Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P08758 (annexin V)
 9,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of nitric oxide synthase (NOS) isoforms was investigated in the established ESKOL hairy cell line and in leukemic cells of patients with hairy cell leukemia (HCL). By reverse transcription-polymerase chain reaction (RT-PCR), these cells were found to spontaneously express inducible NOS (iNOS)-specific mRNA, but not endothelial constitutive NOS (ecNOS) mRNA. The iNOS protein was detected by immunofluorescence in the cytoplasm of permeabilized leukemic cells and ESKOL cells, using different anti-iNOS monoclonal antibodies. A protein of 135 kDa was identified by Western blotting in ESKOL and HCL lysates, confirming the presence of an iNOS in these cells. Cytosolic homogenates displayed NOS catalytic activity, as measured by the conversion of 14C-labelled L-arginine into 14C L-citrulline and by detection in situ using the DAF-2DA (diaminofluorescein diacetate) NO-sensitive fluorescent probe. Ligation of CD23 (low affinity IgE receptor) was found to increase iNOS expression in ESKOL and conversely to decrease the percentage of cells undergoing apoptosis, as measured by the percentage of cells expressing annexin V. These results indicate that, as in chronic B cell lymphocytic leukemia cells (B-CLL) a functional iNOS is expressed constitutively in hairy cells that contributes to protecting these tumoral cells from apoptosis.
Leukemia 2000 Apr
PMID:Expression of a functional inducible nitric oxide synthase in hairy cell leukaemia and ESKOL cell line. 1076 57

We have previously shown that all-trans retinoic acid (ATRA) increases the number of CFU-GM colonies grown from unseparated human bone marrow cells with crude sources of colony stimulating factors. In this study, we further characterized the effect of ATRA on the growth of CFU-GM stimulated by individual cytokines from multiple samples of CD34+ enriched or purified human bone marrow cells. The number of IL-3- or GM-CSF-induced CFU-GM with 3 x 10(-7) M ATRA was 3.25+/-1.13, and 2.17+/-0.8-fold greater respectively, compared to controls without ATRA, while G-CSF had no effect and the ratio of colony-induced with or without ATRA was 1.06+/-0.17 (P = 0.00012). No colonies grew with ATRA + IL-6 or ATRA without a cytokine. Maximum enhancing effect on IL-3-induced CFU-GM occurred when ATRA was added on day 2, gradually diminished when delaying ATRA, and in cultures of day 9 or older adding ATRA had no effect. In 14 days liquid cultures of purified CD34+ cells with IL-3, ATRA increased the number of myeloid differentiated cells to 91-95%, compared to 37-70% with IL-3 alone. In addition, the number of apoptotic cells using the annexin V method increased after 14 days from 5.1% with IL-3 to 17.1% with IL-3 + ATRA and by the TUNEL in situ method from 10-26% to 60-95%, respectively. This study demonstrates that ATRA consistently enhances the growth of myeloid progenitors from CD34+ cells. This effect is dependent on the stimulating cytokine, suggesting the myeloid cells responding to ATRA are the less mature CFU-GMs that are targets of IL-3 and GM-CSF and not the G-CSF-responding mature progenitors. The growth stimulation by ATRA and IL-3 is also associated with granulocyte differentiation and increased apoptosis. These studies further suggest a potential role of pharmacological doses of ATRA on the development of normal human hematopoietic cells.
Leukemia 2000 May
PMID:All-trans-retinoic acid effects the growth, differentiation and apoptosis of normal human myeloid progenitors derived from purified CD34+ bone marrow cells. 1080 20

In the present study, we investigated the in vitro apoptotic response of leukemic cells to the cellular stress induced by homoharringtonine (HHT), a plant alkaloid with antileukemic activity which is currently being tested for treatment of acute and chronic leukemias. A comparison of leukemic cell lines with different p53 gene status revealed a considerably higher sensitivity to HHT-induced apoptosis in the cells with a wt p53, and apoptotic events in wt p53 leukemia cells (MOLT-3 cell line) were studied in more detail. To this end, we examined components of apoptotic cascades including Bax expression and its intracellular localization, changes of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, cytochrome c release from mitochondria and activation of caspases. Bax protein levels did not increase despite an up-regulation of bax at mRNA level. However, Bax translocation from cytosol towards mitochondria was observed. In addition, we observed a release of cytochrome c from the mitochondria, and the localization changes of both Bax and cytochrome c were found already at the early, annexin V-negative stage of HHT-induced apoptosis. HHT-treated MOLT-3 cells revealed loss of MMP as well as activation of caspases demonstrated by DEVD-, IETD- and LEHD-tetrapeptide cleavage activity in the cell lysates. ROS levels only slightly increased in HHT-treated cells and antioxidants did not prevent apoptosis and MMP changes. Therefore, wt p53 leukemic cells respond to HHT-specific cellular stress by induction of ROS-independent apoptotic pathway characterized by translocation of Bax, mitochondrial cytochrome c release and activation of caspases.
Leukemia 2001 Apr
PMID:Apoptotic response to homoharringtonine in human wt p53 leukemic cells is independent of reactive oxygen species generation and implicates Bax translocation, mitochondrial cytochrome c release and caspase activation. 1136 58

Modified and chimeric cytokines have been developed to aid in the recovery of hematopoietic precursor cells after myeloablative chemotherapy. The interleukin-3 (IL-3) receptor agonist, daniplestim, binds to the IL-3 receptor-alpha subunit with 60-fold greater affinity and induces cell proliferation and colony-forming unit formation 10- to 22-fold better than native IL-3. A chimeric cytokine, myelopoietin-1, composed of daniplestim and a G-CSF receptor agonist binds both the IL-3 and G-CSF receptors. While the in vivo effects of daniplestim and myelopoietin-1 are well described, the mechanisms by which they stimulate growth are not well understood. We have investigated the effects of daniplestim and myelopoietin-1 on the prevention of apoptosis in two human hematopoietic cell lines, OCI-AML.5 and AML 193. Daniplestim and myelopoietin-1 prevented apoptosis to a greater degree than native recombinant IL-3 or G-CSF as determined by annexin V/propidium iodide binding and TUNEL assays. Daniplestim and myelopoietin-1 promoted the maintenance of the mitochondrial membrane potential better than native IL-3 or G-CSF. These cytokines promoted a lower redox potential as higher levels of free radicals were detected after cytokine treatment than in cytokine-deprived cells implying increased respiration. These results indicate that daniplestim and myelopoietin-1 are able to prevent apoptosis in hematopoietic cells more effectively than native IL-3 and G-CSF. These effects of daniplestim and myelopoietin-1 may contribute to their effective ability to repopulate hematopoietic precursor cells after chemotherapy.
Leukemia 2001 Aug
PMID:Enhanced ability of daniplestim and myelopoietin-1 to suppress apoptosis in human hematopoietic cells. 1148 May 62

MMP inhibitors are used clinically for the stabilization of tumor growth, thus prolonging survival in cancer patients. However, their role in the treatment of hematopoietic malignancies remains unclear. In the present study, we investigated the effects of a new MMP inhibitor, SI-27, in hematopoietic malignancies. SI-27 alone induces apoptosis in several human myeloid leukemia cell lines such as U937, NB4, and HL60 cells by activating caspase 8, 9, and 3. Apoptosis was measured with annexin V positive staining, a drop in mitochondrial transmembrane potential (deltapsim), presence of hypodiploid DNA, and cleavage of PARP and IkappaBalpha. Furthermore, at lowered concentrations, which did not directly induce apoptosis, SI-27 acted to sensitize U937 cells and other cells to tumor necrosis factor alpha (TNF-alpha)-mediated apoptosis. The accumulation of membrane Fas, the Fas ligand, and TNFR1 were not apparent due to exposure to SI-27, and antagonistic anti-Fas or anti-Fas ligand antibodies did not block SI-27-induced apoptosis. Thus, SI-27-induced apoptosis is not mediated by the Fas pathway. These results suggest that MMP inhibitors, alone or in combination with other cytotoxic agents, can provide a unique method for treating acute myeloid leukemia, refractory to classical anti-cancer drugs, and may thus suppress recurrence.
Leukemia 2001 Aug
PMID:A new matrix metalloproteinase inhibitor SI-27 induces apoptosis in several human myeloid leukemia cell lines and enhances sensitivity to TNF alpha-induced apoptosis. 1148 May 63

The MLL gene is frequently rearranged in leukemias, and MLL chimeric proteins generated by chromosomal translocations play crucial roles in leukemogenesis. Targets of murine Mll include HOX proteins that regulate body pattern formation and hematopoiesis. However, it is not known whether or not the MLL chimeric proteins regulate the HOX gene expression in human leukemia. To address this issue, THP-1 cells, a human leukemia cell line expressing MLL-AF9, were treated with antisense oligodeoxyribonucleotide (ODN) complementary to the coding sequence of the MLL-AF9 junction. Down-regulation of the MLL-AF9 transcript was accompanied by the reduced expression of the HOXA7 and -A10 genes, but not of the HOXA2, -A4, -A5, and -A9 genes. The number of viable cells cultured with 20 microM antisense ODN for 5 days was 10-fold lower than that of the sense ODN-treated control. And the number of the annexin V-/propidium iodide- apoptotic cells in the antisense ODN-treated cells after 3 days of culture was two-fold higher than that in the control. Staining of the antisense ODN-treated cells with Hoechst 33258 showed the morphology characteristic to apoptosis. These results indicate that MLL-AF9 regulates the expression of the selected HOX genes as well as prevents the leukemic cells from apoptosis.
Leukemia 2001 Nov
PMID:Targeted down-regulation of MLL-AF9 with antisense oligodeoxyribonucleotide reduces the expression of the HOXA7 and -A10 genes and induces apoptosis in a human leukemia cell line, THP-1. 1168 16

Dexrazoxane (DEX) prevents the formation of free radical, lipid peroxidation and cardiotoxicity caused by anthracyclines. Due to a concern about its possible interference with anthracyclin cytotoxicity, the in vitro effect of DEX on daunorubicin (DNR) cytotoxicity, cell cycle and induction of apoptosis by annexin-V was investigated. The sensitivity to DEX, DNR and their combination was tested by the MTT assay in human promyelocytic leukemia HL-60, the erythroid blast crisis CML K562 cell lines and in 45 children with ALL and AML. Cell cycle analysis and annexin-V expression were performed by flow cytometry. It has been observed that DEX itself weakly, but significantly caused cytotoxicity in both cell lines and in patient samples, especially in initial ALL samples. DEX sensitized K562 and HL60, but not patient samples, to cytotoxicity of DNR. The percentage of necrotic/apoptotic cells, as detected in cell cycle analysis and annexin V staining, was higher after exposure to DEX +/- DNR, when compared to respective samples not treated with DEX, in both cell lines but not in patient samples. Expression of annexin V induced by DEX in both cell lines was enlarged, regardless of the presence of DNR. This difference was not observed in patient samples, however, the number of cells expressing annexin V was higher after exposure to DEX +/- DNR in comparison to respective samples not treated with DEX. In conclusion, it seems that DEX possibly has no impact on the sensitivity of childhood leukemic blasts to DNR, however, has weak cytotoxic properties itself.
Leukemia 2002 May
PMID:Dexrazoxane has no impact on sensitivity of childhood leukemic blasts to daunorubicin. 1198 42

The leukemogenic property of BCR-ABL in chronic myeloid leukemia (CML) is critically dependent on its protein tyrosine kinase activity. STI571 inhibits the BCR-ABL kinase activity, the growth and the viability of BCR-ABL expressing cells. In this study, we report the apoptotic effect of STI571 in combination with daunorubicin (DNR) on peripheral blood mononuclear cells from 11 CML patients and four BCR-ABL-positive cell lines: AR230, LAMA84, K562 and KCL22. Primary blast cells were identified by flow cytometry on the basis of their low CD45 expression. Nucleus fragmentation, exposure of phosphatidylserines and decrease in mitochondrial membrane potential were measured using acridine orange, FITC-annexin V and DiOC6(3), respectively, to evaluate apoptosis. On cell lines, the effect of DNR was negligible, whereas STI571 induced 10 to 35% of apoptosis in 18 h. STI571 sensitized AR230, LAMA84 and K562 cells to DNR when apoptosis was measured at the mitochondrial and membrane but not the nuclear levels. On CML blast cells, phosphatidyl serine exposure was significantly induced by both DNR and STI571 and was higher when these drugs were used in combination (P < 0.0003). However, the effects of this drug combination were only additive and no sensitization of blast cells to DNR by STI571 was observed. Interestingly, sensitization was evidenced in CML but not normal lymphocytes. These results suggest that other mechanisms additional to Bcr-Abl tyrosine kinase activity could be responsible for DNR resistance, and further investigations are needed to understand its origin.
Leukemia 2002 Jun
PMID:Resistance to daunorubicin-induced apoptosis is not completely reversed in CML blast cells by STI571. 1204 Apr 47

Clotrimazole is an antimycotic imidazole derivative that interferes with cellular Ca(2+) homeostasis. We investigated the effects of clotrimazole on acute lymphoblastic leukemia (ALL) cells. Treatment with 10 microM clotrimazole (a concentration achievable in vivo) reduced cell recovery from cultures of all nine ALL cell lines studied (B-lineage: OP-1, SUP-B15, RS4;11, NALM6, REH, and 380; T-lineage: MOLT4, CCRF-CEM, and CEM-C7). After 4 days of culture, median cell recovery was 10% (range, <1% to 37%) of cell recovery in parallel untreated cultures. Clotrimazole also inhibited recovery of primary ALL cells cultured on stromal feeder layers. After leukemic cells from 16 cases of ALL were cultured for 7 days with 10 microM clotrimazole, median cell recovery was <1% (range, <1% to 16%) of that in parallel untreated cultures. Clotrimazole was active against leukemic cells with genetic abnormalities associated with poor response to therapy and against multidrug-resistant cell lines. In contrast, mature T lymphocytes and bone marrow stromal cells were not affected. Clotrimazole induced depletion of intracellular Ca(2+) stores in ALL cells, which was followed by apoptosis, as shown by annexin V binding and DNA fragmentation. Thus, clotrimazole is cytotoxic to ALL cells at concentrations achievable in vivo.
Leukemia 2002 Jul
PMID:The antifungal antibiotic clotrimazole alters calcium homeostasis of leukemic lymphoblasts and induces apoptosis. 1209 59

The apoptotic pathway activated by chimeric anti-CD20 monoclonal antibodies (rituximab, IDEC.C2B8) was analyzed using the Burkitt lymphoma cell line Ramos. Crosslinking of CD20 (CD20XL) induced apoptosis in Ramos cells, which involved loss of mitochondrial membrane potential (Deltapsi(m)), the release of cytochrome-c (cyt-c), and activation of caspases-9 and -3. Nevertheless, several lines of evidence showed that the apoptotic outcome did not depend on these events. First, under circumstances where Ramos cells display resistance to either CD95- or B cell receptor (BCR)-induced apoptosis, CD20XL-induced apoptosis was not affected, pointing to a distinct pathway. Second, the broad-spectrum caspase inhibitor zVAD-fmk prevented processing of caspase-9, -3 and PARP as well as DNA fragmentation, but did not block apoptosis as measured by annexin V staining, cell size and membrane integrity. Lastly, Bcl-2 overexpression blocked cyt-c release and the decrease in Deltapsi(m), and completely prevented CD95- or BCR-mediated apoptosis; however, it did not affect CD20XL-induced cell death. We conclude that although CD20XL can initiate the mitochondrial apoptosis pathway, CD20-induced apoptosis does not necessarily require active caspases and cannot be blocked by Bcl-2. Since most chemotherapeutic drugs require the activation of caspases to exert their cytotoxicity, these findings provide an important rationale for the use of CD20 mAbs in chemoresistant malignancies.
Leukemia 2002 Sep
PMID:CD20-induced B cell death can bypass mitochondria and caspase activation. 1220 Jun 88


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