Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UNIPROT:P42574 (caspase-3)
45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study the role of cyclooxygenase-2 (COX-2) in primitive neuroectodermal tumor (PNET) the most malignant brain tumors of childhood was investigated. COX-2 expression in human brain tumor biopsy samples (seven/seven) was about 6-8-fold higher than normal brain tissue and several PNET cell lines also express COX-2. The effect of selective COX-2 inhibitors, celecoxib and rofecoxib on the growth of two PNET cell lines (DAOY and PFSK) was determined. Celecoxib was more potent than rofecoxib in suppressing cell growth. Growth inhibition by celecoxib and rofecoxib was independent of Bcl-2 expression. Celecoxib suppressed the expression of Akt and activated the caspase-3 in DAOY and PFSK, whereas rofecoxib did not have such an effect.
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PMID:Overexpression of cyclooxygenase-2 (COX-2) in human primitive neuroectodermal tumors: effect of celecoxib and rofecoxib. 1191 65

Although the influence of selective cyclooxygenase (COX)-2 inhibitors on the proliferation of colon adenocarcinoma cells have been the subject of much investigation, relatively little research has compared the effects of different COX-2 inhibitors. Celecoxib strongly suppressed the proliferation of COX-2 expressing HT-29 cells at 10-40 microM. NS-398 and nimesulide also inhibited cell proliferation, whereas rofecoxib, meloxicam, and etodolac did not. Only celecoxib induced apoptosis of HT-29 cells, as detected on the basis of DNA fragmentation, TUNEL positivity, and caspase-3/7 activation. DNA fragmentation was also increasd in COX-2 non-expressing cell lines (SW-480 and HCT-116) by exposure to celecoxib for 6-24 h. All six COX-2 inhibitors suppressed the production of prostaglandin E(2) by HT-29 cells, suggesting that the pro-apoptotic effect of celecoxib was unrelated to inhibition of COX-2. Inactivation of Akt might explain the differential pro-apoptotic effect of these selective COX-2 inhibitors on colon adenocarcinoma cells.
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PMID:Selective cyclooxygenase-2 inhibitors show a differential ability to inhibit proliferation and induce apoptosis of colon adenocarcinoma cells. 1241 26

Malignant mesothelioma (MM) remains the most lethal pleural, peritoneal and pericardial cancer. Here, we characterize the effects of nonsteroidal anti-inflammatory agents (NSAIDs) on in vitro and in vivo experimental MM models. Unlike primary normal mesothelial cells, the selective cyclooxygenase (COX)-2 inhibitor celecoxib reduced the in vitro proliferation of several MM cells derived from previously untreated MM patients. Moreover, celecoxib significantly inhibited MM cell colony formation in soft agarose (63-78% at 5 x 10(-5) M; p < or = 0.05) and it elicited remarkable antitumor activity, leading to long-term survival in >37% of nude mice bearing intraperitoneal MM. Celecoxib was more efficient in inhibiting MM cell growth than acetylsalicylic acid (10(-6) M-10(-2) M), indometacin (10(-6) M-10(-2) M) and the COX-2 inhibitor NS-398 (10(-6) M-10(-4) M). Efficacy of these different compounds was not related to the amount of COX-2 protein levels present on MM cells. Celecoxib, in a dose- and time-dependent manner, induced MM cell apoptosis, which involved decreased Akt phosphorylation, loss of Bcl-2 and Survivin protein expression and caspase-3 activation. Furthermore, vascular endothelial growth factor (VEGF), an MM autocrine growth factor and Akt inducer, rescued celecoxib-induced apoptosis and Akt dephosphorylation. When the VEGF receptor (KDR/Flk-1) inhibitor, SU-1498, was used in combination with celecoxib, IC50 of celecoxib in vitro was reduced up to 65%. These data demonstrate that celecoxib may have antitumor properties in MM and provide a rationale for the therapeutic use of celecoxib in combination with a selective VEGF inhibitor.
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PMID:Preclinical evaluation of the nonsteroidal anti-inflammatory agent celecoxib on malignant mesothelioma chemoprevention. 1496 68

Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is the only non-steroidal anti-inflammatory drug so far which has been approved by the FDA for adjuvant treatment of patients with familial adenomatous polyposis. The molecular mechanism responsible for the anticarcinogenic effects of celecoxib is still not fully understood. To investigate the extent to which the anticarcinogenic effect of celecoxib depends on COX-2 expression, we transfected human colon carcinoma cells (Caco-2) with the human COX-2 cDNA, in both sense and in antisense orientation, to generate cells which either overexpress COX-2 (human COX-2-sense, hCOX-2-s), express no COX-2 (human COX-2-antisense, hCOX-2-as) or express only very small amounts of COX-2 (control cells). Treatment of these cells with celecoxib dose-dependently (0-100microM) reduced cell survival which was accompanied by an induction of a G(0)/G(1) phase block and apoptosis. The effect of celecoxib treatment on both, cell survival and induction of apoptosis in hCOX-2-as cells was less marked than in the COX-2-expressing cells. Apoptosis was accompanied by an activation of caspase-3 and caspase-9 and cytochrome c release. In contrast, we observed no difference in sensitivity with regard to the induction of a cell cycle block between the different cell clones. The G(0)/G(1) phase block caused by celecoxib correlated with a decrease in expression levels of cyclin A and cyclin B1 and an increase in the expression of the cell cycle inhibitory proteins p21(Waf1) and p27(Kip1) irrespective of the type of cell used. These data indicate that apoptosis-inducing effects of celecoxib partly depend on COX-2 expression of the cells, whereas induction of a cell cycle block occurred COX-2 independently. Thus, the anticarinogenic effects of celecoxib can be explained by both COX-2-dependent and -independent mechanisms.
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PMID:Cyclooxygenase-2 (COX-2)-dependent and -independent anticarcinogenic effects of celecoxib in human colon carcinoma cells. 1504 64

Recently, we demonstrated that the cyclooxygenase-2 (COX-2) inhibitor celecoxib acts to significantly suppress the growth of rat C611B cholangiocarcinoma (ChC) cells in vitro. To establish a molecular mechanism for this growth suppression, we investigated the effects of celecoxib on apoptotic signaling pathways in cultured rat C611B ChC cells. Celecoxib and another COX-2 inhibitor, rofecoxib, at 5 microM were almost equally effective in inhibiting prostaglandin E(2) (PGE(2)) production by these cells, but at this low concentration, neither inhibitor suppressed growth or induced apoptosis. Celecoxib at 50 microM induced prominent apoptosis in these cells, whereas rofecoxib at 50 microM was without effect in either suppressing growth or inducing apoptosis. Celecoxib (50 microM) did not alter Bcl-2, Bcl-x(L), or COX-2 protein levels, nor did it inhibit p42/44 mitogen-activated protein kinase (MAPK) phosphorylation; however, it significantly suppressed serine/threonine kinase Akt/PKB (Akt) phosphorylation and kinase activity in cultured C611B cells. This effect, in turn, directly correlated with Bax translocation to mitochondria, cytochrome c release into cytosol, activation of caspase-9 and caspase-3, and cleavage of poly (ADP-ribose) polymerase (PARP). Addition of 25 microM PGE(2) to C611B cell cultures blocked the apoptotic actions of celecoxib. Rofecoxib (50 microM) was without effect in suppressing Akt phosphorylation and caspase-3 activation. In vivo, celecoxib partially suppressed tumorigenic growth of C611B ChC cells. In conclusion, our results indicate that celecoxib preferentially acts in vitro to induce apoptosis in ChC cells through a mechanism involving Akt inactivation, Bax translocation, and cytochrome c release. Our in vivo results further suggest celecoxib might have potential therapeutic or chemopreventive value against ChC.
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PMID:Celecoxib-induced apoptosis in rat cholangiocarcinoma cells mediated by Akt inactivation and Bax translocation. 1505 7

In the present study, we have shown for the first time that a plant steroid, diosgenin, causes an inhibition of the growth of fibroblast-like synoviocytes from human rheumatoid arthritis, with apoptosis induction associated with cyclooxygenase-2 (COX-2) up-regulation. Celecoxib, a selective COX-2 inhibitor, provoked a large decrease in diosgenin-induced apoptosis even in the presence of exogenous prostaglandin E2, whereas interleukin-1beta, a COX-2 inducer, strongly increased diosgenin-induced apoptosis of these synoviocytes. These findings suggest that the proapoptotic effect of diosgenin is associated with overexpression of COX-2 correlated with overproduction of endogenous prostaglandin E2. We also observed a loss of mitochondrial membrane potential, caspase-3 activation, and DNA fragmentation after diosgenin treatment.
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PMID:Diosgenin, a plant steroid, induces apoptosis in human rheumatoid arthritis synoviocytes with cyclooxygenase-2 overexpression. 1522 73

Celecoxib is a potent nonsteroid antiinflammatory drug (NSAID) that has shown great promise in cancer chemoprevention and treatment. The tumor suppression activity of celecoxib and other NSAIDs have been related to the induction of apoptosis in many cancer cell lines and animal models. While celecoxib is a specific inhibitor of cyclooxygenase (COX)-2, recent data indicate that its apoptotic properties may also be mediated through COX-independent pathways. In our study, we evaluated second generation celecoxib derivatives, lacking COX-2 inhibitory activity, in a premalignant and malignant human oral cell culture model to determine their potential anticancer effect and mechanisms responsible for the COX-independent apoptotic activity. Celecoxib and its derivatives delayed the progression of cells through the G(2)/M phase and induced apoptosis. The derivatives with apolar substituents at the terminal phenyl moiety of celecoxib greatly enhanced apoptosis and cell cycle delay. Apoptosis and cell cycle arrest appeared to be independent of derivative induced inhibition of PDK1 and phosphorylation of Akt and Erk1/2. Derivatives induced apoptosis was mediated by the cleavage and activation of caspase-9 and caspase-3, but not caspase 8, implicating the mitochondrial pathway for apoptosis induction. Inhibitors of caspase-3 and caspase-9 and cyclosporin A, a mitochondrial membrane potential stabilizer, attenuated derivative induced apoptosis. Inhibition of caspase-3 prevented the activation of caspase 8, while the inhibition of caspase-9 inhibitor blocked activation of both caspase 3 and 8 by the derivatives. Apoptosis was independent of Bcl-2. These results indicate that the second generation celecoxib derivatives induce apoptosis in human oral cancer lines by the disruption of mitochondrial membrane potential activating caspase 9 and downstream caspase 3 and 8. This suggests that the modification of the celecoxib structure can lead to highly effective COX-independent growth inhibitory and apoptotic agents in chemoprevention and therapy.
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PMID:Celecoxib derivatives induce apoptosis via the disruption of mitochondrial membrane potential and activation of caspase 9. 1549 25

Celecoxib exhibits cancer preventive and therapeutic effects in animal models and clinical trials. It presumably acts through selective inhibition of cyclooxygenase-2 (COX-2) and subsequent reduction of prostaglandin (PG) synthesis. However, the concentrations of celecoxib required for growth inhibition and apoptosis induction in vitro are higher than those needed for suppression of PGs. Moreover, those concentrations are not achievable in humans raising a controversy regarding the clinical relevance of in vitro data. We investigated the activity of celecoxib alone and in combination with the pro-apoptotic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) on growth and apoptosis of human nonsmall cell lung cancer (NSCLC) cell lines. Celecoxib inhibited growth of thirteen NSCLC cell lines with IC50 values ranging from 19 to 33 microM regardless of their COX-2 expression. Apoptosis was induced in cells with high (A549) as well as low (H1792) COX-2 levels but only at a concentration of 75 microM celecoxib. However, treatment with pharmacologically feasible concentrations of celecoxib (< or = 10 microM) in combination with 4HPR (< or = 2 microM) resulted in a marked suppression of NSCLC cell growth and colony formation. Apoptosis mediated by activation of caspase-3, cleavage of PARP and lamin A was suppressed by addition of antioxidants, suggesting that the generation of reactive oxygen species was partially involved. This study indicates, that celecoxib combined with 4HPR is more effective than treatment with either agent alone in inhibition of growth and induction of apoptosis in NSCLC cells. It suggests further investigations of this combination for lung cancer treatment.
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PMID:Enhanced growth inhibition and apoptosis induction in NSCLC cell lines by combination of celecoxib and 4HPR at clinically relevant concentrations. 1622 24

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.
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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

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.
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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


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