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)

Seventy cases of chronic myelogenous leukemia (CML) were analyzed for the presence of ras mutations using polymerase chain reaction (PCR), oligonucleotide hybridization, and direct PCR sequencing. All cases had preceding cytogenetic and bcr rearrangement studies. Aberrant ras genes were detected in none of 39 patients with Philadelphia (Ph) chromosome or bcr/abl rearrangement positive chronic-phase CML and in only 1 of 18 patients in blast crisis, suggesting that ras mutations have little or no role in initiation or progression of common CML. Seven of 13, or 54% of patients with bcr/abl rearrangement negative chronic phase CML (atypical CML) harbored mutations in ras, however. This high incidence of ras mutations, together with the absence of bcr/abl rearrangement, provides evidence that atypical CML is an entity that is molecularly distinct from common CML. Moreover, the clinical characteristics and the high frequency of ras mutations suggest that atypical CML may constitute a subset of the myelodysplastic syndrome and may be best classified as a variant of chronic myelomonocytic leukemia (CMML).
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PMID:Mutations of the ras protooncogenes in chronic myelogenous leukemia: a high frequency of ras mutations in bcr/abl rearrangement-negative chronic myelogenous leukemia. 268 96

We describe a patient with acute nonlymphocytic leukaemia (ANLL) derived from myelodysplastic syndrome in whom the Philadelphia chromosome (Ph1) first emerged at the late stage of ANLL transformation. Cytogenetically, the Ph1 chromosome was not detected until the late stage of ANLL transformation, 14 months after the transformation following a 3-month history of refractory anaemia with excess of blasts. The cells with and without the Ph1 chromosome had a common abnormal chromosome, t(3;3) (q21;q26). The reverse transcription-polymerase chain reaction analysis showed no bcr/abl message at diagnosis. However, the mRNA encoding P210bcr/abl was detected in the early stage of ANLL transformation. Furthermore, the mRNAs encoding both P210bcr/abl and P190bcr/abl were detected in the late stage of ANLL transformation when the Ph1 chromosome was detected by cytogenetic analysis. These evidences support a multistep pathogenesis of leukaemias, and the products of bcr/abl fusion gene may influence the course of disease.
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PMID:Late-appearing Philadelphia chromosome in a patient with acute nonlymphocytic leukaemia derived from myelodysplastic syndrome: detection of P210- and P190-type bcr/abl fusion gene transcripts at the leukaemic stage. 752 18

Deregulated expression of v-abl and BCR/abl genes has been associated with myeloproliferative syndromes and myelodysplasia, both of which can progress to acute leukemia. These studies identify the localization of the oncogenic form of the abl gene product encoded by the Abelson murine leukemia virus in the nuclei of myeloid cells and the association of the v-Abl protein with the transcriptional regulator cyclic AMP response element-binding protein (CREB). We have mapped the specific domains within each of the proteins responsible for this interaction. We have shown that complex formation is a prerequisite for transcriptional potentiation of CREB. Transient overexpression of the homologous cellular protein c-Abl also results in the activation of promoters containing an intact CRE. These observations identify a novel function for v-Abl, that of a transcriptional activator that physically interacts with a transcription factor.
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PMID:Nuclear localization of v-Abl leads to complex formation with cyclic AMP response element (CRE)-binding protein and transactivation through CRE motifs. 756 61

The immune reactivity of allogeneic lymphocytes plays a major role in the control of leukemia after bone marrow transplantation. In patients with recurrent leukemia after marrow transplantation, chimerism and tolerance provide ideal conditions for adoptive immunotherapy with donor lymphocytes. We studied the effect of donor lymphocyte transfusions on acute and chronic leukemia in relapse after bone marrow transplantation. One hundred thirty-five patients with chronic myeloid leukemia (CML) (N = 84), acute myeloid leukemia (AML) (N = 23), acute lymphoblastic leukemia (ALL) (N = 22), myelodysplastic syndrome (MDS) (N = 5), and polycythemia vera with osteomyelofibrosis (PCV) (N = 1) were treated with transfusions of donor lymphocytes. Patients were monitored for response of leukemia, including in CML, the use of the polymerase chain reaction for bcr/abl mRNA transcripts and for the occurrence of graft-versus-host disease (GVHD) and myelosuppression. Complete remissions were induced by donor lymphocyte transfusions in 54 patients with CML (73%) and in the patient with PCV; complete remissions were also induced in five patients (29%) with AML and a patient with MDS. In contrast, ALL did not respond to adoptive immunotherapy with donor lymphocyte transfusions. Remissions were durable in patients treated for CML in chronic phase (probability of remission: 87% at 3 years). Lymphocyte transfusions were also given to 18 patients with ALL, AML, MDS, and transformed phase CML who were in remission after chemotherapy. These remissions were not durable. Fifty-two patients (41%) developed GVHD of grade 2 or more, and 41 patients (34%) showed signs of myelosuppression. Seventeen patients died without leukemia, 14 patients with GVHD and/or myelosuppression. Donor lymphocyte transfusions exert strong effects against myeloid forms of leukemia and induce durable remissions in CML.
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PMID:Graft-versus-leukemia effect of donor lymphocyte transfusions in marrow grafted patients. 861 35

A 78 year old female was found to have pancytopenia in February 1991. Bone marrow was normocellular with 11.7% blasts and showed dysmegakaryopoietic changes. A diagnosis of MDS (RAEB) was made and she was treated with transfusions and ubenimex. Leukemic transformation was noted in July. On Admission in October 1991, her laboratory examinations revealed the following: WBC 38,900/microliters with 93% blast, Hb 8.0 g/dl, Plt 2.1 x 10(4)/microliters, a hypercellular bone marrow with 74% blasts which were negative for myeloperoxidase (MPO) by light microscopy, but were positive by electron microscopy. Surface marker for CD13 was positive. These findings corresponded to M0 of the FAB subtype. Chromosome analysis revealed Ph1 chromosome with 46XX, t (9;22) (q34;q11) in 3 of 3 cells examined, Southern analysis showed the rearrangement of the break point cluster region (bcr). Reverse transcriptase polymerase chain reaction technique demonstrated the presence of major bcr/abl mRNA. She was treated with transfusions and methyl-prednisolone. Her blast counts declined and Ph1 chromosome was only positive in 1 of 12 metaphases examined. She died of pneumonia in December 1991. Eleven cases with MDS showing Ph1 chromosome have previously been reported. The observations indicate that Ph1 chromosome positive acute leukemias were heterogenous in nature.
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PMID:[RAEB transformed into AML (M0) showing Ph1 chromosome and rearrangement of major cluster region]. 825 8

We report two patients with acute leukemias who expressed two types of bcr/abl mRNA. The first case was an 8-year-old boy with acute mixed leukemia in whom the Ph1 chromosome and p210/p190 types of bcr/abl mRNAs were detected at diagnosis. The second case was a 39-year-old male with acute nonlymphocytic leukemia transformed from myelodysplastic syndrome (refractory anemia with excess of blasts). In the latter case, the p210-type mRNA appeared after leukemic transformation, and the p190-type transcript was detected only during the late stage when the Ph1 chromosome was first observed. The leukemias in these two patients were aggressive in their clinical courses. We conclude that the dual expression of p210 and p190 types of bcr/abl is a factor indicating a poor prognosis, and that, in some patients, p190-type bcr/abl may contribute to disease progression.
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PMID:Acute leukemias expressing p210-and p 190-type bcr/abl mRNAs: report of two cases and review of the literature. 870 9

This report suggests modest changes in the criteria used for the diagnosis of ET and allows tentative recommendations concerning therapy. As outlined in Table I, we believe that absent stainable marrow iron does not necessarily indicate iron deficiency in these patients and that the serum ferritin and RBC mean corpuscular volume should be incorporated in this assessment. Normal values speak strongly against iron-deficient erythropoiesis. A search for the bcr/abl gene rearrangement should be included with the marrow karyotype to exclude CML. Finally, cytogenetic data and morphologic study of the marrow should be used to be certain that a MDS should not be considered. It may be that measurements of serum thrombopoietin levels may be useful in the future. Nonetheless, in principle, ET remains a diagnosis of exclusion as we have originally suggested. For therapy, HU remains an excellent choice for the older patient at risk for thrombosis. Nonetheless, no myelosuppressive therapy remains a perfectly viable option, particularly for the young patient and the older with low thrombotic risk. The roles of anagrelide and alpha interferon in this setting have not been fully defined. Experience with both has still been relatively short. It would be ideal if prospective, randomized trials could be mounted to address these questions. We conclude with confidence that return to older approaches such as 32P and AA in patients who fail on HU is to be discouraged. The use of anagrelide or interferon alfa seems to be a much more appropriate approach. We have not investigated the role of antithrombotic agents such as aspirin in ET. In PV, the combination of aspirin, 300 mg three times daily, and dipyridamole, 75 mg three times daily, failed to reduce the rate of thrombosis and was associated with an increased rate of hemorrhage. It is rational to suggest that lower doses of aspirin (ie, < 325 mg daily) might be associated with less hemorrhage and, perhaps, a beneficial effect on thrombosis. This remains to be shown.
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PMID:Experience of the Polycythemia Vera Study Group with essential thrombocythemia: a final report on diagnostic criteria, survival, and leukemic transition by treatment. 902 60

A 66-year-old man was given a peripheral blood test because of low grade fever. Leukocytosis was detected, and the blood and bone marrow findings were consistent with those of chronic myelomonocytic leukemia. Three months later the hematological findings were: WBC 58,800/microliter (19% blastoid cells, 22% monocytes), Hb 9.0 g/dl, and a platelet count of 116 x 10(4)/microliters. A bone marrow examination revealed the presence of 52.6% blastoid cells and dysmegakaryocytopoiesis, including micromegakaryocytes. Serum and urinary lysozyme levels were elevated. Karyotypic analysis detected t(1; 3) (p36;q21), but not major bcr/abl mRNA. The patient was given a diagnosis of acute transformation of chronic myelomonocytic leukemia. Despite treatment, he died about 3 months later. t(1;3) is occasionally observed in cases of myelodysplastic syndrome (MDS) and leukemia. Patients with t(1;3) often exhibit dysmegakaryocytopoiesis; furthermore, acute leukemia develops more readily in those who also have MDS. Cases of long-term survival are rare.
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PMID:[Acute transformation of chronic myelomonocytic leukemia with t(1;3) (p36;q21) abnormality]. 975 Apr 60

The c-kit proto-oncogene encodes a 145 kd tyrosine kinase transmembrane receptor, which plays a key role in haemopoiesis. The c-kit has been classified as CD117 and is especially useful in the differential diagnosis of acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL). We analysed 104 consecutive cases (55 AML, 23 B-cell lineage ALL, three T-cell ALL, 11 blast crisis of chronic myeloproliferative disorders and 12 cases of myelodysplastic syndromes with more than 10% of blasts) referred to our Hospital for immunophenotypic diagnosis and compared the expression pattern of CD13, CD33 and CD117 using the same fluorochrome (phycoerythrin-PE). The recommendations of the EGIL group were followed in order to establish lineage involvement of the blastic population. The threshold used to assign positivity for CD117 was 10%. Bcr/abl, TEL/AML-1 and MLL rearrangements were assessed by molecular methods. CD117 expression was detected in 91% of AML and MDS. All the negative cases corresponded to acute monocytic leukemias. The calculated specificity for myeloid involvement was 0.86 for CD117, 0.36 for CD13 and 0.44 for CD33 (P < 0.005). CD117 was also positive in four cases of ALL. None of these cases showed bcr/abl or MLL rearrangements. In the light of these findings, CD117 expression should yield a higher score, at least one point, in the system currently applied for the diagnosis of biphenotypic acute leukemias (BAL) as its myeloid specificity is greater than that of CD13 and CD33. Moreover, its absence in AML could identify two subgroups of M5b cases. The coexpression of CD117 with cytoplasmic CD79a is often associated with CD7 reactivity, suggesting a stem cell disorder. CD117 should be included on a routine basis for the immunophenotypic diagnosis of acute leukemias.
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PMID:Enhanced myeloid specificity of CD117 compared with CD13 and CD33. 1022 19

Janus kinase 2 (JAK2) is a cytoplasmic protein-tyrosine kinase that catalyzes the transfer of the gamma-phosphate group of adenosine triphosphate to the hydroxyl groups of specific tyrosine residues in signal transduction molecules. JAK2 mediates signaling downstream of cytokine receptors after ligand-induced autophosphorylation of both receptor and enzyme. The main downstream effectors of JAK2 are a family of transcription factors known as signal transducers and activators of transcription (STAT) proteins. The myeloproliferative disorders (MPD), a subgroup of myeloid malignancies, are clonal stem cell diseases characterized by an expansion of morphologically mature granulocyte, erythroid, megakaryocyte, or monocyte lineage cells. Among the traditionally classified MPD, the disease-causing mutation has been delineated, thus far, for only chronic myeloid leukemia (ie, bcr/abl). In the past 3 months, 7 different studies have Independently described a close association between an activating JAK2 mutation (JAK2V617F) and the classic bcr/abi-negative MPD (ie, polycythemia vera, essential thrombocythemia, myelofibrosis with myeloid metaplasia) as well as the less frequent occurrence of the same mutation in both atypical MPD and the myelodysplastic syndrome. The particular finding is consistent with previous observations that have implicated the JAK/STAT signal transduction pathway in the pathogenesis of bcr/abl-negative MPD, Including the phenotype of growth factor independence and/or hypersensitivity. The current article summarizes this new information and discusses its implications for both classification and diagnosis of MPD.
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PMID:The JAK2V617F tyrosine kinase mutation in myeloproliferative disorders: status report and immediate implications for disease classification and diagnosis. 1600 2


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