Attenuated cell cycle and DNA damage response transcriptome signatures and overrepresented cell adhesion processes imply accelerated progression in patients with lower-risk myelodysplastic neoplasms.

Patients with myelodysplastic neoplasms (MDS) are classified according to the risk of acute myeloid leukemia transformation. Some lower-risk MDS patients (LR-MDS) progress rapidly despite expected good prognosis. Using diagnostic samples, we aimed to uncover the mechanisms of this accelerated progression at the transcriptome level.

Elevated erythroferrone distinguishes erythrocytosis with inherited defects in oxygen-sensing pathway from primary familial and congenital polycythaemia.

Congenital erythrocytoses represent a heterogenous group of rare defects of erythropoiesis characterized by elevated erythrocyte mass. We performed molecular-genetic analysis of 21 Czech patients with congenital erythrocytosis and assessed the mutual link between chronic erythrocyte overproduction and iron homoeostasis. Causative mutations in erythropoietin receptor (EPOR), hypoxia-inducible factor 2 alpha (HIF2A) or Von Hippel-Lindau (VHL) genes were detected in nine patients, including a novel p.

Deep Molecular Response Achieved with Chemotherapy, Dasatinib and Interferon α in Patients with Lymphoid Blast Crisis of Chronic Myeloid Leukaemia.

The treatment outcome in patients with chronic myeloid leukaemia (CML) in blast crisis (BC) is unsatisfactory despite the use of allogeneic stem cell transplantation (ASCT). Moreover, in some patients ASCT is contraindicated, with limited treatment options. We report the case series of two patients with lymphoid BC CML in whom ASCT was not approachable.

Developmental changes in iron metabolism and erythropoiesis in mice with human gain-of-function erythropoietin receptor.

Iron availability for erythropoiesis is controlled by the iron-regulatory hormone hepcidin. Increased erythropoiesis negatively regulates hepcidin synthesis by erythroferrone (ERFE), a hormone produced by erythroid precursors in response to erythropoietin (EPO). The mechanisms coordinating erythropoietic activity with iron homeostasis in erythrocytosis with low EPO are not well defined as exemplified by dominantly inherited (heterozygous) gain-of-function mutation of human EPO receptor (mtHEPOR) with low EPO characterized by postnatal erythrocytosis.

RUNX1 mutations contribute to the progression of MDS due to disruption of antitumor cellular defense: a study on patients with lower-risk MDS.

Patients with lower-risk myelodysplastic syndromes (LR-MDS) have a generally favorable prognosis; however, a small proportion of cases progress rapidly. This study aimed to define molecular biomarkers predictive of LR-MDS progression and to uncover cellular pathways contributing to malignant transformation. The mutational landscape was analyzed in 214 LR-MDS patients, and at least one mutation was detected in 137 patients (64%).

Low Plasma Citrate Levels and Specific Transcriptional Signatures Associated with Quiescence of CD34 Progenitors Predict Azacitidine Therapy Failure in MDS/AML Patients.

To better understand the molecular basis of resistance to azacitidine (AZA) therapy in myelodysplastic syndromes (MDS) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), we performed RNA sequencing on pre-treatment CD34 hematopoietic stem/progenitor cells (HSPCs) isolated from 25 MDS/AML-MRC patients of the discovery cohort (10 AZA responders (RD), six stable disease, nine progressive disease (PD) during AZA therapy) and from eight controls. Eleven MDS/AML-MRC samples were also available for analysis of selected metabolites, along with 17 additional samples from an independent validation cohort. Except for two patients, the others did not carry isocitrate dehydrogenase (IDH)1/2 mutations.

Oxidative DNA Damage, Inflammatory Signature, and Altered Erythrocytes Properties in Diamond-Blackfan Anemia.

Molecular pathophysiology of Diamond-Blackfan anemia (DBA) involves disrupted erythroid-lineage proliferation, differentiation and apoptosis; with the activation of p53 considered as a key component. Recently, oxidative stress was proposed to play an important role in DBA pathophysiology as well. CRISPR/Cas9-created Rpl5- and Rps19-deficient murine erythroleukemia (MEL) cells and DBA patients' samples were used to evaluate proinflammatory cytokines, oxidative stress, DNA damage and DNA damage response.

The specific PKC-α inhibitor chelerythrine blunts costunolide-induced eryptosis.

Costunolide, a natural sesquiterpene lactone, has multiple pharmacological activities such as neuroprotection or induction of apoptosis and eryptosis. However, the effects of costunolide on pro-survival factors and enzymes in human erythrocytes, e.g.

Role of DNA Damage Response in Suppressing Malignant Progression of Chronic Myeloid Leukemia and Polycythemia Vera: Impact of Different Oncogenes.

Inflammatory and oncogenic signaling, both known to challenge genome stability, are key drivers of -positive chronic myeloid leukemia (CML) and V617F-positive chronic myeloproliferative neoplasms (MPNs). Despite similarities in chronic inflammation and oncogene signaling, major differences in disease course exist. Although BCR-ABL has robust transformation potential, V617F-positive polycythemia vera (PV) is characterized by a long and stable latent phase.

Iron chelation and 2-oxoglutarate-dependent dioxygenase inhibition suppress mantle cell lymphoma's cyclin D1.

The patients with mantle cell lymphoma (MCL) have translocation t(11;14) associated with cyclin D1 overexpression. We observed that iron (an essential cofactor of dioxygenases including prolyl hydroxylases [PHDs]) depletion by deferoxamine blocked MCL cells' proliferation, increased expression of DNA damage marker γH2AX, induced cell cycle arrest and decreased cyclin D1 level. Treatment of MCL cell lines with dimethyloxalylglycine, which blocks dioxygenases involving PHDs by competing with their substrate 2-oxoglutarate, leads to their decreased proliferation and the decrease of cyclin D1 level.

[Hemoglobinopathies].

This article summarize molecular-genetic basis of hemoglobinopathies, their classification and phenotypic manifestations. The description of individual subgroups is supplemented with a case reports of patients diagnosed in the Czech population. This paper provides an overview of 14 types of α-thalassemic mutations, 34 β-thalassemic alleles, 4 δβ-thalassemic alleles and 22 hemoglobin variants identified in the Czech population in 876 persons from 579 families.

Discovery of N-(4-Amino-cyclohexyl)-9-cyclopentyl- N-(4-morpholin-4-ylmethyl-phenyl)- 9H-purine-2,6-diamine as a Potent FLT3 Kinase Inhibitor for Acute Myeloid Leukemia with FLT3 Mutations.

FLT3 tyrosine kinase is a potential drug target in acute myeloid leukemia (AML) because patients with FLT3-ITD mutations respond poorly to standard cytotoxic agents and there is a clear link between the disease and the oncogenic properties of FLT3. We present novel 2,6,9-trisubstituted purine derivatives with potent FLT3 inhibitory activity. The lead compound 7d displays nanomolar activity in biochemical assays and selectively blocks proliferation of AML cell lines harboring FLT3-ITD mutations, whereas other transformed and normal human cells are several orders of magnitude less sensitive.

Erythropoietin Signaling Increases Choroidal Macrophages and Cytokine Expression, and Exacerbates Choroidal Neovascularization.

Erythropoietin (EPO) is recognized for neuroprotective and angiogenic effects and has been associated with aging and neovascular age-related macular degeneration (AMD). We hypothesized that systemic EPO facilitates the development of choroidal neovascularization (CNV). Wild type mice expressed murine EPOR (mWtEPOR) in RPE/choroids at baseline and had significantly increased serum EPO after laser treatment.

Two novel mutations (p.(Ser160Pro) and p.(Arg472Cys)) causing glucose-6-phosphate isomerase deficiency are associated with erythroid dysplasia and inappropriately suppressed hepcidin.

Glucose-6-phosphate isomerase (GPI) deficiency, a genetic disorder responsible for chronic nonspherocytic hemolytic anemia, is the second most common red blood cell glycolytic enzymopathy. We report three patients from two unrelated families of Czech and Slovak origin with macrocytic hemolytic anemia due to GPI deficiency. The first patient had 15% of residual GPI activity resulting from two new heterozygous missense mutations c.

Loss of Major DNase I Hypersensitive Sites in Duplicated β-globin Gene Cluster Incompletely Silences HBB Gene Expression.

We report an infant with sickle cell disease phenotype by biochemical analysis whose β-globin gene (HBB) sequencing showed sickle cell mutation (HBB ) heterozygosity. The proband has a unique head-to-tail duplication of the β-globin gene cluster having wild-type (HBB ) and HBB alleles inherited from her father; constituting her HBB /HBB -HBB genotype. Further analyses revealed that proband's duplicated β-globin gene cluster (∼650 kb) encompassing HBB does not include the immediate upstream locus control region (LCR) or 3' DNase I hypersensitivity (HS) element.

Cooperation of germ line JAK2 mutations E846D and R1063H in hereditary erythrocytosis with megakaryocytic atypia.

The role of somatic JAK2 mutations in clonal myeloproliferative neoplasms (MPNs) is well established. Recently, germ line JAK2 mutations were associated with polyclonal hereditary thrombocytosis and triple-negative MPNs. We studied a patient who inherited 2 heterozygous JAK2 mutations, E846D from the mother and R1063H from the father, and exhibited erythrocytosis and megakaryocytic atypia but normal platelet number.

Molecular Characterization of β-Thalassemia in the Czech and Slovak Populations: Mediterranean, Asian and Unique Mutations.

β-Thalassemia (β-thal) is considered rare in Central Europe. As in other malaria-free regions, the presence of β-thal in Central Europe reflects historical and recent immigration, and demographic changes that have influenced the genetic variability of the current populations living in this area. This study assesses the frequency and spectrum of mutations on the β-globin gene in Czech and Slovak subjects with clinical symptoms of thalassemia.

Delayed hemoglobin switching and perinatal neocytolysis in mice with gain-of-function erythropoietin receptor.

Unlabelled: Mutations of the truncated cytoplasmic domain of human erythropoietin receptor (EPOR) result in gain-of-function of erythropoietin (EPO) signaling and a dominantly inherited polycythemia, primary familial and congenital polycythemia (PFCP). We interrogated the unexplained transient absence of perinatal polycythemia observed in PFCP patients using an animal model of PFCP to examine its erythropoiesis during embryonic, perinatal, and early postnatal periods. In this model, we replaced the murine EpoR gene (mEpoR) with the wild-type human EPOR (wtHEPOR) or mutant human EPOR gene (mtHEPOR) and previously reported that the gain-of-function mtHEPOR mice become polycythemic at 3~6 weeks of age, but not at birth, similar to the phenotype of PFCP patients.

DMT1-mutant erythrocytes have shortened life span, accelerated glycolysis and increased oxidative stress.

Background/aims: Deficiency of the divalent metal transporter 1 (DMT1) leads to hypochromic microcytic anemia. We have previously shown that DMT1 deficiency impairs erythroid differentiation and induces apoptosis of erythroid cells. Here we analyzed metabolic processes and survival of mature erythrocytes in order to address potential involvement of erythrocyte defect in the pathophysiology of the disease.