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1.
Cureus ; 16(5): e60961, 2024 May.
Article in English | MEDLINE | ID: mdl-38910682

ABSTRACT

Dengue, commonly referred to as 'breakbone fever,' is a mosquito-borne arboviral infection transmitted by Aedes aegypti, featuring an average incubation period of approximately seven days. Key cytokines such as interferon-gamma (IFN-γ), tumor necrosis factor (TNF)-α, and interleukin (IL)-10 are pivotal in the pathogenesis of dengue. Travelers are particularly susceptible to contracting dengue fever, with disease severity often associated with CD8+ T cell response. Without proper hospitalization during severe cases like dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS), mortality rates can escalate to 50%. Dengue fever can lead to various complications, including neurological manifestations such as encephalopathy, encephalitis, cerebral venous thrombosis, myelitis, posterior reversible encephalopathy syndrome, strokes (both ischemic and hemorrhagic), immune-mediated neurological syndromes (such as mononeuropathy, acute transverse myelitis, Guillain-Barre syndrome, and acute disseminated encephalomyelitis), and neuromuscular complications. Treatment protocols typically involve assessing disease activity using composite indices, pursuing treatment objectives, and administering intravenous fluids according to symptomatology. Given the absence of specific antiviral treatment for dengue, supportive care, particularly hydration, remains paramount during the early stages. It is crucial to recognize that dengue viruses may contribute to the development of neurological disorders, particularly in regions where dengue is endemic. Furthermore, there is a necessity for well-defined criteria for specific neurological complications. Primary prevention strategies primarily revolve around vector control measures, which play a critical role in curtailing the spread of dengue.

2.
Cureus ; 15(3): e35860, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37033521

ABSTRACT

Stroke is a neurologic condition caused either by brain ischemia or brain hemorrhage, where most cases are a result of ischemic brain injury. Stroke more commonly affects the arterial blood supply of the brain, but in rare cases, it is evoked by the occlusion of the venous sinuses that drain blood from the brain. This phenomenon is known as cerebral venous sinus thrombosis (CVST), also referred to as cerebral sinovenous thrombosis. The pathogenesis of CVST is not completely understood, although common risk factors associated with the condition include obesity, hypercoagulable states, oral contraceptive use, intracranial infections, trauma, and, more recently, coronavirus disease 2019 (COVID-19). Immediate medical intervention is required because CVST can result in increased intracranial pressure and diffuse cerebral edema, which can bring about fatal complications that can lead to early death. However, CVST is challenging to diagnose, as its clinical presentation is highly variable. It can range from headaches to signs of elevated intracranial pressure, including nausea, vomiting, and vision problems. In this case report, the patient is a 25-year-old previously healthy African American female who presented with a weeklong headache and acute onset of delirium an hour prior to arrival at the hospital. The patient had prior emergency department (ED) visits from different facilities where head imaging was performed and showed negative results allowing her to return home. The patient was then brought by a friend to our ED due to altered mental status and agitation. Initial computed tomography of the head did not reveal acute abnormalities; however, magnetic resonance angiography and magnetic resonance venography revealed evidence of venous sinus thrombosis and lack of flow requiring urgent attention. The patient was then referred to endovascular neurology, but despite medical intervention, the patient's medical status deteriorated, and she was declared brain dead. Although rare, this case report emphasizes the atypical presentation and the severity of CVST where a young individual with no significant past medical history presented with neurological symptoms that rapidly progressed to complications that caused her early death.

3.
Cureus ; 15(1): e33293, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36606106

ABSTRACT

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease that can cause cartilage and bone damage as well as a disability. Various cytokines play an essential role in disease formation such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6, IL-17, and macrophages; osteoclast is also activated by the cytokines, which cause bone degradation. Early diagnosis is key to optimal therapeutic success, particularly in patients with well-characterized risk factors for poor outcomes such as high disease activity, presence of autoantibodies, and early joint damage. Treatment algorithms involve measuring disease activity with composite indices, applying a treatment-to-target strategy, and using conventional, biological, and new non-biological disease-modifying antirheumatic drugs. After the treatment target of stringent remission (or at least low disease activity) is maintained, dose reduction should be attempted. Although the prospects for most patients are now favorable, many still do not respond to current therapies. The biologics have changed the disease progression over the past few decades, such as TNF-alpha inhibitors (infliximab, etanercept, adalimumab, golimumab, certolizumab), IL-1 inhibitors (anakinra), IL-6 inhibitors (tocilizumab), CD20 inhibitors (rituximab), and cytotoxic T-lymphocyte associated antigen (CTLA)-4 inhibitors (abatacept). In treatment with biologics, only little is known if "biologic-free" remission is possible in patients with sustained remission following intensive biological therapy. Infliximab and etanercept, in the long run, develop the drug antibody. This article has reviewed the action of the cytokine on joints and biological drug's action in blocking the cytokine degradation effect, benefits of biologics, and adverse effects in the long and short term. They are also effective alone or in combination with other drugs.

4.
Cureus ; 14(12): e33094, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36721576

ABSTRACT

Malignancy is a catabolic state, which is precipitated with surgical intervention. Malnutrition is one of the main risk factors for poor outcomes of cancer surgery. We need to screen oncological patients for malnutrition using standardized screening tools, by which patients found to be at nutritional risk are then referred to a registered dietitian for further management. A detailed assessment is required in such patients, which helps in categorizing the patients based on the severity and rendering proper care. Preoperative nutrition care is often overlooked because of the urgency of operating on a cancer patient. Still, studies have shown preoperative nutritional building gives better surgical outcomes and good postoperative quality of life. Preoperative nutrition care includes both early and late preoperative care. For efficient preoperative nutrition care publishing, standard operating procedures at every healthcare center are recommended. Postoperative nutrition care is given to build the patient tackle the surgical trauma, and their diet mainly includes protein to minimize catabolism. Regardless of the route of nutrition delivery, providing appropriate nutrition care in the postoperative period improves cancer patients' condition drastically. Early postoperative nutrition is studied in different cancer surgeries and is considered ideal in cancer surgical patients. There is a need for consensus on the composition of postoperative nutrition. The diet of a cancer patient should include micronutrients like vitamins D and B and minerals along with the usual nutrition care. The use of special diets like branched-chain amino acids and immune nutrition is to be considered on a case-by-case basis and introducing them into the routine care of a patient needs to be studied extensively.

7.
Clin Biochem ; 50(7-8): 436-439, 2017 May.
Article in English | MEDLINE | ID: mdl-27989492

ABSTRACT

OBJECTIVES: Previous studies have reported that salivary concentrations of certain hormones correlate with their respective serum levels. However, most of these studies did not control for potential blood contamination in saliva. In the present study we developed a statistical method to test the amount of blood contamination that needs to be avoided in saliva samples for the following hormones: cortisol, estradiol, progesterone, testosterone and oxytocin. DESIGN & METHODS: Saliva and serum samples were collected from 38 healthy, medication-free women (mean age=33.8±7.3yr.; range=19-45). Serum and salivary hormonal levels and the amount of transferrin in saliva samples were determined using enzyme immunoassays. RESULTS: Salivary transferrin levels did not correlate with salivary cortisol or estradiol (up to 3mg/dl), but they were positively correlated with salivary testosterone, progesterone and oxytocin (p<0.05). After controlling for blood contamination, only cortisol (r=0.65, P<0.001) and progesterone levels (r=0.57, P=0.002) displayed a positive correlation between saliva and serum. Our analyses suggest that transferrin levels higher than 0.80, 0.92 and 0.64mg/dl should be avoided for testosterone, progesterone and oxytocin salivary analyses, respectively. CONCLUSIONS: We recommend that salivary transferrin is measured in research involving salivary hormones in order to determine the level of blood contamination that might affect specific hormonal salivary concentrations.


Subject(s)
Hormones/metabolism , Saliva/metabolism , Adolescent , Adult , Female , Humans , Middle Aged
8.
Blood ; 127(12): 1551-8, 2016 Mar 24.
Article in English | MEDLINE | ID: mdl-26755712

ABSTRACT

The initial report of the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Cancer Research Group trial E1900 (#NCT00049517) showed that induction therapy with high-dose (HD) daunorubicin (90 mg/m(2)) improved overall survival in adults <60 years old with acute myeloid leukemia (AML); however, at initial analysis, the benefit was restricted to younger patients (<50 years) and patients without unfavorable cytogenetics or aFLT3-ITD mutation. Here, we update the results of E1900 after longer follow-up (median, 80.1 months among survivors), focusing on the benefit of HD daunorubicin on common genetic subgroups. Compared with standard-dose daunorubicin (45 mg/m(2)), HD daunorubicin is associated with a hazard ratio (HR) for death of 0.74 (P= .001). Younger patients (<50 years) benefited from HD daunorubicin (HR, 0.66;P= .002), as did patients with favorable and intermediate cytogenetics (HR, 0.51;P= .03 and HR, 0.68;P= .01, respectively). Patients with unfavorable cytogenetics were shown to benefit from HD daunorubicin on multivariable analysis (adjusted HR, 0.66;P= .04). Patients with FLT3-ITD (24%),DNMT3A(24%), and NPM1(26%) mutant AML all benefited from HD daunorubicin (HR, 0.61,P= .009; HR, 0.62,P= .02; and HR, 0.50,P= .002; respectively). HD benefit was seen in the subgroup of older patients (50-60 years) with the FLT3-ITD or NPM1 mutation. Additionally, the presence of an NPM1 mutation confers a favorable prognosis only for patients receiving anthracycline dose intensification during induction.


Subject(s)
Antibiotics, Antineoplastic/therapeutic use , DNA (Cytosine-5-)-Methyltransferases/genetics , Daunorubicin/therapeutic use , Leukemia, Myeloid, Acute/drug therapy , Nuclear Proteins/genetics , fms-Like Tyrosine Kinase 3/genetics , Adolescent , Adult , Antibiotics, Antineoplastic/administration & dosage , Cytogenetics , DNA Methyltransferase 3A , Daunorubicin/administration & dosage , Female , Humans , Induction Chemotherapy/methods , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Male , Middle Aged , Mutation , Nucleophosmin , Prognosis , Survival Analysis , Young Adult
9.
Artif Organs ; 40(3): 233-42, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26333131

ABSTRACT

An intravascular axial flow pump is being developed as a mechanical cavopulmonary assist device for adolescent and adult patients with dysfunctional Fontan physiology. Coupling computational modeling with experimental evaluation of prototypic designs, this study examined the hydraulic performance of 11 impeller prototypes with blade stagger or twist angles varying from 100 to 600 degrees. A refined range of twisted blade angles between 300 and 400 degrees with 20-degree increments was then selected, and four additional geometries were constructed and hydraulically evaluated. The prototypes met performance expectations and produced 3-31 mm Hg for flow rates of 1-5 L/min for 6000-8000 rpm. A regression analysis was completed with all characteristic coefficients contributing significantly (P < 0.0001). This analysis revealed that the impeller with 400 degrees of blade twist outperformed the other designs. The findings of the numerical model for 300-degree twisted case and the experimental results deviated within approximately 20%. In an effort to simplify the impeller geometry, this work advanced the design of this intravascular cavopulmonary assist device closer to preclinical animal testing.


Subject(s)
Fontan Procedure/instrumentation , Heart-Assist Devices , Adolescent , Adult , Computer Simulation , Heart Defects, Congenital/surgery , Hemodynamics , Humans , Hydrodynamics , Models, Cardiovascular , Pressure , Prosthesis Design
10.
Chem Res Toxicol ; 28(12): 2352-63, 2015 Dec 21.
Article in English | MEDLINE | ID: mdl-26447562

ABSTRACT

The DNA of all organisms is metabolically active due to persistent endogenous DNA damage, repair, and enzyme-mediated base modification pathways important for epigenetic reprogramming and antibody diversity. The free bases released from DNA either spontaneously or by base excision repair pathways constitute DNA metabolites in living tissues. In this study, we have synthesized and characterized the stable-isotope standards for a series of pyrimidines derived from the normal DNA bases by oxidation and deamination. We have used these standards to measure free bases in small molecule extracts from rat brain. Free bases are observed in extracts, consistent with both endogenous DNA damage and 5-methylcytosine demethylation pathways. The most abundant free base observed is uracil, and the potential sources of uracil are discussed. The free bases measured in tissue extracts constitute the end product of DNA metabolism and could be used to reveal metabolic disturbances in human disease.


Subject(s)
Brain Chemistry , Brain/metabolism , DNA Damage , Pyrimidines/chemistry , Animals , Chromatography, High Pressure Liquid , Gas Chromatography-Mass Spectrometry , Magnetic Resonance Spectroscopy , Molecular Structure , Oxidation-Reduction , Rats
11.
Neural Plast ; 2015: 708306, 2015.
Article in English | MEDLINE | ID: mdl-26075104

ABSTRACT

The blood-brain barrier (BBB) regulates the transport of micro- and macromolecules between the peripheral blood and the central nervous system (CNS) in order to maintain optimal levels of essential nutrients and neurotransmitters in the brain. In addition, the BBB plays a critical role protecting the CNS against neurotoxins. There has been growing evidence that BBB disruption is associated with brain inflammatory conditions such as Alzheimer's disease and multiple sclerosis. Considering the increasing role of inflammation and oxidative stress in the pathophysiology of bipolar disorder (BD), here we propose a novel model wherein transient or persistent disruption of BBB integrity is associated with decreased CNS protection and increased permeability of proinflammatory (e.g., cytokines, reactive oxygen species) substances from the peripheral blood into the brain. These events would trigger the activation of microglial cells and promote localized damage to oligodendrocytes and the myelin sheath, ultimately compromising myelination and the integrity of neural circuits. The potential implications for research in this area and directions for future studies are discussed.


Subject(s)
Bipolar Disorder/physiopathology , Blood-Brain Barrier/physiopathology , Encephalitis/physiopathology , Models, Neurological , Animals , Bipolar Disorder/etiology , Encephalitis/complications , Humans , Inflammation/metabolism , Inflammation Mediators/metabolism , Matrix Metalloproteinase 9/metabolism , Oxidative Stress
12.
J Clin Immunol ; 35(2): 227-33, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25677497

ABSTRACT

PURPOSE: Severe combined immunodeficiency (SCID) encompasses a group of disorders characterized by reduced or absent T-cell number and function and identified by newborn screening utilizing T-cell receptor excision circles (TRECs). This screening has also identified infants with T lymphopenia who lack mutations in typical SCID genes. We report an infant with low TRECs and non-SCID T lymphopenia, who proved upon whole exome sequencing to have Nijmegen breakage syndrome (NBS). METHODS: Exome sequencing of DNA from the infant and his parents was performed. Genomic analysis revealed deleterious variants in the NBN gene. Confirmatory testing included Sanger sequencing and immunoblotting and radiosensitivity testing of patient lymphocytes. RESULTS: Two novel nonsense mutations in NBN were identified in genomic DNA from the family. Immunoblotting showed absence of nibrin protein. A colony survival assay demonstrated radiosensitivity comparable to patients with ataxia telangiectasia. CONCLUSIONS: Although TREC screening was developed to identify newborns with SCID, it has also identified T lymphopenic disorders that may not otherwise be diagnosed until later in life. Timely identification of an infant with T lymphopenia allowed for prompt pursuit of underlying etiology, making possible a diagnosis of NBS, genetic counseling, and early intervention to minimize complications.


Subject(s)
Neonatal Screening , Nijmegen Breakage Syndrome/diagnosis , Nijmegen Breakage Syndrome/genetics , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , DNA, Circular , Exome , Gene Rearrangement, T-Lymphocyte , High-Throughput Nucleotide Sequencing , Humans , Infant , Infant, Newborn , Male , Nijmegen Breakage Syndrome/immunology , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , T-Lymphocytes/immunology
13.
Blood ; 123(22): e123-33, 2014 May 29.
Article in English | MEDLINE | ID: mdl-24740812

ABSTRACT

Genomic studies have identified somatic alterations in the majority of myeloproliferative neoplasms (MPN) patients, including JAK2 mutations in the majority of MPN patients and CALR mutations in JAK2-negative MPN patients. However, the role of JAK-STAT pathway activation in different MPNs, and in patients without JAK2 mutations, has not been definitively delineated. We used expression profiling, single nucleotide polymorphism arrays, and mutational profiling to investigate a well-characterized cohort of MPN patients. MPN patients with homozygous JAK2V617F mutations were characterized by a distinctive transcriptional profile. Notably, a transcriptional signature consistent with activated JAK2 signaling is seen in all MPN patients regardless of clinical phenotype or mutational status. In addition, the activated JAK2 signature was present in patients with somatic CALR mutations. Conversely, we identified a gene expression signature of CALR mutations; this signature was significantly enriched in JAK2-mutant MPN patients consistent with a shared mechanism of transformation by JAK2 and CALR mutations. We also identified a transcriptional signature of TET2 mutations in MPN patent samples. Our data indicate that MPN patients, regardless of diagnosis or JAK2 mutational status, are characterized by a distinct gene expression signature with upregulation of JAK-STAT target genes, demonstrating the central importance of the JAK-STAT pathway in MPN pathogenesis.


Subject(s)
Genomics , Janus Kinases/metabolism , Myeloproliferative Disorders/genetics , Myeloproliferative Disorders/metabolism , STAT Transcription Factors/metabolism , Signal Transduction , Calreticulin , Case-Control Studies , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Cluster Analysis , Female , Gene Expression Profiling , Homozygote , Humans , Janus Kinase 2/genetics , Janus Kinases/genetics , Male , Mutation , STAT Transcription Factors/genetics , Transcriptome
14.
Blood ; 121(24): 4917-24, 2013 Jun 13.
Article in English | MEDLINE | ID: mdl-23641016

ABSTRACT

Cancer-associated isocitrate dehydrogenase (IDH) mutations produce the metabolite 2-hydroxyglutarate (2HG), but the clinical utility of 2HG has not been established. We studied whether 2HG measurements in acute myeloid leukemia (AML) patients correlate with IDH mutations, and whether diagnostic or remission 2HG measurements predict survival. Sera from 223 de novo AML patients were analyzed for 2HG concentration by reverse-phase liquid chromatography-mass spectrometry. Pretreatment 2HG levels ranged from 10 to 30 000 ng/mL and were elevated in IDH-mutants (median, 3004 ng/mL), compared to wild-type IDH (median, 61 ng/mL) (P < .0005). 2HG levels did not differ among IDH1 or IDH2 allelic variants. In receiver operating characteristic analysis, a discriminatory level of 700 ng/mL optimally segregated patients with and without IDH mutations, and on subsequent mutational analysis of the 13 IDH wild-type samples with 2HG levels >700 ng/mL, 9 were identified to have IDH mutations. IDH-mutant patients with 2HG levels >200 at complete remission had shorter overall survival compared to 2HG ≤200 ng/mL (hazard ratio, 3.9; P = .02). We establish a firm association between IDH mutations and serum 2HG concentration in AML, and confirm that serum oncometabolite measurements provide useful diagnostic and prognostic information that can improve patient selection for IDH-targeted therapies.


Subject(s)
Glutarates/blood , Isocitrate Dehydrogenase/genetics , Leukemia, Myeloid, Acute/blood , Leukemia, Myeloid, Acute/genetics , Mutation, Missense , Adolescent , Adult , DNA Mutational Analysis , Female , Follow-Up Studies , Humans , Isocitrate Dehydrogenase/metabolism , Male , Middle Aged
15.
Nat Genet ; 45(3): 290-4, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23377183

ABSTRACT

Relapsed childhood acute lymphoblastic leukemia (ALL) carries a poor prognosis, despite intensive retreatment, owing to intrinsic drug resistance. The biological pathways that mediate resistance are unknown. Here, we report the transcriptome profiles of matched diagnosis and relapse bone marrow specimens from ten individuals with pediatric B-lymphoblastic leukemia using RNA sequencing. Transcriptome sequencing identified 20 newly acquired, novel nonsynonymous mutations not present at initial diagnosis, with 2 individuals harboring relapse-specific mutations in the same gene, NT5C2, encoding a 5'-nucleotidase. Full-exon sequencing of NT5C2 was completed in 61 further relapse specimens, identifying additional mutations in 5 cases. Enzymatic analysis of mutant proteins showed that base substitutions conferred increased enzymatic activity and resistance to treatment with nucleoside analog therapies. Clinically, all individuals who harbored NT5C2 mutations relapsed early, within 36 months of initial diagnosis (P = 0.03). These results suggest that mutations in NT5C2 are associated with the outgrowth of drug-resistant clones in ALL.


Subject(s)
5'-Nucleotidase/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , 5'-Nucleotidase/metabolism , Base Sequence , Child , Drug Resistance, Neoplasm , Exons , Humans , Molecular Sequence Data , Mutation , Protein Conformation , Recurrence
16.
Leuk Res ; 37(1): 32-6, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23102703

ABSTRACT

Previous small series have suggested that acute myeloid leukemia with t(8;16) is a distinct morphologic and clinical entity associated with poor prognosis. We describe 18 patients with t(8;16) AML, including their clinical, cytomorphologic, immunophenotypic and cytogenetic features. Half of the patients had extramedullary disease, most commonly leukemia cutis, which often preceded bone marrow involvement and six had therapy-related AML. Patients with t(8;16) AML commonly present with clinical and pathological features that mimic APL, with promyelocytes and promyeloblast-like cells and coagulopathy in most patients. Several patients also presented with marrow histiocytes with hemophagocytosis and erythrophagocytosis. Comprehensive molecular analysis for co-occurring genetic alterations revealed a somatic mutation in RUNX1 in 1 of 6 t(8;16) patients with no known AML mutation in the remaining five t(8;16) patients. This suggests that the t(8;16) translocation could be sufficient to induce hematopoietic cell transformation to AML without acquiring other genetic alteration. These data further support classifying t(8;16) AML as a clinically and molecularly defined subtype of AML marked by characteristic clinical and cytomorphologic features that mimic APL, and is associated with very poor survival.


Subject(s)
Chromosomes, Human, Pair 16 , Chromosomes, Human, Pair 8 , Leukemia, Myeloid, Acute/genetics , Leukemia, Promyelocytic, Acute/pathology , Translocation, Genetic , Adult , Aged , Core Binding Factor Alpha 2 Subunit/genetics , Disseminated Intravascular Coagulation/epidemiology , Female , Humans , Immunophenotyping , Leukemia, Myeloid, Acute/mortality , Leukemia, Myeloid, Acute/pathology , Male , Middle Aged , Mutation , Prognosis
17.
Article in English | MEDLINE | ID: mdl-23233557

ABSTRACT

Acute myeloid leukemia (AML) is the most common acute leukemia diagnosed in adults, and the majority of patients with AML die from relapsed disease. Although many studies over the past 4 decades have identified disease alleles in AML, recent genome-wide and candidate gene studies have identified additional recurrent somatic mutations in AML patients with biologic, clinical, and therapeutic importance. Herein we review our current understanding of the molecular pathogenesis of AML and discuss how mutational profiling can be used to refine prognostication in AML and to inform therapeutic approaches. We also review the current challenges in translating genomic studies to the clinical setting, which remains a significant challenge and an urgent priority.


Subject(s)
Genetic Markers/genetics , Hematology/methods , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/therapy , Mutation , Alleles , Animals , Carrier Proteins/genetics , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methyltransferase 3A , DNA Mutational Analysis , DNA-Binding Proteins/genetics , Daunorubicin/pharmacology , Dioxygenases , Genome-Wide Association Study , Genomics , Humans , Isocitrate Dehydrogenase/genetics , Medical Oncology/methods , Mice , Models, Genetic , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics
18.
Nat Genet ; 44(11): 1179-81, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23001125

ABSTRACT

Aging is characterized by clonal expansion of myeloid-biased hematopoietic stem cells and by increased risk of myeloid malignancies. Exome sequencing of three elderly females with clonal hematopoiesis, demonstrated by X-inactivation analysis, identified somatic TET2 mutations. Recurrence testing identified TET2 mutations in 10 out of 182 individuals with X-inactivation skewing. TET2 mutations were specific to individuals with clonal hematopoiesis without hematological malignancies and were associated with alterations in DNA methylation.


Subject(s)
Aging/genetics , DNA Methylation/genetics , DNA-Binding Proteins , Proto-Oncogene Proteins , 5-Methylcytosine/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Dioxygenases , Exome , Female , Hematopoiesis , Humans , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , X Chromosome Inactivation
19.
Cancer Cell ; 22(2): 180-93, 2012 Aug 14.
Article in English | MEDLINE | ID: mdl-22897849

ABSTRACT

Recurrent somatic ASXL1 mutations occur in patients with myelodysplastic syndrome, myeloproliferative neoplasms, and acute myeloid leukemia, and are associated with adverse outcome. Despite the genetic and clinical data implicating ASXL1 mutations in myeloid malignancies, the mechanisms of transformation by ASXL1 mutations are not understood. Here, we identify that ASXL1 mutations result in loss of polycomb repressive complex 2 (PRC2)-mediated histone H3 lysine 27 (H3K27) tri-methylation. Through integration of microarray data with genome-wide histone modification ChIP-Seq data, we identify targets of ASXL1 repression, including the posterior HOXA cluster that is known to contribute to myeloid transformation. We demonstrate that ASXL1 associates with the PRC2, and that loss of ASXL1 in vivo collaborates with NRASG12D to promote myeloid leukemogenesis.


Subject(s)
Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/pathology , Mutation/genetics , Myeloid Cells/pathology , Repressor Proteins/genetics , Animals , Cell Line, Tumor , Cell Proliferation , DNA-Binding Proteins/metabolism , Enhancer of Zeste Homolog 2 Protein , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Gene Silencing , Hematopoietic System/metabolism , Hematopoietic System/pathology , Histones/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Methylation , Mice , Myeloid Cells/metabolism , Polycomb Repressive Complex 2 , Polycomb-Group Proteins , Protein Binding , Repressor Proteins/metabolism , Transcription Factors/metabolism , Tumor Suppressor Proteins/metabolism , Ubiquitin Thiolesterase/metabolism , Up-Regulation/genetics , ras Proteins/metabolism
20.
Nat Rev Cancer ; 12(9): 599-612, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22898539

ABSTRACT

Recent genomic studies have identified novel recurrent somatic mutations in patients with myeloid malignancies, including myeloproliferative neoplasms (MPNs), myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML). In some cases these mutations occur in genes with known roles in regulating chromatin and/or methylation states in haematopoietic progenitors, and in other cases genetic and functional studies have elucidated a role for specific mutations in altering epigenetic patterning in myeloid malignancies. In this Review we discuss recent genetic and functional data implicating mutations in epigenetic modifiers, including tet methylcytosine dioxygenase 2 (TET2), isocitrate dehydrogenase 1 (IDH1), IDH2, additional sex combs-like 1 (ASXL1), enhancer of zeste homologue 2 (EZH2) and DNA methyltransferase 3A (DNMT3A), in the pathogenesis of MPN, MDS and AML, and discuss how this knowledge is leading to novel clinical, biological and therapeutic insights.


Subject(s)
Epigenomics , Mutation , Myelodysplastic Syndromes/genetics , Myeloproliferative Disorders/genetics , DNA Methyltransferase 3A , Humans
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