Hydroxyurea inhibits proliferation and stimulates apoptosis through inducible nitric oxide synthase in erythroid cells.

Hydroxyurea (hydroxycarbamide, HU) arrests cells in the S-phase by inhibiting ribonucleotide reductase and DNA synthesis, significantly contributing to the release of nitric oxide (NO). We investigated the involvement of inducible NO synthase (NOS2) in the cytostatic effect of HU using in vitro shRNA-induced knockdown of the NOS2 transcript (NOS2) or a specific NOS2 inhibitor (1400W) in human erythroleukemic HEL92.1.

Proinflammatory Microenvironment in Adenocarcinoma Tissue of Colorectal Carcinoma.

Cancer-promoting proinflammatory microenvironment influences colorectal cancer (CRC) development. We examined the biomarkers of inflammation, intestinal differentiation, and DNA activity correlated with the clinical parameters to observe progression and prognosis in the adenocarcinoma subtype of CRC. Their immunohistology, immunoblotting, and RT-PCR analyses were performed in the adenocarcinoma and neighboring healthy tissues of 64 patients with CRC after routine colorectal surgery.

Inflammation mediated angiogenesis in chronic lymphocytic leukemia.

Chronic inflammation has been identified in leukemias as an essential regulator of angiogenesis. B-chronic lymphocytic leukemia (CLL) cells secrete high levels of vascular endothelial growth factor (VEGF) and hypoxia inducible factor 1 alpha (HIF1α). The aim was to assess the role of inflammation in activation of angiogenic factors: endothelial nitric oxide synthase (eNOS), HIF1α and VEGF via proliferation related signaling pathways and VEGF autocrine control.

Sex Differences and Cytokine Profiles among Patients Hospitalized for COVID-19 and during Their Recovery: The Predominance of Adhesion Molecules in Females and Oxidative Stress in Males.

The severity and mortality of coronavirus disease 2019 (COVID-19) are greater in males than in females, though the infection rate is the same in the two sexes. We investigated sex hormone differences associated with the hyperinflammatory immune response to SARS-CoV-2 on the basis of patients' cytokine profiles and vaccination statuses. Clinical and laboratory data of 117 patients with COVID-19 were collected to examine sex differences associated with oxidative stress markers, neutrophil extracellular traps (NETs), and plasma cytokine levels up to 5 months from hospital admission.

Quality of Life in Post-COVID-19 Patients after Hospitalization.

The COVID-19 pandemic has had a strong impact on people's quality of life (QoL), which is affected by social and economic changes as well as by mental and physical health. The aim of this study was to determine QoL in post-COVID-19 patients who had required hospitalization, and to identify relevant sociodemographic data. We used questionnaires which considered demographic and socioeconomic data, health and vaccination status, the pandemic situation, and EQ-5D scoring.

Inhibition of proinflammatory signaling impairs fibrosis of bone marrow mesenchymal stromal cells in myeloproliferative neoplasms.

Although bone marrow-derived mesenchymal stromal cells (BM-MSCs) have been identified as a major cellular source of fibrosis, the exact molecular mechanism and signaling pathways involved have not been identified thus far. Here, we show that BM-MSCs contribute to fibrosis in myeloproliferative neoplasms (MPNs) by differentiating into αSMA-positive myofibroblasts. These cells display a dysregulated extracellular matrix with increased FN1 production and secretion of profibrotic MMP9 compared to healthy donor cells.

Inflammation Promotes Oxidative and Nitrosative Stress in Chronic Myelogenous Leukemia.

Chronic inflammation is characterized by the production of reactive oxygen species (ROS), reactive nitrogen species, and inflammatory cytokines in myeloproliferative neoplasms (MPNs). In addition to these parameters, the aim of this study was to analyze the influence of ROS on the proliferation-related AKT/mTOR signaling pathway and the relationship with inflammatory factors in chronic myelogenous leukemia (CML). The activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase is reduced in erythrocytes while levels of the oxidative stress markers malondialdehyde and protein carbonyl are elevated in the plasma of patients with CML.

Neutrophil Death in Myeloproliferative Neoplasms: Shedding More Light on Neutrophils as a Pathogenic Link to Chronic Inflammation.

Neutrophils are an essential component of the innate immune response, but their prolonged activation can lead to chronic inflammation. Consequently, neutrophil homeostasis is tightly regulated through balance between granulopoiesis and clearance of dying cells. The bone marrow is both a site of neutrophil production and the place they return to and die.

Hydroxyurea Induces Bone Marrow Mesenchymal Stromal Cells Senescence and Modifies Cell Functionality In Vitro.

Hydroxyurea (HU) is an antineoplastic agent that functions as an antimetabolite compound by inhibiting the ribonucleotide reductase. HU acts mainly as a cytostatic drug that through DNA replication stress may trigger a premature senescence-like cell phenotype, though its influence on bone marrow-derived mesenchymal stem/stromal cell (BMMSC) functions has not elucidated yet. Our results indicate that HU inhibits the growth of human BMMSC alongside senescence-like changes in both morphology and replicative potential, provokes cell cycle arrest at the S phase without affecting cellular viability and induces the expression of senescence-associated β-galactosidase and p16INK4.

Nitric Oxide Mediation in Hydroxyurea and Nitric Oxide Metabolites' Inhibition of Erythroid Progenitor Growth.

In several systems, hydroxyurea has been shown to trigger nitric oxide (NO) release or activation of NO synthase (NOS). To elucidate this duality in its pharmacological effects, during myelosuppression, we individually examined hydroxyurea's (NO releasing agent) and NO metabolites' (stable NO degradation products) effects on erythroid colony growth and NOS/NO levels in mice using NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). Hydroxyurea and nitrite/nitrate decreased the bone marrow cellularity that was blocked by PTIO only for the NO metabolites.

Nitric Oxide Synthase Dependency in Hydroxyurea Inhibition of Erythroid Progenitor Growth.

Hydroxyurea (HU) causes nitric oxide (NO) bioactivation, acting as both a NO donor and a stimulator of NO synthase (NOS). To examine whether HU effects are NO mediated by chemical degradation or enzymatic induction, we studied human and mouse erythroid cells during proliferation, apoptosis, and differentiation. The HU and NO donor demonstrated persisted versus temporary inhibition of erythroid cell growth during differentiation, as observed by γ- and β-globin gene expression.

An integrated view on society readiness and initial reaction to COVID-19: A study across European countries.

With the wake of the COVID-19 pandemic, the question of society's capability to deal with an acute health crisis is, once again, brought to the forefront. In the core is the need to broaden the perspective on the determinants of a country's ability to cope with the spread of the virus. This paper is about bringing together diverse aspects of readiness and initial reaction to a COVID-19 outbreak.

IL6 inhibition of inflammatory S100A8/9 proteins is NF-κB mediated in essential thrombocythemia.

This study has been performed to determine the mechanism of activation of the myeloid related S100A proteins by inflammatory cytokines in myeloproliferative neoplasm (MPN). Besides microarray analysis of MPN-derived CD34 cells, we analysed the pro-inflammatory IL6 and anti-inflammatory IL10 dependence of NF-κB, PI3K-AKT, and JAK-STAT signalling during induction of S100A proteins in mononuclear cells of MPN, by immunoblotting and flow cytometry. We observed the reduced gene expression linked to NF-κB and inflammation signalling in MPN-derived CD34 cells.

JAK2-mutant hematopoietic cells display metabolic alterations that can be targeted to treat myeloproliferative neoplasms.

Increased energy requirement and metabolic reprogramming are hallmarks of cancer cells. We show that metabolic alterations in hematopoietic cells are fundamental to the pathogenesis of mutant JAK2-driven myeloproliferative neoplasms (MPNs). We found that expression of mutant JAK2 augmented and subverted metabolic activity of MPN cells, resulting in systemic metabolic changes in vivo, including hypoglycemia, adipose tissue atrophy, and early mortality.

Hydroxyurea-induced senescent peripheral blood mesenchymal stromal cells inhibit bystander cell proliferation of JAK2V617F-positive human erythroleukemia cells.

Hydroxyurea (HU) is a nonalkylating antineoplastic agent used in the treatment of hematological malignancies. HU is a DNA replication stress inducer, and as such, it may induce a premature senescence-like cell phenotype; however, its repercussion on bystander cell proliferation has not been revealed so far. Our results indicate that HU strongly inhibited peripheral blood mesenchymal stromal cells (PBMSC) proliferation by cell cycle arrest in S phase, and that, consequently, PBMSC acquire senescence-related phenotypical changes.

A comprehensive mutation study in wide deep-rooted R1b Serbian pedigree: mutation rates and male relative differentiation capacity of 36 Y-STR markers.

Haplotyping of Y-chromosomal short tandem repeats (Y-STRs) reflects the paternal lineage, although, the father-son pair profiles may differ due to the germline mutations. In order to discriminate between closely related males in criminal cases, as well as for the correct application of Y-STRs in the paternity/kinship analysis and determination of the most recent common ancestor in the familial searching or genealogy research, the assessment of mutation rates of routinely used Y-STRs is of a great importance. We genotyped 120 males belonging to one wide deep-rooted pedigree separated by 1-20 meiosis.

β-catenin and PPAR-γ levels in bone marrow of myeloproliferative neoplasm: an immunohistochemical and ultrastructural study.

In accordance with increased proliferation in myeloproliferative neoplasm (MPN), the goal is to evaluate the immunoexpression of: β-catenin, PPAR-γ and Ki67 protein, to compare them with bone marrow ultrastructural characteristics in patients with MPN. Immunoexpression and electron microscopy of bone marrow was analyzed in 30 Ph-negative MPN patients, including per 10 patients with polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The quantity of β-catenin immunoreactive cells was significantly higher in PV then in ET (p < 0.

IL-6 stimulation of DNA replication is JAK1/2 mediated in cross-talk with hyperactivated ERK1/2 signaling.

Myeloproliferative neoplasms (MPNs) are developing resistance to therapy by JAK1/2 inhibitor ruxolitinib. To explore the mechanism of ruxolitinib's limited effect, we examined the JAK1/2 mediated induction of proliferation related ERK1/2 and AKT signaling by proinflammatory interleukin-6 (IL-6) in MPN granulocytes and JAK2V617F mutated human erythroleukemia (HEL) cells. We found that JAK1/2 or JAK2 inhibition prevented the IL-6 activation of STAT3 and AKT pathways in polycythemia vera and HEL cells.

Oxidative and nitrosative stress in myeloproliferative neoplasms: the impact on the AKT / mTOR signaling pathway.

Purpose: A common feature of malignancies is increased reactive oxygen species (ROS) and reactive nitrogen species (RNS). We analyzed the influence of oxidative and nitrosative stress on the activation of AKT/mTOR signaling pathway in myeloproliferative neoplasms (MPN).

Methods: Oxidative stress-induced gene expression in circulatory CD34+ cells of MPN patients was studied by microarray analysis.

TLR4 and RAGE conversely mediate pro-inflammatory S100A8/9-mediated inhibition of proliferation-linked signaling in myeloproliferative neoplasms.

Purpose: Previously, the family of S100A proteins has been found to be associated with inflammation and myelopoiesis and to be able to induce or support myeloproliferation during chronic inflammation. Here, we studied the inflammatory myeloid-related proteins S100A4, S100A8, S100A9 and S100A12 in myeloproliferative neoplasms (MPNs) in order to assess the involvement of chronic inflammation in the pathogenesis of MPN.

Methods: We analyzed the S100A4, S100A8, S100A9 and S100A12 mRNA and protein levels in the bone marrow and circulation of 140 patients with MPN and 15 healthy controls using Western blotting, microarray-based mRNA expression profiling and ELISA assays, respectively.

Quantitative Proteome Heterogeneity in Myeloproliferative Neoplasm Subtypes and Association with Mutation Status.

Apart from well-known genetic abnormalities, several studies have reported variations in protein expression in Philadelphia-negative myeloproliferative neoplasm (MPN) patients that could contribute toward their clinical phenotype. In this context, a quantitative mass spectrometry proteomics protocol was used to identify differences in the granulocyte proteome with the goal to characterize the pathogenic role of aberrant protein expression in MPNs. LC/MS-MS (LTQ Orbitrap) coupled to iTRAQ labeling showed significant and quantitative differences in protein content among various MPN subtypes [polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)], and according to the genetic status of ( presence and allele burden).

Bone marrow microvessel density and plasma angiogenic factors in myeloproliferative neoplasms: clinicopathological and molecular correlations.

Increased angiogenesis in BCR-ABL1 negative myeloproliferative neoplasms (MPNs) has been recognized, but its connection with clinical and molecular markers needs to be defined. The aims of study were to (1) assess bone marrow (BM) angiogenesis measured by microvessel density (MVD) using CD34 and CD105 antibodies; (2) analyze correlation of MVD with plasma angiogenic factors including vascular endothelial growth factor, basic fibroblast growth factor, and interleukin-8; (3) examine the association of MVD with clinicopathological and molecular markers. We examined 90 de novo MPN patients (30 polycythemia vera (PV), primary myelofibrosis (PMF), essential thrombocythemia (ET)) and 10 age-matched controls.

Angiogenic factors are increased in circulating granulocytes and CD34 cells of myeloproliferative neoplasms.

It has been shown that angiogenesis and inflammation play an important role in development of most hematological malignancies including the myeloproliferative neoplasm (MPN). The aim of this study was to investigate and correlate the levels of key angiogenic molecules such as hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) in peripheral blood and bone marrow cells of MPN patients, along with JAK2V617F mutation allele burden and effects of therapy. HIF-1α and VEGF gene expression were decreased, while eNOS mRNA levels were increased in granulocytes of MPN patients.

Proinflammatory Cytokine IL-6 and JAK-STAT Signaling Pathway in Myeloproliferative Neoplasms.

The recent JAK1/2 inhibitor trial in myeloproliferative neoplasms (MPNs) showed that reducing inflammation can be more beneficial than targeting gene mutants. We evaluated the proinflammatory IL-6 cytokine and JAK-STAT signaling pathway related genes in circulating CD34(+) cells of MPNs. Regarding laboratory data, leukocytosis has been observed in polycythemia vera (PV) and JAK2V617F mutation positive versus negative primary myelofibrosis (PMF) patients.

Gene expression profile of circulating CD34(+) cells and granulocytes in chronic myeloid leukemia.

Purpose: We compared the gene expression profile of peripheral blood CD34(+) cells and granulocytes in subjects with chronic myeloid leukemia (CML), with the accent on signaling pathways affected by BCR-ABL oncogene.

Methods: The microarray analyses have been performed in circulating CD34(+) cells and granulocytes from peripheral blood of 7 subjects with CML and 7 healthy donors. All studied BCR-ABL positive CML patients were in chronic phase, with a mean value of 2012±SD of CD34(+)cells/μl in peripheral blood.