Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 3-year-old patient presented with anemia, thrombocytopenia, and blasts in the peripheral blood. A bone marrow aspirate revealed a myelodysplastic syndrome (MDS). A mosaic abnormal female karyotype 46,XX, t(1;19)(q42; p13.1)c[12]/ 47,idem,+21c[3]/ 47,idem,-7,+21c,+mar[7] was obtained on G-banded metaphases from unstimulated bone marrow aspirate cell culture. To rule out constitutional abnormalities, we performed a cytogenetic analysis on the patient's phytohemagglutinin-stimulated peripheral blood and cultured skin fibroblasts. A karyotype of 46,XX,t(1;19) (q42;p13.1)c was found in all 20 peripheral lymphocytes analyzed, confirming the constitutional origin of the translocation. In addition, 5 out of 50 cells from two separate cultures of the skin fibroblasts contained an extra chromosome 21. The presence of two cell lines in multiple cultures indicates that the patient is a true low-level mosaic for trisomy 21. Because of the finding of monosomy 7 and a marker chromosome only in the trisomy 21 clone, we conclude that the leukemic clone arose from a hematopoietic precursor with constitutional trisomy 21. It is also possible that the t(1;19) played some role in the development of the MDS. Because acute myelogenous leukemia (AML) and MDS with Down syndrome (DS) have distinct biologic and clinical features, the identification of DS patients with a mild or normal phenotype in the AML/MDS population is of fundamental importance for clinical diagnosis and management.
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PMID:A case of myelodysplastic syndrome with acquired monosomy 7 in a child with a constitutional t(1;19) and a mosaicism for trisomy 21. 1558 58

A large number of observations have hinted at the fact that location impinges on function of some of the main players of nuclear inositol lipid cycle. PLC beta1 is a well-known example, given that it has been shown that only the enzyme located in the nucleus targets the cyclin D3/cdk4 complex, playing, in turn, a key role in the control of normal progression through the G1 phase of the cell cycle. The PLC beta1 gene, which is constituted of 36 small exons and large introns, maps on the short arm of human chromosome 20 (20pl2, nearby markers D20S917 and D20S177) with the specific probe (PAC clone HS881E24) spanning from exon 19 to 32 of the gene itself. The chromosome band 20pl2 has been shown to be rearranged in human diseases such as solid tumors without a more accurate definition of the alteration, maybe because of the absence of candidate genes or specific probes. Moreover, non-specific alterations in chromosome 20 have been found in patients affected by MDS and acute myeloid leukemia AML. MDS is an adult hematological disease that evolves into AML in about 30% of the cases. The availability of a highly specific probe gave an opportunity to perform in patients affected with MDS/AML, associated with normal karyotype, painting and FISH analysis aimed to check the PLC beta1 gene, given that this signaling molecule is a key player in the control of some checkpoints of the normal progression through the cell cycle. FISH analysis disclosed in a small group of MDS/AML patients with normal karyotype the monoallelic deletion of the PLC beta1 gene. In contrast, PLC beta4, another gene coding for a signaling molecule, located on 20pl2.3 at a distance as far as less than 1 Mb from PLC beta1, is unaffected in MDS patients with the deletion of PLC beta1 gene, hinting at an interstitial deletion. The MDS patients, bearing the deletion, rapidly evolved to AML, whilst the normal karyotype MDS patients, showing non-deletion of PLC beta1 gene, are still alive at least 24 months after the diagnosis. The immunocytochemical analysis using an anti PLC beta1 monoclonal antibody showed that all the AML/MDS patients who were normal at FISH analysis also had normal staining of the nucleus, which is a preferential site for PLC beta1. In contrast, the monoallelic deletion gave rise to a dramatic decrease of the nuclear staining suggesting a decreased expression of the nuclear PLC beta1. The reported data strengthen the contention of a key role played by PLC beta1 in the nucleus, suggest a possible involvement of PLC beta1 in the progression of MDS to AML and pave the way for a larger investigation aimed at identifying a possible high risk group among MDS patients with a normal karyotype.
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PMID:Nuclear phospholipase C beta1, regulation of the cell cycle and progression of acute myeloid leukemia. 1602 64

Therapy-related leukemia or myelodysplasia (t-leuk/MDS) is a serious problem that is increasing in frequency. We studied the clinical characteristics of 96 patients (pts) with a mean age of 48 years, and analyzed the molecular parameters that could predispose to t-leuk/MDS. Hematological malignancies were the most common primary (53%), followed by breast and ovarian cancer (30% combined). The mean latency until the development of t-AML was 45.5 months. Median survival was 10 months. Cytogenetics was abnormal in 89% of pts. FLT3 internal tandem duplications were found in six of 41 (14.6%) pts, of whom four had an abnormal karyotype. Analysis of drug metabolism and disposition genes showed a protective effect of the CYP3A4 1*B genotype against the development of t-leuk/MDS, whereas the CC genotype of MDR1 C3435T and the NAD(P)H:quinone oxidoreductase1 codon 187 polymorphism were both noncontributory. Microsatellite instability (MSI) analysis using fluoresceinated PCR with ABI sequence analyzer demonstrated that 41% of pts had high levels of MSI in four or more of 10 microsatellite loci. Immunohistochemistry demonstrated reduced expression of MSH2 and MLH1 in 6/10 pts with MSI as compared to 0/5 of pts without MSI. In conclusion, genetic predisposition as well as epigenetic events contribute to the etiology of t-AML/MDS.
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PMID:Therapy-related leukemia: clinical characteristics and analysis of new molecular risk factors in 96 adult patients. 1616 58

Double minutes (dmin)-circular, extra-chromosomal amplifications of specific acentric DNA fragments-are relatively frequent in malignant disorders, particularly in solid tumors. In acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), dmin are observed in approximately 1% of the cases. Most of them consist of an amplified segment from chromosome band 8q24, always including the MYC gene. Besides this information, little is known about their internal structure. We have characterized in detail the genomic organization of 32 AML and two MDS cases with MYC-containing dmin. The minimally amplified region was shown to be 4.26 Mb in size, harboring five known genes, with the proximal and the distal amplicon breakpoints clustering in two regions of approximately 500 and 600 kb, respectively. Interestingly, in 23 (68%) of the studied cases, the amplified region was deleted in one of the chromosome 8 homologs at 8q24, suggesting excision of a DNA segment from the original chromosomal location according to the 'episome model'. In one case, sequencing of both the dmin and del(8q) junctions was achieved and provided definitive evidence in favor of the episome model for the formation of dmin. Expression status of the TRIB1 and MYC genes, encompassed by the minimally amplified region, was assessed by northern blot analysis. The TRIB1 gene was found over-expressed in only a subset of the AML/MDS cases, whereas MYC, contrary to expectations, was always silent. The present study, therefore, strongly suggests that MYC is not the target gene of the 8q24 amplifications.
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PMID:MYC-containing double minutes in hematologic malignancies: evidence in favor of the episome model and exclusion of MYC as the target gene. 1645 26

Although trisomy 8 as the sole chromosome aberration is the most common numerical abnormality in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), little is known about its pathogenetic effects. Considering that +8 is a frequent secondary change in AML/MDS, cryptic--possibly primary--genetic aberrations may occur in cases with trisomy 8 as the apparently single anomaly. However, no such hidden anomalies have been reported. We performed a high-resolution genome-wide array-based comparative genome hybridization (array CGH) analysis of 10 AML/MDS cases with isolated +8, utilizing a 32K bacterial artificial chromosome array set, providing >98% coverage of the genome with a resolution of 100 kb. Array CGH revealed intrachromosomal imbalances, not corresponding to known genomic copy number polymorphisms, in 4/10 cases, comprising nine duplications and hemizygous deletions ranging in size from 0.5 to 2.2 Mb. A 1.8 Mb deletion at 7p14.1, which had occurred prior to the +8, was identified in MDS transforming to AML. Furthermore, a deletion including ETV6 was present in one case. The remaining seven imbalances involved more than 40 genes. The present results show that cryptic genetic abnormalities are frequent in trisomy 8-positive AML/MDS cases and that +8 as the sole cytogenetic aberration is not always the primary genetic event.
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PMID:High-resolution genome-wide array-based comparative genome hybridization reveals cryptic chromosome changes in AML and MDS cases with trisomy 8 as the sole cytogenetic aberration. 1649 92

Chromosome arm 11q amplifications involving the mixed lineage leukemia gene (MLL) locus are rare but recurrent aberrations in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We have recently shown that in addition to the MLL core amplicon, independent sequences in 11q23-24 and/or 11q13.5 are coamplified within the same cytogenetic markers in 90% and 60% of patients, respectively. Here we further narrow down the minimal amplicon in 11q13.5 to 1.17 Mb by means of semi-quantitative PCR and FISH analyses. The newly defined amplicon contains seven genes, including the GRB2-associated binding protein 2 (GAB2). Using real-time RT-PCR we show a significant transcriptional upregulation of GAB2 in the patients who have GAB2 coamplified with MLL. Thus, the adaptor molecule GAB2 that has already been shown to enhance oncogenic signaling in other neoplasias appears as a novel target of 11q amplification in AML/MDS.
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PMID:GAB2 is a novel target of 11q amplification in AML/MDS. 1673 98

High-dose steroids are the first line of treatment for acute graft-versus-host disease (aGVHD). Steroid myopathy is a debilitating steroid-induced complication that significantly impairs a patient's performance status. To determine the frequency and severity of steroid myopathy and other steroid related complications in patients with acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) who developed grade >or=2 aGVHD after allogeneic hematopoietic stem cell transplantation (HSCT), we performed a retrospective analysis. Patients were included in the analysis if they had a diagnosis of AML/MDS, underwent an allogeneic HSCT between January 1996 and December 2001 and developed grade >or=2 aGVHD that was treated with 2 mg/kg of methylprednisolone and survived at least 100 days post transplant. A total of 70 patients fulfilled our inclusion criteria. Steroid myopathy was identified in 29 (41%) patients. Steroid myopathy was generally of moderate severity with severe debilitating steroid myopathy seen in only 3% of patients. We concluded that steroid myopathy is a common complication of high-dose steroid therapy after allogeneic HSCT in AML/MDS. Interventions aimed at preventing and treating this complication are warranted and need to be explored in prospective clinical trials.
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PMID:Steroid myopathy in patients with acute graft-versus-host disease treated with high-dose steroid therapy. 1681 37

Aplastic anemia (AA) is a rare hematopoietic stem cell disease, which can be treated with horse antilymphocyte globulin (ALG) for patients not eligible for bone marrow transplantation. ALG gives about 60% overall survival rate (OS) after 5 years, a 30% of persistent complete remission and a 20% early death rate related to failure. ALG has been incriminated in the emergence of 10 to 20% therapy-related AML/MDS (t-AML/MDS) with the usual doses. Questions remain whether higher doses of ALG could improve the response and OS rates and whether the combination with androgens is able to protect patients from t-AML/MDS. We have carried out a single institutional retrospective study of 87 AA treated with higher doses of ALG, twice the usual posology (140 mg/kg instead of 75 mg/kg), combined to androgens. The overall response rate was 77% and the OS rate at 5 years was 78%. Androgens in combination with ALG improved response and OS rates. At diagnosis, 6% of AA had an abnormal karyotype using conventional cytogenetic not related to any time-to-event. Two patients displayed a cytogenetic conversion related to the occurrence of secondary malignancies. The incidence of t-AML/MDS was 2.3% with an estimated 10-year cumulative incidence of 3.1. Our results show that higher doses of ALG combined to androgens are feasible and give results close to those recently describe with the immunosuppressive treatments including ALG associated to cyclosporine, with a low SMD/AML incidence rate.
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PMID:Long-term outcome in acquired aplastic anemia treated with an intensified dose schedule of horse antilymphocyte globulin in combination with androgens. 1683 Jan 41

The influence of Exisulind on the viability and apoptosis of CD34(+) stem cells from patients with advanced myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML)/MDS was investigated. In eight out of 10 patient samples Exisulind reduced the fraction of viable cells by inducing apoptosis. We found evidence that Exisulind-mediated apoptosis depends on c-Jun NH(2)-terminal kinase (JNK) activation. Addition of a specific JNK-inhibitor to Exisulind-treated advanced MDS and AML/MDS cells partly abrogated apoptosis. We propose that Exisulind is tested in clinical phase I/II trials for the treatment of advanced MDS and AML/MDS.
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PMID:Exisulind induces apoptosis in advanced myelodysplastic syndrome (MDS) and acute myeloid leukaemia/MDS. 1697 22

Patients who undergo autologous stem cell transplantation (ASCT) for lymphoma have a significant risk of therapy-related acute myeloid leukemia and myelodysplasia (t-AML/MDS). Compared to that seen in other indications such as breast cancer, multiple myeloma or germ cell tumors, there is a substantially increased risk for t-AML/MDS following ASCT for lymphoma. This risk has largely been attributed to the extent of pre-transplant chemotherapy and radiation therapy. In many of the larger series to date, it has not been possible to directly implicate autologous transplantation itself as a risk factor for t-AML/MDS. Although pre-transplant therapy is certainly an important factor in the development of t-AML/MDS, specific components of the autologous transplantation procedure itself may also contribute to the risk of t-AML/MDS. Specifically, priming chemotherapy, total body irradiation, and the extensive cellular proliferation which occurs during engraftment may all play a role in the development of t-AML/MDS. Furthermore, there is an increasing body of evidence that certain inherited polymorphisms in genes governing drug metabolism, DNA repair and leukemogenesis may influence susceptibility to t-AML/MDS. In this paper, we review the evidence implicating the above risk factors for t-AML/MDS, present a potential mechanism for t-AML/MDS and propose interventions to reduce the rate of t-AML/MDS in lymphoma patients.
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PMID:Does autologous transplantation directly increase the risk of secondary leukemia in lymphoma patients? 1714 1


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