miR-1202 acts as anti-oncomiR in myeloid leukaemia by down-modulating GATA-1 expression.

Transient abnormal myelopoiesis (TAM) is a Down syndrome-related pre-leukaemic condition characterized by somatic mutations in the haematopoietic transcription factor GATA-1 that result in exclusive production of its shorter isoform (GATA-1). Given the common hallmark of altered miRNA expression profiles in haematological malignancies and the pro-leukaemic role of GATA-1, we aimed to search for miRNAs potentially able to modulate the expression of GATA-1 isoforms. Starting from an prediction of miRNA binding sites in the GATA-1 transcript, miR-1202 came into our sight as potential regulator of GATA-1 expression.

Antileukemic effect of azacitidine, a DNA methyltransferase inhibitor, on cell lines of myeloid leukemia associated with Down syndrome.

Myeloid leukemia associated with Down syndrome (ML-DS) responds well to chemotherapy and has a favorable prognosis, but the clinical outcome of patients with refractory or relapsed ML-DS is dismal. We recently reported a case of relapsed ML-DS with an effective response to a DNA methyltransferase inhibitor, azacitidine (AZA). However, the efficacy of AZA for refractory or relapsed ML-DS remains uncertain.

KMT2D deficiency disturbs the proliferation and cell cycle activity of dental epithelial cell line (LS8) partially via Wnt signaling.

Lysine methyltransferase 2D (KMT2D), as one of the key histone methyltransferases responsible for histone 3 lysine 4 methylation (H3K4me), has been proved to be the main pathogenic gene of Kabuki syndrome disease. Kabuki patients with KMT2D mutation frequently present various dental abnormalities, including abnormal tooth number and crown morphology. However, the exact function of KMT2D in tooth development remains unclear.

Lower BCL11B expression is associated with adverse clinical outcome for patients with myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) is an aggressive and genetically heterogeneous disease with poor prognosis. Cellular immune disorder is a common characteristic of this disease and is thought to be related to clinical outcome. Alterations in T cell clonal expansion and T cell dysfunction has been detected in MDS patients.

[Myeloid proliferations related to Down syndrome].

Down syndrome (DS) is related to constitutional trisomy 21 and is characterized by typical dysmorphic features and various congenital abnormalities. DS is also associated with a broad spectrum of hematological findings, such as transient thrombocytopenia in the neonatal period and acute leukemia. Of those hematological abnormalities, transient abnormal myelopoiesis (TAM) and acute myeloid leukemia (AML) have common genetic abnormalities, i.

Epigenetic drug screen identifies the histone deacetylase inhibitor NSC3852 as a potential novel drug for the treatment of pediatric acute myeloid leukemia.

Background: Acute myeloid leukemia (AML) is a heterogeneous disease regarding morphology, immunophenotyping, genetic abnormalities, and clinical behavior. The overall survival rate of pediatric AML is 60% to 70%, and has not significantly improved over the past two decades. Children with Down syndrome (DS) are at risk of developing acute megakaryoblastic leukemia (AMKL), which can be preceded by a transient myeloproliferative disorder during the neonatal period.

[Clinical and laboratory analysis of a neonate with Down syndrome and a novel GATA1 gene mutation].

Objective: To analyze the clinical and molecular biological characteristics of a neonate with myeloid proliferation related to Down syndrome (DS).

Methods: The neonate, who was suspected for Down syndrome, was analyzed in terms of clinical feature, peripheral blood cell morphology, fluorescence in situ hybridization (FISH), immunological classification and other laboratory tests. On hundred and fourteen leukemia-related genes were subjected to next-generation sequencing (NGS).

Characterization of TRKA signaling in acute myeloid leukemia.

Tropomyosin-related kinase A (TRKA) translocations have oncogenic potential and have been found in rare cases of solid tumors. Accumulating evidence indicates that TRKA and its ligand, nerve growth factor (NGF), may play a role in normal hematopoiesis and may be deregulated in leukemogenesis. Here, we report a comprehensive evaluation of TRKA signaling in normal and leukemic cells.

miR-339 Promotes Development of Stem Cell Leukemia/Lymphoma Syndrome via Downregulation of the and Proapoptotic Genes.

The development of myeloid and lymphoid neoplasms related to overexpression of FGFR1 kinases as a result of chromosome translocations depends on the promotion of a stem cell phenotype, suppression of terminal differentiation, and resistance to apoptosis. These phenotypes are related to the stem cell leukemia/lymphoma syndrome (SCLL), which arises through the effects of the activated FGFR1 kinase on gene transcription, which includes miRNA dysregulation. In a screen for miRNAs that are directly regulated by FGFR1, and which stimulate cell proliferation and survival, we identified miR-339-5p, which is highly upregulated in cells carrying various different chimeric kinases.

Disulfiram overcomes bortezomib and cytarabine resistance in Down-syndrome-associated acute myeloid leukemia cells.

Background: Children with Down syndrome (DS) have increased risk for developing AML (DS-AMKL), and they usually experience severe therapy-related toxicities compared to non DS-AMKL. Refractory/relapsed disease has very poor outcome, and patients would benefit from novel, less toxic, therapeutic strategies that overcome resistance. Relapse/resistance are linked to cancer stem cells with high aldehyde dehydrogenase (ALDH) activity.

Acute megakaryoblastic leukemia with acquired trisomy 21 and GATA1 mutations in phenotypically normal children.

Unlabelled: GATA1 mutations are found almost exclusively in children with myeloid proliferations related to Down syndrome (DS). Here, we report two phenotypically and cytogenetically normal children with acute megakaryoblastic leukemia (AMKL) whose blasts had both acquired trisomy 21 and GATA1 mutation. Patient 1 was diagnosed with transient abnormal myelopoiesis in the neonatal period.

New classification of acute myeloid leukemia and precursor-related neoplasms: changes and unsolved issues.

The World Health Organization (WHO) classification of lympho-hematopoietic neoplasms is increasingly based on genetic criteria. Here, we focus on changes that, as compared to the 2001 edition, were introduced into the 2008 WHO classification of acute myeloid leukemia (AML) and related precursor neoplasms. The category of AML with recurrent genetic abnormalities was expanded to account for 60% of AML by adding three distinct entities, i.

Tissue transglutaminase contributes to the all-trans-retinoic acid-induced differentiation syndrome phenotype in the NB4 model of acute promyelocytic leukemia.

Treatment of acute promyelocytic leukemia (APL) with all-trans-retinoic acid (ATRA) results in terminal differentiation of leukemic cells toward neutrophil granulocytes. Administration of ATRA leads to massive changes in gene expression, including down-regulation of cell proliferation-related genes and induction of genes involved in immune function. One of the most induced genes in APL NB4 cells is transglutaminase 2 (TG2).

Congenital acute myeloid leukemia with t(8;16) and t(17;19) double translocation: case presentation and literature review.

Congenital leukemia is uncommon and excluding transient myeloproliferation associated with Down syndrome, makes up approximately 1% of childhood leukemias. A newborn boy was born with multiple subcutaneous nodules and large purpuric papules. Skin biopsy revealed proliferation of atypical hematologic cells in the dermis.

Myeloid proliferation without GATA1 mutations in a fetus with Down syndrome presenting in utero as a pericardial effusion.

An isolated pericardial effusion was observed during a routine prenatal ultrasound in a fetus of 30 and 3/7 weeks gestation. Amniocentesis was performed and revealed a trisomy 21. After prenatal counseling, the parents opted for termination of the pregnancy at 32 weeks.

miR-125b-2 is a potential oncomiR on human chromosome 21 in megakaryoblastic leukemia.

Children with trisomy 21/Down syndrome (DS) are at high risk to develop acute megakaryoblastic leukemia (DS-AMKL) and the related transient leukemia (DS-TL). The factors on human chromosome 21 (Hsa21) that confer this predisposing effect, especially in synergy with consistently mutated transcription factor GATA1 (GATA1s), remain poorly understood. Here, we investigated the role of Hsa21-encoded miR-125b-2, a microRNA (miRNA) overexpressed in DS-AMKL/TL, in hematopoiesis and leukemogenesis.

ERG is a megakaryocytic oncogene.

Ets-related gene (ERG) is a member of the ETS transcription factor gene family located on Hsa21. ERG is known to have a crucial role in establishing definitive hematopoiesis and is required for normal megakaryopoiesis. Truncated forms of ERG are associated with multiple cancers such as Ewing's sarcoma, prostate cancer, and leukemia as part of oncogenic fusion translocations.

Changed concepts and definitions of myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) in the updated 2008 WHO classification.

The purpose of this overview is to discuss the changes in the 2008 WHO classification of myeloid neoplasms, with exclusion of acute myeloid leukaemia. Specific mutations or rearrangements leading to constitutive activation of growth factor receptors or cytoplasmic tyrosine kinases are now recognised as recurrent genetic events characterising the group of myeloproliferative neoplasms (MPN). A newly introduced subgroup consists of patients with persistent eosinophilia and myeloid or lymphoid proliferations harbouring specific genetic changes involving platelet-derived growth factor receptors alpha and beta (PDGFRA and PDGFRB) or fibroblast growth factor receptor 1 (FGFR1).

The key role of stem cell factor/KIT signaling in the proliferation of blast cells from Down syndrome-related leukemia.

Transient leukemia (TL) has been observed in approximately 10% of newborn infants with Down syndrome (DS). Although treatment with cytarabine is effective in high-risk TL cases, approximately 20% of severe patients still suffer early death. In this study, we demonstrate abundant KIT expression in all 13 patients with GATA1 mutations, although no significant difference in expression levels was observed between TL and acute myeloid leukemia.

Trisomy 21 enhances human fetal erythro-megakaryocytic development.

Children with Down syndrome exhibit 2 related hematopoietic diseases: transient myeloproliferative disorder (TMD) and acute megakaryoblastic leukemia (AMKL). Both exhibit clonal expansion of blasts with biphenotypic erythroid and megakaryocytic features and contain somatic GATA1 mutations. While altered GATA1 inhibits erythro-megakaryocytic development, less is known about how trisomy 21 impacts blood formation, particularly in the human fetus where TMD and AMKL originate.

Host immunosurveillance controls tumor growth via IFN regulatory factor-8 dependent mechanisms.

IFN regulatory factor (IRF)-8 plays an important role in normal myelopoiesis. The loss of IRF-8 in myeloid cells results in a chronic myelogenous leukemia-like syndrome, suggesting that IRF-8 behaves as a tumor suppressor gene in certain hematopoietic malignancies. We have been investigating the molecular determinants of solid tumor progression, with an emphasis on apoptotic resistance.

Myeloid maturation block by AML1-MTG16 is associated with Csf1r epigenetic downregulation.

De novo epigenetic changes at histone and DNA level that affect gene transcription in cancer may be less random than we originally thought. Leukemia fusion proteins associated with specific chromosome translocations could mechanistically determine the epigenetic fate of specific target genes critical for normal hematopoiesis. This seems to be the case with AML1-MTG16, a fusion protein resulting from the t(16;21) translocation, a hallmark of therapy-related leukemia and myelodysplastic syndrome.

Menin and MLL cooperatively regulate expression of cyclin-dependent kinase inhibitors.

Mutations in the MEN1 gene are associated with the multiple endocrine neoplasia syndrome type 1 (MEN1), which is characterized by parathyroid hyperplasia and tumors of the pituitary and pancreatic islets. The mechanism by which MEN1 acts as a tumor suppressor is unclear. We have recently shown that menin, the MEN1 protein product, interacts with mixed lineage leukemia (MLL) family proteins in a histone methyltransferase complex including Ash2, Rbbp5, and WDR5.