Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to evaluate the results of high-dose therapy followed by purged autologous stem cell transplantation (ASCT) for patients with low-grade follicular non Hodgkin's lymphoma (LGFL), and the prognostic significance of PCR detection of residual Bcl-2/IgH-positive cells after ASCT. Between 1992 and 1998, 49 patients with LGFL received total body irradiation and high-dose cyclophosphamide followed by purged ASCT. PCR amplification of the Bcl-2/IgH rearrangement was performed at diagnosis, on stem cell collections before and after purging and on bone marrow and blood samples after ASCT. With a median follow-up of 76 months (37-103) 34 patients remain alive and event-free. A total of 20 patients had disease recurrence, three patients developed secondary myelodysplastic syndrome (MDS). In all, 11 patients died; 10 deaths were because of recurrent disease, one because of MDS. Kaplan-Meier estimates of event-free survival (EFS) and overall survival (OS) at 5 years were 65% (+/-7%) and 77% (+/-6%), respectively. Patients who achieved a sustained molecular complete response (CR) had a lower risk of disease recurrence and experienced significantly longer EFS (93% (+/-6%) vs 11% (+/-7%) P=0.0008) and OS (100 vs 55% (+/-12%) P=0.0057). In conclusion, myeloablative therapy followed by purged ASCT may induce long EFS in patients with LGFL. The achievement of sustained molecular CR after ASCT improves EFS and OS.
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PMID:PCR detection of residual Bcl-2/IgH-positive cells after high-dose therapy with autologous stem cell transplantation is a prognostic factor for event-free survival in patients with low-grade follicular non-Hodgkin's lymphoma. 1266 42

In order to observe the expression of Fas, FasL and Bcl-2 and apoptosis of bone marrow CD34(+) cells in patients with myelodysplastic syndrome (MDS), and to explore the relation between the expression of these antigens and apoptosis, the expression of Fas, FasL and Bcl-2 and apoptosis of bone marrow CD34(+) cell were evaluated by flow cytometry in 26 patients with MDS including 9 cases of refactory anemia (RA), 1 case of RA with ringed sideroblasts (RAS), 9 cases of RA with excess blasts (RAEB) and 7 cases of RAEB in transformation (RAEB-t), 10 patients with acute myeloid leukemia (AML) and 6 control patients with normal bone marrow. The results showed that the expression of Fas and FasL of CD34(+) cells significantly increased in all types of MDS patients compared with control group (P < 0.01). The expression of Bcl-2 on CD34(+) cells in RAEB and RAEB-t patients was much higher as compared with that in control group (P < 0.01), but there was no significant difference between RA/RAS patients and control group (P > 0.05). The expression rates of Fas on CD34(+) cells were almost identical in all kinds of MDS, but there was significant difference on the expression of Bcl-2 (RA/RAS < RAEB < RAEB-t). Apoptosis of CD34(+) cells significantly increased in RA/RAS and RAEB patients compared with control group (P < 0.01), but there was no difference between RAEB-t and control group. Moreover, apoptosis of CD34(+) cells in control much higher than that in AML group (P < 0.01). There was no correlation between the expression of Fas or FasL and apoptosis on CD34(+) cell of MDS patients. Nevertheless, there was a negative correlation between the expression of Bcl-2 and apoptosis. It is concluded that apoptosis of CD34(+) cells was affected by a lot of factors in MDS, in which Bcl-2 is an important factor of depressing apoptosis. During the progress from MDS to AML, apoptosis changes from overgoing to deficiency in CD34(+) cell.
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PMID:[Expression of Fas, FasL and Bcl-2 and apoptosis of bone marrow CD34+ cells in patients with myelodysplastic syndrome]. 1284 12

Myelodysplastic syndromes (MDS) are neoplastic dyscrasias characterized by peripheral cytopenia, despite a normocellular or hypercellular bone marrow. In the past decade, it has become apparent that this ineffective hemopoiesis is largely caused by excessive apoptosis of myeloid precursors. There is no evidence for gain-of-function mutations within the apoptotic machinery in MDS. It appears that the apoptosis is a reactive phenomenon fueled by cytokines. The provoking stimulus for the proapoptotic intramedullary milieu in MDS is unknown. The evolution of MDS from early relatively chronic to aggressive and frankly leukemic phenotype is accompanied by a suppression of apoptosis. This metamorphosis correlates with changes in intracellular levels of Bcl-2-family proteins, but the genetic basis for this shift has not been elucidated clearly. Expression profiling and proteomic technologies may offer the best means to unravel this process.
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PMID:Apoptosis in the myelodysplastic syndromes. 1290 39

Excessive apoptosis has a central role in ineffective hematopoiesis in myelodysplastic syndrome (MDS). The aim of the study was to quantify apoptosis and Bcl-2 expression in patients with MDS and to use these parameters in the evaluation of treatment efficacy with compounds modulating proapoptotic cytokines. Bone marrow (BM) samples from eight MDS patients were studied: four with refractory anemia and four with refractory anemia with ringed sideroblasts. Two patients with Hodgkin disease without BM determination were studied for control. Therapy consisted in administration of pentoxyphylline, dexamethasone and ciprofloxacin. Biochemical assay of apoptosis and Bcl-2 was performed using annexin V-biotin conjugate antibody and anti-human Bcl-2 antibody respectively, followed by streptavidine-peroxidase conjugate, and peroxidase substrate. Ultrastructural investigation of BM samples was performed with standard electron microscopy techniques. Most of BM hematopoietic cells in the MDS patients had ultrastructural features of various stages of apoptosis including chromatin condensation and margination, cytoplasm condensation and budding of nuclear and plasma membranes to produce apoptotic bodies. Bcl-2 expression showed an inverse correlation with the rate of the apoptotic process. Periodic evaluation of these two parameters has shown an increase of Bcl-2 expression and a decrease of apoptotic rate in patients who had responded to the treatment. Response to the treatment was appreciated in accordance with their transfusion needs. Treatment efficiency diminished in time. The rate of apoptosis was inversely correlated with the level of Bcl-2 expression. These results confirm the importance of the apoptotic process evaluation in monitoring MDS treatment.
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PMID:Apoptotic rate in patients with myelodisplastic syndrome treated with modulatory compounds of pro-apoptotic cytokines. 1459 56

The nuclear transcription factor NF-kappa B regulates cell survival, proliferation, and differentiation. Little is known about NF-kappa B in myeloid malignancies. In this report, we assessed NF-kappa B in a group of myeloid neoplasms by using an electrophoretic mobility shift assay (EMSA) and immunofluorescence methods in freshly isolated leukemia cells. We analyzed 30 cases of acute myeloid leukemia (AML), 5 cases of myelodysplastic syndrome (MDS), 3 cases of chronic myelomonocytic leukemia (CMML), 15 cases of chronic myeloid leukemia in chronic phase (CML-CP), and 2 cases of chronic myeloid leukemia in blast crisis (CML-BC). Unstimulated cells (bone marrow and peripheral blood) from 17 normal donors and apheresis samples from 6 peripheral blood stem cell donors treated with granulocyte colony-stimulating factor (G-CSF) were used as controls. When EMSA was used, NF-kappa B was elevated in 14 of 30 (47%) cases of AML, in both cases of CML-BC, and in all reference donors treated with G-CSF, but it was at basal levels in all cases of MDS and CML-CP and in normal donors (P = <.01). Immunofluorescence analysis confirmed strong nuclear RelA/NF-kappa B immunoreactivity in AML blasts but not in normal bone marrow. Bcl-2, a downstream molecule, was expressed in cases with elevated NF-kappa B, but not in cases with basal levels of NF-kappa B, suggesting that NF-kappa B is active and provides the cells with survival advantages in vivo. These results suggest that suppression of NF-kappa B may be a useful therapeutic strategy for a subset of patients with AML.
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PMID:Expression of constitutively active nuclear-kappa B RelA transcription factor in blasts of acute myeloid leukemia. 1499 44

Tumor necrosis factor (TNF)-alpha, a potent stimulus of nuclear factor-kappaB (NF-kappaB), is up-regulated in myelodysplastic syndrome (MDS). Here, we show that bone marrow mononuclear cells (BMMCs) and purified CD34+ cells from patients with low-grade/early-stage MDS (refractory anemia/refractory anemia with ring sideroblasts [RA/RARS]) have low levels of NF-kappaB activity in nuclear extracts comparable with normal marrow, while patients with RA with excess blasts (RAEB) show significantly increased levels of activity (P = .008). Exogenous TNF-alpha enhanced NF-kappaB nuclear translocation in MDS BMMCs above baseline levels. Treatment with arsenic trioxide (ATO; 2-200 microM) inhibited NF-kappaB activity in normal marrow, primary MDS, and ML1 cells, even in the presence of exogenous TNF-alpha (20 ng/mL), and down-regulated NF-kappaB-dependent antiapoptotic proteins, B-cell leukemia XL (Bcl-XL), Bcl-2, X-linked inhibitor of apoptosis (XIAP), and Fas-associated death domain (FADD)-like interleukin-1beta-converting enzyme (FLICE) inhibitory protein (FLIP), leading to apoptosis. However, overexpression of FLIP resulted in increased NF-kappaB activity and rendered ML1 cells resistant to ATO-induced apoptosis. These data are consistent with the observed up-regulation of FLIP and resistance to apoptosis with advanced MDS, where ATO as a single agent may show only limited efficacy. However, the data also suggest that combinations of ATO with agents that interfere with other pathways, such as FLIP autoamplification via NF-kappaB, may have considerable therapeutic activity.
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PMID:NF-kappaB and FLIP in arsenic trioxide (ATO)-induced apoptosis in myelodysplastic syndromes (MDSs). 1610 82

To determine the possible roles of survivin in the pathogenesis of myelodysplastic syndrome (MDS) and to explore the relationship between apoptosis and angiogenesis in MDS, the expressions of survivin, Bcl-2 and VEGF were detected in the BM cells of de novo patients with MDS, patients with AML and individuals of control by immunochemical staining and their relationship was analyzed. The results showed that the expression rate and integral of all the three proteins in the low-risk group of MDS, high-risk group of MDS and de novo acute myeloid leukemia patients gradually increased, in addition to expression of Bcl-2 in low-risk group of MDS and control group. The significant differences were observed in every two groups and there were positive relations between the every two proteins. It is concluded that survivin, Bcl-2 and VEGF are all involved in the pathogenesis of MDS, and related with the progression of this disease, the deregulated apoptosis and angiogenesis may be involved in the pathogenesis of MDS through interaction among three proteins mentioned above.
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PMID:[Expressions of survivin, Bcl-2 and VEGF in patients with myelodysplastic syndrome and their relationship]. 1663 95

Although recent data shows that arsenic trioxide (As2O3) is capable of inducing cell death via cell cycle arrest and apoptosis both in acute promyelocytic leukemia (APL) and in non-APL cells, the mechanisms of As2O3-mediated cell death are not fully understood. In this study, we investigated the in vitro effects of As2O3 on cell growth inhibition and cell death in human T-lymphocytic leukemia and myelodysplastic syndrome (MDS) cell lines. As2O3 significantly inhibited the proliferation of Molt-4 and Mutz-1 cells in dose- and time-dependent manner. Autophagic cell death (programmed cell death type II) and apoptosis (programmed cell death type I) were activated together in leukemia cell lines after exposed to As2O3. Numerous large cytoplasmic inclusions and vacuoles were observed in As2O3-treated cells using electron microscope. Furthermore, 3-methyladenine (an autophagy inhibitor) significantly reduced autophagic cell death and sequentially induced apoptosis. Finally, leukemia cells treated with 4 microM As2O3 showed a considerable up-regulation of Beclin-1 (a Bcl-2-interacting protein) expression, which was independent of transcription of mRNA and required protein synthesis. In addition, Molt-4 cells treated with As2O3 exhibited the down-regulation of Bax protein expression, suggesting that Bax may be involved in accumulating of Beclin-1 and triggering autophagic cell death in As2O3-treated leukemia cells. These results may lead to a better understanding of the mechanism of action of As2O3, and provide a suggestion that As2O3 may be of therapeutic value for the treatment of patients with human T-lymphocytic leukemia and myelodysplastic syndrome.
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PMID:Arsenic trioxide induces not only apoptosis but also autophagic cell death in leukemia cell lines via up-regulation of Beclin-1. 1688 51

Arsenic trioxide (As2O3) has been approved for the treatment of acute promyelocytic leukemia (APML) and it is a promising candidate for the treatment of patients with lymphoproliferative disorders, such as relapsed or refractory multiple myeloma and myelodysplastic syndromes. The effects of As2O3 on B cells, specifically which do not express Bcl-2, have not been studied. In this study, we have demonstrated that As2O3, at clinically achievable therapeutic concentrations, induces apoptosis in Bcl-2 negative human B cell line Ramos. As2O3-induced apoptosis is associated with reduced mitochondrial transmembrane potential (delta psi), enhanced generation of intracellular reactive oxygen species (ROS), release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria into cytoplasm, activation of caspases, and upregulation of Bax and Bim expression. Exogenous glutathione (GSH) reverses the As2O3-induced apoptosis in a dose-dependent manner. Altogether, these data indicate that As2O3 induces apoptosis in B cells, regardless of Bcl-2 expression, via the mitochondrial pathway by enhancing oxidative stress.
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PMID:Arsenic trioxide induces apoptosis via the mitochondrial pathway by upregulating the expression of Bax and Bim in human B cells. 1720 11

Myelodysplastic syndrome (MDS), previously known as preleukemia, comprises a spectrum of heterogeneous, clonal disorders of hematopoiesis. A patient's life expectancy can range from a few months to more than a decade. Recent studies provide some insight into the pathophysiology of MDS. One mechanism contributing to the constellation of hypercellular marrow and peripheral blood cytopenia is a significant increase in programmed cell death (apoptosis) in hematopoietic cells. Tumor necrosis factor (TNF)-alpha, Fas ligand, TNF-related apoptosis-inducing ligand, and other proapoptotic cytokines are upregulated in early-stage/low-risk MDS, and neutralization of these signals can improve hematopoiesis. TNF-related apoptosis inducing ligand induces apoptosis preferentially in clonal cells, which can contribute to containment of the clone. In a proportion of patients, MDS will eventually evolve to acute leukemia. This progression has been correlated with upregulation of nuclear factor kappaB; altered expression of adaptor molecules, such as Flice inhibitory protein; and enhanced activity of antiapoptotic members of the Bcl-2 and inhibitors of apoptosis protein families. Also, the ratio of TNF receptors 1 and 2 changes in favor of receptor 2. The role of the microenvironment in the pathophysiology and progression of MDS has remained controversial, although there is evidence that stroma and matrix components, and their interactions with clonal cells, play an important role. Microarray gene-expression studies are consistent with dysregulation of apoptosis, but not all data are in agreement.
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PMID:Apoptosis and antiapoptotic mechanisms in the progression of myelodysplastic syndrome. 1797 24


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