Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Six patients with de novo acute myeloid leukemia (AML) and a t(2;3)(p15-21;q26-27) were identified among approximately 1000 cases enrolled in the GIMEMA trial. The t(2;3) was the sole anomaly in three patients, whereas in three cases monosomy 7, trisomy 15 and 22, and trisomy 14 represented additional aberrations. No cryptic chromosome deletions at 5q, 7q, 12p, and 20q were observed. One patient carried a FLT3 D835 mutation; FLT3 internal tandem duplication (ITD) was not detected in three patients tested. Characterization of the translocation breakpoints using a 3q26 BAC contig specific for the PRDM3 locus showed that the breakpoints were located 5' to EVIl as follows: within myelodysplatic syndrome (MDS) intron 1 (# 3), between MDS1 exons 2 and 3 in three patients (# 1, 2, 4) with a 170bp cryptic deletion distal to the breakpoint in one (# 2), and in a more centromeric position spanning from intron 2 to the 5' region of EVI1 (# 6, 5). A set of 2p16-21 BAC probes showed that the breakpoints on chromosome 2p were located within BCL11A in two separate regions (# 1, 4 and # 2-5), within the thyroid adenoma-associated (THADA) gene (# 6) or distal to the ZFP36L2 locus (# 3). Regulatory elements were present in proximity of these breakpoints. RACE PCR studies revealed a chimeric transcript in 1/6 patient analyzed, but no fusion protein. Quantitative PCR showed a 21-58-fold over-expression of the EVIl gene in all cases analyzed. The patients showed dysplasia of at least two myeloid cell lineages in all cases; they had a low-to-normal platelet count and displayed an immature CD34+ CD117+ immunophenotype. Despite intensive chemotherapy and a median age of 43 years (range 36-59), only two patients attained a short-lived response; one patient is alive with active disease at 12 months, five died at 4-14 months. We arrived at the following conclusions: (a) the t(2;3) is a recurrent translocation having an approximate 0.5% incidence in adult AML; (b) breakpoints involve the 5' region of EVIl at 3q26, and the BCL11A, the THADA gene or other regions at 2p16.1-21; (c) cryptic deletions distal to the 3q26 breakpoint may occur in some cases; (d) the juxtaposition of the 5' region of EVIl with regulatory elements normally located on chromosome 2 brings about EVI1 overexpression; (e) clinical outcome in these cases is severe.
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PMID:Characterization of a recurrent translocation t(2;3)(p15-22;q26) occurring in acute myeloid leukaemia. 1661 48

Acute myeloid leukemia (AML) is a heterogeneous group of disorders characterized by abnormal proliferation of myeloid precursors and a maturation block. Underlying genetic lesions determine an altered expression program (transcriptosome) that can be studied in depth by massive technologies. Alternatively, we selected a pathway profiling strategy based on the current knowledge in order to stratify de novo AML patients and identify those cases which would potentially benefit from the use of new chemotherapeutic agents. One hundred and thirty-two RNA samples obtained from de novo adult AML patients were tested for FLT3, FLT3-LG, NDST1, HDAC2, ATRX, FOS, DNMT1, DNMT3A, DNMT3B, NBS1, RAD50, MRE11A, Meis1 and Meis2 expression using quantitative PCR (qPCR) assays. Clinical and biologic findings were correlated with expression results. Cluster analysis was also performed. FLT3 expression defined three subgroups of patients. The best outcome was found in the group with the lowest FLT3 expression. Intermediate levels of FLT3 were associated with the worst outcome. Patients with low levels of ATRX more frequently presented an adverse karyotype whereas cases with preserved ATRX levels showed an excellent outcome. In accordance with previous results, Meis1 downregulation is a useful surrogate marker indicating a good prognosis in AML patients. Simple qPCR platforms may help to identify different biologic subgroups in AML.
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PMID:Acute myeloid leukemia subgroups identified by pathway-restricted gene expression signatures. 1691 1

The nucleophosmin (NPM1) gene encodes for a multifunctional nucleocytoplasmic shuttling protein that is localized mainly in the nucleolus. NPM1 mutations occur in 50% to 60% of adult acute myeloid leukemia with normal karyotype (AML-NK) and generate NPM mutants that localize aberrantly in the leukemic-cell cytoplasm, hence the term NPM-cytoplasmic positive (NPMc+ AML). Cytoplasmic NPM accumulation is caused by the concerted action of 2 alterations at mutant C-terminus, that is, changes of tryptophan(s) 288 and 290 (or only 290) and creation of an additional nuclear export signal (NES) motif. NPMc+ AML shows increased frequency in adults and females, wide morphologic spectrum, multilineage involvement, high frequency of FLT3-ITD, CD34 negativity, and a distinct gene-expression profile. Analysis of mutated NPM has important clinical and pathologic applications. Immunohistochemical detection of cytoplasmic NPM predicts NPM1 mutations and helps rationalize cytogenetic/molecular studies in AML. NPM1 mutations in absence of FLT3-ITD identify a prognostically favorable subgroup in the heterogeneous AML-NK category. Due to their frequency and stability, NPM1 mutations may become a new tool for monitoring minimal residual disease in AML-NK. Future studies should focus on clarifying how NPM mutants promote leukemia, integrating NPMc+ AML in the upcoming World Health Organization leukemia classification, and eventually developing specific antileukemic drugs.
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PMID:Acute myeloid leukemia carrying cytoplasmic/mutated nucleophosmin (NPMc+ AML): biologic and clinical features. 1700 39

The FMS-like tyrosine kinase-3 (FLT3), which belongs to the class III receptor tyrosine kinase family, expressed by immature hematopoietic cells, plays an important role in the proliferation, differentiation and survival of stem cells. The activating mutations of FLT3 gene have been reported to be of prognostic significance. The most common somatic alteration of the FLT3 gene is the Internal Tandem Duplication (FLT3/ITD), which is caused by the elongation of the juxtamembrane (JM) domain of FLT3. The duplicated fragment size varies from 3 to more than 400 base pair, always occurs in multiples of three while the reading frame is preserved. The elongated segment of DNA can be amplified by polymerase chain reaction (PCR), and the products are separated by gel electrophoresis. The FLT3/ITD is found in 20-40% of adult AML patients and is the most frequent mutation in leukemia. Using native peripheral blood and bone marrow from AML and non-AML patients (total of 19 samples), and samples from the RNA bank (total of eight samples), the authors purpose was to work out a method for FLT3/ITD detection, which can be used in routine diagnostics. All samples produced detectable PCR products, which proofs that this procedure can be used for the detection of FLT3/ITD mutations in daily clinical practice.
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PMID:Prognostic significance and detection of the internal tandem duplication of the FLT3 gene in acute myeloid leukemia. 1739 78

Frameshift mutations in exon 12 of the nucleophosmin gene (NPM1) result in aberrant cytoplasmic localization of the NPM protein (NPMc(+)) and occur in 25% to 35% of adult acute myeloid leukemia (AML). In adults with AML, NPMc(+) has been associated with normal karyotype, FLT3/ITD mutations, high remission induction rates, and improved survival (particularly in patients lacking FLT3/ITD). NPMc(+) has not been well characterized in childhood AML. This study examines the incidence and clinical significance of NPMc(+) in 295 children with newly diagnosed AML treated on a large cooperative group clinical trial (POG-9421). We find that NPMc(+) is relatively uncommon in childhood AML (23 of 295 patients, 8%); and is significantly associated with FLT3/ITD mutations (P = .046), female sex (P = .029), older age (P = .047), and normal cytogenetics (P < .001). There is a favorable impact of NPMc(+) on survival in children lacking FLT3/ITD (5-year EFS, 69% vs 35%; hazard ratio, 0.39; P = .051), which is similar in magnitude to the favorable impact of t(8;21) and inv(16). We conclude that NPMc(+) is relatively rare in childhood AML, particularly in younger children. NPMc(+) does not abrogate the negative prognostic influence of FLT3/ITD mutations, but may contribute to risk stratification in children who lack FLT3/ITD mutations by identifying a group with superior prognosis.
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PMID:The incidence and clinical significance of nucleophosmin mutations in childhood AML. 1744 48

An internal tandem duplication in the fms-like tyrosine kinase 3 gene (FLT3/ITD) is associated with poor prognosis in acute myeloid leukemia (AML), but the impact of mutant level, size, and interaction with nucleophosmin 1 (NPM1) mutations remains controversial. We evaluated these characteristics in a large cohort of young adult AML patients. There was a highly significant trend for worsening in relapse risk (RR) and overall survival (OS) with increasing FLT3/ITD mutant level (P < .001 for both), and even in the low level mutant group (1%-24% of total FLT3 alleles), RR was significantly worse than in the FLT3 wild-type (WT) group (P < .001). In multivariate analysis, mutant level was the most powerful prognostic factor for RR. Mutant size and number had no significant impact on outcome. The beneficial impact of an NPM1 mutation on RR and OS was seen in FLT3/ITD(+) as well as FLT3/WT patients; both markers were highly significant independent predictors of outcome (P < .001). Stratification using both markers identified 3 prognostic groups: good (FLT3/ITD(-)NPM1(+)), intermediate (FLT3/ITD(-)NPM1(-) or FLT3/ITD(+)NPM1(+)), and poor (FLT3/ITD(+)NPM1(-)). Patients with high FLT3/ITD mutant level (greater than 50%) or FLT3/ITD(+) in the absence of an NPM1 mutation may be good candidates for more experimental therapeutic approaches.
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PMID:The impact of FLT3 internal tandem duplication mutant level, number, size, and interaction with NPM1 mutations in a large cohort of young adult patients with acute myeloid leukemia. 1795 27

Clinical research examining the role of hematopoietic stem cell transplantation (HSCT) in the therapy of acute myelogenous leukemia (AML) in adults is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in Table 3, entitled Summary of Treatment Recommendations Made by the Expert Panel for Adult Acute Myelogenous Leukemia, and were reached unanimously by a panel of AML experts. The identified priority areas of needed future research in adult AML include: (1) What is the role of HSCT in treating patients with specific molecular markers (eg, FLT3, NPM1, CEBPA, BAALC, MLL, NRAS, etc.) especially in patients with normal cytogenetics? (2) What is the benefit of using HSCT to treat different cytogenetic subgroups? (3) What is the impact on survival outcomes of reduced intensity or nonmyeloablative versus conventional conditioning in older (>60 years) and intermediate (40-60 years) aged adults? (4) What is the impact on survival outcomes of unrelated donor HSCT vesus chemotherapy in younger (<40 years) adults with high risk disease?
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PMID:The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of acute myelogenous leukemia in adults: an evidence-based review. 1821 77

Acute myeloid leukemia (AML) carrying NPM1 mutations and cytoplasmic nucleophosmin (NPMc+ AML) accounts for about one-third of adult AML and shows distinct features, including a unique gene expression profile. MicroRNAs (miRNAs) are small noncoding RNAs of 19-25 nucleotides in length that have been linked to the development of cancer. Here, we investigated the role of miRNAs in the biology of NPMc+ AML. The miRNA expression was evaluated in 85 adult de novo AML patients characterized for subcellular localization/mutation status of NPM1 and FLT3 mutations using a custom microarray platform. Data were analyzed by using univariate t test within BRB tools. We identified a strong miRNA signature that distinguishes NPMc+ mutated (n = 55) from the cytoplasmic-negative (NPM1 unmutated) cases (n = 30) and includes the up-regulation of miR-10a, miR-10b, several let-7 and miR-29 family members. Many of the down-regulated miRNAs including miR-204 and miR-128a are predicted to target several HOX genes. Indeed, we confirmed that miR-204 targets HOXA10 and MEIS1, suggesting that the HOX up-regulation observed in NPMc+ AML may be due in part by loss of HOX regulators-miRNAs. FLT3-ITD+ samples were characterized by up-regulation of miR-155. Further experiments demonstrated that the up-regulation of miR-155 was independent from FLT3 signaling. Our results identify a unique miRNA signature associated with NPMc+ AML and provide evidence that support a role for miRNAs in the regulation of HOX genes in this leukemia subtype. Moreover, we found that miR-155 was strongly but independently associated with FLT3-ITD mutations.
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PMID:Distinctive microRNA signature of acute myeloid leukemia bearing cytoplasmic mutated nucleophosmin. 1830 31

Almost half of adult acute myelogenous leukemia (AML) is normal cytogenetically, and this subgroup shows a remarkable heterogeneity of genetic mutations at the molecular level and an intermediate response to therapy. The finding of recurrent cytogenetic abnormalities has influenced, in a primary way, the understanding and treatment of leukemias. Yet "normal karyotype AML" lacks such obvious abnormalities, but has a variety of prognostically important genetic abnormalities. Thus, the presence of a FLT3-ITD (internal tandem duplication), MLL-PTD (partial tandem duplication), or the increased expression of ERG or EVI1 mRNAs confer a poor prognosis, and an increased risk of relapse. In contrast, the presence of cytoplasmic nucleophosmin or C/EBPA mutations is associated with lower relapse rates and improved survival. Although resistance to treatment is associated with specific mutations, the degree to which the leukemia resembles a stem cell in its functional properties may provide greater protection from the effects of treatment. Although usually all of the circulating leukemia cells are cleared following treatment, a small residual population of leukemic cells in the bone marrow persists, making this disease hard to eradicate. Increased understanding of the biological consequences of at least some of these mutations in "normal karyotype AML" is leading to more targeted approaches to develop more effective treatments for this disease.
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PMID:Is it important to decipher the heterogeneity of "normal karyotype AML"? 1834 11

Recently, mutations in the nucleophosmin (NPM1) gene were detected in 50-60% of adult acute myelogenous leukemia (AML) patients, mainly with a normal karyotype. In this study, we detected typical NPM1 mutations (types A, B, D) in untreated Chinese AML patients using real-time quantitative polymerase chain reaction (RQ-PCR) followed by sequence analysis. The detection rate of NPM1 mutations in 220 AML patients was 16.4%, including 107 (14.2%) with the French-American-British (FAB) subtype M2, 43 (2.3%) with M3, and 52 (30.8%) with M4/M5. Only one case each with an NPM1 mutation was detected in four M0, seven M1, five M6, and two M7 cases. Eight patients were followed up after treatment, and five patients in hematologic remission continued to test negative for NPM1 mutations within 2-14 months of follow-up. Sequence analysis revealed that all the 36 positive cases were heterozygous for the mutation with 4-bp insertions at nt 959; the 36 cases included 29 (80.6%) cases with type A, four (11.1%) cases with type B, and one rare DD-3 mutation. We also detected two new mutations, namely, CTCG and CAAG insertions, named BJ-01 and BJ-02, respectively. Further, 38.9% (14/36) patients with NPM1 mutations simultaneously exhibited internal tandem duplications in the FLT3 gene, and 66.7% (22/33) patients did not express CD34. The results demonstrated that RQ-PCR was a reliable and sensitive method for detecting NPM1 mutations, for screening AML, and for the quantitative analysis of minimal residual diseases.
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PMID:Nucleophosmin mutations in Chinese adults with acute myelogenous leukemia. 1872 96


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