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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In response to a diverse array of signals, IkappaBalpha is targeted for phosphorylation-dependent degradation by the proteasome, thereby activating NF-kappaB. Here we demonstrate a role of the cleavage product of IkappaBalpha in various death signals. During apoptosis of NIH3T3, Jurkat, Rat-1, and L929 cells exposed to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (
TRAIL
), Fas, serum deprivation, or TNF-alpha, respectively, IkappaBalpha was cleaved in a caspase-dependent manner. In vitro and in vivo cleavage assays and site-directed mutagenesis showed that
caspase-3
cleaved IkappaBalpha between Asp31 and Ser32. Expression of the cleavage product lacking amino-terminus (1-31), DeltaIkappaBalpha, sensitized otherwise resistant NIH3T3 fibroblast cells to apoptosis induced by TNF-alpha or
TRAIL
, and HeLa tumor cells to TNF-alpha. DeltaIkappaBalpha was more pro-apoptotic compared to wild type or cleavage-resistant (D31E)IkappaBalpha mutant and the sensitization elicited by DeltaIkappaBalpha was as effective as that by the dominant negative mutant, (S32,36A)IkappaBalpha, in NIH3T3 cells. DeltaIkappaBalpha suppressed the transactivation of NF-kappaB induced by TNF-alpha or
TRAIL
, as reflected by luciferase-reporter activity. Conversely, expression of the p65 subunit of NF-kappaB suppressed TNF-alpha-,
TRAIL
-, and serum deprivation-induced cell death. On the contrary, DeltaIkappaBalpha was less effective at increasing the death rate of HeLa cells that were already sensitive to death signals including
TRAIL
, etoposide, or taxol. These results suggest that DeltaIkappaBalpha generated by various death signals sensitizes cells to apoptosis by suppressing NF-kappaB activity.
...
PMID:Caspase cleavage product lacking amino-terminus of IkappaBalpha sensitizes resistant cells to TNF-alpha and TRAIL-induced apoptosis. 1194 89
Second mitochondria-derived activator of caspases (Smac)/DIABLO is a mitochondrial protein that is released into the cytosol along with cytochrome c (cyt c) during the execution of the intrinsic pathway of apoptosis. Smac/DIABLO promotes apoptosis by neutralizing the inhibitory effect of the inhibitor of apoptosis (IAP) family of proteins on the processing and activities of the effector caspases. Present studies demonstrate that, upon engagement of the mitochondrial pathway of apoptosis, epothilone (Epo) B derivative BMS 247550, a novel nontaxane antimicrotubule agent, as well as the death ligand
Apo-2L
/
TRAIL
(tumor necrosis factor-alpha-related apoptosis-inducing ligand) induce the mitochondrial release and cytosolic accumulation of Smac/DIABLO, along with cyt c, in human acute leukemia Jurkat T cells. While it had no activity alone, ectopic overexpression of Smac/DIABLO or treatment with the N-terminus heptapeptide (Smac-7) or tetrapeptide (Smac-4) of Smac/DIABLO significantly increased Epo B- or
Apo-2L
/
TRAIL
-induced processing and PARP cleavage activity of
caspase-3
. This produced a significant increase in apoptosis of Jurkat cells (P <.05). Increased apoptosis was also associated with the down-regulation of XIAP, cIAP1, and survivin. Along with the increased activity of
caspase-3
, ectopic overexpression of Smac/DIABLO or cotreatment with Smac-4 also increased Epo B- or
Apo-2L
/
TRAIL
-induced processing of caspase-8 and Bid, resulting in enhanced cytosolic accumulation of cyt c. This was not due to increased assembly and activity of
Apo-2L
/
TRAIL
-induced DISC (death-inducing signaling complex) but dependent on the feedback activity of
caspase-3
. These findings demonstrate that cotreatment with the N-terminus Smac/DIABLO peptide is an effective strategy to enhance apoptosis triggered by the death receptor or mitochondrial pathway and may improve the antitumor activity of
Apo-2L
/
TRAIL
and Epo B.
...
PMID:Ectopic overexpression of second mitochondria-derived activator of caspases (Smac/DIABLO) or cotreatment with N-terminus of Smac/DIABLO peptide potentiates epothilone B derivative-(BMS 247550) and Apo-2L/TRAIL-induced apoptosis. 1196 12
Apo2L/
TRAIL
is a member of the tumor necrosis factor (TNF) family of cytokines that induces death of cancer cells but not normal cells. Its potent apoptotic activity is mediated through its cell surface death domain-containing receptors, DR4 and DR5. Apo2L/
TRAIL
interacts also with 3 "decoy" receptors that do not induce apoptosis, DcR1, DcR2, which lack functional death domains, and osteoprotegerin (OPG). The aim of our study was to investigate the cytotoxic activity of Apo2L/
TRAIL
on established osteogenic sarcoma cell lines (BTK-143, HOS, MG-63, SJSA-1, G-292 and SAOS2) and in primary cultures of normal human bone (NHB) cells. When used alone, Apo2L/
TRAIL
at 100 ng/ml for 24 hr induced greater than 80% cell death in only 1 (BTK-143) of the 6 osteogenic sarcoma cell lines. In contrast, Apo2L/
TRAIL
-resistant cells were susceptible to Apo2L/
TRAIL
-mediated apoptosis in the presence of the anticancer drugs, Doxorubicin (DOX), Cisplatin (CDDP) and Etoposide (ETP) but not Methotrexate (MTX) or Cyclophosphamide (CPM). Importantly, neither Apo2L/
TRAIL
alone nor in combination with any of these drugs affected primary normal human bone cells under equivalent conditions. Apo2L/
TRAIL
-induced apoptosis, and its augmentation by chemotherapy in the resistant cell lines was mediated through caspase-8 and
caspase-3
activation. Furthermore, Apo2L/
TRAIL
-induced apoptosis and its augmentation by chemotherapy was effectively inhibited by caspase-8 zIETD-fmk and
caspase-3
zDEVD-fmk protease inhibitors and by the pan-caspase inhibitor zVAD-fmk. The pattern of basal Apo2L/
TRAIL
receptor mRNA expression, or expression of the intracellular caspase inhibitor FLICE-inhibitory protein, FLIP, could not be readily correlated with resistance or sensitivity to Apo2L/
TRAIL
-induced apoptosis. However, the augmentation of Apo2L/
TRAIL
effects by chemotherapy was associated with drug-induced up-regulation of death receptors DR4 and DR5 mRNA and protein. No obvious correlation was seen between the expression of OPG mRNA or protein and susceptibility of cells to Apo2L/
TRAIL
-induced apoptosis. Stable over-expression of a dominant negative form of the Fas-associated death domain protein (FADD) in the Apo2L/
TRAIL
-sensitive BTK-143 cells completely inhibited Apo2L/
TRAIL
-induced cell death. Our results indicate that chemotherapy and Apo2L/
TRAIL
act synergistically to kill cancer cells but not normal bone-derived osteoblast-like cells, which has implications for future therapy of osteosarcoma.
...
PMID:Chemotherapeutic agents sensitize osteogenic sarcoma cells, but not normal human bone cells, to Apo2L/TRAIL-induced apoptosis. 1199 38
Apo2L/
TRAIL
exhibits enhanced apoptotic activity in tumor xenograft models when used in combination with the topoisomerase 1 inhibitor CPT-11. To investigate the cellular mechanisms involved in this increased tumor-killing activity, a series of in vitro experiments were conducted using the human colon carcinoma cell line (HCT116). Apo2L/
TRAIL
induced a transient upregulation of DR5 mRNA, while CPT-11 increased both death and decoy receptor expression. Upregulation of decoy receptors by CPT-11 was partially inhibited by co-administration of Apo2L/
TRAIL
. CPT-11 treatment resulted in accumulation of cells at G(2)M-phase and correlated with a substantial increase in the protein levels of the cyclin-dependent kinase inhibitor p21. However, cells co-treated with CPT-11 and Apo2L/
TRAIL
, or pretreated with CPT-11 for up to 24 h followed by 2 h Apo2L/
TRAIL
, resulted in a caspase-dependent degradation of p21, reversal of G(2)-M phase arrest with a concomitant increase in apoptosis. The sequential treatment produced the greatest induction of DR5 and DR4,
caspase-3
-like cleavage/activation and p21 degradation, as well as increased apoptosis. These data indicate that the up-regulation of Apo2L/
TRAIL
ligand and its death receptors as well as cleavage of p21 protein in the Apo2L/
TRAIL
plus CPT-11 treatment contributes to the positive cooperation between these agents in enhancing tumor cell apoptosis.
...
PMID:Enhanced tumor killing by Apo2L/TRAIL and CPT-11 co-treatment is associated with p21 cleavage and differential regulation of Apo2L/TRAIL ligand and its receptors. 1203 63
Mitochondrion is one of the master players in both apoptosis and necrosis. We studied the role of mitochondrial function in
TRAIL
-induced apoptosis.
TRAIL
killed SK-Hep1 cells with characteristic features of apoptosis such as DNA fragmentation, sub-G1 ploidy peak and cytochrome c translocation. In contrast, mitochondrial DNA-deficient SK-Hep1 rho(0) cells were resistant to
TRAIL
. Dissipation of mitochondrial potential or cytochrome c translocation did not occur in rho(0) cells after
TRAIL
treatment.
TRAIL
induced translocation of Bax subsequent to the cleavage of Bid in parental cells. However, Bax translocation was absent in rho(0) cells, accounting for the failure of cytochrome c release in rho(0) cells. Forced expression of Bax induced
caspase-3
activity in rho(0) cells. Incubation of rho(0) cells with ADP+Pi to increase intracellular ATP restored sensitivity to
TRAIL
. Despite different sensitivity to
TRAIL
, parental cells and rho(0) cells did not show significant difference in susceptibility to agonistic anti-Fas antibody, TNF-alpha or staurosporine. Our results indicate that
TRAIL
-induced apoptosis is dependent on intact mitochondrial function and susceptibility of mitochondrial DNA-deficient cells to apoptosis depends on the type of apoptotic stimuli. Tumor cells with mitochondrial mutations or dysfunction might have the ability to evade tumor surveillance imposed by
TRAIL
in vivo.
...
PMID:Resistance of mitochondrial DNA-deficient cells to TRAIL: role of Bax in TRAIL-induced apoptosis. 1208 29
All human melanoma cell lines (assessed by annexin V and TUNEL assays) were resistant to apoptosis induction by
TRAIL
/Apo2L protein.
TRAIL
/Apo2L activated caspase-8 and
caspase-3
, but subsequent apoptotic events such as poly(ADP-ribose) polymerase cleavage and DNA fragmentation were not observed. To probe the molecular mechanisms of cellular resistance to apoptosis, melanoma cell lines were analyzed for expression of apoptosis regulators (apoptotic protease-associated factor-1, FLIP, caspase-8, caspase-9,
caspase-3
, cellular inhibitor of apoptosis, Bcl-2, or Bax); no correlation was observed.
TRAIL
/Apo2L was induced in melanoma cell lines by IFN-beta and had been correlated with apoptosis induction. Because IFN-beta induced other gene products that have been associated with apoptosis, it was postulated that one or more IFN-stimulated genes might sensitize cells to
TRAIL
/Apo2L. Melanoma cell lines were treated with IFN-beta for 16-24 h before treatment with
TRAIL
/Apo2L. Regardless of their sensitivity to either cytokine alone, >30% of cells underwent apoptosis in response to the combined treatment. Induction of apoptosis by IFN-beta and
TRAIL
/Apo2L in combination correlated with synergistic activation of caspase-9, a decrease in mitochondrial potential, and cleavage of poly(ADP-ribose) polymerase. Cleavage of X-linked inhibitor of apoptosis following IFN-beta and
TRAIL
/Apo2L treatment was observed in sensitive WM9, A375, or WM3211 cells but not in resistant WM35 or WM164 cells. Thus, in vitro IFN-beta and
TRAIL
/Apo2L combination treatment had more potent apoptotic and anti-growth effects when compared with either cytokine alone in melanoma cells lines.
...
PMID:IFN-beta pretreatment sensitizes human melanoma cells to TRAIL/Apo2 ligand-induced apoptosis. 1209 88
Dendritic cells (DC) are potent antigen-presenting cells (APC) specialized in T-cell mediated immune responses, and also play critical roles in the homeostasis of T cells for controlling immune responses. In the present study, we demonstrated that during mouse bone-marrow-derived DC activation of ovalbumin (OVA)-specific Ia-kb-restricted T hybridoma cells, MF2.2D9 and OVA257-264-specific H-2kb-restricted RF33.70 T cells, respectively, both hybridomas undergo cell death, partially mediated via apoptotic ligand-tumour necrosis factor-alpha (TNF-alpha)-related apoptosis-inducing ligand (
TRAIL
). Lipopolysaccharide enhanced the cytotoxic effect on the two activated T hybridoma cells, which was correlated with up-regulation of
TRAIL
-expression on DC to some extent. The activation of
caspase-3
in activated T hybridoma cells cocultured with DC contributed to the programmed cell death pathway T cells underwent. Therefore, our results show that activation-induced cell death of T hybridoma cells can be influenced by DC, suggesting that DC may be involved in elimination of activated T cells at the end of primary immune responses.
...
PMID:Involvement of tumour necrosis factor-alpha-related apoptosis-inducing ligand in enhanced cytotoxicity of lipopolysaccharide-stimulated dendritic cells to activated T cells. 1210 Jul 18
Death induced by doxorubicin (dox) in neuroblastoma (NB) cells was originally thought to occur via the Fas pathway, however since studies suggest that caspase-8 expression is silenced in most high stage NB tumors, it is more probable that dox-induced death occurs via a different mechanism. Caspase-8 silenced N-type invasive NB cell lines LAN-1 and IMR-32 were investigated for their sensitivity to dox, and compared to S-type noninvasive SH-EP NB cells expressing caspase-8. All cell lines had similar sensitivities to dox, independently of caspase-8 expression. Dox induced
caspase-3
, -7, -8 and -9 and Bid cleavage in S-type cells and death was blocked by caspase inhibitors but not by oxygen radical scavenger BHA. In contrast, dox-induced death in N-type cells was caspase-independent and was inhibited by BHA. Dox induced a drop in mitochondrial membrane permeability in all cell lines. Dox-induced death in S-type cells gave rise to apoptotic nuclei, whereas in N-type cells nuclei were non-apoptotic in morphology. Transfection of SH-EP cells with a dominant negative FADD mutant inhibited
TRAIL
-induced death, but had no effect on dox-induced apoptosis. These results suggest that S-type cells undergo apoptosis after dox treatment independently of death receptors, whereas N-type cells are killed by a caspase-independent mechanism.
...
PMID:Doxorubicin-induced death in neuroblastoma does not involve death receptors in S-type cells and is caspase-independent in N-type cells. 1220 25
LIGHT is a member of tumor necrosis factor (TNF) superfamily, and its receptors have been identified as lymphotoxin-beta receptor (LTbetaR) and the herpesvirus entry mediator (HVEM)/ATAR/TR2, both of which lack the cytoplasmic sequence termed the "death domain." The present study has demonstrated that LIGHT inhibits TNFalpha-mediated apoptosis of human primary hepatocytes sensitized by actinomycin D (ActD), but not Fas- or
TRAIL
-mediated apoptosis. Furthermore, LIGHT does not prevent some cell lines such as HepG2 or HeLa from undergoing ActD/TNFalpha-induced apoptosis. This protective effect requires LIGHT pretreatment at least 3 h prior to ActD sensitization. LIGHT stimulates nuclear factor-kappaB (NF-kappaB)-dependent transcriptional activity in human hepatocytes like TNFalpha. The time course of NF-kappaB activation after LIGHT administration is similar to that of the pretreatment required for the anti-apoptotic effect of LIGHT. LIGHT inhibits
caspase-3
processing on the apoptotic protease cascade in TNFalpha-mediated apoptosis but not Fas-mediated apoptosis. In addition, increased
caspase-3
and caspase-8 activities in ActD/TNFalpha-treated cells are effectively blocked by LIGHT pretreatment. However, LIGHT does not change the expression of TNFRp55, TNFRp75, and Fas. These results indicate that LIGHT may act as an anti-apoptotic agent against TNFalpha-mediated liver injury by blocking the activation of both
caspase-3
and caspase-8.
...
PMID:LIGHT, a member of the tumor necrosis factor ligand superfamily, prevents tumor necrosis factor-alpha-mediated human primary hepatocyte apoptosis, but not Fas-mediated apoptosis. 1239 1
Apo2 ligand (Apo2L/
TRAIL
) is a member of the tumor necrosis factor (TNF) cytokine family. Apo2L/
TRAIL
can selectively induce programmed cell death in transformed cells, although its wide tissue distribution suggests potential physiological roles. We have investigated the expression, in human osteoblast-like cells (NHBC), of Apo2L/
TRAIL
and the known Apo2L/
TRAIL
death receptors, DR4 and DR5, and the Apo2L/
TRAIL
decoy receptors, DcR-1, DcR-2, and osteoprotegerin (OPG). NHBC expressed abundant mRNA corresponding to each of these molecular species. Immunofluorescence staining demonstrated that Apo2L/
TRAIL
protein was abundant within the cytoplasm of NHBC and OPG was strongly expressed at the cell surface. DR5 and DcR-2 were present in the cell membrane and cytoplasm and DcR-1 was confined to the nucleus. DR4 staining was weak. Neither Apo2L/
TRAIL
alone, nor in combination with chemotherapeutic agents of clinical relevance to treatment of osteogenic sarcoma, induced cell death in NHBC, as assessed morphologically and by activation of
caspase-3
. In contrast, the human osteogenic sarcoma cell lines, BTK-143 and G-292, were sensitive to exogenous Apo2L/
TRAIL
alone, and to the combined effect of Apo2L/
TRAIL
/cisplatin and Apo2L/
TRAIL
/doxorubicin treatments, respectively. In NHBC, we observed strong associations between the levels of mRNA corresponding to the pro-apoptotic molecules, Apo2L/
TRAIL
, DR4, and DR5, and those corresponding to pro-survival molecules, DcR-1, DcR-2, OPG, and FLIP, suggesting that the balance between pro-survival and pro-apoptotic molecules is a mechanism by which NHBC can resist Apo2L/
TRAIL
-mediated apoptosis. In contrast, osteogenic sarcoma cells had low or absent levels of DcR-1 and DcR-2. These results provide a foundation to explore the role of Apo2L/
TRAIL
in osteoblast physiology. In addition, they predict that therapeutic use of recombinant Apo2L/
TRAIL
, in combination with chemotherapeutic agents to treat skeletal malignancies, would have limited toxic effects on normal osteoblastic cells.
...
PMID:Human osteoblasts are resistant to Apo2L/TRAIL-mediated apoptosis. 1239 39
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