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)

The CEACAM1 cell adhesion molecule is a member of the carcinoembryonic antigen family. In the mouse, four distinct isoforms are generated by alternative splicing. These encode either two or four immunoglobulin domains linked through a transmembrane domain to a cytoplasmic domain that encompasses either a short 10-amino acid tail or a longer one of 73 amino acids. Inclusion of exon 7, well conserved in evolution, generates the long cytoplasmic domain. A potential caspase recognition site in mouse, rat, and human CEACAM1-L also becomes available within the peptide encoded by exon 7. We used CEACAM1-L-transfected mouse colon carcinoma CT51 cells treated with three different apoptotic agents to study its fate during cell death. We found that CEACAM1-L is cleaved resulting in rapid degradation of most of its 8-kDa cytoplasmic domain. Caspase-mediated cleavage was demonstrated using purified recombinant caspases. The long cytoplasmic domain was cleaved specifically by caspase-3 in vitro but not by caspase-7 or -8. Moreover cleavage of CEACAM1-L in apoptotic cells was blocked by addition of a selective caspase-3 inhibitor to the cultures. Using point and deletion mutants, the conserved DQRD motif in the membrane-proximal cytoplasmic domain was identified as a caspase cleavage site. We also show that once CEACAM1-L is caspase-cleaved it becomes a stronger adhesion molecule than both the shorter and the longer expressing isoforms.
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PMID:The cell adhesion molecule CEACAM1-L is a substrate of caspase-3-mediated cleavage in apoptotic mouse intestinal cells. 1263 8

Natural Killer (NK) cells can induce apoptosis in target cells in at least four ways: by secretion of granzyme B/perforin (GrB/P) and via the CD95L, TRAIL and TNF-alpha pathways. In this study we examined the pathways used by interleukin-2 activated rat NK (A-NK) cells to induce apoptosis in the rat colon carcinoma cell line CC531s. Co-incubation of A-NK cells with CC531s cells for three hours resulted in 70% apoptosis in the latter. Addition of the GrB/P pathway-inhibitor concanamycin A reduced the number of apoptotic cells to 54%. Blockade of the CD95L, TRAIL and TNF-alpha pathways by specific antibodies hardly had an additional effect. However, co-incubation with transfected MEC cells that expressed CD95L or 2PK3-cells that expressed TRAIL did induce apoptosis in CC531s cells. Furthermore the A-NK cells contained CD95L and TRAIL. However, comparison of non- and permeabilized cells revealed that the majority of TRAIL was present in the cytosol of A-NK cells and was not available for induction of apoptosis. The presence of elevated levels of bcl-2 in CC531 cells reduced the sensitivity towards induction of apoptosis both by A-NK cells as well as the CD95L and TRAIL expressing cell lines. Using the caspase-inhibitors ac-IEPD-CHO, ac-DEVD-CHO and zVAD-fmk, it was shown that inhibition of the effector caspase-3 prevented A-NK cell induced apoptosis in CC531-bcl-2 cells, but not in CC531s cells. In conclusion, A-NK cells kill by secretion of GrB/P and not by the CD95L, TRAIL or TNF pathways albeit both CD95L and TRAIL are produced by the A-NK cells.
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PMID:Interleukin-2 activated NK cells do not use the CD95L- and TRAIL-pathways in the rapid induction of apoptosis of rat colon carcinoma CC531s cells. 1267 69

Sodium salicylate is known to induce apoptosis in a variety of cancer cells. However, the molecular mechanism for salicylate-induced apoptosis is yet unclear. Here we show that in HCT116 colon carcinoma cells, 10 mM sodium salicylate induces caspase-3 activation and degradation of its substrates, poly(ADP-ribose) polymerase (PARP), beta-catenin, and retinoblastoma (Rb). In contrast, sodium salicylate did not exert any significant effects on the expression of Fas L that is implicated in extrinsic apoptotic pathway and the levels of Bcl-2 family proteins, Bcl-2, Bcl-xsl, and Bad, which are involved in intrinsic apoptotic pathway, and anti-apoptotic molecules, c-IAP1 and HSP73. In addition, 10 mM salicylate induced p53 tumor suppressor protein that plays an important role in cell cycle arrest or apoptosis and the induction seemed to be linked to its phosphorylation at Set 15. To investigate the signal pathways for salicylate-induced apoptosis, we examined the effects of sodium salicylate on protein kinase activities. Sodium salicylate activated p38MAPK through phosphorylation at Thr 180/Tyr 182 and Akt/PKB at Ser 473, whereas it partially activated ERK1/2 through its phosphorylation at Thr 202/Tyr 204. We also show that SB203580 (a specific p38MAPK inhibitor), but not other protein kinase inhibitors (PD98059, LY294002, and wortmannin), significantly prevented salicylate-induced apoptosis. These results suggest that sodium salicylate-induced apoptosis in HCT116 colorectal cancer cells is mediated by p38MAPK.
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PMID:Sodium salicylate induces apoptosis in HCT116 colorectal cancer cells through activation of p38MAPK. 1285 2

In cells lacking a functional p53 tumor suppressor protein, the endogenous free radical nitric oxide (NO) appears to inhibit apoptosis, and thereby promotes growth of cancer cells. In order to elucidate the underlying mechanisms on a molecular basis, we used HT-29 human colon carcinoma cells, carrying a p53 loss-of-function mutation, and examined the effects of NO on apoptosis when induced either by the flavonoid flavone or by the chemotherapeutic drug camptothecin (CPT), which is able to scavenge NO by superoxide anion production. Caspase-3 activation as well as nuclear fragmentation, both indicative of apoptosis, were dose dependently inhibited by the NO-liberating agents sodium nitroprusside (SNP) or S-nitroso-N-acetyl-D,L-penicillamine (SNAP) when apoptosis was initiated by flavone with only minor effects on apoptosis when initiated by camptothecin. The transcript levels of 9 apoptosis-related genes were assessed and NO liberation was shown to completely and specifically prevent the flavone-induced but not camptothecin-induced decrease in bcl-X(L) mRNA levels. These results were also confirmed at the protein level. The effects of NO on the mitochondrial apoptosis pathway were further evidenced by the scavenging of superoxide anions as produced in mitochondria of cells undergoing apoptosis. Scavenging of mitochondrial superoxide anions by NO prevents the downregulation of bcl-X(L), the depolarization of the mitochondrial membrane potential, the cytochrome c release and finally the activation of caspase-3. In conclusion, NO effectively inhibits apoptosis by scavenging superoxide anions generated in the mitochondria of p53 mutant cells and thereby prevents the downregulation of the antiapoptotic factor bcl-X(L), which controls the mitochondrial apoptosis pathway.
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PMID:Nitric oxide suppresses apoptosis in human colon cancer cells by scavenging mitochondrial superoxide anions. 1286 25

Epithelial cell apoptosis is an important regulator of normal gut mucosal turnover; however, excessive apoptosis may inhibit mucosal restitution during pathophysiologic states. Apoptosis is induced by oxidative stress and cytokines, but regulation by specific nutrients has been infrequently studied under these conditions. Glutamine (Gln) is an important metabolic fuel for intestinal epithelial cells and a precursor to the antioxidant glutathione (GSH), which has antiapoptotic effects. In cultured intestinal epithelial cells, Gln depletion increases oxidant-induced apoptosis. This study examined whether Gln protects against apoptosis induced by the cytokine tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) in the human colon carcinoma cell line, HT-29. TRAIL-induced apoptosis in HT-29 cells was characterized by an increase in the percentage of cells in the sub-G1 fraction by flow cytometry, nuclear condensation and the activation of caspase-8 and caspase-3. TRAIL-induced apoptosis was completely prevented by Gln, but not inhibited by other amino acids, including the GSH constituents, glutamate, cysteine and glycine. Similar antiapoptotic effects of Gln occurred when apoptosis was induced by a combination of tumor necrosis factor-alpha and interferon-gamma. Cellular GSH was oxidized during TRAIL-induced apoptosis. This effect was completely blocked by Gln, however, inhibition of GSH synthesis with buthionine sulfoximine did not alter Gln antiapoptotic effects. Furthermore, glutamate prevented GSH oxidation in response to TRAIL but did not protect against TRAIL-induced apoptosis. These results show that Gln specifically protects intestinal epithelial cells against cytokine-induced apoptosis, and that this occurs by a mechanism that is distinct from the protection against oxidative stress mediated by cellular GSH.
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PMID:Glutamine prevents cytokine-induced apoptosis in human colonic epithelial cells. 1451 85

It is well known that dysfunction of the apoptotic pathway confers apoptosis resistance and results in a low sensitivity of human cancer cells to therapeutic agents. A novel strategy to overcome the resistance is to target the apoptotic pathway directly. To identify molecular targets in the apoptotic pathway that are differentially regulated in cancer and normal cells, we have examined the levels of apoptotic effectors and inhibitors in human tumor and normal cell lines as well as in cancer and normal tissues. These include three pancreatic cancer lines (BXPC-3, MIA PaCa-2, and Panc-1), four breast cancer cell lines (MDA-MB-231, MDA-MB-435, MDA-MB-361, and MCF-7), and colon carcinoma line (SW620). Additionally, breast carcinoma tissue specimens were examined. Compared with normal human fibroblast and mammary epithelial cell lines, we detected high basal levels of caspase-3 and caspase-8 activities and active caspase-3 fragments in the tumor cell lines and cancer tissues in the absence of apoptotic stimuli. Furthermore, the tumor cells expressed high levels of survivin and XIAP, two members of the inhibitor of apoptosis (IAP) protein family. When the activity of these IAPs was blocked by expression of dominant-negative mutant survivin (survivinT34A) and XIAP-associated factor 1, respectively, apoptosis was induced in tumor but not normal cell lines. Moreover, down-regulation of both survivin and XIAP significantly enhanced tumor-cell apoptosis as compared with inhibition of either survivin or XIAP alone. These results suggest that up-regulated IAP expression counteracts the high basal caspase-3 activity observed in these tumor cells and that apoptosis in tumor cells but not normal cells can be induced by blocking IAP activity. Therefore, IAPs are important molecular targets for the development of cancer-specific therapeutic approaches.
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PMID:Coexistence of high levels of apoptotic signaling and inhibitor of apoptosis proteins in human tumor cells: implication for cancer specific therapy. 1458 79

beta-Lapachone is a naturally occurring quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae) with cancer chemopreventive properties. The objective of the present study was to investigate the effect of beta-lapachone on the cell growth and apoptosis in human colon carcinoma tumor cell line HCT-116. Exposure of HCT-116 cells to beta-lapachone resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometric analysis. This increase in apoptosis was associated with a decrease in Bcl-2 protein expression, an increase in caspase-3 activity, a decrease in intact poly(ADP-ribose) polymerase protein levels and degradation of beta-catenin. After beta-lapachone treatment, the nuclear protein levels of NF-kappaB and the activity of NF-kappaB-DNA binding were markedly decreased. beta-Lapachone treatment also resulted in inhibition of the transcriptional activity of NF-kappaB-luciferase reporter plasmid suggesting that beta-lapachone-induced apoptosis may be partly regulated through the inactivation of NF-kappaB.
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PMID:beta-Lapachone-induced apoptosis is associated with activation of caspase-3 and inactivation of NF-kappaB in human colon cancer HCT-116 cells. 1459 80

Anti-cancer properties of palm oil have been attributed to the presence of tocotrienols and carotenoids. Studies from various laboratories have shown that tocotrienol-rich fraction (TRF) of palm oil inhibits cell growth and induces apoptosis in both preneoplastic and neoplastic cells. However, the mechanism by which TRF induces apoptosis remains largely unknown. Since several chemopreventive agents have been shown to utilize p53 pathway in negative regulation of cell growth, using human colon carcinoma RKO cells which express wild type p53, we investigated the effect of TRF on components of p53 signaling network. Treatment of cells with TRF resulted in a dose- and time- dependent inhibition of growth and colony formation. Further, TRF treatment of RKO cells resulted in the induction of WAF1/p21 which appears to be independent of cell cycle regulation and is transcriptionally upregulated in p53 dependent fashion. These results were further confirmed by using cells that express luciferase from a p53 responsive promoter where TRF treatment leads to activation of p53 reporter activity. TRF treatment also resulted in alteration in Bax/Bcl2 ratio in favor of apoptosis, which was associated with the release of cytochrome c and induction of apoptotic protease-activating factor-1. This altered expression of Bcl2 family members triggered the activation of initiator caspase-9 followed by activation of effector caspase-3. These signaling cascades lead to condensed chromatin, DNA fragmentation and shrinkage of cell membrane resulting into apoptosis. Our data suggest that TRF-induced apoptosis in colon carcinoma cells is mediated by p53 signaling network which appears to be independent of cell cycle association.
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PMID:Tocotrienol-rich fraction of palm oil activates p53, modulates Bax/Bcl2 ratio and induces apoptosis independent of cell cycle association. 1471 90

Although a high alimentary intake of antioxidant vitamins such as ascorbic acid may play an important role in cancer prevention, a high level of antioxidants may have quite different effects at different stages of the transformation process. In cancer development, the resistance of cells to apoptosis is one of the most crucial steps. We have tested the effects of ascorbic acid on apoptosis in HT-29 human colon carcinoma cells when induced by two potent apoptosis inducers, the classical antitumor drug camptothecin or the flavonoid flavone. Apoptosis was assessed based on caspase-3-like activity, plasma membrane disintegration and finally nuclear fragmentation and chromatin condensation. Ascorbic acid dose-dependently inhibited the apoptotic response of cells to camptothecin and flavone. RT-PCR analysis and western blot analysis revealed that ascorbic acid specifically blocked the decrease of bcl-X(L) by camptothecin or flavone. An increased generation of mitochondrial O(2)(-.) precedes the down-regulation of bcl-X(L) by camptothecin and flavone and ascorbic acid at a concentration of 1 mM prevented the generation of this reactive oxygen species. In conclusion, ascorbic acid functions as a potent antioxidant in mitochondria of human colon cancer cells and thereby blocks drug-mediated apoptosis induction allowing cancer cells to become insensitive to chemotherapeutics.
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PMID:Ascorbic acid suppresses drug-induced apoptosis in human colon cancer cells by scavenging mitochondrial superoxide anions. 1475 75

Podophyllotoxin and some of its derivatives are cyclolignans currently used for removing warts and in the clinical treatment of malign neoplasms. As such, they have been an objective of the scientific community for decades, in the search for more potent and more selective anticancer agents. Our interest in the chemoinduction of drug selectivity led us to the design and preparation of new podophyllotoxin derivatives by reaction of podophyllic aldehyde with aliphatic, aromatic, and heteroaromatic amines. Several of the resulting imines displayed a significant selectivity against human colon carcinoma cells, even higher than that of the starting aldehyde. Additional biological studies indicate that these derivatives induce microtubule depolymerization, arrest cells at the G2/M phase of cell cycle, and are able to induce a delayed apoptosis after 48 h of treatment, characterized by caspase-3 activation.
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PMID:Synthesis and biological evaluation of new selective cytotoxic cyclolignans derived from podophyllotoxin. 1497 1


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