bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of the Human α-Globin Genes by GKLF.
Authors: Moi Paolo , Marini Giuseppina Maria , Porcu Loredana , Asunis Isadora , Loi Maria Giuseppina , Cabriolu Lisa Anna , Cao Antonio 
Published: April 2020

Abstract
EKLF and related Krueppel-like factors (KLFs) are variably implicated in the regulation of the β- and β-like globin genes. Prompted by the observation that four KLF sites are distributed in the human α-globin promoter, we investigated if any of the β-globin cluster regulating KLFs could also act to modulate the expression of the α-globin genes. We found that, among the globin regulating KLFs (EKLF, LKLF, BKLF, GKLF, KLF6, FKLF and FKLF2), only GKLF and BKLF bound specifically to three out of four KLF sites. In K562 cells, over-expressed GKLF transactivated at high levels a α-globin-luciferase reporter and its action was impaired by point mutations of the KLF sites that disrupted GKLFDNA binding. In K562 cells stably transfected with a Tet-off regulated GKLF expression cassette, GKLF induction stimulated the expression of the endogenous α-globin genes. In a complementary assay in K562 cells, knocking down GKLF expression with small interfering RNAs caused a parallel decrease in the transcription of the α-globin genes. All experiments combined support a main regulatory role of GKLF in the control of α-globin gene expression.
Role of Cjun in Gγ-Globin Gene Trans-Activation.
Authors: Kodeboyina Sirisha , Zein Sima , Lee Moosueng , Balamurugan Parimaladevi , Yao Xiao , Pace Betty 
Published: April 2020

Abstract
Previous studies from our laboratory demonstrated the role of the G-CRE (Gγ-globin cAMP response element) in drug-mediated fetal hemoglobin induction. The G-CRE located at −1222 to −1229 in the promoter of Gγ-globin gene, contains binding site for trans-factors CREB1, ATF-2 and cJun. We previously demonstrated binding of phosphorylated CREB1 and ATF-2 to this element via p38 MAPK signaling triggered by sodium butyrate (NaB) and trichostatin A (TSA). Electrophoretic mobility shift assays with a probe containing the AC → TG mutation in the G-CRE (TGTGGTCA, m2) abolished trans-factor binding to the G-CRE. Furthermore, Gγ promoter activity was abolished in the PGL3 luciferase reporter vector driven by the Gγ promoter (−1500 to +36) carrying the m2 mutation. (Sangerman et al. Blood108:3590–9, 2006). Subsequent studies in our laboratory were aimed at understanding the role of trans-factor cJun, an AP-1 family member, as a regulator of Gγ-globin expression via the G-CRE site. In K562 cells treated with 2mM NaB or 0.3μM TSA for 48 hrs, cJun phosphorylation increased 2.8-fold and 6.4-fold respectively by western blot analysis. Chromatin immunoprecipitation studies showed 16-fold chromatin enrichment in the −1225 Gγ-globin region compared to IgG control studies indicative of significant cJun binding in vivo at steady state. Electrophoretic mobility shift assays using cJun monoclonal antibody demonstrated a supershifted DNA-protein complex confirming binding of cJun to the G-CRE probe. To gain evidence for a functional role of cJun, we performed enforced expression studies using the pLen-cJun vector. In a concentration dependent manner, over-expression of cJun increased luciferase activity up to 350-fold in the luciferase reporter plasmid controlled by the Gγ-promoter (−1500 to +36). As predicted from binding studies, the m2 mutation in this promoter abolished the cJunmediated trans-activation confirming that the G-CRE is required to mediate effects of cJun. We are currently investigating the ability of cJun to trans-activate the endogenous Gγ-globin gene in K562 cells. To achieve this goal, K562 stable lines were established with the expression vectors pLen-cJun and empty vector. A complete analysis of the stable lines is in progress. Future investigations to identify other components of the functional CREB1/ATF2/cJun enhanceosome complex bound to the G-CRE will be performed using affinity chromatography and mass spectrometry. This information will be used to develop strategies for fetal hemoglobin induction.
TPO Exerts a Protective Effect on Iron-Induced Apoptosis Via Erk1/2 Signaling in Human Mesenchymal Stem Cells.
Authors: Zhang Wei , Yang Mo , Chan Shing , Chan Godfrey ChiFung 
Published: April 2020

Abstract
Osteoporosis is a very common problem among adolescent and adult patients with thalassaemia major (TM). The pathogenesis of osteoporosis in TM is related to several factors including iron overload. Bone is derived from osteoblasts. And osteoblasts are differentiated from mesenchymal stem cells (MSC). Therefore, iron-overload induced MSC damage may contribute to osteopenia and osteoporosis. The effect of iron-overload on MSC has not been investigated previously. We hypothesize that iron-overload may induce apoptosis in MSC by caspase-dependent pathway, and haematopoietic growth factor thrombopoietin (TPO) and calcium channel blocker amlodipine may have a protective effect on iron-induced apoptosis in these cells. We have shown that iron (FeCl3) reduced hMSCs viability in a dose-dependent manner (0–0.6 mM) (n=5). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.3 mM) for 72 hrs (n=4). The expression of active caspase-3 was significantly increased in iron-treated cells (0.15mM, 0.3mM) (n=5). Iron treatment also increased the proportion of cells containing JC-1 monomers, indicating a trend in the drop of mitochondrial membrane potential. TPO exerted protective effect on iron-induced apoptosis in hMSCs. Human MSCs were cultured in the presence of iron (0.3 mM) with or without TPO (50 ng/ml) for 72 hrs (n=4). The cell viability was significantly increased with the treatment of TPO. Dot-plot analysis of annexin V/PI staining demonstrated that TPO significantly reduced the population of apoptotic cells. Incubation with TPO also decreased the iron-induced caspase-3 expression. Flow cytometric dot-plot analysis of hMSCs also showed trends of amelioration of the increase in JC-1 monomers in the iron plus TPO. The population of phospho-Erk1/2 was also significantly increased in TPO-treatment, and the increased phospho-Erk was significantly reversed by the upstream signaling inhibitor PD098059. Calcium channel blocker amlodipine (10−9M) also had a protective effect on iron-induced apoptosis in these cells. Our findings suggest that iron-overload induces apoptosis in hMSCs via the caspase-dependent pathway and that TPO and amlodipine might exert a protective effect on iron-induced apoptosis via the activation of Erk1/2 signaling. The use of either haematopoietic growth factor or calcium channel blocker for the protection of hMSCs from iron induced toxicity is a novel concept. Our study has the potential in minimizing the bone damage induced by iron-overload in patients with thalassaemia major.
Taxanes Induce a Rapid Mobilization of Different Populations of Circulating Endothelial Progenitors by SDF-1 Modulation in Cancer Patients.
Authors: Bono Anna , Quarna Jessica , Marighetti Paola , Calleri Angelica , Antoniotti Pierluigi , Mancuso Patrizia , Voest Emile E , Langenberg Marlies , Roodhart Jeanine , Shaked Yuval , Kerbel Robert S , Bertolini Francesco 
Published: April 2020

Abstract
There is increasing clinical evidence that the addition of certain anti-angiogenic drugs can enhance the anti-cancer activity of many different chemotherapeutic drugs. Hypotheses to explain how anti-angiogenic drugs act as chemosensitizing agents include the “cancer vessel normalization” scenario and the ability of anti-angiogenic drugs to slow down tumor regrowth and thus increase the degree and durability of the tumor response. We have previously observed in preclinical studies a mobilization of circulating endothelial progenitors (CEPs) several days after the administration of maximum tolerable dose (MTD) cyclophosphamide (Bertolini et al, 2003), and suggested that such a CEP mobilization may facilitate tumor cell repopulation during the subsequent drug-free break that is necessary to allow recovery from the toxic side effects of such therapy. We report here preclinical and clinical evidence that several chemotherapeutics, and in particular taxanes, induce a rapid CEP increase. In previous mouse studies (Shaked et al, Cancer Cell, in press 2008), 4–24 hours after MTD administration of taxanes we observed a 3–8 fold CEP increase (depending on the mice strain, drug and dose administered). A similarly rapid CEP mobilization was observed (albeit at a less relevant level) after 5-FU administration, but not after the administration of drugs such as gemcitabine, anthracycline derivates or topo-isomerase inhibitors. The rapid mobilization induced by taxanes resulted in a colonization of treated tumors by CEPs, that was abrogated by the previous administration of anti-angiogenic drugs blocking VEGF or VEGFR2. A rapid increase in circulating SDF-1 levels was similarly observed after taxane administration, and inhibition of the CXCR4-SDF-1 axis by monoclonal antibodies blocked CEP mobilization and significantly enhanced the anti-tumor activity of taxanes. In clinical studies in cancer patients in Milan and Utrecht (n=54), we observed that MTD taxanes induced a rapid (by 4 hours) increase in circulating SDF-1 levels and a parallel 2–4 fold increase in a variety of different CEP populations (evaluated by six-colour flow cytometry as viable CD45- CD34+VEGFR2+ cells, CD133+ cells, CD45-CD133+ cells, CD45-CD34+CD133+ cells and CD45-CD34+CD133+CXCR4+ cells). Circulating levels of G-CSF, VEGF, VEGFR1 and VEGFR2 were not significantly modulated 4–24 hours after taxane administration. Taken together, our data indicate a novel SDF-1-related mechanism explaining the chemosensitizing activity of anti-angiogenic drugs and suggest that VEGF/VEGFR and SDF-1 inhibition can increase the anti-cancer efficacy of taxanes. Further investigations about chemotherapy-induced CEP mobilization might have a clinical impact in cancer and vascular medicine.
Activation of Endothelial Cells by Cocaine.
Authors: Hobbs William , Chen Junmei , Lopez Jose A. 
Published: April 2020

Abstract
Cocaine use is associated with cardiac ischemia, sudden death, and stroke in patients with few additional risk factors for cardiovascular disease. Despite the very short halflife of cocaine in circulation (less than 1 hr), the risk of these cardiovascular events remains elevated for up to one week after cocaine ingestion. Pathologic findings following cocaine-associated cardiac events include platelet-rich microthrombi and accelerated atherosclerosis. In addition, observational studies have identified increased levels of von Willebrand Factor (VWF) at steady state in plasma of chronic cocaine abusers, which increase following cocaine challenge. Plasma VWF is derived primarily from endothelial cells, with a smaller contribution from platelets. Thus, cocaine may activate platelets and/or endothelial cells contributing to tissue ischemia, in addition to its well-known effects of vasoconstriction and increased tissue metabolic demand. When first released, VWF is hyperadhesive and capable of spontaneously binding platelets. This form, termed ultralarge VWF (ULVWF) because some of the multimers are extremely large, is normally rapidly processed by the metalloprotease ADAMTS13 into the smaller, less reactive forms usually found in plasma. Failure of this process, due to congenital or acquired deficiency of ADAMTS13, leads to accumulation of ULVWF, and in its most severe form produces the devastating microthrombotic disease, thrombotic thrombocytopenic purpura (TTP). We hypothesized that cocaine could activate the endothelium to secrete ULVWF, and thus promote thrombosis and/or vaso-occlusion. To test this possibility, we exposed cultured human umbilical vein endothelial cells (HUVEC) to various concentrations of cocaine. We found that 0.5 mg/ml cocaine, a concentration comparable to peak blood levels detectable in cocaine abusers, induced secretion of ULVWF almost as efficiently as did 25 μM histamine, a potent ULVWF secretogogue. If platelets were then perfused over the endothelium in a parallel plate flow chamber at 2.5 dyne/cm2, they spontaneously formed beads-on-a-string structures on the attached ULVWF strands. We also evaluated the ability of cocaine metabolites to induce ULVWF release. Neither norcocaine nor ecoginine methyl ester (both minor metabolites) stimulated ULVWF release. However, benzoylecgonine, the major cocaine metabolite (detectable in plasma up to 6–8 days after cocaine use) potently induced ULVWF release, as detected by the formation of ULVWF strings and accumulation of higher molecular weight VWF multimers in the HUVEC supernatant on non-reducing agarose gels. These effects of cocaine are likely to contribute to cardiovascular syndromes associated with cocaine use, including the triggering of vasoocclusive crises in sickle cell anemia, and may explain the observed association of cocaine use with TTP. Furthermore, these results suggest that clinical management of cocaineinduced ischemia or vaso-occlusion may benefit from therapies aimed at disrupting ULVWF.
Vascular Branching Morphogenesis of the Placenta Requires Expression of Ott1(Rbm15) in the Trophoblast Compartment.
Authors: Raffel Glen D. , Chu Gerry C , Cullen Dana E. , Bronson Roderick T , Bernard Olivier A , Gilliland D. Gary 
Published: April 2020

Abstract
OTT1(RBM15) is a transcriptional activator/repressor known to be a fusion partner in t(1;22) infant acute megakaryocytic leukemia. Conditional deletion of Ott1 in adult mice resulted in expansions of the megakaryocytic, myeloid and pluripotent Lin−Sca-1+c-Kit+ populations and a block in pre B lymphoid development, suggesting a global regulatory role in hematopoiesis. Germline deletion of Ott1 is homozygous lethal after E9.5, producing developmentally delayed embryos with open notochords. Further investigation into the cause of embryonic death revealed a placental defect characterized by arrested vascular branching morphogenesis of the invading fetal vessels, leading to embryonic demise through inadequate oxygenation. Histopathology and in situ hybridization of Ott1-deficient placentas identified a dramatic reduction in the spongiotrophoblast and syncytiotrophoblast layers. Expression of Vegf, a critical element of placental vasculogenesis, was still observed, thus excluding the requirement for Ott1 in its induction. By using Sox2-cre with a conditional allele of Ott1, complete excision of Ott1 was achieved within the embryo yet the placental trophoblast compartment was left undeleted. These embryos were now able to form normal placentas with intact vascular branching morphogenesis and survive to term. This result demonstrates that Ott1-mediated vascular branching morphogenesis is regulated by the trophoblast compartment rather than the invading fetal vasculature. Additionally, the Sox2-cre-deleted pups manifested cardiac ventricular septal defects and hyposplenia and succumbed during the perinatal period. Hox, Notch and hypoxia-related pathways are important for both cardiac and splenic development, however downstream target gene expression was not perturbed. In summary, Ott1-dependent pathways, in addition to their implicit involvement in a congenital leukemia, are essential for vascular branching morphogenesis in the placenta and organogenesis of the mesoderm-derived heart, spleen and blood. Mutation of OTT1 or alterations in its regulation may therefore underlie human disorders such as placental insufficiency, asplenia or congenital cardiac malformations.
Carcinoembryonic Antigen (CEA) Regulates Tumor-Angiogenesis in Colon Carcinomas.
Authors: Braemswig Kira , Poettler Marina , Kalinowska Wazlawa , Zielinski Christoph , Prager Gerald W 
Published: April 2020

Abstract
Human carcinoembryonic antigen (CEA) is a cell surface adhesion molecule member of the Immunoglobulin Superfamily (IgSF). Aberrant upregulation and secretion of soluble CEA is a common feature found in a wide variety of human cancers such as colon, breast and lung. Previous in vitro and in vivo results have demonstrated that CEA can affect tumor cell behavior including the inhibition of cell differentiation and apoptosis. However, any functional effects on angiogenic endothelial cell behavior are so far unknown. In the present work we found that in endothelial cells exogenous CEA led to a time and dose dependent increase in ERK phosphorylation, which was inhibited by the specific MEK inhibitor U0126. Thereby, the observed CEA effect was comparable in time and intense with the canonical angiogenic growth factor VEGF. The CEA-induced ERK phosphorylation was not affected by the blockage of VEGFR-2 / flk-1 using a specific inhibiting peptide (CBO-P11), which indicates a VEGF-independent mechanism. Furthermore, co-stimulation of endothelial cells with VEGF and CEA shows synergistic effects on ERK phosphorylation. While in endothelial cells no endogenous expression of CEA is detected, its putative receptor, the CEA receptor (CEAR), is highly expressed as shown by immunohistochemical staining of paraffin-embedded colon carcinoma sections as well as in biochemical analyses. When an activating antibody against CEAR was used, CEA-induced ERK phosphorylation was mimicked, while downregulation of CEAR by siRNA diminished CEA-induced signal transduction, significantly. To test a biological relevance of our findings, we first measured endothelial cell proliferation: CEA led to a dose dependent increase in endothelial cell proliferation in vitro, which again revealed a synergistic effect with VEGF. Thereby, CEA-induced endothelial cell proliferation was again independent of VEGFR-2 / flk-1. A biological role of CEA in tumor-angiogenesis was reflected by an in vivo model using CEA Mimotope immunized BALB/c mice, which were transplanted with MethA/CEA overexpressing tumor cells. Immunohistological analyses of these tumors revealed a significantly reduced vascular density, which was accompanied with diminished tumor growth. Our data provide first evidence of CEA as a novel pro-angiogenic activator of endothelial cells, which results in an increase in endothelial cell proliferation, independent of VEGFR-2. Furthermore, by targeting CEA in an in vivo mouse model, tumor-angiogenesis was markley reduced, indicating a potential therapeutic target in cancer.
Genetic Polymorphisms of β-Cell Differentiation Confer Risk of Alterations of Glucose Metabolism in Survivors of Childhood Acute Lymphoblastic Leukemia.
Authors: Surapolchai Pacharapan , Hongeng Suradej , Mahachoklertwattana Pat , Pakakasama Samart , Winaichatsak Angkana , Wisanuyothin Nittaya , Pasomsub Ekawat , Mahasirimongkol Surakameth , Sirachainan Nongnuch 
Published: April 2020

Abstract
Purpose: Long-term survivors of acute lymphoblastic leukemia (ALL) seem to be at risk of insulin resistance, impaired glucose tolerance and may develop typical signs of metabolic syndrome with disturbances in lipid metabolism. The aim of the present study was to study the prevalence of alterations in glucose metabolism and the predisposing factors of these disturbances in survivors of childhood ALL. Furthermore, we intended to identify the role of such genetic polymorphisms affecting β-cell function and glucose metabolism and possibly to develop them as markers for monitoring β-cell dysfunction following treatment for ALL in the future.
Patients and methods: In 131 ALL survivors after cessation of therapy, an oral glucose tolerance test was performed to determine β-cell function/insulin sensitivity. Six single-nucleotide polymorphisms of PAX4 and TCF7L2 genes were genotyped in order to evaluate the association between these polymorphisms and β-cell function/insulin sensitivity.
Results: Ten out of 131 (7.6%) survivors had impaired glucose tolerance (IGT) while 40 out of 131 (30.5%) had insulin resistance (IR) and demonstrated characteristics of metabolic syndrome (hyperinsulinemia, hypertriglyceridemia, low HDL-C). In the logistic regression analysis, the most important factor predicting IGT and IR was older current age (p= 0.010 and &lt;0.001, respectively) while the PAX4 R192H mutation (rs2233580) was significant associated only to IGT after adjusted for age (p=0.043) (adjusted OR 5.28, 95%CI 1.06–26.40).
Conclusion: Our findings suggest that older age of childhood ALL survivors is the most important risk factor of IGT and IR, underlining the need to continue regular and long-term screening till adulthood. Moreover, after adjusted for age, the PAX4 R192H variant (rs2233580) seemed to be associated with IGT. If this association is confirmed, institution of lifestyle and therapeutic measures may be needed to reduce metabolic risk and diabetes.
Molecular Response in Core Binding Factor Acute Myelogenous Leukemia with Fludarbine, Cytarabine, G-CSF and Gemtuzumab Ozogamicin.
Authors: Borthakur Gautam , Faderl Stefan , Verstovsek Srdan , Jones Dan , Estrov Zeev , O’Brien Susan , Bass Joyce , Kantarjian Hagop 
Published: April 2020

Abstract
Background: Core binding factor associated acute myelogenous leukemias (CBF AML) are characterized by unique fusion transcripts that are amenable to molecular monitoring. Multiple log reduction in the fusion transcript level has been reported to be associated with lower relapse rates in CBF AML (Liu-Yin JA et al. ASH 2007# 543). Addition of gemtuzumab ozogamicin (GO) to induction and consolidation has resulted in improved disease free survival (DFS) in patients with AML and “standardrisk” or “favorable cytogenetics” (Burnett,A. et al. ASH 2006#13). Historical data from M.D. Anderson Cancer Center indicates that induction/consolidation therapy with fludarabine, cytarabine and granulocyte colony stimulating factor (GCSF) (FLAG) results in improved event free survival (EFS) (median EFS not reached after median followup of 118 weeks) in patients with CBF AML (Borthakur et al. 2008, Cancer in press).
Method: In an attempt to improve upon these results we have initiated a study incorporating GO with FLAG (GO-FLAG) in induction/consolidation for treating patients with newly diagnosed CBF AML. We report on molecular responses in patients enrolled in this study. Extracted RNA is reverse transcribed and analyzed by real-time quantitative PCR for the fusion transcript associated with CBF leukemias. Values are expressed as a percentage of fusion transcript to normalizing ABL transcripts. The sensitivity of detection is approximately 1 in 100,000 for AML1-ETO and 1 in 10,000 for CBFb-MYH11.
Results: Seventeen (Inv 16=6/t 8;21=11) patients (male=15)[median age 49 years (range, 29–73)]have been treated to date with a median follow-up of 10 months (range,1–16). Patient characteristics at presentation include median WBC 10.4 (range, 1.5–41.5) x 106/ml, hemoglobin 9.3 (range, 7.8–11.9) gm/dL, platelet count 22 (range, 6–365) x 109/ml. Additional cytogenetic abnormalities were present in 10 patients; +8 and –Y being most frequent. Two patients had kit mutations. All patients achieved complete remission (CR) except one (partial remission). Two patients died in CR from infectious complications. There has been no relapse. Median pre-treatment value for fusion transcript to Abl ratio by Q-PCR is 100 (range, 100–857). After induction the median Q-OCR value dropped to 0.04 (range, 0–9.17) and after three cycles of therapy the median value is 0.01 (range, 0–0.12).
Conclusion: Induction/consolidation therapy with GO-FLAG regimen in CBF AML results in excellent molecular response. Further patient accrual and follow-up will generate information about impact on overall and disease/event free survival.