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)

Radiation leukemia virus (RadLV)-induced preleukemic (PL) latency is characterized by the appearance of virus-infected PL cells in the thymus. The survival of these PL cells is dependent upon autostimulation with interleukin 4 (IL-4). We have intervened prophylactically in RadLV-induced preleukemia by using cyclosporin-A (CSA), which inhibits IL-4 production, and an immunotoxin (ITx) that kills PL cells. CSA efficiently inhibited IL-4 secretion from RadLV-induced PL and leukemic cells, and its administration to PL mice caused a significant delay in their death. An ITx consisting of anti-RadLV glycoprotein-70 (gp70) antibody coupled to ricin A chain efficiently inhibited protein synthesis in virus-infected cells in vitro and, when injected into PL mice, also delayed their death. Combined treatment with CSA and ITx prevented 75% of the treated PL mice from developing lymphoma. These results show that the development of malignancy from a premalignant state can be averted by a combination of therapeutic modalities that decrease the size and growth rate of the premalignant cell population.
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PMID:Treatment of premalignancy: prevention of lymphoma in radiation leukemia virus-inoculated mice by cyclosporin A and immunotoxin. 173 46

The myelodysplastic syndrome is a paradigm of human preleukaemia. Normal haemopoiesis is progressively displaced by an abnormal clone derived from a mutated stem cell. The initial mutation is unknown but its occurrence may be related to the overall load of random mutations which are a consequence of both intrinsic DNA defects and external mutagens. Evolution of the pathological population is marked by an increasing load of genetic lesions at the molecular and cytogenetic levels. Ras mutations can be detected in the blood of about 50% of MDS patients. Fms mutations are less common but these lesions can be found both in patients and in haematologically normal subjects who have previously received cytotoxic therapy suggesting that they can occur early in the preleukaemic process. Clonal haemopoiesis in the absence of either ras or fms mutations can occur in these subjects. The data suggest the inability of mutant ras or fms genes alone to produce observable preleukaemic changes but that subjects with these mutations may be predisposed to future MDS. Ras mutations are a common accompaniment of a wide variety of malignancies and experimental transfection of the mutant gene can induce a malignant phenotype in cultured cells. There are many possible mechanisms for this transformation which may be relevant in a clinical context. Experimentally observed effects include a direct influence on the cell cycle, the induction of drug resistance and the stimulation of autocrine growth factor production. It may eventually be possible to define which gene mutations are important in conferring a malignant state, which determine phenotype and which are of incidental significance.
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PMID:Gene mutations in myelodysplasia. 173 70

Epidemiological studies indicating that exposure to organic solvents is a risk factor for haematological malignancies are reviewed. Exposure to benzene is a risk factor for ANLL. A preleukaemic phase with pancytopenia is common and may be associated with a normo- or hypercellular marrow with morphological characteristics suggesting MDS. There are indications that other organic solvents than benzene may be leukaemogenic. Certain chromosome aberrations are characteristic in leukaemic cells from solvent exposed ANLL patients. The average latency time from start of occupational exposure until diagnosis is about 10-11 years. There is epidemiological evidence that exposure to organic solvents may also increase the risk of lymphoproliferative malignancies, i.e. ALL, NHL, HD and myeloma.
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PMID:Exposure to organic solvents and risk of haematological malignancies. 173 76

MDS is primarily a disease of the elderly. Cases who give a history of exposure to X-rays, cytotoxic drugs or leukaemogenic chemicals may be younger. Many cases of MDS present because of an incidental blood count. The most prominent clinical features are those of anaemia, neutropenia, thrombocytopenia. Because haemopoietic tissue is also dysfunctional the pathological effect is often greater than the figures would suggest, even leading to infection of bleeding with normal neutrophil or platelet counts. Occult abscesses are a particular feature. Despite documented abnormalities of the lymphoid system, neither infections characteristic of T-cell immunodeficiency nor autoimmunity is a problem. The proliferation of monocytes in CMML leads to organomegaly, leukaemia cutis, serous effusions and vasculitic lesions caused by the mishandling of circulating immune complexes. Cancer is no commoner than in age-matched controls, but coincident lymphoid tumours do occur. Many patients require long-term blood transfusion and will run into problems of iron overload unless precautions are taken.
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PMID:Clinical features of MDS. 173 80

The median latency of 2 degrees MDS/AL is 4 to 5 years. A high percentage of patients with 2 degrees MDS/AL convert to 2 degrees AL. Survival of either is less than 1 year. A constellation of morphologic abnormalities from all 3 cell lines produces a unique appearance. Both 2 degrees MDS and 2 degrees AL are difficult to classify by the FAB system. With the exception of the identification of karyotypic abnormalities, the biology of 2 degrees MDS/AL remains largely unexplored. Alterations of chromosomes 5 and 7 predominate, but other associated cytogenetic abnormalities are being increasingly recognized. A synthesis of data regarding 2 degrees MDS/AL resulting from the treatment of several primary malignancies generates the tentative conclusions that (a) many of the alkylating agents, and the nonclassic alkylating agent procarbazine, are leukemogens; (b) melphalan is a more potent leukemogen than cyclophosphamide. None of the other alkylating agents has been clearly established to be more or less potent than another; (c) increasing duration or amount of alkylator-based chemotherapy increases the risk of leukemogenesis; (d) low doses of radiation delivered to large volumes of bone marrow are weakly leukemogenic. High doses of radiation delivered to small volumes are not. Due to the latter, there is minimal additive risk for 2 degrees MDS/AL among studies using alkylator-based chemotherapy and radiotherapy, either concurrently or sequentially; (e) the older patient (greater than 40) is at increased risk for 2 degrees MDS/AL, at least in Hodgkin's disease. Children may be at lesser risk than adults, and younger children at lesser risk than older children; (f) the risk of 2 degrees MDS/AL peaks within the first decade after treatment for the primary malignancy. The incidence rates during the second decade are low. Identified occupational/environmental risks for 2 degrees MDS/AL include benzene, ambient and diagnostic radiation exposure, and perhaps ethylene oxide. The similarities in karyotype abnormalities among leukemic cells of those whose occupations expose them to chemical hazard, and those who are exposed to cytotoxic agents, suggest that many more environmental leukemogens have yet to be discovered. Karyotype is an important prognostic factor for both achievement of CR and for survival. Nonaggressive treatment approaches have not proven useful, although the use of hematopoietic growth factors offers promise in this area. Combination chemotherapy is justified in patients with adequate performance statuses and "favorable" karyotypes. Allogeneic bone marrow transplantation is currently the only curative approach, and can be applied without attempts to first reduce the leukemic burden.
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PMID:Leukemias and myelodysplastic syndromes secondary to drug, radiation, and environmental exposure. 173 70

Traditionally, cisplatin has not been regarded among chemotherapeutic drugs as a carcinogenic risk to humans because it is not a classical alkylating agent. A review of recently published experimental data indicates that cisplatin is mutagenic, clastogenic, capable of inducing cell transformation, able to act as an initiator in classical mouse skin initiation/promotion experiments, and carcinogenic in laboratory animals. Notably, it causes myeloid leukemia in BD IX rats. These observations demonstrate that cisplatin should be considered a potent carcinogen in experimental settings. A review of the literature identified 65 instances of subsequent cancer in patients receiving cisplatin-based chemotherapy for an initial malignancy. The majority of second cancers were acute nonlymphocytic leukemias or myelodysplasia. In only one instance was cisplatin the sole antineoplastic drug given to patients. The routine use of cisplatin in conjunction with other known or suspected human carcinogens makes it impossible to use these anecdotal reports as a basis for assessing cisplatin's carcinogenicity in humans. Two quantitative epidemiologic studies have addressed this question: One suggested that the combination of cisplatin and doxorubicin is leukemogenic in humans, while the other implicated etoposide rather than cisplatin as the leukemogen. Formal epidemiologic studies of appropriate cohorts of cisplatin-treated patients are needed to resolve the question of its carcinogenicity in humans.
J Natl Cancer Inst 1992 Mar 04
PMID:Is cisplatin a human carcinogen? 173 80

Four patients with acute leukemia displayed trisomy 13 as the primary chromosome abnormality. The two patients with acute nonlymphocytic leukemia FAB-type M1 (ANLL-M1) had the karyotypes 47,XY,+13/48,XY,+13,+13 and 47,XX,+13, a patient with the hypogranular form of ANLL M3 had 47,XX,+13, and the fourth patient, who had acute undifferentiated leukemia (AUL), had the karyotype 47,XY,+13/48,XY,+8,+13. Including these four cases, a total of 24 hematologic neoplasms with an extra chromosome 13 as the sole aberration have now been reported. Except for the AUL, all have been of myeloid origin--20 ANLL, one myelodysplastic syndrome, and two chronic myeloproliferative disorders. Trisomy 13 as the sole acquired karyotypic abnormality therefore seems to be strongly associated with myeloid differentiation of the neoplastic cells and with a differentiation block leading to acute leukemia.
Cancer Genet Cytogenet 1991 Oct 01
PMID:Trisomy 13 as a primary chromosome aberration in acute leukemia. 174 68

A case of refractory anemia with sideroblastosis and a number of bone-marrow blasts slightly over the limit which separates the I/II and III FAB-subtypes of myelodysplastic syndromes is described. The leukemic-like type of in vitro growth and the multiple karyotypic changes observed in the bone-marrow cells at presentation were both indicators of the malignant nature of the disorder and underlined the importance of these studies in assessing diagnosis and prognosis in patients with preleukemic disorders. The role that the chromosome aberrations, del(11)(q14) and del(18)(q21), both found in 100% of the bone-marrow metaphases examined, may play in the pathogenesis of the disease is also discussed.
Cancer Genet Cytogenet 1991 Oct 15
PMID:In vitro bone marrow cell culture and cytogenetic analysis in a case of myelodysplasia. 175 65

A case of trisomy 13 is presented: a 73-year-old man with acute nonlymphocytic leukemia (ANLL), FAB borderline M1/M2, and peripheral leukocyte and platelet counts that were difficult to control with chemotherapy. A literature review shows that 35 cases of trisomy 13 are known at present. They are characterized by male predominance (76%), preferentially myeloid disorders (ANLL, myelodysplastic syndromes, chronic myeloid leukemia), leucocytosis, and relatively high platelet counts and hemoglobins. It is suggested that trisomy 13 is a specific nosologic entity with male predominance and characterized by interference with proliferation and differentiation in the myeloid differentiation series.
Cancer Genet Cytogenet 1991 Nov
PMID:Trisomy 13: a preferentially male chromosome aberration interfering specifically with myeloid proliferation and differentiation? Report of a case and review of the literature. 175 88

Three patients, one with Philadelphia (Ph) chromosome positive chronic myelocytic leukemia (CML) and two with primary acquired myelodysplastic syndromes (MDS), have been identified to have a t(3;21)(q26;q22). In the patient with CML, the t(3;21) was detected only in the blast phase. The t(3;21) as the sole abnormality appeared at presentation of MDS [refractory anemia with excess blasts (RAEB)] in one patient and remained as such when progression to RAEB in transformation (RAEB-t) occurred. The other patient with MDS had the t(3;21), in addition to other changes, during the progression of the disease. Thus, t(3;21) may characterize myeloid crises of clonal hematopoietic stem cell disorders (HSCD) and indicates a poor prognosis. As a primary cytogenetic event it may be also involved in the genesis of myelodysplasia with subsequent leukemic transformation.
Cancer Genet Cytogenet 1991 Dec
PMID:Translocation (3;21) characterizes crises in myeloid stem cell disorders. 175 92


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