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)

This paper reports clinical and cytogenetic data from 125 cases with t(9;11)(p21-22;q32) which were accepted for a European Union Concerted Action Workshop on 11q23. This chromosome abnormality is known to occur predominantly in acute myeloid leukemia (AML) FAB type M5a and less often in AML M4; in this series it was also found to occur, uncommonly, in other AML FAB types, in childhood acute lymphoblastic leukemia (ALL) (nine cases), in relatively young patients with myelodysplastic syndrome (MDS) (five cases), acute biphenotypic leukemia (two cases), and acute undifferentiated leukemia (one case). All age groups were represented but 50% of the patients were aged less than 15 years. The t(9;11) was the sole abnormality in 57 cases with AML; trisomy 8 was the most common additional abnormality (23 cases, including seven with further abnormalities), and 28 cases had other additional abnormalities. Among the t(9;11)+ve patients with AML, the white cell count (WBC) and age group were significant predictors of event-free survival; central nervous system (CNS) involvement or karyotype class (sole, with trisomy 8, or with other), also contributed to prognosis although our data could not show these to be independent factors. The best outcome was for patients aged 1-9 years, with low WBC, and with absence of CNS disease or presence of trisomy 8. For patients aged less than 15 years, the event-free survival for ALL patients was not significantly worse than that of AML patients.
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PMID:Hematological malignancies with t(9;11)(p21-22;q23)--a laboratory and clinical study of 125 cases. European 11q23 Workshop participants. 959 83

We describe a patient with acute myeloblastic leukemia (AML-M0) whose cells had a t(2;11)(p21;q23). Fluorescence in situ hybridization analysis with a probe for MLL showed that it was split, hybridizing to both the derivative 2 and 11 chromosomes. Nineteen other patients with 2p;11q translocations have been described; breakpoints in 14 of these are the same as in the case we describe. The phenotype of these patients is quite variable, with 14 patients having myelodysplastic syndrome which evolved to AML in six. Four patients had AML and two had acute lymphoblastic leukemia. MLL status has been studied in two other patients; one had MLL rearranged and one did not.
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PMID:MLL is involved in a t(2;11)(p21;q23) in a patient with acute myeloblastic leukemia. 988 82

Abnormalities of chromosome band 13q14 occur in hematologic malignancies of all lineages and at all stages of differentiation. Unlike other chromosomal translocations, which are usually specific for a given lineage, the chromosomal translocation t(12;13)(p12;q14) has been observed in both B-cell and T-cell precursor acute lymphoblastic leukemia (BCP-, TCP-ALL), in differentiated and undifferentiated acute myeloblastic leukemia (AML), and in chronic myeloid leukemia (CML) at progression to blast crisis. The nature of these translocations and their pathologic consequences remain unknown. To begin to define the gene(s) involved on chromosome 13, we have performed fluorescence in situ hybridization (FISH) using a panel of YACs from the region, on a series of 10 cases of acute leukemia with t(12;13)(p12;q14) and 1 case each with "variant" translocations including t(12;13)(q21;q14), t(10;13)(q24;q14) and t(9;13)(p21;q14). In 8/13 cases/cell lines, the 13q14 break fell within a single 1.4 Mb CEPH MegaYAC. This YAC fell immediately telomeric of the forkhead (FKHR) gene, which is disrupted in the t(2;13)(q35;q14) seen in pediatric alveolar rhabdomyosarcoma. Seven of the 8 cases with breaks in this YAC were AML. In 4/13 cases, the 13q14 break fell within a 1.7-Mb YAC located about 3 Mb telomeric of the retinoblastoma (RB1) gene: all 4 cases were ALL. One case of myelodysplastic syndrome exhibited a break within 13q12, adjacent to the BRCA2 gene. These data indicate the presence of myeloid- and lymphoid-specific breakpoint cluster regions within chromosome band 13q14 in acute leukemia.
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PMID:Myeloid- and lymphoid-specific breakpoint cluster regions in chromosome band 13q14 in acute leukemia. 1037 68

Cytogenetic studies were performed in 140 patients with myelodysplastic syndrome (MDS) at diagnosis. Chromosome 11 anomalies were found in 7 cases (5%); 2 of these patients had refractory anemia (RA), 2 had refractory anemia with excess of blasts (RAEB), 1 had RAEB in transformation (RAEB-t), and 2 had chronic myelomonocytic leukemia (CMMoL) according to the French-American-British (FAB) Cooperative Group criteria. The chromosome 11 abnormalities comprised trisomy 11 (2 patients), monosomy 11 (1 patient), del(11)(q23) (2 patients), add(11)(p15) (1 patient), and der(11) t(3;11)(p21;q23) (1 patient). Abnormalities involving band q23 of chromosome 11 occurred in 3 cases and were the most common alteration. However, specific chromosomal alterations were not associated with any FAB classification group. These findings and their implications in the biology of MDS are discussed.
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PMID:Chromosome 11 abnormalities in myelodysplastic syndromes. 1052 36

We describe a 41-year-old man with CD7-positive acute myeloid leukemia (AML-M0) with trilineage-myelodysplasia. Chromosome analysis of the bone marrow cells showed 46.XY.t(2;4;12) (p21;q12;p13). Cytological and clinical features of our case were quite similar to those of AML with t(4;12)(q11-12;p13). The karyotypic interpretation was confirmed by fluorescence in situ hybridization (FISH) by using the whole-chromosome painting probes specific for chromosomes 2, 4, and 12. FISH analysis with the use of the YAC 936e2 probe, which covers the TEL gene, did not show the split signal, suggesting that a gene other than TEL was involved in the leukemogenesis of the present case. Our case with AML with t(2;4;12)(p21;q12;p13) appears to be the first case of a variant type of AML with t(4;12) (q11-12;p13).
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PMID:A new translocation, t(2;4;12)(p21;q12;p13), in CD7-positive acute myeloid leukemia: a variant form of t(4;12). 1054 63

The aim oof this study was to investigate the immunohistochemical expression of p53, mdm2, and waf1/p21 proteins in myelodysplastic syndromes (MDS), acute myelogenous leukaemias (AML), and chronic myeloproliferative disorders (CMPD). Paraffin-sections of bone marrow biopsies from 30 cases of MDS (6 cases of RAEB and RAEB-T) 22 AML (4 cases occurring in the setting of MDS), 16 chronic myeloproliferative disorders (CMPD), and 10 cases without alterations were investigated by immunohistochemistry for p53, waf1/p21, mdm2 and Ki67 proteins. P53 was detected in immature myeloid cells in 6/30 MDS (20%) and in 6/22 AML (27%) while it was not expressed in CMPD. Of the 6 p53 positive AML, 3 occurred as evolution of MDS and 3 were de novo acute leukaemias. Waf1/p21 was detected in 5/22 (23%) AML in immature myeloid cells. Waf1/p21 was also expressed in 18/30 (60%) MDS and 10/16 (63%) CMPD in variable proportion (5-25%) of the mature myeloid cells and megakaryocytes. Waf1/p21 was not detected in immature myeloid cells in MDS and CMPD. Mdm2 protein was expressed in 3/30 (10%) MDS in the immature myeloid cells and in 1/22 AML in blastic cells. The combined immunophenotypes of immature myeloid cells of MDS were: p53+/mdm2+/waf1-: 3, p53+/mdm2-/waf1-: 3, while the immunohistochemical patterns of AML were: p53+/mdm2-/waf1-: 4, p53+/mdm2+/waf1+: 1, p53+/mdm2-/waf1+: 1, p53-/mdm2-/waf1+: 3. Ki67/MIB1 staining was found in at least 30% of immature myeloid cells in MDS and AML and in at least 20% of these cells in CMPD. In conclusion, our results indicate that p53 protein is overexpressed in the myeloid lineage in a proportion of AML and MDS, while is not detected in CMPD and normal bone marrow, p53 expression was much more frequent in AML occurring as an evolution of MDS than in de novo AML. The combined immunophenotypes of p53 positive AML and MDS suggest that p53 overexpression may be due to mutation, in some AML and MDS cases with the p53+/mdm2-/waf1- phenotype. However, it would be also possible that p53 protein accumulation is not related to p53 mutation but to inhibition of p53/mdm2 binding due to mdm2 defects and/or other events related to cell stress signals. On the other hand, waf1/p21 protein overexpression without p53 expression in some AML could be p53-independent and may represent an attempt to control the high proliferation rate which was evidenced by Ki67/MIB1 immunostaining. However, the possibility of p21 to arrest cell-cycle, in these cases of AML, seems to be overridden, suggesting that cell-cycle deregulation may be involved in a proportion of AML.
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PMID:Immunohistochemical detection of p53, mdm2, waf1/p21, and Ki67 proteins in bone marrow biopsies in myelodysplastic syndroms, acute myelogenous leukaemias and chronic myeloproliferative disorders. 1059 72

We describe a 55-year-old Japanese woman with therapy-related myelodysplastic syndrome (t-MDS) with 2 independent clones, t(1;2)(p36;p21) and t(11;12)(pl5;ql3). She was diagnosed with acute myeloid leukemia (AML) with cytological features of the bone marrow and peripheral blood. Cytogenetic evaluation revealed a 46,XX karyotype. She received chemotherapy and achieved complete remission (CR). Despite maintenance chemotherapy, she suffered a relapse. Chromosomal analysis showed t(1;2)(p36;p21) in 2 of 20 metaphases. At second CR, this clone transiently disappeared. Nine months later, t(1;2) (p36;p21) was detected again in 3 of 20 metaphases while the patient remained in CR. Six months later, bone marrow examination disclosed trilineage dysplasia without an excess of blasts, suggesting MDS. t(1;2)(p36;p21) was observed in 16 of 20 metaphases. The clinical course and serial cytogenetic findings were diagnostic of t-MDS. The duration of t-MDS was 6 years. During this period, persistent t(1;2)(p36;p21) and transient t(11;12)(p15;q13) were found. When t-MDS evolved toAML, cytogenetic evaluation revealed 46,XX,t(1;2)(p36;p21),del(7)(q22),add(19)(p13).
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PMID:Two independent clones in myelodysplastic syndrome following treatment of acute myeloid leukemia. 1193 66

Chromosome bands 1p36 and 3p21 are known to be recurring breakpoints in therapy-related (t-) leukemia. We identified a recurring translocation, t(1;3)(p36;p21), in eight patients with various hematologic malignancies: three patients with ALL, one with chronic myelogenous leukemia (CML) in accelerated phase (AP), two with MDS, and two with AML(M3). Five of the eight patients had a history of chemotherapy, including alkylating agents in three, before the translocation was detected. In two of these five patients, the t(1;3)(p36;p21) emerged only at relapse or in the accelerated phase of CML. The karyotypes of the patients were complex, including -7 and structural abnormalities of 5q, 6q, 7q, 9p, and 11q23. Survival time varied among patients (25 days to more than 16 years). Using FISH with 13 1p35-36 cosmid probes (tel-FB12-CA5-G7-FD2-CB1-ED8-FD9-G32-AE3-G50-AD8-GG4-G43-cen), we delineated the 1p36 breakpoint in two patients with MDS and ALL as lying between FB12 and FD2 (between BAC47P3 and PAC963K15), with a small deletion near the breakpoint in both cases. In the patient with MDS, there was also a deletion at 3p21.3, as detected with the cosmid probe cosNRL9. The results of the present study suggest that t(1;3)(p36;p21) in hematologic diseases is associated with prior exposure to mutagens, including alkylating agents.
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PMID:t(1;3)(p36;p21) is a recurring therapy-related translocation. 1197 52

The t(2;11)(p21;q23) is a rare recurrent aberration observed in myelodysplastic syndrome (MDS) and acute myeloblastic leukemia (AML). It has been suggested that t(2;11) is specifically associated with a deletion of the long arm of chromosome 5 (5q). A 63-year-old man was initially diagnosed as AML with del(5)(q23q32) as a sole abnormality. At relapse, t(2;11;17)(p21;q23;q11) in association with del(5q) appeared in 14 of 20 cells by G-banding. Spectral karyotyping confirmed three derivative chromosomes, der(11)t(2;11), der(17)t(11;17), and der(2)t(2;17). Fluorescence in situ hybridization analysis with a probe for MLL demonstrated that the breakpoint at 11q23 was telomeric to the MLL gene. Nine of 10 reported cases with t(2;11) and del(5q) had MDS including 5q- syndrome and four of them evolved to AML, as observed in the present case. Our results indicated that t(2;11;17) was a secondary genetic change, which appeared during disease progression after del(5q) was observed. Furthermore, considering another reported case, the MLL gene seems to be not involved in the pathogenesis of MDS/AML with t(2;11) and del(5q).
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PMID:New complex t(2;11;17)(p21;q23;q11), a variant form of t(2;11), associated with del(5)(q23q32) in myelodysplastic syndrome-derived acute myeloblastic leukemia. 1239 82

Frequent genetic alterations in hematopoietic neoplasias (chromosomal translocations, point mutations, etc.) have provided biologic targets for the development of effective novel therapies. A rapidly increasing body of knowledge provides evidence also for multiple epigenetic alterations in these disorders, which can complement or even precede genetic aberrations. Gene inactivation ('silencing') of tumor suppressor and growth inhibitory genes (e.g. the cyclin-dependent kinase inhibitors p16, p15, p21) is frequently mediated by DNA methylation of gene promoters. The acetylation state of histones (functionally linked to the DNA methylation state by the methylcytosine binding protein 2, recruiting histone deacetylases) provides a second major epigenetic silencing mechanism. Therapeutic reversal strategies are being developed for acute leukemias, myelodysplastic syndromes and malignant lymphomas. Since the discovery of the DNA methyltransferase (Dnmt) inhibitory activity of two azanucleosides (5-azacytidine, 5-aza-2'-deoxycytidine/decitabine) even at doses with minimal nonhematologic toxicity, both have been clinically studied in several myeloid neoplasias, particularly in elderly patients unable to tolerate aggressive treatment. Further development of agents counteracting aberrant methylation is directed at more targeted approaches, for example, antisense molecules against Dnmts. Histone deacetylases (HDACs) can be inhibited by numerous compounds (sodium phenylbutyrate, valproic acid, novel compounds such as depsipeptide), which have entered the clinical arena in similar indications as Dnmt inhibitors. Impressive effects of HDAC inhibition in acute promyelocytic leukemia models (PML/RARA expression) translate the finding of HDAC recruitment by this chimeric transcription factor to its target genes. The recent discovery of recruitment by PML/RARA also of Dnmt activity to the retinoic acid receptor-beta promoter makes it an interesting candidate for Dnmt inhibitors. Studies combining a 're-expressor' strategy with inhibitors of Dnmts and HDACs are underway. Thus, resensitization to biological agents such as retinoids, colony-stimulating factors and other differentiation inducers may be envisioned.
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PMID:Epigenetic targets in hematopoietic malignancies. 1452 73


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