CXB (10.0 microg mL(-1)) combination was 4 times higher than CXB and untreated control group, respectively. Further, TUNEL staining showed significant apoptosis of A549 cells treated with aerosolized DOC alone or in combination with CXB when compared with CXB and untreated cells. The RT-PCR experiments showed similar expression of
COX-2
in both control and treated groups. PPAR-gamma expression was increased in the combination treatment (0.01 microg mL(-1) DOC and 10 microg mL(-1) CXB) as compared with control (untreated), DOC (0.01 microg mL(-1)) and CXB (10 microg mL(-1)) treatments. Our results indicate the potential of inhalation delivery of DOC in the treatment of lung cancer.
...
PMID:Anti-cancer effect of celecoxib and aerosolized docetaxel against human non-small cell lung cancer cell line, A549. 1653 99
Celecoxib, a specific
cyclooxygenase-2
(
Cox-2
) inhibitor, has been shown to possess antitumor activity in a variety of cancer cells. However, the antitumor activity of celecoxib in hematopoietic tumors, especially in chronic myeloid leukemia (CML), has not been well established. This study was designed to investigate the effect of celecoxib on growth and apoptosis in a human CML cell line (K562 cells) or in primary CML cells, and to examine the synergistic actions of celecoxib and hydroxyurea or imatinib on K562 cell proliferation and apoptosis. Celecoxib significantly inhibited the growth of both K562 and primary CML cells and induced apoptosis in a dose-dependent fashion. The IC50 of celecoxib was 46 microM for inhibition of K562 cell proliferation. The effect of celecoxib on growth inhibition was accompanied by the downregulation of cyclin D1 and cyclin E and p-Rb expression, the upregulation of P16(INK4a) and P27KIP expression, and a G1-S phase arrest of the cell cycle. The pro-apoptotic effect of celecoxib was determined to be mediated by
caspase-3
activation. When K562 cells were pretreated with DEVD-fmk, a specific inhibitor of caspases, the apoptotic activity of celecoxib was, in part, abrogated. Importantly, we demonstrated for the first time that K562 cells were
Cox-2
-positive both at the mRNA and protein levels. We noted the following observations: (i) we detected
Cox-2
mRNA in K562 cells by reverse transcription-PCR (RT-PCR) and protein expression by western blot analysis; (ii)
Cox-2
expression in K562 cells was stimulated by IL-1beta, a specific inducing agent of
Cox-2
expression; (iii) primary CML cells from CML patient bone marrow also exhibited
Cox-2
protein expression. Furthermore,
Cox-2
expression was downregulated at higher doses of celecoxib (80-160 microM), suggesting a
Cox-2
-dependent mechanism was involved in the drug's effects of growth inhibition and induction of apoptosis. In addition, a synergistic effect was observed when cells were exposed to low-dose celecoxib (40 microM) and hydroxyurea (10 mM) or a combination of celecoxib (40 microM) and imatinib (0.2 microM). These findings provide the basis for uncovering the mechanism of celecoxib's antitumor effects and developing a new therapeutic strategy for treating CML.
...
PMID:Antitumor effects of celecoxib on K562 leukemia cells are mediated by cell-cycle arrest, caspase-3 activation, and downregulation of Cox-2 expression and are synergistic with hydroxyurea or imatinib. 1655 May 20
Expression of
cyclooxygenase-2
(
Cox-2
), an inducible enzyme responsible for the production of prostaglandins from arachidonic acid, is elevated in human prostate tumor samples. The aim of this study was to investigate whether expression of
Cox-2
is effective against prostate cancer cell apoptosis triggered by sanguinarine, the quaternary benzophenanthridine alkaloid with antineoplastic properties. Sanguinarine effectively induced apoptosis in LNCaP human prostate cancer epithelial cells as assessed by
caspase-3
activation assay, Annexin V staining assay, or by visual analysis for the apoptotic morphology changes. Sanguinarine-mediated apoptosis was associated with the increase of nitric oxide (NO) formation in prostate cancer cells as assessed by measurements of nitrites with Sievers nitric oxide analyzer as well as flow cytometry analysis using NO fluorescent sensor. Activation of NO synthase (NOS) activity was crucial for sanguinarine-induced cell death because NOS inhibitor L-NMMA efficiently protected cells from apoptosis. Adenovirus-mediated transfer of
Cox-2
into LNCaP cells inhibited sanguinarine-induced apoptosis and prevented an increase in NO production. Surprisingly, NO donors failed to induce apoptosis in LNCaP cells, suggesting that constitutive NO generation is not sufficient for triggering apoptosis in these cells. Besides NO generation, NOS is also capable of producing superoxide radicals. Sanguinarine-induced production of superoxide radicals, and the addition of MnTBAP, a scavenger of superoxide radicals, efficiently inhibited sanguinarine-mediated apoptosis. These results suggest that
Cox-2
expression rescues prostate cancer cells from sanguinarine-induced apoptosis by a mechanism involving inhibition of NOS activity, and that coadministration of
Cox-2
inhibitors with sanguinarine may be developed as a strategy for the management of prostate cancer.
...
PMID:Cyclooxygenase 2 rescues LNCaP prostate cancer cells from sanguinarine-induced apoptosis by a mechanism involving inhibition of nitric oxide synthase activity. 1658 99
Sepsis induced by exposure to lipopolysaccharide (LPS) can be life-threatening and lead to multiple-organ dysfunction. Sepsis-associated cardiac dysfunction is a primary cause of mortality. The response of isolated cardiac myocytes to LPS exposure is poorly understood. Cultured neonatal rat ventricular cardiomyocytes were used to evaluate the response to LPS exposure. Other authors have reported that LPS exposure at doses sufficient to induce tumor necrosis factor alpha (TNF-alpha) production and apoptosis in adult cardiomyocytes do not induce apoptosis in neonatal cardiomyocytes. We therefore hypothesized that neonatal cardiomyocytes have innate protective mechanisms that protect from septic damage. Cultured neonatal rat ventricular cardiomyocytes were stimulated by exposure to LPS for varying lengths of time. NFkappaB signaling pathways, TNF-alpha production, and Akt activation were monitored. We also assessed the induction of apoptosis in these cells by monitoring
caspase-3
activity. LPS rapidly stimulates nuclear translocation of NFkappaB and Akt activation. TNF-alpha production is also stimulated. However, high doses of LPS are unable to induce apoptosis in these cells, and protection is not a function of Akt activation. LPS treatment also stimulated the levels of
cyclooxygenase-2
and the production of downstream metabolites, specifically PGE2 and 15deoxyDelta12-14PGJ2 (15dPGJ2). Specific inhibition of
cyclooxygenase-2
activity induced apoptosis in the presence of LPS, whereas direct exposure to 15dPGJ2 at pharmacological levels induced apoptosis. Neonatal rat ventricular cardiomyocytes have innate protective mechanisms that prevent apoptotic cell death after LPS exposure. Metabolic products of arachidonic acid metabolized by the cyclooxygenase pathway can be potentially apoptotic or antiapoptotic. The balance of these products within these cells may define the cellular response to LPS exposure.
...
PMID:The response of neonatal rat ventricular myocytes to lipopolysaccharide-induced stress. 1668 21
Growing evidence indicates that inducible
cyclooxygenase-2
(
COX-2
) is involved in the pathogenesis of inflammatory disorders and various types of cancer. Endothelial progenitor cells recruited from the bone marrow have been shown to be involved in the formation of new vessels in malignancies and discussed for being a key point in tumour progression and metastasis. However, until now, nothing is known about an interaction between COX and endothelial progenitor cells (EPC). Expression of COX-1 and
COX-2
was detected by semiquantitative RT-PCR and Western blot. Proliferation kinetics, cell cycle distribution and rate of apoptosis were analysed by MTT test and FACS analysis. Further analyses revealed an implication of Akt phosphorylation and
caspase-3
activation. Both COX-1 and
COX-2
expression can be found in bone-marrow-derived endothelial progenitor cells in vitro.
COX-2
inhibition leads to a significant reduction in proliferation of endothelial progenitor cells by an increase in apoptosis and cell cycle arrest.
COX-2
inhibition leads further to an increased cleavage of
caspase-3
protein and inversely to inhibition of Akt activation. Highly proliferating endothelial progenitor cells can be targeted by selective
COX-2
inhibition in vitro. These results indicate that upcoming therapy strategies in cancer patients targeting
COX-2
may be effective in inhibiting tumour vasculogenesis as well as angiogenic processes.
...
PMID:Inhibition of cyclooxygenase (COX)-2 affects endothelial progenitor cell proliferation. 1689 39
Celecoxib is being evaluated as a chemopreventive agent. However, its mechanism of action is not clear because high doses were used for in vitro studies to obtain antitumor effects. We found that celecoxib inhibited the growth of premalignant and malignant human bronchial epithelial cells with IC(50) values between 8.9 and 32.7 micromol/L, irrespective of
cyclooxygenase-2
(
COX-2
) expression. Normal human bronchial epithelial cells were less sensitive to celecoxib. Because these concentrations were higher than those attainable in vivo (<or=5.6 micromol/L), we surmised that combining celecoxib with the synthetic retinoid N-(4-hydroxyphenyl) retinamide (4HPR) might improve its efficacy. Treatment of premalignant lung cell lines with combinations of clinically relevant concentrations of celecoxib (<or=5 micromol/L) and 4HPR (<or=0.25 micromol/L) resulted in greater growth inhibition, apoptosis induction, and suppression of colony formation than did either agent alone. This combination also decreased the levels of Bcl-2, induced the release of mitochondrial cytochrome c, activated caspase-9 and
caspase-3
, and induced cleavage of poly(ADP-ribose)polymerase at concentrations at which each agent alone showed no or minimal effects. Furthermore, combinations of celecoxib and 4HPR suppressed the phosphorylation levels of serine/threonine kinase Akt and its substrate glycogen synthase kinase-3beta more effectively than the single agents did. Accordingly, overexpression of constitutively active Akt protected bronchial epithelial cells from undergoing apoptosis after incubation with both celecoxib and 4HPR. These findings indicate that activation of the mitochondrial apoptosis pathway and suppression of the Akt survival pathway mediate the augmented apoptosis and suggest that this combination may be useful for lung cancer chemoprevention.
...
PMID:Involvement of mitochondrial and Akt signaling pathways in augmented apoptosis induced by a combination of low doses of celecoxib and N-(4-hydroxyphenyl) retinamide in premalignant human bronchial epithelial cells. 1701 36
Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a transcription factor important in fat metabolism and PPAR-gamma agonists were recently demonstrated to affect proliferation, differentiation, and apoptosis of different cell types. In the present study, two PPAR-gamma agonists, 15-deoxy-delta (12,14)-prostaglandin J2 (15d-PGJ2) and a synthetic PPAR-gamma agonist troglitazone (TGZ), were used to investigate activated PPAR-gamma-induced apoptosis on human monocyte leukemia U937 and Mono Mac 6 cells in vitro. The results showed that both U937 and Mono Mac 6 cells demonstrated constitutive activation of COX-2 expression; treatment by 15d-PGJ2 and TGZ could induce apoptosis remarkably in human monocyte leukemia cells by disruption of mitochondrial membrane potential, activation of
caspase-3
, and causing cleavage of the caspase substrate poly (ADP-ribose) polymerase (PARP). Further studies revealed that treatment by both 15d-PGJ2 and TGZ remarkably downregulated COX-2 expression in these two kind of monocyte leukemia cells as measured by reverse transcriptase PCR (RT-PCR) and Western blot. Furthermore, the expression of Bcl-2 and Bcl-Xl and Mcl-1 was downregulated while Bax expression was upregulated concurrently after the cells were treated by these two agonists, and no variations were found in other Bcl-2 family members such as Bak, Bid, and Bad. Taken together, our results demonstrate for the first time that downregulation of
cyclooxygenase-2
expression, disruption of mitochondrial membrane potential, activation of
caspase-3
, downregulation of Bcl-2, Bcl-Xl, and Mcl-1, and upregulation of Bax are involved in PPAR-gamma agonists-induced apoptosis in these two human monocyte leukemia cells.
...
PMID:Downregulation of cyclooxygenase-2 expression and activation of caspase-3 are involved in peroxisome proliferator-activated receptor-gamma agonists induced apoptosis in human monocyte leukemia cells in vitro. 1708 25
Sulindac sulfide and sulindac sulfone have demonstrated anti-neoplastic and chemo-preventive activity against various human tumors, but few studies have examined the relative effectiveness of these drugs against squamous cell carcinoma of the head and neck (SCCHN). These compounds are metabolites of the nonsteroidal anti-inflammatory drug sulindac and differ in their ability to inhibit
cyclooxygenase-2
(
COX-2
) enzyme function. Sulindac sulfide (the sulindac metabolite with
COX-2
inhibitory function) demonstrated strong cell growth inhibition as measured by MTT and growth assays in UM-SCC-1 and SCC-25 cells, while sulindac sulfone had only moderate effect. Growth inhibition by sulindac sulfide was associated with a significant increase in percent G cells and activation of
caspase-3
. Sulindac sulfide induced expression of p21wafl/cipl in a dose-dependent fashion, decreased cyclin D1 protein levels, and increased Rb hypophosphorylation. p21waf1/cip1 protein levels increased without a significant increase in wild-type p53, suggesting that sulindac sulfide induces a p53-independent pathway regulating p2lwafl/ciP1 protein levels in SCCHN. Sulindac sulfide also induced dose-dependent expression of PPAR-gamma. In contrast, sulindac sulfone did not significantly alter apoptosis, cell cycle distribution or G1 checkpoint protein expression at doses below 200 microM. These results demonstrate the differential activity of sulindac metabolites and support the hypothesis that sulindac sulfide induced perturbations in SCCHN cellular proliferation could be regulated both by p21waf1/cip1-dependent cytostatic and caspase-dependent cytotoxic pathways.
...
PMID:Differential activity of sulindac metabolites against squamous cell carcinoma of the head and neck is mediated by p21waf1/cip1 induction and cell cycle inhibition. 1717 18
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