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)

Previously we reported that neu differentiation factor (NDF)/heregulin (HRG) elevates tyrosine phosphorylation of its receptors erbB-3, erbB-4, and erbB-2 (through heterodimer formation). We also showed that both NDF/HRG and antibodies to erbB-2 can arrest growth and induce differentiation in breast cancer cells. In this study, we report on the mechanism of NDF/HRG-induced cellular effects. We show that NDF/HRG and antibodies to erbB-2 receptors up-regulate expression of p53 by stabilizing the protein. This is accompanied by up-regulation of the p53 inducible gene, p21CIP1/WAF1, in a variety of cell lines: MCF7 and their derivatives (MCF7/HER2, MN1 and MCF-7-puro), ZR75T and LnCap cells. The induction of p21 is further enhanced when cells are treated with both NDF/HRG and DNA-damaging chemotherapeutic agents (i.e. doxorubicin). The NDF/HRG mediated induction of p21 is dependent on wildtype p53, as it fails to occur in cells expressing dominant negative p53 (MDD2). Furthermore, p21 induction is capable of inactivating cdk2 complexes as measured by Histone H1 phosphorylation assays. Finally, we show that in primary cultures of breast and other cancers, p21 is significantly induced in response to NDF/HRG treatment. Collectively, these observations suggest that the mechanism of breast cancer cell growth inhibition and differentiation via erbB receptors activation is through a p53-mediated pathway.
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PMID:Neu differentiation factor (Heregulin) activates a p53-dependent pathway in cancer cells. 870 May 12

The ETV6/TEL gene has been reported to fuse to PDGFRbetab MDS1/EVI1, BTL, ACS2, STL, JAK2, ABL, CDX2, TRKC, AML1, and MN1. Among them, PDGFRbeta, ABL, JAK2, and TRKC are tyrosine kinases (TK). We identified a novel ETV6 partner gene, ARG (ABL-related gene or ABL2), another TK gene in a cell line established from a patient with acute myelogenous leukemia (AML-M3) with a t(15;17)(q22;q11.2) and a t(1;12)(q25;p13), which has the remarkable feature to differentiate to mature eosinophils in culture with all-trans retinoic acid and cytokines. The ETV6/ARG transcripts consisted of exon 1 to 5 of ETV6 and the 3' portion of ARG starting from exon 1B or exon 2, resulting in an open reading frame for a fusion protein consisting of the entire PNT oligomerization domain of ETV6 and all of the functional domains of ARG including the TK domain. This is the same protein structure as identified in the other ETV6 TK fusion proteins. The reciprocal ARG/ETV6 transcript was not expressed, and the normal ETV6 allele was not deleted or rearranged. Although the ABL is known to be involved in various human malignancies, ARG has not been involved in human malignancies despite its high homology to ABL. Thus, this is the first report showing involvement of ARG in human leukemia. The ETV6/ARG protein may be involved in the unique differentiation capacity of this cell line. (Blood. 2000;95:2126-2131)
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PMID:A new ETV6/TEL partner gene, ARG (ABL-related gene or ABL2), identified in an AML-M3 cell line with a t(1;12)(q25;p13) translocation. 1070 84

Normal cytogenetics are detected pretreatment in approximately 45% of patients with de novo acute myeloid leukaemia (AML); thus this constitutes the single largest cytogenetic group of AML. Recently, molecular genetic alterations with prognostic significance have been reported in these patients. They include internal tandem duplication of the FLT3 gene, partial tandem duplication of the MLL gene, mutations of the CEBPA and NPM1 genes and aberrant expression of the BAALC, ERG and MN1 genes. Additionally, gene-expression profiling has been applied to identify prognostically relevant subgroups. Substantial progress has been made in the understanding of molecular pathways deregulated in leukaemogenesis and how these defects can be targeted by novel therapeutic compounds. Here we critically review the molecular heterogeneity among AML patients with normal cytogenetics and discuss how these data may translate into a prognostic, molecular-based treatment stratification that may improve the currently unsatisfactory outcome of these patients.
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PMID:Clinical outcome of de novo acute myeloid leukaemia patients with normal cytogenetics is affected by molecular genetic alterations: a concise review. 1748 84

We have evaluated 9 new molecular markers (ERG, EVI1, MLL-PTD, MN1, PRAME, RHAMM, and WT1 gene-expression levels plus FLT3 and NPM1 mutations) in 121 de novo cytogenetically normal acute myeloblastic leukemias. In the multivariate analysis, high ERG or EVI1 and low PRAME expressions were associated with a shorter relapse-free survival (RFS) and overall survival (OS). A 0 to 3 score was given by assigning a value of 0 to favorable parameters (low ERG, low EVI1, and high PRAME) and 1 to adverse parameters. This model distinguished 4 subsets of patients with different OS (2-year OS of 79%, 65%, 46%, and 27%; P = .001) and RFS (2-year RFS of 92%, 65%, 49%, and 43%; P = .005). Furthermore, this score identified patients with different OS (P = .001) and RFS (P = .013), even within the FLT3/NPM1 intermediate-risk/high-risk subgroups. Here we propose a new molecular score for cytogenetically normal acute myeloblastic leukemias, which could improve patient risk-stratification.
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PMID:Molecular stratification model for prognosis in cytogenetically normal acute myeloid leukemia. 1939 19

Acute myeloid leukemia (AML) is a heterogenous disorder that results from a block in the differentiation of hematopoietic progenitor cells along with uncontrolled proliferation. In approximately 60% of cases, specific recurrent chromosomal aberrations can be identified by modern cytogenetic techniques. This cytogenetic information is the single most important tool to classify patients at their initial diagnosis into three prognostic categories: favorable, intermediate, and poor risk. Currently, favorable risk AML patients are usually treated with contemporary chemotherapy while poor risk AML patients receive allogeneic stem cell transplantation if suitable stem cell donors exist. The largest subgroup of AML patients (aproximately 40%) have no identifiable cytogenetic abnormalities and are classified as intermediate risk. The optimal therapeutic strategies for these patients are still largely unclear. Recently, it is becoming increasingly evident that it is possible to identify a subgroup of poorer risk patients among those with normal cytogenic AML (NC-AML). Molecular risk stratification for NC-AML patients may be possible due to mutations of NPM1, FLT3, MLL, and CEBPalpha as well as alterations in expression levels of BAALC, MN1, ERG, and AF1q. Further prospective studies are needed to confirm if poorer risk NC-AML patients have improved clinical outcomes after more aggressive therapy.
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PMID:Molecular prognostic markers for adult acute myeloid leukemia with normal cytogenetics. 1949 Jun 47

Although the cancer stem cell (CSC) concept implies that CSCs are rare, recent reports suggest that CSCs may be frequent in some cancers. We hypothesized that the proportion of leukemia stem cells would vary as a function of the number of dysregulated pathways. Constitutive expression of MN1 served as a 1-oncogene model, and coexpression of MN1 and a HOX gene served as a 2-oncogene model. Leukemia-initiating cell (LIC) number and in vitro expansion potential of LICs were functionally assessed by limiting dilution analyses. LIC expansion potential was 132-fold increased in the 2- compared with the 1-oncogene model, although phenotypically, both leukemias were similar. The 2-oncogene model was characterized by granulocyte-macrophage colony-stimulating factor (GM-CSF) hypersensitivity and activated STAT/ERK signaling. GM-CSF hypersensitivity of the 2-oncogene model (MN1/HOXA9) was lost in Stat5b(-/-) cells, and the LIC expansion potential was reduced by 86- and 28-fold in Stat5b(-/-) and Stat1(-/-) cells, respectively. Interestingly, in 201 acute myeloid leukemia (AML) patients, coexpression of MN1 and HOXA9 was restricted to patients with the poorest prognosis and was associated with highly active STAT signaling. Our data demonstrate the functional heterogeneity of LICs and show that STAT signaling is critical for leukemia stem cell self-renewal in MN1- and HOXA9-expressing leukemias.
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PMID:Modeling the functional heterogeneity of leukemia stem cells: role of STAT5 in leukemia stem cell self-renewal. 1989 22

Alkylating agents, topoisomerase II inhibitors, ionizing radiation, and other hematotoxins induce DNA damage in hematopoietic stem cells that results in lesions such as balanced and unbalanced chromosome rearrangements, -5/del(5q) and/or -7/del(7q), as well as other submicroscopic genetic lesions. Together with epigenetic alterations, these result in dysplasia, clonal expansion, and ultimately myeloid leukemia. Combinations of lesions are required to induce overt leukemia. Altering a small subset of signaling pathways leads to disruption of normal self-renewal, proliferation, differentiation, and apoptotic mechanisms that control the development of hematopoietic stem cells and their differentiation into mature effector cells. Recent studies have shown that cytogenetically normal (CN-) AML is quite heterogeneous at the molecular level. Patients with CN-AML harboring mutations in NPM1, FLT3, CEBPA, WT1 or expressing high levels of BAALC, ERG, or MN1 have distinctly different clinical outcomes. NPM1 mutations are independently associated with higher remission rates and longer disease-free and overall survival in AML. Copy number alterations (CNAs) are deletions or amplifications of single genes. CNAs have been found at the breakpoints of known chromosomal translocations. Fewer CNAs have been detected in AML than in pediatric ALL. Micro-RNAs (miRs) are non-coding small RNA molecules containing about 22 nucleotides that are typically encoded within introns. They hybridize to complementary mRNA targets and modulate protein expression by inhibiting translation and/or inducing degradation of target messenger RNAs. This new class of genes has recently been shown to play a pivotal role in malignant transformation. miRs are down-regulated in many tumors and thus appear to function as tumor suppressor genes. Distinctive genome-wide miR expression profiles have been associated with different subsets of AML. A miR signature that is associated with clinical outcome in patients with high-risk molecular features of AML (those who have FLT3-ITD or wild-type NPM1) has been reported. This subgroup constitutes approximately 65% of patients with CN-AML and one-third of all patients with AML <60 years old. Down-regulation of the miR-181 family contributes to an aggressive leukemia phenotype through mechanisms associated with the activation of pathways of innate immunity mediated by toll-like receptors and interleukin-1beta.
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PMID:Micro-RNAs and copy number changes: new levels of gene regulation in acute myeloid leukemia. 1982 34

We have analyzed brain and acute leukemia, cytoplasmic (BAALC) gene expression and other genetic markers (ERG, EVI1, MN1, PRAME, WT1, FLT3, and NPM1 mutations) in 127 intermediate-risk acute myeloid leukemia (AML) patients: 98 cytogenetically normal and 29 with intermediate-risk cytogenetic alterations. High versus low BAALC expressers showed a higher refractoriness to induction treatment (31% vs 10%; p = .005), lower complete remission rate after salvage therapy (82% vs 97%; p = .010), and lower 3-year overall (23% vs 58%, p < .001) and relapse-free survival (26% vs 52%, p = .006). Similar results were found when cytogenetic subgroups were analyzed separately. Multivariate models confirmed the unfavorable prognosis of this marker. In conclusion, BAALC is a relevant prognostic marker in intermediate-risk AML.
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PMID:BAALC is an important predictor of refractoriness to chemotherapy and poor survival in intermediate-risk acute myeloid leukemia (AML). 1994 49

We investigated the benefit of adding all-trans retinoic acid (ATRA) to chemotherapy for younger patients with nonacute promyelocytic acute myeloid leukemia and high-risk myelodysplastic syndrome, and considered interactions between treatment and molecular markers. Overall, 1075 patients less than 60 years of age were randomized to receive or not receive ATRA in addition to daunorubicin/Ara-C/thioguanine chemotherapy with Ara-C at standard or double standard dose. There were data on FLT3 internal tandem duplications and NPM1 mutations (n = 592), CEBPA mutations (n = 423), and MN1 expression (n = 195). The complete remission rate was 68% with complete remission with incomplete count recovery in an additional 16%; 8-year overall survival was 32%. There was no significant treatment effect for any outcome, with no significant interactions between treatment and demographics, or cytarabine randomization. Importantly, there were no interactions by FLT3/internal tandem duplications, NPM1, or CEBPA mutation. There was a suggestion that ATRA reduced relapse in patients with lower MN1 levels, but no significant effect on overall survival. Results were consistent when restricted to patients with normal karyotype. ATRA has no overall effect on treatment outcomes in this group of patients. The study did not identify any subgroup of patients likely to derive a significant survival benefit from the addition of ATRA to chemotherapy.
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PMID:The impact on outcome of the addition of all-trans retinoic acid to intensive chemotherapy in younger patients with nonacute promyelocytic acute myeloid leukemia: overall results and results in genotypic subgroups defined by mutations in NPM1, FLT3, and CEBPA. 1996 47

Cytogenetic aberrations have long been recognized as the most important prognostic variable in acute myeloid leukemia (AML) and are now a major stratification tool for post-remission therapy. Cytogenetics-based stratification improves survival. Patients with AML and normal cytogenetics, the largest single subgroup, have had a very heterogeneous outcome with standard chemotherapy in multiple clinical trials. Hence it is difficult to recommend a "one size fits all" kind of treatment for this heterogeneous population of AML patients. New emerging data from preclinical, retrospective, and large, randomized controlled studies indicate that in addition to cytogenetic abnormalities, many other molecular aberrations are operative in the response to treatment as well as in the risk of relapse. Such molecular markers are being tested for developing targeted therapies and may help in improved stratification of patients in the selection of post-remission therapy. Emerging evidence reveals that at the submicroscopic level, AML with normal cytogenetics may carry poor prognostic genetic lesions or "molecular signatures" as is the case with FLT3 mutations and overexpression of BAALC, ERG or MN1, or may have aberrations that predict better risk as is the case with isolated NPM1 or CEBPA mutations. Later studies have tried to explore the interaction of various prognostically important genes in this group of AML patients. The utility of the evolving data for bedside management of such patients is expected to improve with the wider application of modern tools, using the proposed clinical outcome models, and probably by development of a risk-scoring system based on the relative risk associated with each molecular aberration. The goals include identifying those patients most likely to benefit from upfront allogeneic HSCT and sparing good-prognosis patients from unnecessary transplant-related morbidity. The following is an outline of the most common molecular changes, their impact on the outcome of AML patients with normal cytogenetics and challenges in their wide scale application in risk stratification.
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PMID:The challenge of risk stratification in acute myeloid leukemia with normal karyotype. 2006 45


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