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)

The ras proto-oncogenes encode membrane bound proteins (p21) which are structurally distinct from the proteins encoded by the activated transforming ras genes. These activated ras genes have been identified in various human tumors as well as their preneoplastic lesions such as colorectal tumors (20-40%), pancreatic carcinomas (95%), lung carcinomas (20-30%), myelodysplasia (40%) and acute myeloid leukemia (30%). The activation of ras p21 is due to amino acid substitutions at positions 12, 13 or 61 of the p21 protein. This report describes two monoclonal antibodies designated D129 and D146 raised against a synthetic peptide corresponding to amino acids 5-16 of ras p21 activated by the substitution of aspartic acid for glycine at position 13. D129 and D146 react specifically with the peptide with the aspartic acid substitution at position 13, but not with the peptide with valine at position 13 or the peptide containing the normal glycine at position 13. Western blot analysis demonstrates that D129 and D146 react specifically with p21 extracted from transformed NIH3T3 fibroblast lines containing aspartic acid at position 13. These studies also demonstrate that D146 is able to detect the activated p21 with aspartic acid at position 13 that is shed into the culture media. Studies demonstrate that MAb D146 specifically immunoprecipitates the cellular p21 with aspartic acid at position 13 from transformed NIH3T3 cells, whereas D129 cannot immunoprecipitate the activated p21. Using a sandwich ELISA format, D146 is able to detect the p21 with position 13 aspartic acid from cell extracts and culture fluids. The ability of D146 to function in the ELISA format raises the possibility that this assay maybe a quick and effective way of determining the presence of activated p21 with aspartic acid at position 13 in human fluids and tissues.
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PMID:Characterization of monoclonal antibodies specific to the activated ras p21 with aspartic acid at position 13. 220 49

A patient with M2-ANLL and a 46,XX,del(5)(q22q33), t(2;11)(p21;q24) karyotype is described. The diagnosis was made after a short period of myelodysplastic syndrome. After chemotherapy consisting of Daunorubicin and Arabinosylcytosine in continuous infusion, the patient reached a complete remission. The chromosome pattern described here has been observed in two other patients with refractory anemia and refractory anemia with excess of blasts, respectively. The breakpoints on the chromosomes 2, 5 and 11 allow us to hypothesize the involvement of N-myc, c-fms, GM-CSF and IL-3 genes.
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PMID:5q- and t(2;11) in a patient with M2 acute non-lymphocytic leukemia. Case report. 262 43

A whole-arm translocation involving the short arm of chromosome 7 and the long arm of chromosome 1 occurs nonrandomly in myelodysplastic syndrome and acute nonlymphocytic leukemia. In situ hybridization, using alpha satellite DNA specific for the centromeric regions of chromosomes 1 (probe pSD1-1) and 7 (probe p21-4), was performed to determine the exact breakpoints of the translocation. Both probes hybridized to the centromeric region of the translocation chromosome in metaphases from two patients with myelodysplastic syndrome. Both probes hybridized with approximately equal strength to either chromosome 1 or 7 and to the 1;7 translocation chromosome, suggesting that the t(1;7) had retained the chromosome-specific alpha satellite DNA from both chromosomes. These studies permit us to propose a new description, t(1;7)(cen;cen), for this translocation.
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PMID:Determination of the breakpoints of 1;7 translocations in myelodysplastic syndrome by in situ hybridization using chromosome-specific alpha satellite DNA from human chromosomes 1 and 7. 274 17

Abnormal thrombopoiesis has been described in acute leukemias associated with inv(3) (q21q26.2) or t(3;3)(q21;q26.2). We reviewed 13 patients seen at the Mayo Clinic since 1979 with inversions of chromosome 3 or related abnormalities; 12 acquired and one constitutional. The patient with the constitutional abnormality had an inv(3)(p21q29) and mild leukocytosis and thrombocytosis. Among the 12 patients with acquired abnormalities, five had inv(3) (q21q26.2), three had t(3;3)(q21;q26.2), one had del(3)(q12q21), one had ins(6;3) (p21;q21q26.2), one had inv(3)(p21q12), and one had r(3)(p?21q?21). Each of these patients developed acute leukemia; eight had antecedent myelodysplastic syndrome, eight presented with platelet counts greater than 100 x 10(3)/microliters, and six had atypical megakaryocytic hyperplasia. Five patients had ringed sideroblasts in their marrow, an antecedent refractory anemia with ringed sideroblasts, or erythroleukemia. Seven patients received chemotherapy but showed no response. From the time of chromosome study, the median duration of survival was 4 months. Our results suggest that 1) although abnormal megakaryocytopoiesis is observed in patients with inv(3)(q21q26.2), multiple hematopoietic lineages are also involved in the neoplastic process; 2) an antecedent myelodysplastic syndrome is common in acute leukemia with inv(3) or related abnormalities; 3) affected patients have a poor survival and are resistant to conventional chemotherapy; and 4) abnormal megakaryocytopoiesis in acute leukemia may also be associated with pericentric inversions of chromosome 3.
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PMID:Acute leukemia with abnormal thrombopoiesis and inversions of chromosome 3. 275 70

A rearrangement of the short arm of chromosome #12 with a breakpoint at band 12 was found in 4 out of 15 patients with CMML: two deletions, one simple translocation (9;12)(p21;p12) and one complex t(11;12;13)(p11;p12;q21). Their haematological and clinical characteristics were investigated together with those of 5 other similar published cases. Although this alteration is not very frequent in this myelodysplastic syndrome, and is also found in various other malignant blood disorders, it is clearly a non-random phenomenon, the consequences of which are discussed.
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PMID:[Rearrangement of the short arm of chromosome 12 in chronic myelomonocytic leukemias]. 347 41

Three patients with dysmyelopoietic preleukemia had a marrow clone with translocation t(2;11)(p21;q23) as the only chromosome change. In one patient, the cytogenetically altered cells disappeared following treatment with 13-cis-retinoic acid. Although these patients did not constitute a homogeneous clinical subgroup, the 2p;11q translocation should probably be added to the short list of nonrandom karyotypic alterations involving 11q23 that have been described in various hematopoietic disorders.
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PMID:A 2p;11q chromosome translocation in dysmyelopoietic preleukemia. 396 13

FLT4 is a recently cloned receptor tyrosine kinase cDNA, which is characterized by seven immunoglobulin-like loops in its extracellular domain. We have previously mapped the FLT4 gene to chromosome segment 5q33-qter using somatic cell hybrids. Here we have refined the localization to band 5q35 by fluorescence in situ hybridization and show that the gene is translocated to chromosomes 2 and 6 in the t(2;5)(p23;q35) and t(5;6)(q35;p21) translocations, respectively, of Ki-I-positive lymphomas, as well as to chromosome 3 in the t(3;5)(q25.1;q34) translocation, which is occasionally found in myelodysplastic syndromes and acute myeloid leukemia. No evidence was obtained for a rearrangement or deregulation of the translocated FLT4 gene. We further show that abundant FLT4 mRNA expression occurs only in erythroid and megakaryoblastoid cell lines among nine leukemia cell lines studied.
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PMID:FLT4 receptor tyrosine kinase gene mapping to chromosome band 5q35 in relation to the t(2;5), t(5;6), and t(3;5) translocations. 768 67

Mutation of the ras oncogenes is the most commonly detected molecular abnormality in acute myelogenous leukemia and myelodysplastic syndromes (MDS). This molecular event may either be acquired by different subclones or by all malignant cells. The availability of the ras p21 monoclonal antibody Y13 259 makes possible the direct study of the distribution of the ras gene product in human malignant cells. The bone marrow smears from 41 patients with MDS were analysed by two independent observers after treatment with MoAb Y13 259, biotinylated goat antirat IgG, streptavidin, peroxidase and staining with diaminobenzidine. A high proportion of strongly positive smears was found among patients with MDS. This positivity was found in 25% of refractory anemia, in 80% of the refractory anemias with excess of blasts, and in 90% of those in transformation, while all 7 cases with chronic myelomonocytic leukemia were found positive. The percentage of positivity may suggest that activation of ras oncogene in associated with disease progression.
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PMID:Analysis of immunohistochemical results of the ras oncogene product p21 in myelodysplastic syndromes. 835 32

The active form of vitamin D3 [1 alpha, 25-dihydroxyvitamin-D3 (1 alpha, 25(OH)2D3)] modulates the proliferation and differentiation of hematopoietic cells. Analogs of 1 alpha, 25(OH)2D3 that have greater potency may have the potential as adjuvant therapy for high-risk patients in remission for acute myelogenous leukemia (AML) and myelodysplastic syndromes. A new generation of 11 analogs of 1 alpha, 25(OH)2D3 has been synthesized, and we examined their effects on the human leukemic cell line HL-60. This cell line provides a sensitive monitor of activity of the 1 alpha, 25(OH)2D3 analogs. All the compounds were potent, producing a 50% clonal inhibition (ED50) in the range of 10(-8) to 10(-11) mol/L; nine of the 11 analogs had ED50s at concentrations that were at least 10-fold lower than those for the parental 1,25(OH)2D3. The most active compound [cmpd LA, (22R)-1 alpha, 25-(OH)2-16,22,23-triene-D3] had an ED50 of 2 x 10(-11) mol/L; it was also tested on clonogenic cells from patients with AML, and it achieved an ED50 of approximately 6 x 10(-11) mol/L, while 1 alpha, 25(OH)2D3 produced an ED50 of approximately 10(-8) mol/L on the same population of cells. Five different cell surface markers were examined on HL-60 cells exposed to the 1 alpha, 25(OH)2D3 analogs: HLA-DR and CD11b were induced by all of the compounds; CD13 was induced by six of the 12 compounds, including 1,25(OH)2D3; CD14 was strongly induced by all compounds; and CD38 was induced rather weakly by nine of 12 analogs. WAF1/CIP1/p21, a cyclin-dependent kinase inhibitor (CDKI), which is important in blocking the cell cycle, was examined by Western blot and was found to be induced by all of the compounds, suggesting a possible mechanism by which these analogs inhibit leukemic growth. The induction of WAF1 occurred at concentrations of vitamin D analogs as low as 10(-10) mol/L. This structure-function study showed that a new series of 1 alpha, 25(OH)2D3 analogs was active in clonal inhibition, as well as induction of differentiation and WAF1 expression of HL-60 cells. The key structural motifs included C-16 double bond, double and/or triple bonds in the side chain, lengthening of the side chain, 20-epi-conformation of the side chain, replacement of six hydrogens at the end of the side chain with fluorines, and the removal of C-19. Consideration should be given to further in vivo testing of toxicity and efficacy to move toward a clinical trial, especially in a setting of minimal residual disease.
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PMID:A new series of vitamin D analogs is highly active for clonal inhibition, differentiation, and induction of WAF1 in myeloid leukemia. 882 40

In this study we report 11 cases with chromosome abnormalities involving 3p21. Nine cases were diagnosed as myelodysplastic syndrome (MDS), and two as acute myeloid leukemia (AML). Six of nine MDS cases were secondary to a primary malignant disease. In two patients, AML was secondary to breast cancer and polycythemia vera (PV). Seven of eleven patients had a history of intensive polychemotherapy and/or radiation therapy for 3.5 to 5 years. The mean interval from initial therapy to secondary disease was 13.2 years. Complex chromosomal aberrations were found in all 11 cases. Band 3p21 was involved in translocations in 9 patients and in deletions in 2 patients. A t(3;16)(p21;p13) was found in two cases. Additional abnormalities frequently included a -5, -7, as well as deletions or rearrangements of these 2 chromosomes. Data reported in this paper suggest that 3p21 is a recurrent treatment-related breakpoint in MDS and AML and is likely to contain a gene involved in the pathogenesis of this disease.
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PMID:3p21 is a recurrent treatment-related breakpoint in myelodysplastic syndrome and acute myeloid leukemia. 897 89


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