bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dysregulation of BMPR2, Arginase II and HMGA2 Expression in Idiopathic Myelofibrosis and Secondary Myelofibrosis.
Authors: Liu Enli , Frost Adaani E. , Popat Uday R. , Prchal Josef T. 
Published: October 2019

Abstract
Idiopathic myelofibrosis (IMF) is a fatal clonal myeloproliferative disorder, characterized by variable pancytopenia, splenomegaly, leukoerythroblastic blood smear, marrow fibrosis (MF), and myeloid metaplasia. Like all myeloproliferative disorders, it is due to an acquired somatic mutation of a single hematopoietic progenitor. MF has also been reported in systemic lupus and metastatic malignancies involving bone marrow. We have recently demonstrated the occurrence of MF in 85% patients with pulmonary hypertension (PH), which (unlike IMF) is associated with polyclonal hematopoiesis and normal number of circulating CD34+ cells. The pathophysiological mechanisms resulting in IMF and secondary MF (SMF) in PH remain still unclear. To date, 52 heterozygous germline mutations in the gene (BMPR2) encoding the bone morphogenetic protein type II receptor (BMPR-II) have been found to characterize many cases of familial (Lane, 2000) and sporadic primary PH (PPH) (Thomson, 2000). Recently, increased activity of arginase in pulmonary tissue of patients with PH was found. This may contribute to the pathogenesis of pulmonary hypertension by decreasing the substrate for NO synthesis. We examined BMPR2 and Arginase II mRNA levels by quantitative real-time RT-PCR in mononuclear cells (MNC), platelets (PLT) and granulocytes (GNC) from IMF patients and PH patients with secondary MF. We show for the first time that the mRNA level of BMPR2 is increased in PLT and GNC of IMF compared with normal controls. Arginase II mRNA was significantly increased in GNC of IMF as well as PH patients with SMF. Rearrangement and over expression of high-mobility group AT-hook2 (HMGA2) gene in myeloid progenitors in two patients with IMF was recently reported. This gene is known to play a major role in fetal growth and development, and is expressed in trace amount in adult lung, kidney, and synovia. We found significantly increased HMGA2 mRNA expression in MNC of IMF patients. In summary, the biomarkers studied here can be abnormal in both IMF and PH with secondary MF and may not be useful to discriminate between the two types of MF. Dysregulation of BMPR2, Arginase II and HMGA2 expression may play a pathophysiological role in MF of both IMF and PH.
Expression of BMPR2 , Arginase II and HMGA2 in Blood Cells of IMF and SMF
Gene Cells Control (ΔCT) Idiopathic MF (ΔCT) Secondary MF (ΔCT) *The P value represents a significant difference of gene expression in IMF or SMF compared with normal controls. A lower ΔCT indicates a higher gene expression. BMPR2 PLT 18.5±1.2 16.7±1.4 (p=0.038) * 18.4±2.2 (p=0.881) GNC 19.2±1.0 18.3±1.3 (p=0.009) * 19.1±1.2 (p=0.893) MNC 18.3±1.2 19.2±1.8 (p=0.059) 19.0±2.7 (p=0.554) Arginase II GNC 24.5±0.6 21.9±1.7 (p=0.000) * 22.6±1.2 (p=0.004) * MNC 24.4±3.5 24.4±3.9 (p=0.965) 22.5±2.4 (p=0.222) HMGA2 MNC 32.4±1.6 29.3±1.7 (p=0.000) * 30.8±1.8 (p=0.085)
BMS-354825 Is a SRC/ABL Inhibitor with High Nanomolar Activity Against the Kit D816v Mutation, Which Drives Systemic Mastocytosis and Is Imatinib-Resistant.
Authors: Shah Neil P. , Lee Francis Y. , Sawyers Charles L. , Akin Cem 
Published: October 2019

Abstract
The vast majority of systemic mastocytosis cases are associated with a somatic KIT oncoprotein point mutation which substitutes a valine for aspartic acid (D816V), resulting in KIT receptor auto-phosphorylation in a ligand-independent manner. Previous reports have demonstrated that this mutation is inherently imatinib-resistant. Although interferon-alpha has some activity against aggressive systemic mastocytosis, major responses are uncommon, and the drug is associated with significant toxicity. To date, there remains no effective therapy for systemic mastocytosis. We recently described BMS-354825, a novel orally bioavailable SRC/ABL inhibitor that has activity against multiple imatinib-resistant BCR-ABL isoforms in vitro (Shah et al, Science 305:399, 2004). BMS-354825 is presently undergoing evaluation in a phase I clinical trial of imatinib-resistant CML patients, and is showing signs of clinical efficacy. Pharmacokinetic analysis suggests that high nanomolar concentrations of the compound can be safely achieved in humans (see Sawyers et al, Talpaz et al, abstracts submitted for this meeting). To determine if this compound warrants study in other human hematologic conditions, we tested BMS-354825 for activity against human mastocytosis cell lines HMC-1560 and HMC-1560,816, carrying an activating c-kit mutation in juxtamembrane domain (codon 560) with or without a second mutation in tyrosine kinase domain (codon 816), respectively. While 1 um imatinib failed to inhibit the growth of HMC-1560,816 cells carrying the tyrosine kinase domain c-kit mutation, BMS-354825 led to an almost complete growth inhibition at the same concentration, with an IC50 of 0.1–1 uM. In addition, growth of HMC-1560 cells carrying the juxtamembrane c-kit mutation alone was more effectively inhibited by BMS-354825 as compared to imatinib (IC50 of <0.01 vs 0.01–0.1 micromolars respectively). Significantly, detection of phospho-KIT by Western blot analysis was significantly reduced in the presence of BMS-354825 at nanomolar concentrations. An ex vivo assessment of D816V-harboring mast cell sensitivity using a flow cytometric method in systemic mastocytosis bone marrow samples is ongoing. Our findings suggest that studies to evaluate BMS-354825 for the treatment of systemic mastocytosis are warranted. Additionally, the compound may harbor activity in other disease settings that contain activating KIT mutations.
Sepsis-Induced Coagulation in the Baboon Lung Is Associated with Decreased Endothelial Tissue Factor Pathway Inhibitor.
Authors: Tang Haiwang , Ivanciu Lacramioara , Hamm Todd , Taylor Fletcher B. , Lupu Cristina , Lupu Florea 
Published: October 2019

Abstract
Activation of tissue factor (TF)-dependent coagulation is an early event in the pathogenesis of sepsis, responsible for microvascular thrombosis and consequent organ injury. We hypothesized that sepsis-induced TF procoagulant activity may be paralleled by a decreased expression or function of its natural inhibitor, tissue factor pathway inhibitor (TFPI). To test this hypothesis we used a non-human primate sepsis model in which adult baboons were infused with live E. coli at 109 CFU/kg (sublethal dose), 1010 CFU/kg (lethal dose) or saline (control group) and the animals were sacrified after 2, 8, or 24 hours. Lung tissue was snap frozen for protein and mRNA extraction or fixed and processed for light and electron microscopy. Tissue cryosections were immunostained using double/multiple fluorescence labeling approaches for TF, TFPI, factor VII/FVIIa and fibrin, in conjunction with cell markers for endothelial cells (CD31 or von Willebrand factor), leukocytes (PSGL-1), macrophages (CD68), PMN (myeloperoxidase) and platelets (gpIIb/IIIa). Large amounts of TF were detected in leukocytes, endothelial cells and platelet-rich microthrombi, starting from 2 hours and throughout the examined period. Concomitantly, confocal and electron microscopy analysis revealed increased leukocyte infiltration, platelet aggregates and fibrin deposition in the intravascular and interstitial compartments. In addition, TF induction was documented by semiquantitative RT-PCR, ELISA, western blot and factor Xa activation assays. Whereas TFPI mRNA showed only a modest increase, tissue-associated TFPI protein was found considerably decreased, especially during the first eight hours post E. coli infusion. Moreover, TFPI inhibitory activity of lung extracts from septic animals was 6–8 fold lower comparing to controls. TF activity measurements in the presence of inhibitory anti TFPI antibodies showed that only a very small fraction of endogenous TF was inhibited by tissue-associated TFPI, suggesting that most of the active TFPI available in the vascular compartment was depleted. The decrease of TFPI inhibitory potency cannot be exclusively explained by its proteolytic degradation, as we did not find significant amounts of truncated TFPI on western blots. In conclusion, our studies demonstrate that the exposure to septic and inflammatory stimuli lead to a decrease of TFPI-dependent endothelial anticoagulant potential, simultaneous with a strong TF-dependent procoagulant response. Activation of TF-dependent coagulation pathway not adequately countered by TFPI may have important roles in the pathogenesis of sepsis-associated disseminated intravascular coagulation. Strategies aimed to restore the physiological anticoagulant function of TFPI may help preventing sepsis-induced multiple organ dysfunction syndrome and death.
The Inhibitor of VEGF-Receptors Tyrosine Kinase PTK-787 Blocks the Invasive Potential of Adult T-Cell Leukemia Cells through the Endothelium.
Authors: Bazarbachi Ali , Harb Roa , Khoury Hilda , Haddad Lara , Kfoury Youmna , Atweh Lamia , Hamadeh Eva , Hermine Olivier , de The Hugues , El-Sabban Marwan E. 
Published: October 2019

Abstract
Extravasation of tumor cells through the endothelial barrier is a critical step in cancer metastasis. HTLV-I associated adult T-cell leukemia/lymphoma (ATL) is an aggressive disease characterized by multiple organ invasion. We have shown that ATL-derived cells induce angiogenesis and communicate with endothelial cells through gap junctions. This results in induction of endothelial-derived metalloproteinases, sub-endothelial basement membrane degradation followed by endothelial cell retraction allowing neoplastic lymphocytes extravasation. In this study we have used the specific tyrosine kinase inhibitor of VEGF receptors PTK787, functional blocking antibodies against VEGF and the gap junction communication inhibitor18-a-G to dissect the respective role of VEGF signaling pathway and cell-to-cell communication in endothelial cell retraction and tumor cell extravasation. PTK787 has mild growth inhibitory and cytotoxic effects on both endothelial and tumor cells at a concentration of 50μM and significantly inhibited cell proliferation at 100μM. Hence, 20μM PTK787 which did not exhibit any cytotoxic or antiproliferative effects on both cell types was used in experiments that last 24 hours or longer (in vitro tube formation assay and invasion assay). Endothelial cells monolayers incubated with either ATL derived cells or their cell-free conditioned medium for 48 hours induced in vitro tube formation in Matrigel angiogenesis assay. This was inhibited by both anti-VEGF antibody and 18-a-G and to a greater extent and in a dose dependent manner by PTK787. Importantly, PTK787, and to a lesser extent anti-VEGF antibody and 18-alpha-G significantly attenuated the ability of ATL-derived cells to traverse endothelial cell monolayers in double compartment invasion assays. Signaling cascade that is activated upon VEGF stimulation of endothelial cells was investigated in confluent endothelial cells cocultured with ATL derived cells or cell-free conditioned medium in the absence or presence of PTK787 or anti-VEGF antibody, using phospho-specific antibodies against FAK Tyr 861, FAK Tyr 397, Src, ERK, PLCgamma, and Akt/PKB, known to be signal mediators in the Ras-Raf-MEKK-ERK signaling cascade. The addition of ATL derived cells or cell-free conditioned medium resulted in a transient activation of the above signal mediators with a peak increase at 15 minutes and gradual return to baseline after 60 minutes. This activation was down regulated in the presence of anti-VEGF antibody and to a greater extent in the presence of PTK787. This data establishes a novel role of VEGF signaling in tumor cell invasion and supports the potential use of PTK787 in the treatment of ATL and other hematological malignancies with angiogenic and invasive properties.
Tumor Necrosis Factor-α-Converting Enzyme (ADAM17) Mediates GPIbα Shedding from Platelets In Vitro and In Vivo.
Authors: Bergmeier Wolfgang , Piffath Crystal L. , Cheng Guiying , Dole Vandana S. , Zhang Yuhua , von Andrian Ulrich H. , Wagner Denisa D. 
Published: October 2019

Abstract
Interaction of the platelet receptor GPIb-V-IX with von Willebrand factor exposed at a site of vascular injury is an essential step in the initiation of a hemostatic plug. Proteolytic cleavage (shedding) of the GPIbα subunit was first described more than 25 years ago, the protease mediating this event as well as its physiological function, however, have not been elucidated. We have recently reported that shedding of GPIbα and platelet clearance induced by platelet storage or mitochondrial injury involves a platelet-derived metalloproteinase(s). Here we show that GPIbα shedding in response to mitochondrial injury or physiological activation is inhibited in platelets obtained from chimeric mice, which express inactive tumor necrosis factor-α converting enzyme (TACEΔZn/ΔZn) in blood cells only. Shedding was also inhibited in mouse and human platelets in the presence of two potent TACE inhibitors, TAPI and TMI-1. Our data further suggest that TACE is important in the regulation of GPIbα expression in vivo, as we observed an ~ 90% reduction in soluble GPIbα (glycocalicin) in plasma of TACEΔZn/ΔZn chimeras as well as significantly increased levels of GPIbα on circulating platelets. In contrast, shedding of P-selectin from activated platelets was not affected by the mutation in TACE. Mitochondrial damage in TACEΔZn/ΔZn platelets did not result in reduced posttransfusion recovery or impaired hemostatic function of such platelets in mice, indicating that TACE not only mediates GPIbα shedding but that it may also be crucial for the development of cellular changes leading to platelet clearance. In conclusion, our data demonstrate that TACE is expressed in platelets and that it is the key enzyme mediating shedding of GPIbα. Inhibition of TACE during platelet storage could be a powerful means to improve the effectiveness of platelet transfusions.
Akt-1 Regulates Angiogenesis in Skin.
Authors: Byzova Tatiana , Chen Juhua , Somanath Payaningal R. 
Published: October 2019

Abstract
The major mechanism to adapt to ischemic conditions is the development of neovascularization, i.e. angiogenesis, a process driven by members of VEGF family of growth factors. Phosphoinositide 3-kinase/Akt pathway is a critical component of the signaling network that regulates endothelial cell function related to angiogenesis. VEGF treatment of endothelial cells results in rapid phosphorylation of Akt. Our studies demonstrated that Akt kinase activity is necessary for VEGF-induced and integrin-mediated endothelial cell adhesion and migration. Moreover, cell transfection with a constitutive active form of Akt (myr-Akt) leads to increased function of integrin receptors. Using Akt-1 null mice we found that Akt-1 controls VEGF-induced and integrin-dependent endothelial cell responses in vitro. Impaired endothelial cell migration and adhesion to extracellular matrix and a reduced rate of cell proliferation were observed in Akt-1 (−/−) endothelial cells compared to WT. There are three Akt isoforms with different tissue distribution, however, it appears that Akt-1 is a predominant isoform in skin and in skin microvasculature. This observation prompted us to perform series of in vivo experiments designed to assess the angiogenic response in skin in the absence of Akt-1. Angiogenesis assay using matrigel plugs revealed that the weight and hemoglobin content of matrigel plugs is about two fold higher in Akt (−/−) mice compared to WT mice. Tumor angiogenesis also appears to be enhanced in Akt(−/−) mice, resulting in the significantly lower degree of tumor necrosis. Blood vessels in Akt (−/−) mice appear to be smaller in diameter and have reduced laminin content. Our analysis revealed significant changes in blood vessel wall matrix composition of Akt (−/−) mice as compared to WT animals. These changes resulted in increased vascular permeability in skin of Akt (−/−) mice. Akt-1 is known to target multiple cellular processes including adhesive properties, cell survival, transcription and translation. It appears that the phenotype of Akt-1 (−/−) mice depends on the equilibrium between pro-angiogenic and anti-angiogenic roles of Akt-1 and reveals a central role for Akt-1 in the regulation of matrix production and maturation of blood vessels.
Time To Complete Remission Is Not a Significant Prognostic Factor in AML: A Report on 1,959 Consecutive Patients Registered to 6 Studies of the Eastern Cooperative Oncology Group (ECOG).
Authors: Rowe Jacob M. , Kim Haesook T. , Cassileth Peter A. , Litzow Mark R. , Wiernik Peter H. , Tallman Martin S. 
Published: October 2019

Abstract
Prognostic factors for AML at diagnosis include cytogenetics, FLT3 ITD, age, MDR status and white cell count at presentation. Several groups (Blood2000; 95:72; BJH1999; 107:69; Haematologica2004; 89:528) have reported that time to achievement of complete remission (CR) is an independent post-induction prognostic factor in AML. Furthermore, some investigators have classified patients who do not achieve CR with one cycle as primary induction failure. Between 1983 and 1993 1,959 patients were registered to 6 consecutive ECOG studies (E3483, PC486, E1490, E2491/INT0129, E3489 and E3993). These studies were for patients age 18–55 years (E3483, PC486 and E3489); age 56–70 years (E1490); age >56 years (E3993) and with no age limit (E2491/ INT0129). Of these 1,959 patients, 1261 achieved CR (64%) and were available for analysis. All patients received standard induction therapy, consisting of daunorubicin 60 mg/m2 (E3483, PC486 and E1490), or 45 mg/m2 (E2491/ INT0129) or idarubicin 12 mg/m2 (E3489), or a randomization between daunorubicin 45 mg/m2, idarubicin 12 mg/m2 or mitoxantrone 12 mg/m2 (E3993) - all for 3 days - together with cytarabine 100–200 mg/m2 by continuous infusion for 7 days. It should be noted that in the North American Intergroup APL study (E2491/ INT0129) patients who received ATRA in induction are excluded from this analysis. All patients were to receive a second cycle of identical induction therapy if the day 10–14 bone marrow demonstrated unequivocal residual leukemia. Identical study-specific post-remission therapy, including consolidation therapy and/or allogeneic or autologous bone marrow transplantation, was given to all patients who went into CR - irrespective if this was achieved after 1 or 2 cycles. This retrospective analysis compared patients who achieved CR after 1 cycle versus 2 cycles of induction therapy. The data were obtained from the ECOG database that recorded the number of days that patients received induction therapy (≤8 days vs >8 days). The table presents the data for disease-free survival (DFS) and overall survival (OS). These data are based on the Cox model, adjusting for other variables.
Total Failed Median DFS/OS (mo) 5-year DFS/OS p-value DFS 1 cycle 406 321 10.2 24.4% 2 cycles 855 629 11.9 28.6% 0.07 OS 1 cycle 406 287 23.7 36.1% 2 cycles 855 583 24.1 35.7% 0.7
In this large cohort of patients, by multivariate analysis, age, WBC at diagnosis were significant factors for DFS and OS. However, the number of cycles given for induction or the time to achieve a CR in AML patients could not be demonstrated to have any independent prognostic significance. These data suggest that post-remission strategies in AML should not be influenced by the number of cycles required to achieve CR.
A Phase 2 Evaluation of Single Agent Clofarabine as First Line Treatment for Older Patients with AML Who Are Not Considered Fit for Intensive Chemotherapy.
Authors: Burnett Alan K. , Russell Nigel , Kell Jonathan W. , Milligan Donald , Culligan Dominic 
Published: October 2019

Abstract
Patients over 70 years represent a significant proportion of patients with AML. They respond poorly to intensive chemotherapy. Although 50% of patients can achieve CR, only 8% are alive at 2 years (MRC Database). In addition significant numbers of these patients either do not wish to undergo, or are not considered fit for intensive chemotherapy. This represents a significant unmet medical need. Nucleoside analogues (Ara-C) provide an active group of agents in AML, Fludarabine however is ineffective at tolerable doses. Clofarabine has been modified by introducing a Fluorine in the 2′ position which confers reduced susceptibility to cleavage of the glycosidic linkage and also reduced toxicity caused by halogenated nucleobases. As such the drug has potential use as an oral formulation. Previous clinical and in vitro studies have established a dose schedule at 40mg/m2 days 1–5. This is associated with CRs in relapse/refractory AML, but with grade ¾ liver toxicity in 25% of patients.
Because of these characteristics we undertook a non-randomised study using a dose of 30mg/m2 days 1-5 IV, which could be repeated for up to 4 courses at a minimum of 28 days apart. The target patient group were patients >70 years, or patients 60–70 with a cardiac history, who were not considered fit for conventional chemotherapy.
Twenty-eight patients entered the study: 16 males, 12 females of a median age 71 years (range 60 – 79). The FAB distribution was, M0=1;M1=9; M2=8; M4=2; M5=4; M6=3; Unknown=1. The cytogenetic risk group (MRC criteria) were 26 standard and 2 unfavourable risk. All patients received course 1. Five patients died before response could be assessed from causes which were not thought to be associated with the drug. One patient is too early to assess response. Five did not enter complete remission although there was a reduction in bm blasts from 58 to 18%, 55 to 20% and 30 to 15% in 3 cases. Sixteen patients (59%) achieved complete remission after course 1. Grade 3 toxicity was seen in 3 patients, but this recovered in all cases in a few days. Patients who did not enter CR did not show haematological recovery after course 1 and were considered treatment failures. Of the 16 patients who entered CR, haematological recovery to ANC 1.0 x 109/l took 28 days (range 21–42) Platelets to 50x109/l took 25 days (range 21–38).
Conclusions: Clofarabine is an active agent when used alone as first line treatment. It is well tolerated but is associated with cytopenia of an average 28 days. At the dose chosen for this study grade ¾ liver toxicity was uncommon. The drug is a candidate for evaluation in a randomised trial and/or in combination schedules, and lower doses should be explored in older patients. This study was partially supported by an unrestricted grant from Bioenvison Inc.