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)

Alpha-Tocopheryl succinate (alpha-TOS), but not a-tocopherol, triggered apoptosis in Jurkat T cells. Apoptosis was induced by alpha-TOS in a time- and concentration-dependent mode, and signs of apoptosis were visible at concentrations of alpha-TOS as low as 30 microM, and within 3-5 h after addition of the ester. Employing a specific fluorogenic substrate, caspase-3 was found to be activated rapidly in response to alpha-TOS at 50 microM. We also found that Jurkat T cells challenged with alpha-TOS, when exposed to the lysosomotropic weak base acridine orange, showed decreased lysosomal uptake of the dye. This is suggestive of the involvement of lysosomal destabilisation in apoptosis of the cells. Apoptosis of Jurkat T cells induced with alpha-TOS also involved a drop in the mitochondrial membrane potential, although this phenomenon occurred after the initiation of lysosomal rupture. All apoptotic features observed with alpha-TOS were very similar to those found when cross-linking of the Fas receptor triggered apoptosis. These findings are consistent with the recent idea that vitamin E can contribute to elimination of malignant cells by the induction of apoptosis, and can be of (patho)physiological significance.
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PMID:alpha-tocopheryl succinate-induced apoptosis in Jurkat T cells involves caspase-3 activation, and both lysosomal and mitochondrial destabilisation. 1009 76

The mechanism of cell death caused by cytokine deprivation remains largely unknown. FL5.12 cells (a murine prolymphocytic cell line), following interleukin-3 (IL-3) withdrawal, undergo a decrease in intracellular glutathione (GSH) that precedes the onset of apoptosis. In the present study, the induction of apoptosis following IL-3 withdrawal or GSH depletion with DL-buthionine-[S,R,]-sulfoximine (BSO) was examined. Both conditions caused time-dependent increases in phosphatidylserine externalization, acridine orange and ethidium bromide staining, decreases in mitochondrial membrane potential, processing and activation of caspase-3 and proteolysis of the endogenous caspase substrate poly(adenosine diphosphate ribose)polymerase (PARP). Apoptosis induced by IL-3 deprivation but not BSO also caused lamin B1 cleavage, suggesting activation of caspase-6. Despite a more profound depletion of GSH after BSO than withdrawal of IL-3, the extent of apoptosis was somewhat lower. Benzyloxycarbonyl-Val-Ala-Asp(OMe)fluoromethyl ketone (z-VAD.fmk) blocked this caspase activity and prevented cell death after BSO exposure but not after IL-3 deprivation. Following IL-3 withdrawal, the caspase inhibitors z-VAD.fmk and boc-asp(OMe)fluoromethylketone (boc-asp.fmk) prevented the cleavage and activation of caspase-3, the breakdown of lamin B1 and partially mitigated PARP degradation. However, the externalization of phosphatidylserine, the fall in mitochondrial membrane potential and subsequent apoptotic cell death still occurred. These results suggest that IL-3 withdrawal may mediate cell death by a mechanism independent of both caspase activation and the accompanying loss of GSH.
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PMID:Apoptosis in hematopoietic cells (FL5.12) caused by interleukin-3 withdrawal: relationship to caspase activity and the loss of glutathione. 1020 May 49

A variety of molecular changes occur during the process of apoptosis. Much of the recent work has focused on changes in critical cellular proteins, proteins necessary for the initiation and continuation of the apoptotic process. Given the fact that numerous membrane changes occur throughout the apoptotic process, we initiated an investigation aimed at determining the major lipid changes that occurred during programmed cell death. When ionizing radiation was used to initiate the apoptotic process in Jurkat cells, one of the major changes that occurred within 24 h was an increase in a species with a m/z of 572 as determined by negative ion electrospray mass spectrometry. This particular mass ion displayed high performance liquid chromatography characteristics of a neutral lipid species. Further analysis by collision-induced-dissociation tandem mass spectrometry indicated only one daughter species indicative of a Cl adduct and therefore a parental mass of 537. Comparison to a commercial C16 ceramide yielded identical spectra by mass spectrometry (MS) and MS/MS analysis in the negative ion mode. Increases in C16 ceramide levels occurred 2 h after initiation of apoptosis by ionizing radiation, and its accumulation paralleled apoptosis as determined by cellular morphology. Interestingly, radiation-sensitive Jurkat cells displayed increased levels of long term C16 ceramide accumulation, whereas radiation-resistant K562 cells did not. These findings were supported by increases in caspase-3 activity in Jurkat cells, whereas caspase-3 activity in K562 cells remained unchanged. C16 ceramide accumulation and sensitivity to ionizing radiation was investigated further in a melanoma cell line. Only those cells that were radiation sensitive (approximately 70-75%) displayed increases in long term ceramide accumulation. Taken together, these results indicated a correlation between increases in C16 ceramide accumulation and radiation sensitivity. Increases in long term C16 ceramide accumulation were also seen in Fas-induced apoptosis, which occurred at time points greater than 2 h. Analysis of mitochondrial modifications using the mitochondrial probe nonyl acridine orange (NAO) indicated that initial increases in C16 ceramide levels closely paralleled the decrease in mitochondrial mass during Fas or radiation-induced apoptosis. Taken together, these results support a role for C16 ceramide in the effector (mitochondrial) phase of apoptosis.
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PMID:Mass spectrometric identification of increased C16 ceramide levels during apoptosis. 1052 41

In order to maintain epidermal structural homeostasis, keratinocytes need to modulate their proliferation, differentiation, and cell death. Although terminal differentiation of keratinocytes is characterized by cornified cell envelope (CE) formation and one major mechanism of cell death is apoptosis, the precise relationship between these processes remains obscure. Using normal human cultured keratinocytes (NHK), we compared A23187-induced CE formation and ultraviolet B irradiation (UVB)-induced apoptosis. A23187 stimulated CE formation in 1 mM Ca(2+)-pretreated NHK cells. CE formation was detected by 1 h and the maximal induction was observed at 6 h. Morphological analysis using acridine orange staining revealed that UVB-irradiated NHK cells show distinctive round, homogeneous fragmented nuclear beads, a characteristic feature of apoptotic cells, while A23187-treated cells showed enlarged nuclei with weak chromatin staining, which is not typical of apoptosis. The UVB-irradiated NHK cells did not show CE formation. Caspase activation is a characteristic event during apoptosis. Although UVB irradiation increased caspase 3 activity, no increase in caspase 3 activity was detected during A23187-induced CE formation. Multiple nucleosome-sized fragments of DNA were observed in UVB-treated NHK cells, but not in A23187-treated NHK cells. FACS analyses using anti-annexin V antibody and propidium iodide (PI) showed that UVB irradiation induced both annexin V-positive and PI-negative early apoptotic cells and annexin V-positive and PI-positive late apoptotic cells. On the other hand, A23187-treated NHK cells showed only annexin V-negative and PI-positive non-apoptotic dying cells. Cell death assay revealed a significantly increased apoptotic cells in UVB-irradiated NHK cells, but not in A23187-treated NHK cells. UVB irradiated NHK cells showed increased cytosolic transglutaminase activity, while A23187-treated NHK cells showed increased membrane-associated transglutaminase activity. These results indicate that CE formation is distinct from apoptosis in epidermal keratinocytes.
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PMID:Cornified cell envelope formation is distinct from apoptosis in epidermal keratinocytes. 1095 41

Arsenic trioxide (As(2)O(3)) can induce clinical remission in patients suffering from acute promyelocytic leukemia, through induction of apoptosis and activation of caspases. We investigated the potential use of As(2)O(3) in human gastric cancer and its possible mechanisms. Human gastric cancer cell lines AGS and MKN-28 were treated with various concentrations (0.1 to 100 microM) of As(2)O(3) for 24 to 72 hr. Apoptosis was determined by acridine orange staining, flow cytometry and DNA fragmentation. Protein levels of p53, p21(waf1/cip1), c-myc, bcl-2 and bax were detected by Western blotting. Effects of As(2)O(3) on caspase-3 protease activity, its protein concentration and cleavage of poly(ADP)-ribose polymerase (PARP) were also studied. As(2)O(3) inhibited cell growth and induced apoptosis in both cell lines, though AGS cells were more sensitive. As(2)O(3) induced apoptosis in AGS cells in a concentration- and time-dependent manner. Treatment resulted in a marked increase in p53 protein levels as early as 4 hr. Co-incubation with p53 anti-sense oligo-nucleotide suppressed As(2)O(3)-induced intracellular p53 over-expression and apoptosis. As(2)O(3) increased the activity of caspase-3, with appearance of its 17 kDa peptide fragment, and cleavage of PARP, with appearance of the 85 kDa cleavage product, both in parallel with the induction of apoptosis. Both the tripeptide caspase inhibitor zVAD-fmk and the specific caspase-3 inhibitor DEVD-fmk partially suppressed As(2)O(3)-induced caspase-3 activation and apoptosis. As(2)O(3) inhibits cell growth and induces apoptosis in gastric cancer cells, involving p53 over-expression and activation of caspase-3. The potential use of this compound in the treatment of gastric cancer is worth further investigation.
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PMID:Arsenic trioxide induces apoptosis in human gastric cancer cells through up-regulation of p53 and activation of caspase-3. 1114 41

Glucocorticoids decrease the replication of cells of the osteoblastic lineage and the function of the osteoblast. However, under certain conditions, they enhance the differentiation of osteoblastic cells, an effect that appears contradictory to their inhibitory actions on cell function. In this study we examine the effects of cortisol on the proliferation, differentiation, and fate of osteoblastic enriched cells from 22-day-old fetal rat calvariae (osteoblastic cells) in the absence and presence of beta-glycerophosphate. In the absence of beta-glycerophosphate, there was a progressive accumulation of DNA and cells, which was impaired by cortisol. In the presence of beta-glycerophosphate, there was an initial accumulation of DNA and cells followed by a marked decline that was prevented by cortisol. Despite the sustained number of cells, cortisol did not affect their mineralization, and inhibited Core binding factor a1 (Cbfa1), but not alkaline phosphatase, osteocalcin, or type I collagen transcripts. The decrease in cell number by cortisol observed in the absence of beta-glycerophosphate was due to a decrease in DNA synthesis, whereas the increase in cell number observed in the presence of beta-glycerophosphate was due to a relative increase in DNA synthesis and a decrease in apoptosis as determined by DNA fragmentation and acridine orange staining of the cells. This was correlated by a decrease in transcripts of proapoptotic genes and caspase 3 activity, and an increase of antiapoptotic genes. In conclusion, cortisol decreases the replication of cells of the osteoblastic lineage, but under conditions of differentiation/mineralization, cortisol prevents terminal differentiation of the cells and maintains an immature cell population.
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PMID:Cortisol inhibits the differentiation and apoptosis of osteoblasts in culture. 1134 47

The caspase family of proteases is speculated to have a crucial role in apoptosis. The effect of treatment with adriamycin (ADR), cisplatin (CDDP), 5-fluorouracil (5-FU), vinblastine (VLB), IFN-alpha, or IFN-gamma on the activation of caspase-3, -6, -8, and -9 in renal cell carcinoma (RCC) cells was investigated, to clarify the mechanisms of chemo- and immunotherapeutic agent-mediated apoptosis. Caspase activity was determined by a quantitative colorimetric assay. Apoptosis was monitored by acridine-orange staining assay. Treatment of ACHN cells with CDDP, VLB, IFN-alpha, or IFN-gamma did not activate caspase-3, but its activity was increased 7.2-fold (p = 0.0001) with ADR and 2.8-fold (p = 0.0385) with 5-FU in comparison with control. Furthermore, when the ADR treatment time was shortened from 24 to 8 or 2 h, the same caspase-3 activation occurred. Activation of caspase-3 was also observed in six freshly isolated human RCC cells after the treatment with ADR. Of the six freshly derived RCC cells treated with 5-FU, caspase-3 activity was increased 3.1-fold (p = 0.0051) and 2.4-fold (p = 0.0346) in two of them, respectively. Epirubicin and pirarubicin, compounds closely related to ADR, also respectively enhanced 4.2-fold (p = 0.0052) and 2.8-fold (p = 0.0147) caspase-3 activity in ACHN cells. The activation of caspase-3 observed with a colorimetric assay was confirmed with immunocytochemical analysis using the anti-active caspase-3 mAb, which specifically recognizes the active form of caspase-3. Furthermore, both active caspase-3 and apoptosis triggered by either ADR or 5-FU were inhibited significantly by the general caspase inhibitor Z-VAD-FMK, or a specific caspase-3 inhibitor DMQD-CHO. These findings provide a mechanistic explanation for anthracyclines and 5-FU induced-apoptosis.
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PMID:Activation of caspase-3 in renal cell carcinoma cells by anthracyclines or 5-fluorouracil. 1140 17

This paper studies the cytotoxic effect induced by the topoisomerase I inhibitor camptothecin in human osteosarcoma Saos-2 cells, which lack p53 and contain a non-functional form of the product of the retinoblastoma gene, pRb. Cytotoxicity induced by camptothecin was dose- and time-dependent; the treatment with 100 nM camptothecin reduced cell viability by 50% at 32 h and by 75% at 72 h of exposure. The cytotoxic effect was caused by apoptosis, as ascertained by morphological evidence, acridine orange-ethidium bromide staining and flow cytometric analysis. Apoptosis was accompanied by both the activation of caspase-3 and the fragmentation of poly(ADP-ribose) polymerase. Treatment with camptothecin caused a threefold increase in the activity of c-Jun N-terminal kinase (JNK) and an eightfold increase in the level of phosphorylated c-Jun. The introduction of the RB gene into Saos-2 cells reduced the rate of cell growth. Moreover, stable clones of transfected cells were resistant to camptothecin. Exposure to 100 nM camptothecin for 72 h reduced the viability of transfected cells by only 10%; moreover, very modest effects were observed on the activity of JNK as well as on the level of phosphorylated c-Jun. The results reported in this paper support the conclusion that the expression of wild-type pRb in Saos-2 cells exerts an anti-apoptotic influence through the control of JNK activity.
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PMID:pRb suppresses camptothecin-induced apoptosis in human osteosarcoma Saos-2 cells by inhibiting c-Jun N-terminal kinase. 1141 38

Apoptosis induced in the IL3-dependent murine pro-B lymphocytic (FL5.12) cell line by the 5-lipoxygenase activating protein inhibitor MK886 is accompanied by the rapid loss of the anti-apoptotic bcl-x(L) and bcl-2, but not the proapoptotic bax proteins (Datta et al., J. Biol. Chem. 273, 28163-28169, 1998). Since several reports indicate important roles for noncaspase proteases in apoptosis, the participation of lysosomes, as well as serine, cysteine, or aspartic acid proteases, in the effects of MK886 were investigated. Consistent with the involvement of various proteases, lysosomal degranulation was evident, as observed by a decrease in acridine orange fluorescence at 2 h and an increase in cytosolic beta-hexosaminidase activity at 4 h after treating FL5.12 cells with 10 microM MK886. The disappearance of bcl-x(L) from FL5.12 cells upon MK886 treatment was prevented in a dose-dependent manner by pretreatment with leupeptin, pepstatin, phenylmethylsulfonyl fluoride, or the broad-spectrum caspase inhibitor Boc-D-FMK. Each of the noncaspase protease inhibitors partially inhibited MK886-induced apoptosis as measured by phosphatidylserine externalization and DNA fragmentation. The noncaspase inhibitors also blocked about half of the increase in caspase-3-like activity. Boc-D-FMK completely inhibited this enzyme and prevented apoptosis. None of the inhibitors were able to directly inhibit activated caspase-3 in cell lysates, suggesting their effects were upstream of caspase activation. These observations suggest the involvement of various proteases, possibly originating from lysosomes, upstream of active caspase-3, in the loss of bcl-x(L) protein and in the signaling pathway of MK886-induced apoptosis in FL5.12 cells. This pathway may be unique to MK886 since these same protease inhibitors had only minimal effects on etoposide-induced apoptosis and the accompanying moderate loss of bcl-x(L) in FL5.12 cells.
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PMID:Proteolytic loss of bcl-x(L) in FL5.12 Cells undergoing apoptosis induced by MK886. 1148 88

Aspirin- and non-steroidal anti-inflammatory drug (NSAID)-induced apoptosis is one of the important mechanisms for their anti-tumour effect in gastric cancer. We aimed at determining the role of bcl-2 family proteins and caspases in the apoptotic process. Gastric cancer cell lines AGS (wild-type p53) and MKN-28 (mutant p53) were used. Cell proliferation was measured by MTT assay. Apoptosis was determined by acridine orange staining. Protein expressions were determined by western blotting. Aspirin and indomethacin inhibited cell proliferation and induced apoptosis in both cells. AGS cells were more sensitive compared with MKN-28 cells. The pro-apoptotic proteins bax and bak were overexpressed after treatment, while the protein level of bcl-2 remained unchanged. Apoptosis was accompanied by an increase in caspase-3 activity and cleavage of caspase-3 and poly(ADP-ribose) polymerase. Inhibition of caspase-3 rescued aspirin-induced apoptosis. Our results suggest that one of the major pathways which mediates the anti-tumour response of aspirin and indomethacin in gastric cancer cells is through up-regulation of bax and bak and activation of caspase-3. Bax and bak are important in the chemoprevention of gastric cancer.
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PMID:Non-steroidal anti-inflammatory drugs induce apoptosis in gastric cancer cells through up-regulation of bax and bak. 1153 60


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