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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
L-Ascorbic acid (LAA) is being investigated clinically for the treatment of patients with
acute myeloid leukemia
(
AML
) based on the observed effects of LAA on
AML
progenitor cells in vitro. However, the mechanism for LAA-induced cytoreduction remains to be elucidated. LAA at concentrations of 0.25-1.0 mM induced a dose- and time-dependent inhibition of proliferation in three
AML
cell lines and also in leukemic cells from peripheral blood specimens obtained from three patients with
AML
. In contrast, ovarian cancer cell lines were only minimally affected. Flow cytometric analysis showed that LAA at concentrations of 0.25-1.0 mM could significantly induce apoptosis in the
AML
cell lines. LAA induced oxidation of glutathione to oxidized form (GSSG) and subsequent H(2)O(2) accumulation in a concentration-dependent manner, in parallel to induction of apoptosis. The direct role of H(2)O(2) in the induction of apoptosis in
AML
cells was clearly demonstrated by the finding that catalase could completely abrogate LAA-induced apoptosis. Induction of apoptosis in LAA-treated
AML
cells involved a dose-dependent increase of Bax protein, release of cytochrome C from mitochondria to cytosol, activation of caspase 9 and
caspase 3
, and cleavage of poly[ADP-ribose]polymerase. In conclusion, LAA can induce apoptosis in
AML
cells, and this is clearly due to H(2)O(2) which accumulates intracellularly as a result of oxidation of reduced glutathione by LAA.
...
PMID:L-Ascorbic acid induces apoptosis in acute myeloid leukemia cells via hydrogen peroxide-mediated mechanisms. 1531 65
Bcr-Abl-expressing primary or cultured leukemia cells display high levels of the antiapoptotic heat shock protein (hsp) 70 and are resistant to cytarabine (Ara-C), etoposide, or Apo-2L/TRAIL (TNF-related apoptosis-inducing ligand)-induced apoptosis. Conversely, a stable expression of the cDNA of hsp70 in the reverse orientation attenuated not only hsp70 but also signal transducers and activators of transcription 5 (STAT5) and Bcl-x(L) levels. This increased apoptosis induced by cytarabine, etoposide, or Apo-2L/TRAIL. Ectopic expression of hsp70 in HL-60 cells (HL-60/hsp70) inhibited Ara-C and etoposide-induced Bax conformation change and translocation to the mitochondria; attenuated the accumulation of cytochrome c, Smac, and Omi/HtrA2 in the cytosol; and inhibited the processing and activity of caspase-9 and
caspase-3
. Hsp70 was bound to death receptors 4 and 5 (DR4 and DR5) and inhibited Apo-2L/TRAIL-induced assembly and activity of the death-inducing signaling complex (DISC). HL-60/hsp70 cells exhibited increased levels and DNA binding activity of STAT5, which was associated with high levels of Pim-2 and Bcl-x(L) and resistance to apoptosis. Expression of the dominant negative (DN) STAT5 resensitized HL-60/hsp70 cells to cytarabine, etoposide, and Apo-2L/TRAIL-induced apoptosis. Collectively, these findings suggest that hsp70 inhibits apoptosis upstream and downstream of the mitochondria and is a promising therapeutic target for reversing drug-resistance in chronic myeloid leukemia-blast crisis and
acute myeloid leukemia
cells.
...
PMID:Mechanistic role of heat shock protein 70 in Bcr-Abl-mediated resistance to apoptosis in human acute leukemia cells. 1538 81
Antiapoptotic proteins like the inhibitor of apoptosis proteins (IAPs) are molecular markers potentially useful for the characterization of
acute myeloid leukemia
(
AML
). We screened 92 adults with de novo
AML
for the protein expression of various IAPs, Bcl-2 family members and the proform of
Caspase-3
using quantitative immunoblot and flow cytometry. XIAP expression correlated with myelomonocytic French-American-British (FAB) subtypes M4/M5 (P < 0.05) and expression of monocytic markers (CD 14, CD 36; P < 0.05; CD 4, HLA-DR; P < 0.01) in
AML
blasts. In addition, XIAP was overexpressed in normal monocytes but undetectable in granulocytes. In
AML
, XIAP expression was significantly lower in patients with favorable than intermediate or poor cytogenetics (n = 74; P < 0.05). In total, 62 of the examined patients were treated according to the German
AML
Cooperative Group (AMLCG) 92 protocol. These patients were analyzed for prognostic significance of apoptosis-related proteins. Patients expressing low levels of XIAP enjoyed better overall survival than patients expressing high amounts of XIAP (mean, 9 (n = 41) versus 19 months (n = 21); P < 0.05). Other IAPs, most importantly Survivin, were of no prognostic value. We conclude that XIAP but not other IAP family members is associated with monocytic differentiation in normal and malignant myelopoiesis, and may be of prognostic significance for overall survival in adult de novo
AML
.
...
PMID:XIAP expression correlates with monocytic differentiation in adult de novo AML: impact on prognosis. 1557 Feb 90
The DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR) has significant therapeutic value for the treatment of patients with myelodysplastic syndrome (MDS),
acute myeloid leukemia
(
AML
) and chronic myeloid leukemia (CML). The demethylating effect of 5-Aza-CdR has been well characterized. In contrast, less is known about the molecular events downstream of the methylation inhibition. Here, 5-Aza-CdR induced apoptosis in
AML
cells (both p53 mutant and wild-type) but not in epithelial or normal PBMCs. Cell death was accompanied by activation of the mitochondrial apoptosis pathway, as shown by release of cytochrome c and AIF and loss of mitochondrial membrane potential (DeltaPsim). Activation of
caspase-3
(but not -6 and -8) was detectable using Western blot analysis and measurement of caspase enzymatic activity. 5-Aza-CdR treatment resulted in the induction of p21, which correlated with the arrest of
AML
cells in the G1 cell cycle phase. Induction of p21 expression was independent of its promoter methylation status but mediated by 5-Aza-CdR-induced reexpression of the tumor-suppressor p73, a known upstream regulator of p21. The p73 promoter was hypermethylated in
AML
cell lines and in primary
AML
cells but not in epithelial cells, which were resistant toward 5-Aza-CdR. Therefore, 5-Aza-CdR-mediated specific killing of myeloid cells might be dependent on its ability to revert p73 promoter methylation and to reexpress p73 mRNA. In addition, exogenous expression of p73 rendered epithelial cells sensitive to apoptosis induced by 5-Aza-CdR or other cytostatic drugs. We therefore conclude that p73 is a relevant target for methylation-dependent efficacy of 5-Aza-CdR in
AML
cells.
...
PMID:5-Aza-2'-deoxycytidine induces p21WAF expression by demethylation of p73 leading to p53-independent apoptosis in myeloid leukemia. 1560 9
As a promising new class of anticancer drugs, camptothecins have advanced to the forefront of several areas of therapeutic and developmental chemotherapy. In the present study, we report that NSC606985, a rarely studied camptothecin analog, induces apoptosis in
acute myeloid leukemia
(
AML
) cells NB4 and U937 and inhibits the proliferation without cell death in breakpoint cluster region-Abelson murine leukemia (bcr-abl) kinase-carrying leukemic K562 cells. For apoptosis induction or growth arrest, nanomolar concentrations of NSC606985 are sufficient. At such low concentrations, this agent also significantly inhibits the clonogenic activity of hematopoietic progenitors from patients with
AML
. For apoptosis induction, NSC606985 rapidly induces the proteolytic activation of protein kinase Cdelta (PKCdelta) with loss of mitochondrial transmembrane potential (DeltaPsim) and
caspase-3
activation. Cotreatment with rottlerin, a PKCdelta-specific inhibitor, completely blocks NSC606985-induced mitochondrial DeltaPsim loss and
caspase-3
activation, while the inhibition of
caspase-3
by z-DEVD-fluoromethyl ketone (Z-DEVD-fmk) only partially attenuates PKCdelta activation and apoptosis. These data indicate that NSC606985-induced PKCdelta activation is an early event upstream to mitochondrial DeltaPsim loss and
caspase-3
activation, while activated
caspase-3
has an amplifying effect on PKCdelta proteolysis. In addition, NSC606985-induced apoptosis by PKCdelta also involves
caspase-3
-independent mechanisms. Taken together, our results suggest that NSC606985 is a potential agent for the treatment of
AML
.
...
PMID:Nanomolar concentration of NSC606985, a camptothecin analog, induces leukemic-cell apoptosis through protein kinase Cdelta-dependent mechanisms. 1567 40
This study was aimed to investigate the effects of human bone marrow fibroblastoid stromal cell line (HFCL) on chemosensitivity of
acute myeloid leukemia
sensitive HL-60 cell line and multidrug-resistant (MDR) HL-60/VCR cell line in vitro co-culture. Setting up co-culture system of HL-60 or HL-60/VCR cells in direct contact with HFCL cells, or with HFCL cells separated by transwell, and exposing HL-60 or HL-60/VCR cells to different concentrations of topotecon (TPT), morphologic evidence for apoptosis was determined by staining with Wright-Giemsa stain and acridine orange/ethidium bromide (AO/EB). Cell cycle, sub-G(1) and annexin V FITC staining were detected by flow cytometry. The expression of active
caspase-3
, Bcl-2 and Pgp was detected by Western blot. The results showed that HL-60 or HL-60/VCR cells treated by TPT revealed characteristic apoptotic morphological changes by Wright-Giemsa and AO/EB staining. The percentage of annexin V-positive cells and apoptotic cells decreased when they were cocultured with HFCL cells. The proportion of G(0)/G(1) HL-60 or HL-60/VCR cells treated by TPT increased and the sub-G(1) appeared significantly, but apoptotic and sub-G cells reduced after direct contact with HFCL cells. Meanwhile, although HL-60 or HL-60/VCR cells treated by TPT expressed activated
caspase-3
, and the expression of Bcl-2 decreased, the expression of activated
caspase-3
decreased and Bcl-2 increased after direct contact with HFCL cells. In conclusion, HFCL stromal cells can prevent TPT-induced apoptosis in HL-60 and HL-60/VCR cells via modulation of Bcl-2 and active
caspase-3
.
...
PMID:[Effect of bone marrow stromal cells on the apoptotic sensitivity of HL-60 and HL-60/VCR cells]. 1585 94
The mechanisms involved in the apoptotic effect of LCY-2-CHO [9-(2-chlorobenzyl)-9H-carbazole-3-carbaldehyde], a synthetic carbazole derivative identified as an anti-inflammatory compound, were studied. Cell cycle analysis by propidium iodide staining in human THP-1 monocytic leukemia cells showed the ability of LCY-2-CHO to increase cell population in sub-G1 stage with time- and concentration-dependent manners. LCY-2-CHO-mediated cell death was also demonstrated by DNA laddering and was not related to the release of lactate dehydrogenase. Apoptosis in THP-1 cells induced by LCY-2-CHO was accompanied by the Bid cleavage, collapse of mitochondrial transmembrane potential, the release of cytochrome c and the activation of
caspase-3
. The apoptotic effect of LCY-2-CHO was diminished by the presence of zVEID-fmk (caspase-6 inhibitor), zIETD-fmk (caspase-8 inhibitor), and zVAD-fmk (non-selective caspase inhibitor), but was not altered by several antioxidants, and cathepsin inhibitor. The Bid cleavage and loss of mitochondrial transmembrane potential, but not the cytochrome c release, were reversed by zIETD-fmk. Comparing the cell selectivity of LCY-2-CHO, we found T-cell acute lymphoblastic CEM leukemia cells were sensitive to 1 microM LCY-2-CHO,
acute myeloid leukemia
HL-60 cells underwent apoptosis at 10 microM, while adherent cancer cells, such as PC3, HT29 and MCF-7, were resistant to 30 microM LCY-2-CHO within 24-h incubation. Taken together in the present study, we demonstrated LCY-2-CHO might be apoptotic for malignant hematopoietic cells but not anchorage-dependent cells. This action is mediated by an intrinsic caspase-dependent apoptotic event involving mitochondria.
...
PMID:Cell apoptosis induced by a synthetic carbazole compound LCY-2-CHO is mediated through activation of caspase and mitochondrial pathways. 1589 95
The DNA antimetabolite gemcitabine is an anticancer agent with shown preclinical and clinical utility and a low toxicity profile. In this study, we sought to identify and optimize drug partners for binary and tertiary combinations with gemcitabine for use in the treatment of
acute myelogenous leukemia
(
AML
). Drug interaction was assessed by growth inhibition assay with metabolic end points. The combination index method was used to evaluate combinations of gemcitabine with fludarabine, paclitaxel, chlorambucil, doxorubicin, mitoxantrone, and SN-38 in U937 human
AML
cells. A three-dimensional method was used to determine the effect of dose ratio and schedule on drug interaction. Mechanisms underlying interactions related to cell cycle effects and apoptosis were assessed by flow cytometric and
caspase-3
and -7 assays, respectively. The most synergistic binary combination was gemcitabine + fludarabine. The most synergistic tertiary combination was gemcitabine + fludarabine + paclitaxel, where the interaction was sequence dependent with paclitaxel given before gemcitabine + fludarabine, producing a 2-fold increase in synergy. Cell cycle analysis did not reveal a significant G(2)-M arrest, suggesting that the synergistic effect of paclitaxel in this combination, which produced the greatest caspase activation, might be independent of microtubule stabilization. In contrast, the gemcitabine + fludarabine + mitoxantrone combination was synergistic and schedule independent. Moreover, few ratios of gemcitabine + fludarabine to mitoxantrone were antagonistic, which could be important for clinical translation. In conclusion, synergistic interactions with gemcitabine occurred with several drugs, the most promising being gemcitabine + fludarabine, gemcitabine + fludarabine + paclitaxel, and gemcitabine + fludarabine + mitoxantrone. These findings provided a rationale for clinical trials of gemcitabine + fludarabine and gemcitabine + mitoxantrone where responses were observed in heavily pretreated
AML
patients.
...
PMID:Preclinical evaluation of gemcitabine combination regimens for application in acute myeloid leukemia. 1593 Mar 61
The effect of the recombinant Notch ligand proteins Jagged1 and Delta1 on drug-sensitivity of leukemia and lymphoma cells was examined. Four
acute myeloid leukemia
(
AML
) cell lines were cultured in ligand-coated wells and control wells, with cytosine arabinoside (Ara-C), doxorubicin, or mitoxantrone, and nine lymphoid leukemia or lymphoma cell lines were cultured with dexamethasone. The growth was evaluated with a colorimetric assay. The drug-induced growth suppression was slightly reduced by the ligand stimulation in 4 out of 17 combinations of cells versus drugs, such as NB4 cells versus Ara-C. In the remainder, the ligands did not significantly affect the drug-sensitivity. To investigate the possible molecular mechanism of the protective effect, the influence of Jagged1 on Ara-C-induced activation of
caspase-3
and PARP, and dephosphorylation of NF-kappaB was examined in NB4 cells. However, Jagged1 did not obviously affect the activation and dephosphorylation. It is known that stromal cells reduce drug-induced cytotoxicity of leukemia cells. According to our results, the role of Notch ligands in the stroma-mediated resistance seems to be minor and occurs only in a limited context. However, the ligand-coated culture-plates are more similar to the microenvironment in human bone marrow than ordinary plates. We will further examine the clinical usefulness of the drug-sensitivity test using the ligand-coated plates.
...
PMID:Effect of notch ligands on in vitro sensitivity to chemo-therapeutic drugs in leukemia and lymphoma cells. 1607 82
Cytokine stimulation induces proliferation and growth of
acute myeloid leukemia
(
AML
) blasts and high levels of cytokines have been associated with poor prognosis in
AML
. The Jak-Stat pathway constitutes a major mediator of cytokine activity. We investigated whether WP-1034, a novel Jak-Stat inhibitor, is active against
AML
blasts. OCIM2 and fresh
AML
cells were incubated with 1 to 6 microM WP-1034 to determine its effect on proliferation. WP-1034 effectively inhibited proliferation of OCIM2 cells and fresh
AML
samples. We then analyzed the expressions of Stat 1, 3, and 5, as well as Phospho-Stat 1, 3, and 5 by Western immunoblotting after incubation of OCIM2 cells without and with 1 to 10 microM WP-1034 for 2 hours, and at 5 microM from 20 minutes up to 4 hours and found that WP-1034 blocked Stat 3 and 5 activation. Analysis of cell cycle status by PI staining and flow cytometry showed that WP-1034 caused cell cycle arrest of OCIM2 cells in sub-Go phase. We then evaluated the induction of apoptosis of OCIM2 cells following incubation with WP-1034 at 3 to 6 microM by annexin V-CY5 assay and analyzed
caspase 3
and PARP cleavage using Western immunoblotting. We found that WP-1034 induced apoptosis of OCIM2 cells and that induction of apoptosis involved cleavage of
caspase 3
and the DNA repair enzyme poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP). Taken together, our data suggest that WP-1034 is a potent inhibitor of
AML
cell proliferation by inhibition of Stat 3 and 5 and induction of caspase-dependent apoptosis.
...
PMID:WP-1034, a novel JAK-STAT inhibitor, with proapoptotic and antileukemic activity in acute myeloid leukemia (AML). 1615 16
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