Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have recently reported that retinoic acid (RA) induced the expression of trkA, the high affinity receptor for nerve growth factor (NGF), in human chronic myelogenous leukemia K562 cells. In this paper, we examined the ability of several other differentiation inducers to regulate the expression of trkA and NGF in K562 cells. We found that the expression of trkA was dramatically induced by the two megakaryocyte lineage inducers sodium butyrate (NaBut) and phorbol 12-myristate 13-acetate (PMA), but not by the two erythrocyte lineage inducers hemin or 1-beta-D-arabinofuranosyl cytosine (Ara-C). Furthermore, activation of the up-regulated trkA receptor by exogenous NGF potentiated the megakaryocytic differentiation of K562 cells induced by NaBut and PMA. Our results demonstrated that trkA is one of the essential genes that are up-regulated and involved in the megakaryocytic differentiation of K562 leukemia cells triggered by these differentiation inducers. Our findings suggest that NGF, in addition to its pivotal roles in the nervous system, may also play important roles in hematopoietic differentiation.
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PMID:Nerve growth factor potentiated the sodium butyrate- and PMA-induced megakaryocytic differentiation of K562 leukemia cells. 1097 79

Chronic myeloid leukemia (CML) is a hematological malignancy resulting from clonal expansion and massive accumulation of leukemic myeloid cells that retain differentiation and maturation capacity. Since CML cell accumulation has been related to apoptosis inhibition by the product of the BCR-ABL gene, attempts to eradicate leukemic cells would require therapeutic drugs able to overcome this inherent resistance. Here, we investigated in vitro the apoptotic effect of all-trans retinoic acid (ATRA) and cytosine arabinoside (ARA-C), employed alone, in combination or in sequence, on freshly isolated cells from 10 patients with chronic-phase CML. Our cell cultures showed that both ATRA and ARA-C were able to induce apoptosis in CML cells, even if ARA-C resulted more effective than ATRA. The combined use of ATRA and ARA-C seemed to have only an additive effect while the sequential use did not show any advantage. These in vitro observations indicate that ATRA and ARA-C may be effective in reducing CML cells through apoptosis induction, suggesting that it could be worthwhile to examine ATRA and ARA-C combinations in the therapy of CML.
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PMID:In vitro apoptotic response of freshly isolated chronic myeloid leukemia cells to all-trans retinoic acid and cytosine arabinoside. 1115 76

Unequivocally, complete remission (CR) is a prerequisite for the cure for acute leukemia. The history of drug therapy for acute leukemia has taught us that only after CR rates exceed 90% can a satisfactorily high cure rate be obtained, as is observed in acute lymphoblastic leukemia in children and acute promyelocytic leukemia (APL). In multicenter studies of adult acute myeloid leukemia (AML), CR rates hardly exceed 80% with currently available cytotoxic drugs, except for a small fraction of patients having AML with t(8;21) or inv(16). CR rates and survival of adult patients with AML in 4 studies by the Japan Adult Leukemia Study Group from 1987 to 1997 do not improve at all when appropriately adjusted. The remarkable effects of all-trans-retinoic acid in APL and STI571 in chronic myeloid leukemia have shown us the direction of cancer therapy in the 21st century. We should shift the paradigm from nonspecific cytotoxic chemotherapy to therapy that specifically targets the genes or gene products that are responsible for leukemogenesis.
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PMID:How high can we increase complete remission rate in adult acute myeloid leukemia? 1118 81

Bcr/abl fusion gene, in experimental models, induces survival to growth factor deprivation and hypersensitivity to IL3. However, conflicting data were reported about chronic myeloid leukemia (CML) progenitors. We investigated the responsiveness of purified CML CFU-GM to GM-CSF/IL3 and their survival to growth factor deprivation. CFU-GM hypersensitivity to IL3 and/or GM-CSF was found in 3/11 CML cases only. CML CFU-GM survived well in stroma-free 'mass' culture (5 x 10(4) cells/ml) without cytokine addition, up to day 11, average recovery being around 95% in medium + 10% fetal bovine serum and 67-81% in serum-free medium. Conversely, normal progenitors declined steadily, particularly after extensive purification (18 +/- 10% recovery at the 7th day), and in serum-free medium (4 +/- 6% recovery). By contrast, normal and CML CFU-GM declined in a similar way in limiting dilution cultures (1-10 cells/50 microl). We also investigated the effects of retinoic acid and alpha-interferon on CFU-GM survival. Both all-trans- and 13-cis retinoic acid, particularly in combination with alpha-interferon, reduced CML CFU-GM recovery down to normal progenitors' values. In conclusion, hypersensitivity to CSFs is rare in CML, whereas resistance to growth factor deprivation has been confirmed in mass, but not in limiting, dilution cultures. Both stereoisomers of retinoic acid, at therapeutic concentrations and in combination with alpha-interferon, can overcome the survival advantage of CML progenitors.
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PMID:Growth advantage of chronic myeloid leukemia CFU-GM in vitro: survival to growth factor deprivation, possibly related to autocrine stimulation, is a more common feature than hypersensitivity to GM-CSF/IL3 and is efficiently counteracted by retinoids +- alpha-interferon. 1123 66

Over the past 20 years, there has been a marked increase in our knowledge of the molecular mechanisms of human hematological malignancies. The development of mechanism-based therapy is expected to extend the frontiers of chemotherapy. All-trans retinoic acid (ATRA) therapy for acute promyelocytic leukemia (APL), initially established as differentiation therapy, has been recognized to target PML-RAR alpha protein, an APL-specific chimeric transcriptional factor, and to modulate the function. Recently, encouraging results have emerged in the treatment of chronic myeloid leukemia with a tyrosine-kinase inhibitor. In addition to the oncoprotein-targeted therapy, the clinical effectiveness of humanized monoclonal antibodies to differentiation antigens has been recognized. Molecule-targeted therapy is reviewed herein.
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PMID:[Molecule targeted therapy for hematological malignancies]. 1124 32

Vasculitis may accompany neoplasias and be of paraneoplastic type or associated with drugs used in patient treatment. We evaluated skin biopsies of twenty-eight cases with vasculitis accompanying leukemias reviewed and clinical outcome was evaluated. Eleven of the 28 cases had paraneoplastic vasculitis and 17 had vasculitis associated with various drugs including chemotherapy, cytokines and antibacterial agents. Paraneoplastic vasculitis was seen in 3 cases with chronic myelocytic leukemia in blastic phase, 5 patients with acute myeloblastic leukemia, and 3 with myelodysplastic syndrome. Drugs responsible for the 17 cases of vasculitis included hydroxyurea, vincristine, cytosine-arabinoside, methotrexate, all-trans retinoic acid, granulocyte-colony stimulating factor, interferon and antibiotics. Paraneoplastic vasculitis is not rare in leukemias and may be a manifestation of the blastic phase of chronic myeloid leukemia. Furthermore paraneoplastic vasculitis can be fatal in myelodysplastic syndromes and may be present clinically before the specific diagnosis is made. Drugs used in routine therapy may be the cause of the vasculitis, thus skin biopsy should be performed in all cutaneous lesions in patients with hemopoietic neoplasias.
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PMID:Vasculitis and leukemia. 1142 10

The accuracy of cytogenetic diagnosis in the management of hematological malignancies has improved significantly over the past 10 years. Fluorescence in situ hybridization (FISH), a technique of molecular cytogenetics, has played a pivotal role in the detection of unique sub-microscopic chromosomal rearrangements that helped in the identification of chromosomal loci, which contain genes involved in leukemogenesis. We studied the feasibility and sensitivity of the FISH technique for molecular analysis of translocations markers, t(9;22) and t(15;17) for accurate molecular diagnosis and for monitoring the disease in 21 patients with chronic myeloid leukemia (CML) who received interferon-alpha and/or chemotherapy (7 patients), bone marrow transplantation (14 patients), and 14 patients with acute promyelocytic leukemia (APL) who received all-trans-retinoic acid (ATRA) and/or chemotherapy. We also applied conventional karyotyping (CK) for identification of t(9;22) and t(15;17) at diagnosis. All CML cases had a Ph; t(9;22) and except for two cases all APL had t(15;17). The FISH studies on CML marrows in complete cytogenetic remission (CCR) (100% Ph- by CK) achieved by IFN-alpha, showed 0-2.5% of cells with BCR-ABL fusion in first cytogenetic remission (Controls, range 0.5-1.5%). Repeat follow-up FISH studies could be done in two cases in remission, which demonstrated 0-10% of cells with BCR-ABL fusion. Evaluation of Ph positive status of CML marrow at diagnosis by CK (100% Ph+ cells) and FISH (80-92% BCR-ABL fusion) pointed the existence of dormant clone of normal residual hematopoietic cells along with actively proliferating clones of Ph positive cells. Fluorescence in situ hybridization analysis of post-BMT CML marrows in CCR (0% Ph+ mitoses) could detect MRD with range of 1-6%. Among 14 patients, 9 who showed percentage of BCR-ABL positive cells (0.0-1.5%) almost similar to normal controls, 6 patients had comparatively good prognosis (disease-free survival 7-14 months). Of five patients with residual leukemic cells in the range of 2-6%, 4 relapsed within a period of 3-24 months. Fourteen APL patients in CCR [100% t(15;17) negative cells by CK] were evaluated by FISH to check the presence of residual leukemic cells. In these patients FISH could efficiently detect 1-14.5% of residual cells with PML-RARA (patients mean MRD 5%, controls mean MRD 3.5%, P=.02). Since the time of FISH analysis, 5 to 7 patients with higher fraction of leukemic cells (5-11%) relapsed within a short period (1-7 months). On the contrary, 5 of 7 patients with either absence or low percentage of PML-RARA positive cells remained in complete remission for 11-24 months. Our data show that FISH has a potential to detect and measure the fraction of aberrant malignant cells in remission marrows, induced by BMT in CML and chemotherapy in APL. These findings encourage the investigations on a large scale to merit its potential for identification of patients at high risk. In the present studies, FISH on interphase cells also demonstrated its efficiency in the molecular diagnosis by its ability to detect BCR-ABL and PML-RARA fusion in CML with masked/variant Ph and t(15;17) negative APL, respectively. The efficiency of technique in molecular diagnosis was also proved in one of the CML patients who progressed to myeloid blastic phase where interphase FISH could identify an extra BCR-ABL fusion on both chromosomes 9 indicating insertion of BCR into ABL and its duplication.
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PMID:Fluorescence in situ hybridization: a highly efficient technique of molecular diagnosis and predication for disease course in patients with myeloid leukemias. 1175 52

Combination of STI571, a tyrosine kinase inhibitor, with other drugs may be beneficial in the treatment of chronic myeloid leukaemia (CML). We measured the effects of STI571, AG490, farnesyltransferase inhibitor (FTI), interferon alpha (IFN-alpha), cytosine arabinoside (Ara-C) and all-trans retinoic acid (ATRA), singly and in combination, on clonogenic leukaemic cell proliferation. STI571, IFN-alpha and ATRA each reduced proliferation by 50-60%; AG490, FTI and Ara-C had less effect. Comparing the observed and expected (i.e. additive) effects of drug combinations showed STI571 + FTI, STI571 + AG490 and IFN-alpha + ATRA were additive; STI571 + IFN-alpha, IFN-alpha + Ara-C and STI571 + AG490 + FTI were less than additive. Thus, STI571 + FTI, STI571 + AG490 and IFN-alpha + ATRA may be better combination therapies for CML than STI571 + IFN-alpha, IFN-alpha + Ara-C or STI571 + AG490 + FTI.
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PMID:Effects of combinations of therapeutic agents on the proliferation of progenitor cells in chronic myeloid leukaemia. 1184 11

Loss of the inhibition of apoptosis is important in leukemogenesis and may influence the prognosis. Survivin is an inhibitor of apoptosis that shows selective expression during fetal development and in human malignancies. Survivin expression was examined in human leukemias using the reverse transcriptase-polymerase chain reaction. Survivin gene expression was detected in 17 of 31 patients with acute myelocytic leukemia and 11 of 16 patients with acute lymphocytic leukemia but was not identified in normal bone marrow cells. Survivin expression was lower in patients with M3 acute myelocytic leukemia than in patients with other types of acute leukemia. Survivin was not detected in the chronic phase of chronic myelocytic leukemia but was observed in 5 of 7 patients with chronic myelocytic leukemia in blastic crisis. These findings suggest a relationship between survivin gene expression and hematopoietic cell differentiation. In fact, survivin gene expression was down-regulated during the differentiation of HL-60 cells after treatment with dimethyl sulfoxide or all-trans-retinoic acid. Moreover, the disease-free survival rates of patients with survivin expression were lower than in patients without survivin expression. Accordingly, survivin may have a role in leukemogenesis as well as in other malignancies. Detecting survivin may also provide prognostic information.
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PMID:Expression of the antiapoptosis gene survivin in human leukemia. 1193 62

Arsenic trioxide (As(2)O(3)) was recently demonstrated to be an effective inducer of apoptosis in patients with relapsed acute promyelocytic leukemia (APL) as well as in patients with APL in whom all-trans-retinoic acid and conventional chemotherapy failed. Chronic myelogenous leukemia cells are highly resistant to chemotherapeutic drugs. To determine if As(2)O(3) might be useful for the treatment of chronic myelogenous leukemia, we examined the ability of As(2)O(3) to induce apoptosis in K562 cells. In vitro cytotoxicity of As(2)O(3) was evaluated in K562 cells by a MTT assay; the IC(50) value for As(2)O(3) was determined to be 10 microM. When analyzed by agarose gel electrophoresis, the DNA fragments became evident after incubation of the cells with 20 microM As(2)O(3) for 24 h. We also found morphological changes and chromatin condensation of the cells undergoing apoptosis. Activation of caspase-3 was observed 6 h after treatment with 20 microM As(2)O(3) by a Western blot analysis. Next, we examined the MAP kinase-signaling pathway of As(2)O(3)-induced apoptosis in K562 cells. As(2)O(3) at 10 microM strongly induced the activation of p38 and JNK 1/2, while ERK 1/2 was inhibited. In addition, pretreatment of SB203580, a specific inhibitor of p38, inhibited As(2)O(3) induced apoptotic cell death. These results suggest that As(2)O(3) is able to induce the apoptotic activity in K562 cells, and its apoptotic mechanism may be associated with the activation of p38.
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PMID:Arsenic trioxide induces apoptosis in chronic myelogenous leukemia K562 cells: possible involvement of p38 MAP kinase. 1229 96


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