Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Caffeic acid phenethyl ester (CAPE), an active component of propolis, has many biological and pharmacological activities including antioxidant, anti-inflammation, antiviral action, and anticancer effect. Our previous studies showed that CAPE exhibited significant cytotoxicity in oral cancer cells. Herein we further investigated the cytotoxicity potential of CAPE and the mechanism of its action in C6 glioma cells. The data exhibited that C6 glioma cells underwent internucleosomal DNA fragmentation 24 hr after the treatment of CAPE (50 microM). The proportion of C6 glioma cells with hypodiploid nuclei was increased to 24% at 36 hr after the exposure. Further results showed that CAPE induced the release of cytochrome c from mitochondria into cytosol, and the activation of CPP32. CAPE application also enhanced the expression of p53, Bax, and Bak. Finally, the potential signaling components underlying CAPE induction of apoptosis were elucidated. We found that CAPE activated extracellular signal-regulated kinase (ERKs) and p38 mitogen-activated protein kinase (p38 MAPK) in C6 glioma cells. More importantly, p38 kinase formed a complex with p53 after the treatment of CAPE for 0.5 hr. The expression of p53, phospho-serine 15 of p53, and Bax, and inactivate form of CPP32 was suppressed by a pretreatment of a specific p38 MAPK inhibitor, SB203580. The resultant data suggest that p38 MAPK mediated the CAPE-induced p53-dependent apoptosis in C6 glioma cells.
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PMID:Involvement of tumor suppressor protein p53 and p38 MAPK in caffeic acid phenethyl ester-induced apoptosis of C6 glioma cells. 1463 86

Khat is the Celastraceus edulis plant, a flowering evergreen tree or large shrub, which grows in the Horn of Africa and southwestern Arabia. Khat use has been associated with development of oral cancer, but its molecular effects remain controversial. This study describes a novel cytotoxic effect of whole khat extract on three leukemia cell lines. Cells were exposed to khat extract and harvested for analysis by fluorescent and electron microscopy, trypan blue exclusion, as well as immunoblotting to characterize the mode of cell death. In a separate series, cells were pretreated with a panel of caspase inhibitors for possible inhibitory effects. Khat induced a rapid cell death effect in HL-60, Jurkat, and NB4 cells that occurred within 2 h of exposure. The treated cells retained their ability to exclude trypan blue dye, a key feature in the apoptotic process. Exposed cells consistently developed morphological features of manifest apoptosis. Z-VAD, a pan-caspase inhibitor, completely inhibited toxic activity for up to 8 h, with partial inhibition by other caspase-specific agents. Western blot analysis showed specific cleavage of caspase-3 in khat-exposed cells. This study shows that khat induces cell death by apoptosis in a process sensitive to inhibition by caspase inhibitors, suggesting that subcellular interactions could be of particular relevance for the biological effects of khat in the cell death process and possibly carcinogenesis.
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PMID:Catha edulis (Khat) induces cell death by apoptosis in leukemia cell lines. 1503 57

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

Fluorine compounds are widely used for the prevention of caries, and recently sodium fluorosilicate has been used in water fluorination. The cytotoxic effects of sodium fluorosilicate in several osteosarcoma and oral cancer cells were evaluated in this study by measurement of inhibition of cell proliferation. Human osteogenic sarcoma (HOS) cells were the most sensitive to sodium fluorosilicate treatment. Induction of apoptosis, such as nucleosomal DNA fragmentation and the appearance of apoptotic bodies, were observed in HOS cells by agarose gel electrophoresis and by flow cytometric analysis, respectively. The molecular mechanism of apoptosis induction in HOS was investigated by Western blot analysis. The level of Bcl-2 was decreased and consequent release of cytochrome c was increased. Caspase-3 was activated and the cleavage of poly (ADP-ribosyl) polymerase was increased. In conclusion, sodium fluorosilicate induces apoptosis in HOS cells through decrease in Bcl-2, the release of cytochrome c to the cytosol and activation of caspase-3.
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PMID:Induction of apoptosis by sodium fluorosilicate treatment in human osteogenic sarcoma (HOS) cells. 1581 63

S-phase kinase associated protein 2 (Skp2) is a member of an F-box family of substrate-recognition subunits of SCF ubiquitin-protein ligase complexes that has been implicated in the ubiquitin-mediated degradation of several key regulators of mammalian G1 progression, including the cyclin-dependent kinase inhibitor p27Kip1, a dosage-dependent tumor suppressor protein. The anti-sense effect was confirmed in two cell lines of oral cancer cells that also exhibited over-expression of the Skp2 protein. In this study, we examined the mechanism responsible for anti-sense-mediated growth inhibition of oral cancer cells in vitro and in vivo. Skp2-anti-sense treatment induced apoptosis characterized by an increase in the early apoptosis, fragmentation of nuclei and activation of caspase-3, -8 and -9. Moreover, the growth of xenograft tumors was markedly suppressed by Skp2-anti-sense treatment. Furthermore, histological specimen revealed apoptotic cell death was increased in Skp2-anti-sense treated tumors. Our results suggest that down-regulation of Skp2 appears to induce apoptosis in oral cancer cells, targeting this molecule could represent a promising new therapeutic approach for this type of cancer.
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PMID:Down-regulation of S-phase kinase associated protein 2 (Skp2) induces apoptosis in oral cancer cells. 1605 17

Several drugs of aziridinylbenzoquinone analogs have undergone clinical trials as potential antitumor drugs. These bioreductive compounds are designed to kill tumor cells preferentially within the hypoxic microenvironment. From our previous reported data, it was found that the synthesized 2-aziridin-1-yl-3-[(2-[2-[(3-aziridin-1-yl-1,4-dioxo-1,4-dihydronaphthalen-2-yl)thio]ethoxy]ethyl)thio]naphthoquinone (AZ-1) is a bioreductive compound with potent lethal effect on oral cancer cell, OEC-M1. It was found in this study that the lethal effect of the oral cancer cell lines OEC-M1 induced by AZ-1 was mediated through the cell cycle arrest and apoptosis pathway. The LC50 values of OEC-M1 and KB cells induced by AZ-1 compound were 0.72 and 1.02 microM, respectively, which were much lower than that of normal fibroblast cells (SF with LC50 = 5.6 microM) with more than 90% of normal fibroblasts surviving as compared to control at a concentration of AZ-1 as high as 2 microM. It was interesting to note that the LC50 of monotype diaziridinylbenzoquinone compound, diaziquone (AZQ), was 50 microM on OEC-M1 cells. Comparing the cytotoxicity of AZ-1 and AZQ on OEC-M1 cells, AZ-1 is approximately 70 times more potent than AZQ. By using Western blot, both G2/M phase cell cycle arresting protein, cyclin B, and anti-apoptotic protein, bcl-2, were expressed in OEC-M1 cell when the concentrations of AZ-1 were increased from 0.125 to 0.5 microM and then decreased from 1 to 2 microM of AZ-1 treatment as compared with control for 24 h. Both proteins were expressed most abundantly at 0.5 microM AZ-1. However, the expression of bcl-2 protein in OEC-M1 was significantly decreasing in a dose-dependent manner and was only about 50% protein level at 2 microM AZ-1 for 48h as compared with control. The cell survival check protein p53 increased from 1.72- to 2.8-fold and 1.36- to 2.16-fold at concentrations of AZ-1 from 0.125 to 2.0 microM in a dose-dependently increasing manner on OEC-M1 as compared with control for 24 and48 h treatments, respectively. The apoptotic-related phenomena were observed, which included apoptotic body formation and the enzyme activity change of caspase-3. The apoptotic bodies and caspase-3 activity of OEC-M1 were induced only at 2 microM AZ-1 for a 24h treatment, yet apoptotic body formation was observed at as low as 0.5 microM AZ-1 and in a dose-dependently increasing manner for a 48 h treatment. The caspase-3 activity was increased 20.6%, 26.8%, and 84.2%, respectively, at 0.5, 1, and 2muM concentrations of AZ-1 for a 48 h treatment as compared with control. These results indicate that AZ-1 induced the cell death of OEC-M1 through the G2/M phase arrest of cell cycle and anti-apoptosis first and then apoptosis following a 48 h treatment. All of the pathway might be associated with bcl-2 and p53 protein expression. We propose that the AZ-1 could be used as anti-oral cancer drug for future studies with animal models.
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PMID:The lethal effect of bis-type azridinylnaphthoquinone derivative on oral cancer cells (OEC-M1) associated with anti-apoptotic protein bcl-2. 1621 38

Evidence has accumulated that dietary polyphenols, in particular, flavonoids, have protective effects against oral cancer. In this study, we have examined the effects of quercetin, a major dietary flavonoid, on cell growth and necrosis/apoptosis and cell cycle regulation in human oral squamous carcinoma SCC-9 cells. Quercetin induced dose- and time-dependent, irreversible inhibition of cell growth and cellular DNA synthesis. Light microscopy and lactate dehydrogenase measurements showed modifications in the morphology and membrane integrity of these cells after quercetin treatment. Propidium iodide/annexin V staining showed that quercetin induced necrosis at 24 h and 48 h, whereas at 72 h cells underwent apoptosis, correlating with caspase-3 activation. Flow cytometry studies of the cell cycle distribution showed that quercetin induced mainly S-phase arrest. Thymidylate synthase (TS), a key S-phase enzyme, was inhibited in a time- and dose-dependent fashion by quercetin at the protein level. A lack of effect on TS mRNA suggested that TS down-regulation occurred at the translational level. In conclusion, our data support a view that quercetin initially induces a stress response, resulting in necrosis of these oral epithelial cells. Prolonged exposure of the surviving cells to quercetin causes apoptosis, presumably mediated by inhibition of TS protein.
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PMID:Quercetin induces necrosis and apoptosis in SCC-9 oral cancer cells. 1657 83

Iron is essential for neoplastic cell growth, and iron chelators have been tested for potential anti-proliferative and anti-cancer effects, but the effects of iron chelators on oral cancer have not been clearly elucidated. To determine the mechanism of cell death induced by iron chelators, we explored the pathways of the three structurally related mitogen-activated protein (MAP) kinase subfamilies during iron chelator-induced apoptosis and differentiation of immortalized human oral keratinocytes (IHOK) and oral cancer cells (HN4). The iron chelator deferoxamine (DFO) exerted potent time- and dose-dependent inhibitory effects on the growth and apoptosis of IHOK and HN4 cells. DFO strongly activates p38 MAP kinase and extracellular signal-regulated kinase (ERK), but does not activate c-Jun N-terminal kinase/stress-activated protein kinase. Of the three MAP kinase blockers used, the selective p38 MAP kinase inhibitor SB203580 and ERK inhibitor PD98059 protected IHOK and HN4 cells against iron chelator-induced cell death, which indicates that the p38 and ERK MAP kinase is a major mediator of apoptosis induced by this iron chelator. Interestingly, treatment of IHOK and HN4 cells with SB203580 and PD98059 abolished cytochrome c release, as well as the activation of caspase-3 and caspase-8. DFO suppressed the expression of epithelial differentiation markers such as involucrin, CK6, and CK19, and this suppression was blocked by p38 and ERK MAP kinase inhibitors. Collectively, these data suggested that p38 and ERK MAP kinase plays an important role in iron chelator-mediated cell death and in the suppression of differentiation of oral immortalized and malignant keratinocytes, by activating a downstream apoptotic cascade that executes the cell death pathway.
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PMID:p38 and ERK MAP kinase mediates iron chelator-induced apoptosis and -suppressed differentiation of immortalized and malignant human oral keratinocytes. 1669 18

Coptidis rhizoma (C. rhizoma) had been demonstrated as an antioxidant and anticancer agent, however, its antioral cancer mechanism still remains unclear. Using water extracts of C. rhizoma, growth and apoptosis-related experiments for the treatment of multi-stage of oral cancer were carried out on immortalized human oral keratinocytes (IHOK), primary oral cancer cells (HN4), metastatic oral cancer cells (HN12) and human skin keratinocytes (HaCaT) by MTT assay, three-dimensional (3-D) raft cultures, western blotting, cell cycle analysis, nuclear staining and cytochrome c expression related to the apoptosis signaling pathway. C. rhizoma inhibited the proliferation of immortalized and malignant oral keratinocytes in a dose- and time-dependent manner. In 3-D organotypic culture, C. rhizoma-treated cells showed less maturation than the control cells, displaying low surface keratinization and decreased epithelial thickness. The major mechanism of growth inhibition by C. rhizoma appears to be the induction of apoptosis, which is supported by the results of the cell cycle analysis, FITC-annexin V staining, DNA fragmentation assay and DAPI staining. The induction of apoptosis by C. rhizoma was more prominent in immortalized keratinocytes than in malignant oral keratinocytes. Cytochrome-c release from mitochondria, accompanied by the activation of caspase-3, was observed in C. rhizoma-treated IHOK and oral cancer cells. These results suggest that C. rhizoma has apoptotic effects in immortalized and malignant oral keratinocytes via the mitochondrial signaling pathway.
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PMID:Extract of Coptidis rhizoma induces cytochrome-c dependent apoptosis in immortalized and malignant human oral keratinocytes. 1680 85

We investigated the anticancer effects of green and black tea polyphenols alone and in combination with bovine milk lactoferrin (bLF) on human tongue squamous carcinoma (CAL-27) and normal human gingival fibroblast (HGF) cells. Both green (Polyphenon-E;P-E) and black tea polyphenols (Polyphenon-B;P-B) preferentially inhibit the growth of CAL-27 cells in a dose-dependent manner. Based on the IC(50) values, P-E was found to be more effective than P-B and the combination of P-E and bLF (1:2 ratio) exhibited synergistic inhibition of CAL-27 cells. Analysis of the mechanism revealed nuclear fragmentation and condensation with appearance of the A(o) peak indicative of apoptosis. Furthermore, tea polyphenols transduced the apoptosis signal via generation of reactive oxygen species and decrease in the Bcl-2/Bax ratio thereby inducing mitochondrial permeability transition with consequent activation of caspase-3. Overall, the potency of cytotoxic and apoptosis inducing effects of dietary agents on CAL-27 cells was in the order P-E and bLF combination (1:2 ratio)>P-E>P-B. These results suggest that a "designer" approach may be useful for oral cancer prevention strategies.
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PMID:In vitro evaluation of the anticancer effect of lactoferrin and tea polyphenol combination on oral carcinoma cells. 1725 15


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