LEF1-AS1, long non-coding RNA, inhibits proliferation in myeloid malignancy

LEF1 antisense RNA 1 (LEF1-AS1) is an antisense long non-coding RNA encoded in the lymphoid enhancer-binding factor 1 (LEF1) locus. LEF1-AS1 is a conserved transcript dysregulated in hematopoiesis. This study aimed to functionally characterize the role of this transcript in myeloid malignancy and explore a possible regulatory effect of LEF1-AS1 upon LEF1. We show that LEF1-AS1 is highly expressed in normal hematopoietic stem cells but barely detectable in myeloid malignant cell lines. Additionally, bone marrow cells from myelodysplastic syndrome (n=12) and acute myeloid malignancy patients (n=28) expressed significantly reduced levels of LEF1-AS1 compared to healthy controls (n=15). Artificial LEF1-AS1 over-expression inhibited proliferation in HL60 and led to an upregulation of tumor suppressors p21 and p27, and reduced ERK1/2 activation. Unexpectedly, no underlying modulation of LEF1 was detected. Ectopic expression of LEF1-AS1 also inhibited proliferation in HELA, a cell line lacking endogenous expression of LEF1, supporting a LEF1-independent mechanism. Additionally, transient over-expression of LEF1-AS1 in AML patient cells also led to reduced proliferation and colony formation capacity. We used a mass spectrometry-based proteomics approach. Proteomic quantification identified the modulation of an important metabolic regulator, Fumarase, and concomitant accumulation of the metabolite fumarate23430213025FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2013/17227-

Low Bone Mass Density Is Associated With Hemolysis In Brazilian Patients With Sickle Cell Disease.

To determine whether kidney disease and hemolysis are associated with bone mass density in a population of adult Brazilian patients with sickle cell disease. Bone involvement is a frequent clinical manifestation of sickle cell disease, and it has multiple causes; however, there are few consistent clinical associations between bone involvement and sickle cell disease. Patients over 20 years of age with sickle cell disease who were regularly followed at the Hematology and Hemotherapy Center of Campinas, Brazil, were sorted into three groups, including those with normal bone mass density, those with osteopenia, and those with osteoporosis, according to the World Health Organization criteria. The clinical data of the patients were compared using statistical analyses. In total, 65 patients were included in this study: 12 (18.5%) with normal bone mass density, 37 (57%) with osteopenia and 16 (24.5%) with osteoporosis. Overall, 53 patients (81.5%) had bone mass densities below normal standards. Osteopenia and osteoporosis patients had increased lactate dehydrogenase levels and reticulocyte counts compared to patients with normal bone mass density (p<0.05). Osteoporosis patients also had decreased hemoglobin levels (p<0.05). Hemolysis was significantly increased in patients with osteoporosis compared with patients with osteopenia, as indicated by increased lactate dehydrogenase levels and reticulocyte counts as well as decreased hemoglobin levels. Osteoporosis patients were older, with lower glomerular filtration rates than patients with osteopenia. There was no significant difference between the groups with regard to gender, body mass index, serum creatinine levels, estimated creatinine clearance, or microalbuminuria. A high prevalence of reduced bone mass density that was associated with hemolysis was found in this population, as indicated by the high lactate dehydrogenase levels, increased reticulocyte counts and low hemoglobin levels.66801-

Identification of protein-coding and non-coding RNA expression profiles in CD34+ and in stromal cells in refractory anemia with ringed sideroblasts

<p>Abstract</p> <p>Background</p> <p>Myelodysplastic syndromes (MDS) are a group of clonal hematological disorders characterized by ineffective hematopoiesis with morphological evidence of marrow cell dysplasia resulting in peripheral blood cytopenia. Microarray technology has permitted a refined high-throughput mapping of the transcriptional activity in the human genome. Non-coding RNAs (ncRNAs) transcribed from intronic regions of genes are involved in a number of processes related to post-transcriptional control of gene expression, and in the regulation of exon-skipping and intron retention. Characterization of ncRNAs in progenitor cells and stromal cells of MDS patients could be strategic for understanding gene expression regulation in this disease.</p> <p>Methods</p> <p>In this study, gene expression profiles of CD34⁺cells of 4 patients with MDS of refractory anemia with ringed sideroblasts (RARS) subgroup and stromal cells of 3 patients with MDS-RARS were compared with healthy individuals using 44 k combined intron-exon oligoarrays, which included probes for exons of protein-coding genes, and for non-coding RNAs transcribed from intronic regions in either the sense or antisense strands. Real-time RT-PCR was performed to confirm the expression levels of selected transcripts.</p> <p>Results</p> <p>In CD34⁺cells of MDS-RARS patients, 216 genes were significantly differentially expressed (q-value ≤ 0.01) in comparison to healthy individuals, of which 65 (30%) were non-coding transcripts. In stromal cells of MDS-RARS, 12 genes were significantly differentially expressed (q-value ≤ 0.05) in comparison to healthy individuals, of which 3 (25%) were non-coding transcripts.</p> <p>Conclusions</p> <p>These results demonstrated, for the first time, the differential ncRNA expression profile between MDS-RARS and healthy individuals, in CD34⁺cells and stromal cells, suggesting that ncRNAs may play an important role during the development of myelodysplastic syndromes.</p

ANKHD1 regulates cell cycle progression and proliferation in multiple myeloma cells

ANKHD1 is a multiple ankyrin repeat containing protein, highly expressed in cancers, such as acute leukemia. the present study was undertaken to determine the expression and functional significance of ANKHD1 in human Multiple Myeloma (MM). We found that ANKHD1 is highly expressed in MM patient cells and cell lines. in vitro, lentiviral mediated ANKHD1-shRNA inhibited proliferation and delayed S to G2M cell cycle progression in glucocorticoid resistant (U266) and sensitive (MM1S) MM cells. Further ANKHD1 silencing resulted in upregulation of cyclin dependent kinase inhibitor p21 irrespective of the p53 status of the MM cell lines. These data suggest that ANKHD1 might have a role in MM cell proliferation and cell cycle progression by regulating expression of p21. (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.Instituto Nacional de Ciencia e Tecnologia do Sangue(INCTS)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Campinas Hemoctr Unicamp, Hematol & Hemotherapy Ctr, Inst Nacl Ciencia & Tecnol Sangue, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, São Paulo, BrazilWeb of Scienc

De novo AML exhibits greater microenvironment dysregulation compared to AML with myelodysplasia-related changes

The interaction between the bone marrow microenvironment and malignant hematopoietic cells can result in the protection of leukemia cells from chemotherapy in both myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). We, herein, characterized the changes in cytokine expression and the function of mesenchymal stromal cells (MSC) in patients with MDS, AML with myelodysplasia-related changes (MRC), a well-recognized clinical subtype of secondary AML, and de novo AML. We observed a significant inhibitory effect of MDS-MSC on T-lymphocyte proliferation and no significant differences in any of the cytokines tested. AML-MSC inhibited T-cell proliferation only at a very low MSC/T cell ratio. When compared to the control, AML-MRC-derived MSC presented a significant increase in IL6 expression, whereas de novo AML MSC presented a significant increase in the expression levels of VEGFA, CXCL12, RPGE2, IDO, IL1 beta, IL6 and IL32, followed by a decrease in IL10 expression. Furthermore, data indicate that IL-32 regulates stromal cell proliferation, has a chemotactic potential and participates in stromal cell crosstalk with leukemia cells, which could result in chemoresistance. Our results suggest that the differences between AML-MRC and de novo AML also extend into the leukemic stem cell niche and that IL-32 can participate in the regulation of the bone marrow cytokine milieu.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Univ Estadual Campinas, Hematol & Transfus Med Ctr, Hemoctr Unicamp, Inst Nacl Ciencia & Tecnol Sangue, Sao Paulo, BrazilUniv Sao Paulo, Ribeirao Preto Med Sch, Dept Internal Med, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Biol Sci, Sao Paulo, BrazilFed Univ Vale do Sao Francisco, Paulo Afonso, BA, BrazilUniv Fed Sao Paulo, Dept Biol Sci, Sao Paulo, BrazilWeb of Scienc

Irs2 Silencing Increases Apoptosis And Potentiates The Effects Of Ruxolitinib In Jak2v617f-positive Myeloproliferative Neoplasms.

The recurrent V617F mutation in JAK2 (JAK2V617F) has emerged as the primary contributor to the pathogenesis of myeloproliferative neoplasms (MPN). However, the lack of complete response in most patients treated with the JAK1/2 inhibitor, ruxolitinib, indicates the need for identifying pathways that cooperate with JAK2. Activated JAK2 was found to be associated with the insulin receptor substrate 2 (IRS2) in non-hematological cells. We identified JAK2/IRS2 binding in JAK2V617F HEL cells, but not in the JAK2WT U937 cell line. In HEL cells, IRS2 silencing decreased STAT5 phosphorylation, reduced cell viability and increased apoptosis; these effects were enhanced when IRS2 silencing was combined with ruxolitinib. In U937 cells, IRS2 silencing neither reduced cell viability nor induced apoptosis. IRS1/2 pharmacological inhibition in primary MPN samples reduced cell viability in JAK2V617F-positive but not JAK2WT specimens; combination with ruxolitinib had additive effects. IRS2 expression was significantly higher in CD34+ cells from essential thrombocythemia patients compared to healthy donors, and in JAK2V617F MPN patients when compared to JAK2WT. Our data indicate that IRS2 is a binding partner of JAK2V617F in MPN. IRS2 contributes to increased cell viability and reduced apoptosis in JAK2-mutated cells. Combined pharmacological inhibition of IRS2 and JAK2 may have a potential clinical application in MPN.

Fermented Papaya Preparation For β-thalassemia?

This article comments on the results obtained by Fibach et al., which showed reduction of oxidative status in red blood cells of patients with β- and E-β-thalassemia (β-thal) treated with fermented papaya preparation. The study was a three-center, prospective study, including eight patients with β-thal intermedia, four β-thal major and seven E-β-thal patients. The patients received 3 g of fermented papaya preparation (FPP) two- to three-times a day after meals, respectively, for 3 months. A marked decrease in reactive oxygen species, lipid peroxidation and phosphatidylserine externalization and an increase in GSH were detected in both groups of patients, indicating that FPP is efficient in reducing the oxidative stress of these red blood cells. The results are very encouraging as all parameters analyzed indicated the reduction of red blood cells oxidative stress by the action of a natural and inexpensive product.3265-

Polyphenolic Flavonoid Compound Quercetin Effects in the Treatment of Acute Myeloid Leukemia and Myelodysplastic Syndromes

Flavonoids are ubiquitous groups of polyphenolic compounds present in most natural products and plants. These substances have been shown to have promising chemopreventive and chemotherapeutic properties with multiple target interactions and multiple pathway regulations against various human cancers. Polyphenolic flavonoid compounds can block the initiation or reverse the promotion stage of multistep carcinogenesis. Quercetin is one of the most abundant flavonoids found in fruits and vegetables and has been shown to have multiple properties capable of reducing cell growth in cancer cells. Acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) therapy remains a challenge for hematologists worldwide, and the outcomes for patients with both disorders continue to be poor. This scenario indicates the increasing demand for innovative drugs and rational combinative therapies. Herein, we discuss the multitarget effects of the flavonoid quercetin, a naturally occurring flavonol, on AML and MDS