Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.36 (caspase-1)
 6,285 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apoptosis is a morphologically distinct form of programmed cellular death that plays a central role during embryogenesis, tissue homeostasis, and to remove not necessary or potentially dangerous cells. Moreover, disregulation of genes mediating or modulating apoptosis contributes to the pathogenesis of a number of human diseases, including cancer, autoimmune diseases, neurodegenerative disorders, viral infections and acquired immunodeficiency syndrome. A number of genes and molecules promoting or protective against cell death is at present-day known and an important information about the external and internal signals involved in stimulation and suppression of apoptosis is also emerging. In the intracellular pathway of the death deregulation of [Ca2+](i) plays a pivotal role. Increased ionized intracellular calcium stimulates both the activation of enzymes (protein kinases, endonucleases, proteases and phospholipases) and plasma membrane K+ channels. This calcium-mediated activation leads to morphostructural changes, such as cell shrinkage, cytoplasmatic blebbing, nuclear chromatin condensation and DNA degradation into oligonucleosomal fragments. At least some genes of the cell death pathway have been conserved throughout animal evolution; ced-3 e ced-9 that regulate the initiation of cellular suicide in the nematode Caenorhabditis elegans are homologous to genes that in mammalian cells are thought to play a similar role (interleukin-1 beta converting enzyme [ICE] family, Bcl-2). It is possible to suppose that these regulators could constitute a target for treatment of disorders related with disregulation of apoptosis.
 ...
PMID:[Genes, molecules, and mechanisms regulating programmed cell death]. 973 54

The extracellular microenvironment of tumors differs from most normal tissues. Many tumors have relatively acidic extracellular pH (pHe), although the intracellular pH (pHi) of tumor cells remains normal due to efficient maintenance of a large proton gradient across the membrane. This difference between tumors and normal tissues might be exploited therapeutically by disruption of the mechanisms which regulate pHi, so that tumor cells are killed by intracellular acid-induced injury. To investigate the mechanisms by which intracellular acidification leads to cell death, we have studied the roles of the anti-apoptotic gene bcl-2 and its pro-apoptotic binding partner bax, the Stress Activated Protein Kinases (SAPK/JNK), and the caspase proteases in mediating acid-induced cell death. While expression of bcl-2 in human bladder cancer MGH-U1 cells had no effect on acid-induced death, overexpression of bax enhanced cell death, consistent with its pro-apoptotic function. Inhibition of SAPK, through expression of a dominant negative mutant of its activator, SEK1 protected cells from acid-induced cell death. Caspase activation, as measured by poly (ADP-ribose) polymerase cleavage, was absent after lethal intracellular acidification. Consistent with this observation, inhibition of ICE proteases by the peptide z-VAD.fmk did not protect against acid-induced cell killing. We conclude that acid-induced cell death depends on bax and on SAPK signaling pathways but not on the caspase proteases. Therapeutic manipulation of bax and SAPK may enhance acid-induced tumor cell killing.
Cancer Metastasis Rev 1998 Jun
PMID:Inhibition of apoptotic signaling pathways in cancer cells as a mechanism of chemotherapy resistance. 977 Jan 20

A novel anticancer drug, cytotrienin A, isolated from Streptomyces sp., induces apoptosis (or programmed cell death) in human promyelocytic leukemia HL-60 cells within 4 h. To elucidate the mechanism of this process, we performed an in-gel kinase assay using myelin basic protein (MBP) as a substrate and found the activation of kinase with an apparent molecular mass of 36 kDa (p36 MBP kinase). The dose of cytotrienin A required to activate p36 MBP kinase was consistent with that required to induce apoptotic DNA fragmentation in HL-60 cells. This p36 MBP kinase was activated with kinetics distinct from the activation of JNK (c-Jun N-terminal kinase)/stress-activated protein kinase and p38 MAPK (mitogen-activated protein kinase). Importantly, the p36 MBP kinase was immunologically different from MAPK superfamily molecules such as ERK1, JNK isoforms, and p38 MAPK. In addition, the p36 MBP kinase activation and apoptotic DNA fragmentation were inhibited by antioxidants such as N-acetylcysteine and reduced-form glutathione. The p36 MBP kinase activation was also observed during hydrogen peroxide (H2O2) and okadaic acid-induced apoptosis. Although a specific inhibitor of caspase-3-like proteases (Ac-DEVD-CHO) or a specific inhibitor of caspase-1-like proteases (Ac-YVAD-CHO) did not block the cytotrienin A-, H2O2-, or okadaic acid-induced apoptosis, a broad specificity inhibitor of caspases (Z-Asp-CH2-DCB) strongly inhibited the apoptosis of HL-60 cells. Surprisingly, Z-Asp-CH2-DCB inhibited the activation of p36 MBP kinase induced by cytotrienin A or H2O2, but did not inhibit the activation of JNK/stress-activated protein kinase and p38 MAPK. Taken together, these results indicate that p36 MBP kinase activation is downstream of the activation of Z-Asp-CH2-DCB-sensitive caspases, and reactive oxygen species could be included in the apoptotic events. Moreover, according to the Western blotting using the antibodies against MST1/Krs2 or MST2/Krs1, it is suggested that the p36 MBP kinase is an active proteolytic product of MST1/Krs2 and MST2/Krs1, which are originally cloned by virtue of its homology to the budding yeast Ste20 kinase. Thus, the p36 MBP kinase might be a common component of the diverse signaling pathways leading to apoptosis, and controlling this p36 MBP kinase pathway might be a novel strategy for cancer chemotherapy.
Cancer Res 1998 Nov 01
PMID:Caspase-mediated activation of a 36-kDa myelin basic protein kinase during anticancer drug-induced apoptosis. 980 95

Immunotoxins composed of antibodies linked to plant or bacterial toxins are being evaluated in the treatment of cancer. It is known that the toxin moieties of immunotoxins, including Pseudomonasexotoxin A (PE), diphtheria toxin, and ricin, are capable of inducing apoptosis. Since the efficiency of induction of apoptosis and the apoptosis pathway may have direct effects on the therapeutic usefulness of immunotoxins, we have studied how B3(Fv)-PE38, a genetically engineered immunotoxin in which the Fv fragment of an antibody is fused to a mutated form of PE, induces apoptosis of the MCF-7 breast cancer cell line. We show for the first time that a PE-containing immunotoxin activates ICE/ced-3 proteases, now termed caspases, and causes characteristic cleavage of the "death substrate" poly(ADP)-ribose polymerase (PARP) to an 89 kDa fragment with a time course of cleavage comparable to that induced by TNFalpha. Also the fluorescent substrate, DEVD-AFC, is cleaved 2-4-fold more rapidly by lysates from B3(Fv)-PE38 treated MCF-7 cells than untreated control cells, suggesting that a CPP32-like caspase is involved in B3(Fv)-PE38-mediated apoptosis. B3(Fv)-PE38-induced PARP cleavage is inhibited by several protease inhibitors known to inhibit caspases (zVAD-fmk, zDEVD-fmk, zIETD-fmk) as well as by overexpression of Bcl-2 providing additional evidence for caspase involvement. zVAD-fmk, a broad spectrum inhibitor of most mammalian caspases, prevents the early morphological changes and loss of cell membrane integrity produced by B3(Fv)-PE38, but not its ability to inhibit protein synthesis, arrest cell growth, and subsequently kill cells. Despite inhibition of apoptosis, the immunotoxin is still capable of selective cell killing, which indicates that B3(Fv)-PE38 kills cells by two mechanisms: one requires caspase activation, and the other is due to the arrest of protein synthesis caused by inactivation of elongation factor 2. The fact that an immunotoxin can specifically kill tumor cells without the need of inducing apoptosis makes such agents especially valuable for the treatment of cancers that are protected against apoptosis, e.g., by overexpression of Bcl-2.
 ...
PMID:Role of caspases in immunotoxin-induced apoptosis of cancer cells. 983 86

In this study, we elucidate signaling pathways induced by photodynamic therapy (PDT) with hypericin. We show that PDT rapidly activates JNK1 while irreversibly inhibiting ERK2 in several cancer cell lines. In HeLa cells, sustained PDT-induced JNK1 and p38 mitogen-activated protein kinase (MAPK) activations overlap the activation of a DEVD-directed caspase activity, poly(ADP-ribose) polymerase (PARP) cleavage, and the onset of apoptosis. The caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk) and benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone (zDEVD-fmk) protect cells against apoptosis and inhibit DEVD-specific caspase activity and PARP cleavage without affecting JNK1 and p38 MAPK activations. Conversely, stable overexpression of CrmA, the serpin-like inhibitor of caspase-1 and caspase-8, has no effect on PDT-induced PARP cleavage, apoptosis, or JNK1/p38 activations. Cell transfection with the dominant negative inhibitors of the c-Jun N-terminal kinase (JNK) pathway, SEK-AL and TAM-67, or pretreatment with the p38 MAPK inhibitor PD169316 enhances PDT-induced apoptosis. A similar increase in PDT-induced apoptosis was observed by expression of the dual specificity phosphatase MKP-1. The simultaneous inhibition of both stress kinases by pretreating cells with PD169316 after transfection with either TAM-67 or SEK-AL produces a more pronounced sensitizing effect. Cell pretreatment with the p38 inhibitor PD169316 causes faster kinetics of DEVD-caspase activation and PARP cleavage and strongly oversensitizes the cells to apoptosis following PDT. These observations indicate that the JNK1 and p38 MAPK pathways play an important role in cellular resistance against PDT-induced apoptosis with hypericin.
 ...
PMID:The activation of the c-Jun N-terminal kinase and p38 mitogen-activated protein kinase signaling pathways protects HeLa cells from apoptosis following photodynamic therapy with hypericin. 1008 20

Previous studies (Y. Guo and N. Kyprianou, Cell Growth Diff., 9: 185-193, 1998) have demonstrated that overexpression of transforming growth factor (TGF) beta type II receptor (TbetaRII) gene in human prostate cancer cells LNCaP, which are refractory to TGF-beta1 and lack TbetaRII receptor expression, can restore TGF-beta1 sensitivity and suppress in vitro tumorigenic growth by inhibiting cell proliferation. In the present study, we investigated the effect of TbetaRII receptor overexpression in LNCaP cells on apoptosis induction and tumorigenicity. The ability of LNCaP cells that overexpress TbetaRII to undergo apoptosis in response to TGF-beta1 was examined by DNA fragmentation and terminal transferase-mediated dUTP-biotin end labeling analysis. To explore the potential apoptotic nature of TGF-beta1-mediated antitumor effect against human prostate cancer cells, the expression of apoptotic proteins bcl-2 and bax was examined by Western blot analyses. The significance of caspase 1 in TGF-beta1-mediated apoptosis was also determined by examining the expression and activation of caspase 1 by reverse transcription-PCR and Western blot analyses, respectively. Comparative analysis of tumorigenicity of the parental LNCaP and TbetaRII-overexpressing clones in severely combined immunodeficient mice revealed a significant suppression of tumor growth in TbetaRII transfectant clones compared with parental LNCaP cells and neomycin-control clones (P < 0.05). A significantly higher incidence of endogenous apoptosis was observed in TbetaRII clone-61-derived tumor compared with the parental LNCaP tumors. This induction of apoptosis in the LNCaP tumors with restored TGF-beta1 signaling was associated with decreased bcl-2 expression, increased bax, and caspase-1 immunoreactivty. Moreover, an increased expression of the cyclin-dependent kinase inhibitor p27Kip1 was detected in TbetaRII-overexpressing tumors compared with the parental tumors. LNCaP TbetaRII transfectant cells exhibited a marked induction of apoptosis, paralleled with a decreased bcl-2 expression in response to TGF-beta1 treatment in vitro. This TGF-beta1-mediated apoptosis induction in TbetaRII transfectant cells was significantly protected by the caspase-1 inhibitor (zVAD-fmk) in a dose-dependent manner. Furthermore, a significant temporal induction of caspase-1 mRNA and protein expression was detected in TbetaRII cells in response to TGF-beta1 treatment. Our findings suggest that restoration of TGF-beta1 signaling suppresses tumorigenicity of human prostate cancer cells by inducing apoptosis, potentially via a caspase-1-mediated pathway.
Cancer Res 1999 Mar 15
PMID:Restoration of transforming growth factor beta signaling pathway in human prostate cancer cells suppresses tumorigenicity via induction of caspase-1-mediated apoptosis. 1009 72

ETS1 is a cellular homologue of the product of the viral ets oncogene of the E26 virus, and it functions as a tissue-specific transcription factor. It plays an important role in cell proliferation, differentiation, lymphoid cell development, transformation, angiogenesis, and apoptosis. ETS1 controls the expression of critical genes involved in these processes by binding to ets binding sites present in the transcriptional regulatory regions. The ETS1 gene generates two proteins, p51 and a spliced variant, p42, lacking exon VII. In this paper we show that p42-ETS1 expression bypasses the damaged Fas-induced apoptotic pathway in DLD1 colon carcinoma cells by up-regulating interleukin 1beta-converting enzyme (ICE)/caspase-1 and causes these cancer cells to become susceptible to the effects of the normal apoptosis activation system. ICE/caspase-1 is a redundant system in many cells and tissues, and here we demonstrate that it is important in activating apoptosis in cells where the normal apoptosis pathway is blocked. Blocking ICE/caspase-1 activity by using specific inhibitors of this protease prevents the p42-ETS1-induced apoptosis from occurring, indicating that the induced ICE/caspase-1 enzyme is responsible for killing the cancer cells. p42-ETS1 activates a critical alternative apoptosis pathway in cancer cells that are resistant to normal immune attack, and thus it may be useful as an anticancer therapeutic.
 ...
PMID:The p42 variant of ETS1 protein rescues defective Fas-induced apoptosis in colon carcinoma cells. 1009 31

Our previously performed experiments clearly showed a significant VDR-mediated growth inhibitory effect of 1,25-dihydroxyvitamin D3 and its synthetic analogs in a variety of human cancer cells including human colon and breast cancer, soft tissue sarcoma, and malignant melanoma cell lines. The mechanisms by which 1, 25-dihydroxyvitamin D3 and its synthetic analogs growth inhibit human cancer cells is poorly elucidated. The exposure of human colon cancer cells HT-29 to 1,25-dihydroxyvitamin D3 or its analog, 1alpha, 25-dihydroxy-16-ene-23yne-26,27-hexafluoro-19-nor-choleca lci ferol (Ro 25-6760), at the 10(-6) M concentration resulted in significant growth inhibition with induction of the apoptotic process after three days of treatment detected by TUNEL assay and agarose gel electrophoresis of DNA. As a logical link with DNA fragmentation analyses and TUNEL assay, cleavage of the 116 kDa PARP protein was accompanied by the appearance of a characteristic 85 kDa fragment of PARP in a population of floating cells after both treatments. The results of cell cycle analysis showed a G0/G1 phase block after three days of administration of either compound when compared with untreated cells. On day 4, G0/G1 cell cycle arrest remained on the same level in comparison with control. Paralleling the G0/G1 phase block, was a notable decrease in the number of cells in the S phase which also became significant after three days of treatment. The results of these experiments show that the newly developed 19-nor synthetic vitamin D3 analog, Ro 25-6760, as well as 1, 25-dihydroxyvitamin D3, induced the expression of p21waf1, resulted in a significant G1/G0 cell cycle arrest leading to impressive growth inhibition and induction of apoptosis associated with proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) showing a possible involvement of apoptosis-specific activation of the ICE/CED-3 proteolitic pathway.
 ...
PMID:Novel 19-nor-hexafluoride vitamin D3 analog (Ro 25-6760) inhibits human colon cancer in vitro via apoptosis. 1020 Mar 51

Glutathione-doxorubicin (GSH-DXR) effectively induced apoptosis in rat hepatoma cells (AH66) at a lower concentration than DXR. After 24 h of drug treatment, DNA fragmentation of the cells was observed at the concentration of 1.0 microM DXR or 0.01 microM GSH-DXR. Increase in caspase-3 activity and DNA fragmentation were observed within 12 h and 15 h after treatment with either drug. Intracellular caspase-3 activity was increased in a dose-dependent manner after treatment with DXR or GSH-DXR, and caspase-3 activity correlated well with the ability to induce DNA fragmentation. When the cells were treated with either DXR or GSH-DXR for only 6 h, apoptotic DNA degradation and caspase-3 activation occurred 24 h after treatment. DNA fragmentation caused by these drugs was prevented completely by simultaneous treatment with the caspase-3 inhibitor, acetyl-Asp-Glu-Val-Asp-aldehyde (DEVD-CHO), at 10 microM. By contrast, DNA fragmentation was not prevented by the caspase-1 inhibitor, acetyl-Tyr-Val-Ala-Asp-aldehyde (YVAD-CHO), at the same concentration as DEVD-CHO, and caspase-1 was not activated at all by the treatment of AH66 cells with both DXR and GSH-DXR. These results demonstrate that DXR and GSH-DXR induce apoptotic DNA fragmentation via caspase-3 activation, but not via caspase-1 activation, and that GSH-DXR enhances the activation of caspase-3 approximately 100-fold more than DXR. Moreover, the findings suggested that an upstream apoptotic signal that can activate caspase-3 is induced within 6 h by treating AH66 cells with the drug.
Br J Cancer 1999 May
PMID:Caspase-3 activation during apoptosis caused by glutathione-doxorubicin conjugate. 1036 Jun 48

The production in colon cancer of interferon-gamma (IFN-gamma), a type-1 T-helper (TH1) cytokine, is considered as a marker of good prognosis. We asked whether interleukin-18 (IL-18), which strongly induces IFN-gamma and regulates Fas ligand (Fas-L)-dependent cytotoxicity, may play a role in colon homeostasis, and if its expression was modulated in colon adenocarcinomas. We analyzed 14 specimens of colon adenocarcinomas, 6 of normal colon mucosa of the series, and 6 colon-tumor cell lines. The expression of IL-18, of ICE protease, involved in the processing of this cytokine, and of the downstream effectors of IL-18, IFN-gamma and Fas-L was analyzed by RT-PCR. We further performed IL-18 immunostaining of normal and tumor specimens. The results were correlated with tumor dissemination and clinical outcome. We report the synthesis of IL-18 in human normal colon, mainly by epithelial cells of the mucosa. Out of the 6 tumor cell lines, 4 expressed IL-18 transcripts, but neither ICE mRNA nor secreted forms of IL-18 were detected. We observed decreased or abolished synthesis of IL-18 in colon adenocarcinomas, as compared with normal mucosa. Thus, half of the colon-cancer tissues (7/14 cases) expressed neither IFN-gamma nor Fas-L. This feature was correlated with the existence of distant metastases (Fischer's exact test, p = 0.02) and an unfavorable outcome. These findings suggest that production of IL-18 in human colon may play a role in homeostasis and in tumor immune surveillance, by enhancing IFN-gamma production and Fas-L-dependent cytotoxicity of immune cells.
Int J Cancer 1999 Jun 21
PMID:Modulation of interleukin-18 expression in human colon carcinoma: consequences for tumor immune surveillance. 1037 55


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>