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

Cytogenetic analysis is considered pivotal for assessing the remission rate in CML patients on IFN therapy. On the basis of general agreement, at least 25 metaphases should be analyzed in each case. The main limitations to this approach are: 1) the small number of analyzable metaphases generally found in cytogenetic preparations from IFN-alpha-treated patients; and 2) the inability of this technique for scoring interphase cells. We compared the results of cytogenetic analysis and double-color FISH detection of bcr/abl genes fusion in 13 CML patients on IFN-alpha therapy (marrow sampling for cytogenetic and FISH analysis was carried out after 12 months in all patients and repeated after 18 months of IFN therapy in patients 4, 6, and 8). In five specimens, 20 to 25 cells were evaluable for cytogenetic examination, in another five no analyzable metaphases were scored, and in the remaining six samples two to 14 cells could be analyzed. With FISH detection at least 100 cells were easily scored in each specimen (mean number, 175). Comparing the results carried out with the two methods in different samples it emerged that cytogenetic analysis led to improper conclusions as regards the rate of Ph positivity, even in those patients where 20-25 metaphases were analyzed. Although many more cases have to be studied to establish the role of FISH analysis in Ph-positive patients, we are of the opinion that cytogenetic analysis is unfit for easily and accurately assessing the actual quality of remission in IFN-treated subjects.
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PMID:Cytogenetic analysis is non-informative for assessing the remission rate in chronic myeloid leukemia (CML) patients on interferon-alpha (IFN-alpha) therapy. 749 36

Treatment with interferon-alpha (IFN-alpha) adequately controls the leukemic cell mass in the majority of newly diagnosed patients with chronic myeloid leukemia (CML). However, the degree of response ranges from no 'hematologic' response to complete suppression of the leukemic clone. The mechanism(s) by which IFN-alpha elicits these responses is unknown, but in vitro studies have indicated that IFN-alpha might function by (1) selective toxicity against the leukemic clone, (2) enhancement of 'immune' regulation, and (3) modulation of bone marrow microenvironmental regulation of hematopoiesis. Using in vitro clonogenic assays we were unable to demonstrate that IFN-alpha selectively inhibited the proliferation of CML progenitor cells. We also found no difference in the expression of LFA-3 on normal or CML CD34+ cells. However, by panning and co-culturing hematopoietic cells on monolayers of bone marrow stromal cells, grown with and without IFN-alpha, we found that IFN-alpha enhanced the adhesion of CML progenitors to stromal cells, whereas adhesion by normal progenitor cells was essentially unaffected. This enhanced adhesion by CML progenitor cells was associated with a reduction in neuraminic acid levels in the extracellular matrix overlying stromal cells. Therefore, it is possible that one of the mechanisms by which IFN-alpha exerts its regulatory effect on the leukemic clone is through enhancement of hematopoietic cell-microenvironmental cell interactions.
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PMID:Potential mechanisms of action of interferon-alpha in CML. 750 44

Interferons (INF) are glycoproteins with protean antiviral, immunomodulator, and antiproliferative actions. In Haematology, IFN-alpha is the most widely used. Diffusion into the spleen, bone marrow and liver is good. Hairy cell leukemia is probably the malignant blood disorder which responds best to IFN. At some time during their treatment, nearly 90% of the patients require IFN. Treatment initiation is indicated when pancytopenia (polynuclear neutrophils below 1 x 10(9)/L) develops or in case of a very voluminous spleen. IFN-alpha 2a, 2b and 2c are active (leukocyte IFN is used less often, as is IFN-beta; IFN-gamma is ineffective). The standard dose is 3 x 10(6) U, three times a week for 12 weeks. Smaller doses and maintenance treatment is sometimes proposed. Haematological remission occurs in almost all cases, if not a misdiagnosis must be considered (villous lymphocyte lymphoma). Relapse usually occurs at the end of treatment, but sensitivity to IFN is not altered and final survival is improved. Nearly 90% of the patients are alive at 4 years. Although IFN is active in chronic myeloid leukemia, research in this area continues. Clinical trials have reported haematologic relapse in 90% and complete cytogenetic response in 15 to 35% of the patients. The effect on Ph+ cells is not observed with classical chemotherapies. Initial dose is generally 5 x 10(6) U/m2/day. High doses are not always well tolerated, but cytogenetic response is only seen in patients in haematologic and cytopenic remission. IFN therapy improves survival over classical treatments (median 62 versus 39 months). Survival is better after good cytogenetic response or complete remission. Combined chemo-IFN therapy is currently under study in an attempt to improve cytogenetic response. In terms of the molecular biology however, residual disease is almost always present and relapse is frequent.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Interferons. Treatment of malignant hemopathies with interferons]. 751 80

We previously reported the cloning, and characterization of a receptor tyrosine kinase, axl, from two patients with chronic myelogenous leukemia. Herein, we describe the expression pattern of axl in normal and malignant hematopoietic tissue axl message is detected in normal human bone marrow but not significantly in normal blood leukocytes. Cell separation experiments showed that axl is expressed in hematopoietic CD34+ progenitor and marrow stromal cells, at low levels in peripheral monocytes, but not in lymphocytes or granulocytes. Consistent with the normal pattern of axl expression, axl RNA was found predominantly in diseases of the myeloid lineage: 39 of 66 (59%) patients with myeloproliferative disorders (acute myeloid leukemia, chronic myeloid leukemia (CML) in chronic phase, CML in myeloid blast crisis, and myelodysplasia) showed significant axl transcription, as compared with 1 of 45 (2%) lymphoid leukemias (chronic lymphocytic leukemia, acute lymphocytic leukemia, and CML in lymphoid blast crisis). Treatment of K562 cells with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), administration of interferon alpha (IFN alpha) to normal monocytes, and treatment of U937 cells with TPA and IFN tau significantly induced axl expression, supporting a role for this kinase in the intracellular signaling of myeloid cells through a variety of biochemical pathways. These results suggest that the axl kinase may be operative in normal and malignant myeloid biology.
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PMID:Expression of axl, a transforming receptor tyrosine kinase, in normal and malignant hematopoiesis. 752 95

We have developed an in vitro assay to assess and predict the potential efficacy of in vivo interferon-alpha (IFN-alpha) treatment (5 x 10(6) units/m2 per day) for patients with chronic myelogenous leukemia (CML). Although determining the numbers and affinities of IFN-alpha receptors on CML cells has been developed as a method for predicting treatment response to IFN-alpha, it fails to predict response in CML. Previously, we and others observed that mitogens, toxins and lectins that bind to cell-surface receptors are endocytosed, escaping endosomes in order to act directly on cellular targets. Therefore, we tested the ability of low concentrations of IFN-alpha (5-10 units) to act directly on DNA polymerase (Pol) in purified chromatin nucleoprotein complexes (NPC). NPC were prepared by a methodology that uses direct treatment of leukocyte nuclei with MspI to generate six NPC-containing fractions (S1, M1, S2, M2, 0.1K and R). We found three general categories of in vitro DNA synthesis response for the six different NPC fractions isolated from the white blood cells of patients with CML (n = 19) before their treatment with IFN-alpha. IFN-alpha induced either stimulation, inhibition or had no apparent effect on Pol activity in the six different NPC fractions in a blind assay. In most of the NPC fractions isolated from the leukocytes of patients with progressive CML and in those from CML patients who failed to show a clinical response to IFN-alpha, this cytokine stimulated or had no effect on Pol activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interferon-alpha directly inhibits DNA polymerase activity in isolated chromatin nucleoprotein complexes: correlation with IFN-alpha treatment outcome in patients with chronic myelogenous leukemia. 754 66

The mechanisms by which interferon-alpha (IFN-alpha) restores normal hematopoiesis in chronic myelogenous leukemia (CML) are not well understood. We have recently demonstrated that IFN-alpha acts directly on CML hematopoietic progenitors to restore their adhesion to marrow stroma by modulating beta 1 integrin receptor function. In the present study we examined the effect of IFN-alpha treatment of marrow stroma on subsequent adhesion of CML progenitors. Stromal layers were preincubated with IFN-alpha (10,000 microns/ml) for 48 h. Subsequent coincubation with CML progenitors for 2 h resulted in significantly increased adhesion of CML progenitors. We demonstrated that alpha 4 beta 1 and alpha 5 beta 1 integrin receptors were involved in the enhanced adhesion of CML progenitors, suggesting that IFN-alpha-treated stroma can upregulate CML integrin function. This effect is due, at least in part, to IFN-alpha-induced increased stromal production of the chemokine macrophage inflammatory protein-1 alpha (MIP-1 alpha), which upregulates beta 1 integrin-dependent adhesion of CML progenitors to stroma. Thus, IFN-alpha treatment of marrow stroma restores beta 1 integrin-dependent adhesion of CML progenitors, at least in part through induction of MIP-1 alpha production. These observations provide further insights into mechanisms by which IFN-alpha may restore normal hematopoiesis in CML.
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PMID:Treatment of marrow stroma with interferon-alpha restores normal beta 1 integrin-dependent adhesion of chronic myelogenous leukemia hematopoietic progenitors. Role of MIP-1 alpha. 754 95

The influence of tetra phorbol diesther (TPA) on primary blast cells of patients with acute leukemia and blastic crises of chronic myelogenous leukemia and the influence of the condition medium (CM) of the primary and TPA-treated blast cells on the proliferation of HL-60 cell line has been studied. The level of interferon-alpha (IFN-alpha) in CM was tested. TPA inhibited proliferation and induced macrophage-like differentiation of primary AML blast cells and these changes were accompanied by modulation of IFN-alpha expression in CM. The effect of blast CM on proliferation of HL-60 was both inhibitory and stimulating and depended on the time of treatment and individual characteristics of patients. It has been shown that the level of IFN-alpha in CM was not correlated with antiproliferative effect of CM. The role of individual differences in capability of primary blast cells to be induced by differentiated agents and the nature of these differences are discussed.
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PMID:[Effect of phorbol ester on the proliferation and differentiation of blast cells from leukemia patients and blast secretion of biologically active products]. 755 32

There is increasing evidence for a relationship between specific genomic alterations and the distinctive features of leukemia, including the course and the response to treatment. In Philadelphia (Ph) positive chronic myeloid leukemia (CML) the BCR/ABL fusion genes can be transcribed in at least two different mRNAs that can either include (a2b3) or exclude (a2b2) the exon 3 of the major breakpoint cluster region in chromosome 22. We identified by polymerase chain reaction the transcript type in 146 patients with Ph+ CML who were enrolled in a prospective study of treatment with alpha-interferon (alpha-IFN) for at least 1 year, and were followed for 39 to 84 months (median 60 months). The transcript was a2b3 in 84 cases (57%) and a2b2 in 62 cases (43%). A trend in favor of a2b3 cases was observed, as to the karyotypic response after 1 year of alpha-IFN treatment (39% in the a2b3 cases vs 24% in the a2b2 cases) and 5-year survival rate, that was 71% (95% CI 59-82) in a2b3 cases vs 57% (95% CI 41-73) in a2b2 cases. However, these differences were not significant, and we conclude that the identification of the transcript type by current methodology does not predict for response to alpha-IFN and for prognosis. Further studies may be required to confirm that conclusion, or to detect a true smaller difference.
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PMID:Chronic myeloid leukemia, BCR/ABL transcript, response to alpha-interferon and survival. The Italian Cooperative Study Group on Chronic Myeloid Leukemia. 756 4

Alpha-interferon (alpha-IFN) therapy is an effective agent in early chronic phase (ECP) chronic myeloid leukemia (CML), achieving hematologic control in the majority and major cytogenetic response (MCR) (reduction in Ph' +ve metaphases to < 35%) in a substantial minority. Currently no pretreatment markers exist to ascertain likelihood of meaningful response. The site of breakpoint in M-bcr and relationship to prognosis is controversial. Studies have been hampered by variation in definition of breakpoint and difference in treatment protocols. In this study of ECP CML patients, Southern analysis and reverse transcription polymerase chain reaction (RT-PCR) were used to determine breakpoint location. Patients received alpha-IFN (9 x 10(6) units/day) and dose-adjusted hydroxyurea (HU) to maintain granulocyte count between 1.0-2.0 x 10(9)/l for 6 months or more. Twelve of 31 patients entered on the study achieved a MCR. The Sokal index did not predict for cytogenetic response to alpha-IFN. Eight of 11 patients with 5' breakpoint achieved MCR compared to only four of 20 patients with 3' breakpoint (P = 0.007). These results suggest site of M-bcr rearrangement may be predictive of response to alpha-IFN therapy. If verified by further study, this may allow more appropriate use of alpha-IFN with respect to other modalities such as allogeneic transplant.
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PMID:Cytogenetic response to alpha-interferon is predicted in early chronic phase chronic myeloid leukemia by M-bcr breakpoint location. 759 82

A patient with a chronic myeloproliferative disease associated with a 100% t(5;12) translocation was treated with 3 million U per day of IFN-alpha 2a. Besides being consistently Ph-negative, the search for BCR/ABL hybrid transcripts by means of RT-PCR was also negative. Total cytogenetic conversion to diploid hematopoiesis was obtained, but after discontinuation of IFN a 50% relapse of t(5;21) mitoses was found, and treatment was resumed. There is some degree of consensus that the mechanism by which IFN-alpha suppresses the Ph+ clone in CML consists in the restoration of normal adhesion of CML progenitors to the marrow stroma, by preventing transcription of the BCR/ABL mRNA, and hence expression of the p210 tyrosine kinase. However, if the 'faulty adhesion' hypothesis, and its correction by IFN-alpha, is to be considered correct, this case proves that it must include also Ph-negative, not BCR-ABL rearranged clonal myeloid proliferations.
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PMID:Chronic clonal myeloproliferative disease associated with a t(5;21) translocation. Complete but transient hematologic and cytogenetic remission induced by interferon-alpha. 759 88


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