bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Obligate Role of TAK1 in the Survival of Hematopoietic Stem Cells and Progenitors in Mice.
Authors: Tang Minghui , Xia Zhenbiao , Zhang Shubin , Zhang Shanshan , Wei Xudong , Breslin Peter , Wei Wei , Diaz Manuel , Akira Shizuo , Zhang Jiwang 
Published: October 2019

Abstract
TGFβ1-activated kinase 1 (TAK1), a member of the MAPKKK family, is a key mediator of stress and proinflammatory signals. TAK1 can be activated by inflammation-mediating cytokines, including tumor necrosis factor-α (TNF-α and interleukin-1b (IL-1β), as well as by T- and B- cell receptors (TCR/BCR), and Toll-like receptors (TLRs) signals. Activated TAK1 induces the nuclear localization of NF-kB and the activation of JNK/AP1 by stimulating IKKβ and MKK3/MKK6 phosphorylation respectively. TAK1 has been found to play an important role in inflammation, immunity, T- and B-cell activation, and epithelial cell survival. The TAK1−/ − phenotype is lethal in mice at the early embryonic stage. We found higher levels of TAK1 expression and activity in hematopoietic stem cells and progenitors (HSC/Ps), and reduced expression and activity in differentiated mature hematopoietic cells. To study the role of TAK1 in bone marrow hematopoiesis, we generated inducible-TAK1 knockout mice by crossing TAK1loxp mice with Mx1Cre mice, the latter being an interferon-inducible Cre mouse line. After injection of polyI:C to induce the knockout, we found that all the TAK1 knockout mice died within 8 to 10 days after the first polyI:C injection, showing severe hematopoietic and other defects; heterozygotes were phenotypically comparable to wild-type control animals. The TAK1 deletion in these mice resulted in ablation of bone marrow hematopoiesis due to the loss of C-Kit+ HSC/Ps. Annexin-V staining showed a 3-fold increase in apoptosis in the C-Kit+ HSC/Ps from TAK1 mutant mice compared to those from littermate control mice. Almost all of the mutant animals showed intestinal bleeding as well as other hemorrhaging due to the significant reductions in platelet counts. In reciprocal bone marrow transplantation experiments, we found that the TAK1-mutant bone marrow microenvironment was able to support the growth and function of wild-type HSC/Ps, while HSC/Ps from TAK1−/ − mice failed to grow within the wild-type bone marrow microenvironment. These observations suggest that the bone marrow ablation phenotype which develops in TAK1-mutant mice is the result of intrinsic defects in HSC/P’s. We propose that TAK1-mutant HSC/Ps might mediate a survival signal for HSC/Ps stimulated by hematopoietic growth factors and cytokines, such as stem cell factor (SCF). The details of possible mechanisms by which this phenomenon might occur is currently under active investigation by our group.
Targeting Cdk4/6 in Combination Therapy Overcomes Proteasome Inhibitor Resistance in Multiple Myeloma through Synergistic Mitochondria Depolarization.
Authors: Huang Xiangao , Louie Tracey , Di Liberto Maurizio , Rice Jun , Jayabalan David , Zhang Kang , Palladino Michael , Chen Isan , Toogood Peter , Niesvizky Ruben , Moore Malcolm A.S. , Chen-Kiang Selina 
Published: October 2019

Abstract
Deregulation of Cdk4 or Cdk6 is central to the loss of cell cycle control in cancer. In myeloma, over-expression of Cdk4-cyclin D1 or Cdk6-cyclin D2 predisposes primary bone marrow (BM) myeloma cells to proliferation in vivo1. Conversely, silencing Cdk4/6 by its physiologic inhibitor, p18INK4c, is required for G1 cell cycle arrest during the generation of normal plasma cells2. Targeting Cdk4/6, therefore, is critical for the control of disease progression and drug resistance in myeloma, but no Cdk4/6-specific inhibitor was available. We have now targeted Cdk4/6 in combination therapy in myeloma using PD 0332991 (Pfizer), a novel orally bioactive, small molecule Cdk4/6-specific inhibitor. We demonstrate that as a single agent, PD 0332991 rapidly inhibits Cdk4/6 (IC50 ∼ 60 nM) and induces exclusive G1 cell cycle arrest in primary human myeloma cells in the presence of BM stromal cells. Non-invasive whole body imaging reveals that PD 0332991 nearly completely prevents tumor growth in a rapidly disseminated xenograft human myeloma model without overt toxicity3. Because PD 0332991 is reversible and does not induce apoptosis when used as a specific Cdk4/6 inhibitor, we have further developed two strategies to target Cdk4/6 in combination therapy. In the first, the release of PD 0332991-induced G1 arrest leads to synchronous S phase reentry and preferential killing of cycling myeloma cells by cytotoxic agents. In the second, prolonging PD 0332991-induced G1 arrest markedly sensitizes primary myeloma cells to killing by cytotoxic agents including the proteasome inhibitors bortezomib and NPI-0052, as well as the steroid dexamethasone. The Cdk4/6-based combination therapy rapidly reduces tumor load in animal models. More importantly, it overcomes drug resistance in primary myeloma cells isolated from refractory relapse patients despite the protection from BM stromal cells. Synergistic killing of myeloma cells lies in the synergistic induction of mitochondria depolarization. Based on this study and the favorable outcome of a PD 0332991 Phase I clinical trial, a Phase I/II PD 0332991-bortezomib clinical trial for myeloma is underway. Targeting Cdk4/6 by PD 0332991 in combination with a selective cytotoxic agent, therefore, represents the first promising cell cycle-based therapy in myeloma, and possibly other cancers.
Relocation of Cell Iron. A Mode of Chelation with Application to Diseases of Regional Iron Accumulation.
Authors: Cabantchik Zvi I. , Sohn Yan S. , Breuer William , Munnich Arnold 
Published: October 2019

Abstract
Iron raises to toxic levels in mitochondria of excitable cells in some forms of neuro-degeneration with brain accumulation (NBIA), in sideroblastic anemia and in Friedreich’s ataxia (FA), often leaving the cytosol iron-depleted. In anemia of chronic disease (ACD) iron is withheld by macrophages, while iron levels in extracellular fluids (e.g. plasma) are drastically reduced. Although excessive iron deposition occurring in organs of iron overloaded (IO) patients can be reduced with iron chelators, it is uncertain whether this is applicable to conditions where iron accumulates within selected tissues/cells in the absence of systemic IO.
Objective. We assessed whether deferiprone (DFP), a membrane-permeant bidentate chelator in clinical use for treating systemic IO, might serve as an iron relocating agent in settings of regional iron accumulation by a. capturing labile iron accumulated in cell compartments and b. conveying the chelated iron either to other cell locations for metabolic integration or to transferrin for systemic reutilization.
Methods. DFP capacity to shuttle iron intracellularly and transcellularly was assessed in macrophages (J774) and heart (H9c2) cell models using organelle-targeted fluorescent iron-sensors in conjunction with fluorescence microscopy imaging. We employed pairs of sensors targeted to different cell compartments and iron-evoked quenching and chelator-evoked dequenching as means to trace DFP mediated iron transfer. Mitochondrial iron accumulation was generated with succinylacetone or by silencing genes affecting mitochondrial iron metabolism.
Results. DFP facilitated iron transfer: a. from iron-laden cell organelles to other cell compartments or to medium (and vice versa) and b. from iron loaded macrophages to pre-erythroid MEL cells (for chemically induced hemoglobin synthesis) either directly or via transfer to extracellular transferrin.
Discussion The results of this study indicate that relocation of cell accumulated iron can be used as a modality of chelation for treating conditions of regional iron accumulation by applying chelators able to permeate into cell compartments but also to transfer the chelated iron to cell acceptors or to the extracellular iron carrier transferrin.
Enhanced Anticoagulant Activity of Factor VIII Inhibitors Due to Positive Cooperativity between Two Classes of Anti-Factor VIII C2 Antibodies.
Authors: Meeks Shannon L. , Healey John F. , Barrow Rachel T. , Parker Ernest T. , Lollar Pete 
Published: October 2019

Abstract
We recently identified 5 distinct structural classes of anti-human factor VIII (fVIII) C2 domain monoclonal antibodies (MAbs) in a murine model of hemophilia A. Three classes, Groups A, B, and C, consist of MAbs with non-overlapping epitopes. Group AB MAbs overlap epitopes of Group A and B MAbs, and Group BC MAbs overlap epitopes of Group B and C MAbs. Concentration dependent binding of biotinylated Group A MAbs to fVIII bound to a microtiter plate was studied in the presence and absence of Group BC MAbs by ELISA. Surprisingly the binding of all 3 Group A antibodies tested, ESH4, 3E6, and I54, was increased in the presence of Group BC antibodies. Group A antibodies block the binding of fVIII to von Willebrand factor (VWF) and phospholipid. Group BC antibodies inhibit the proteolytic activation of fVIII but do not block the binding of fVIII to VWF and phospholipid. To establish functional relevance, the effect of Group BC MAbs on the ability of Group A MAbs to block fVIII binding to VWF was determined by ELISA. Group A MAbs were serially diluted into fixed concentrations of Group BC MAbs and then incubated with fVIII in solution for 2 hours. The fVIII - antibody mixtures were added to microtiter wells coated with VWF, and fVIII binding to VWF was measured. Group BC MAbs increased the ability of ESH4 and 3E6 to inhibit the binding of fVIII to VWF, consistent with the observation that the binding of Group A and Group BC antibodies is positively cooperative. We previously have shown that antibody-mediated inhibition of fVIII binding to VWF is correlated with inhibition of fVIII binding to phospholipid and with fVIII inhibitor titers. Although most Group BC MAbs have high inhibitory titers against fVIII, Group BC MAb D105 is only minimally inhibitory at 0.8 Bethesda units/mg IgG. Because D105 increased the binding of ESH4 to fVIII like other Group BC MAbs, the effect of D105 on the inhibitor titer of ESH4 was investigated using the Bethesda assay. The inhibition of fVIII was significantly increased by the presence of D105 (Fig. 1). This study identifies increased binding of Group A MAbs to fVIII in the presence of Group BC MAbs using 3 different assays. Our results suggest that the cooperative interaction of fVIII antibody epitopes affects the overall inhibitor patient phenotype and that inhibitors with very low inhibitor titers can significantly increase the inhibitory effects of other anti-fVIII antibodies.
Figure Figure
Burdern of Long-Term Morbidity after Hematopoietic Cell Transplantation: A Report from the Bone Marrow Transplant Survivor Study (BMTSS).
Authors: Sun Can-Lan , Francisco Liton , Kawashima Toana , Robison Leslie L. , Baker K.S. , Weisdorf Daniel , Forman Stephen J. , Bhatia Smita 
Published: October 2019

Abstract
Long-term survival is an expected outcome after HCT. However, no study has assessed the burden of long-term morbidity in these survivors, or attempted to identify subpopulations at highest risk for severe, debilitating conditions. In this study, we determined the prevalence and severity of chronic health conditions in a large population of long-term HCT survivors and compared these outcomes with their siblings. BMTSS, a collaborative effort between City of Hope National Medical Center and University of Minnesota, examined self-reported chronic health conditions in individuals who underwent HCT between 1976 and 1998, and survived two or more years. A severity score (grade 1 through 4, ranging from mild to life-threatening or disabling) was assigned to each health condition according to the Common Terminology Criteria for Adverse Events (version 3). A partial list of conditions graded as severe or life-threatening (grade 3 or 4) included congestive heart failure, second malignant neoplasms, coronary artery disease, cerebrovascular accident, renal failure/dialysis/renal transplant, and active chronic graft vs. host disease. Adverse psychosocial outcomes were not included. Cox proportional-hazard models were used to estimate hazard ratios and their 95% confidence intervals. We compared the prevalence and severity of chronic conditions in 1013 HCT survivors (455 autologous, 460 related donor, and 98 unrelated donor HCT survivors) with 309 siblings. The median age at study participation was 44 (range 18–73) and 45 years (range 17–79) for survivors and siblings, and the median follow-up for the survivors was 7.3 years (range 2–28) from HCT. Among the 1013 survivors, 69% had at least one chronic condition, and 29% had a severe or life-threatening condition (grade 3 or 4). The comparable figures in siblings were 39% and 7%, respectively (p<0.001 compared to survivors). After adjustment for age at HCT, sex and race/ethnicity, survivors were 2.4 times as likely as their siblings to develop any chronic health conditions (95%CI, 2.0–2.9), and 4.5 times more likely to develop severe/life threatening conditions (95%CI, 3.0–6.7). Groups at highest risk for a severe or life-threatening condition are summarized in the Table. Among survivors, the cumulative incidence of a chronic health condition reached 84% at 20 years post HCT, with a cumulative incidence of 55% for severe/life threatening conditions at 15 years after HCT. The chronic health burden of this population is significant, and life-long follow-up of patients who receive transplantation is recommended.
Table: Groups at highest risk for severe or life-threatening condition Risk Factors Relative Risk 95% CI Siblings 1.0 __ CML 5.8 3.8–8.9 AML 4.9 3.2–7.5 ALL 5.2 3.3–8.3 Allogeneic sibling donor 5.9 3.9–8.7 Unrelated donor 7.4 4.9–11.1 TBI 5.0 3.4–7.5
High-Throughput Sequence Analysis of the Tyrosine Kinome in Acute Myeloid Leukemia.
Authors: Loriaux Marc , Levine Ross , Tyner Jeffrey , Frohling Stephan , Scholl Claudia , Stoffregen Eric , Wernig Gerlinde , Erickson Heidi , Eide Chris , Berger Roland , Bernard Olivier , Griffin James , Stone Richard , Meyerson Matthew , Heinrich Michael , Deininger Michael , Gilliland Gary , Druker Brian 
Published: October 2019

Abstract
Mutations that result in constitutive tyrosine kinase activation occur in a wide spectrum of human malignancies, including acute myeloid leukemia (AML). Although activating mutations in the tyrosine kinases FLT3 and c-KIT occur in a significant proportion of patients with AML, the genomic events responsible for oncogenic signaling in most patients with AML have not been identified. To determine whether other aberrantly activated tyrosine kinases contribute to the pathogenesis of AML, we employed high throughput (HT) DNA sequence analysis to screen the exons encoding domains implicated in kinase activation (activation loop), and autoinhibition (juxtamembrane domains) in 85 tyrosine kinase genes in 192 AML patients without FLT3 or c-KIT mutations. The screen identified 34 non-synonymous sequence variations in 25 different kinases that had not been reported in single-nucleotide polymorphism (SNP) databases. These included a novel activating allele in FLT3, and a previously described activating mutation in MET (METT1010I). The majority of the novel sequence variants were cloned into their respective tyrosine kinase cDNA, and stably expressed in the factor-dependent Ba/F3 hematopoietic cell line. Apart from one FLT3 allele, none of the other novel variants showed evidence of constitutive phosphorylation by immunoblot analysis, and none transformed Ba/F3 cell lines to factor independent growth. These findings indicate that the majority of these alleles are not potent activators of tyrosine kinase activity in this cellular context, and that a significant proportion of non-synonymous sequence variants identified in HT DNA sequencing screens may not have functional significance. Although several explanations are possible for this observation, these data are consistent with recent reports that a significant fraction of such sequence variants are “passenger” rather than “driver” alleles, in cancer, and underscore the importance of functional assessment of candidate disease alleles.
TG101348: A Dual-Acting JAK2/FLT3 Small Molecule Kinase Inhibitor for the Treatment of AML.
Authors: Tam Betty , Mak Chi Ching , Stoughton Silva , Virata Cyrus , Lohse Dan , Hanna Ehab , Alomia Marcela , Jamieson Catriona , Doukas John , Noronha Glenn , Martin Michael , Soll Richard , Hood John 
Published: October 2019

Abstract
A number of genetic mutations have been identified in the development of acute myeloid leukemia (AML), including mutations in the proto-oncogene N-RAS, p53, c-Kit and the FMS-like receptor tyrosine kinase 3 (FLT3). FLT3 plays an important role in the formation of early stem/progenitor cells during hematopoietic development. FLT3 is mutated in ∼30% of AMLs, with internal tandem duplications (ITD) in the juxtamembrane region being the most common (FLT3-ITD). This results in constitutive activation of FLT3 kinase activity and patients harboring such mutations do not respond well to conventional treatments and demonstrate poor clinical prognosis. There is growing evidence that the JAK/STAT pathway may also contribute to the etiology of AML. For instance, the JAK2 V617F point mutation driving various chronic myeloproliferative disorders (MPDs) has recently been detected in de novo AMLs and STAT3/5 phosphorylation is commonly elevated in AML patients. We have developed TG101348, a selective JAK2/FLT3 small molecule inhibitor which has the potential to treat both MPDs and AML. In in vitro based assays, TG101348 was capable of inhibiting the proliferation of human AML cell lines representing a variety of mutations. In AML cell lines carrying mutations in N-RAS such as KG-1, HL-60, and THP-1, EC50s ranged from ∼300 nM-1000 nM. In TF-1a AML cells, which harbor a mutation in p53, TG101348 demonstrated an EC50 of 493 nM. Most interestingly, for these cell lines, FLT3/VEGFR2 specific small molecule inhibitors such SU5416 were significantly less effective, demonstrating EC50s that were generally >10-fold higher. TG101348 was most potent against the FLT3-ITD positive cells lines, MV411 (EC50=57 nM) and MOLM13 (EC50=69 nM). In MV411 cells, TG101348 functionally inhibited FLT3 autophosphorylation, and phosphorylation of downstream intermediates including STAT5, ERK, and AKT. In a human MV411 xenograft models, oral administration (120mg/kg, BID) of TG101348 resulted in complete regression of the subcutaneously implanted MV411 tumors. Taken together, these data suggest that the dual-acting JAK2/FLT3 kinase inhibitor TG101348 may have a therapeutic advantage in that it has the capacity to block multiple pathways critical for dysregulated cell proliferation and survival in AML.
A Phase I Trial of Two Sequence-Specific Schedules of Decitabine and Vorinostat in Patients with Acute Myeloid Leukemia (AML).
Authors: Yee Karen W.L. , Minden Mark D. , Brandwein Joseph , Schimmer Aaron , Schuh Andre , Gupta Vikas , Messner Hans A. , Foley Ronan , Wasi Parveen , Zwiebel James A. , Leber Brian 
Published: October 2019

Abstract
Background: Epigenetic silencing of genes has been documented in AML. This phase I trial evaluates the safety, tolerability, and maximum tolerated dose (MTD) of two schedules of administration of the hypomethylating agent decitabine in combination with the pan-selective histone deacetylase inhibitor vorinostat.
Methods: Patients receive escalating doses of oral vorinostat administered either sequentially [100 mg bid (n=4), 200 mg bid (n=4), or 200 mg tid (n=8) Days 6–21] or concurrently [100 mg (n=3) or 200 mg (n=6) bid Days 1–21 or 200 mg tid (n=2) Days 1–14] with decitabine (20 mg/m2/d IV Days 1–5) every 28 days.
Results: Twenty-seven patients with AML have been treated. Median age was 67 years (range, 32–82 years). Median ECOG status 1 (range, 0 to 2). Eighteen patients (67%) had received prior therapy (median, 1 regimen; range, 0 to 4 regimens); 3 had received a prior allogeneic stem cell transplant. A total of 85 cycles have been administered, with a median of 2 cycles (range, 1 to 13 cycles); 10 patients (37%) have received 3 or more cycles of therapy. One of 7 patients treated at dose level 3 of the sequential schedule developed dose-limiting toxicities (DLT), consisting of grade 3 fatigue, weakness, and mucositis. Therefore, the MTD was not reached in the 3 planned dose levels of the sequential schedule. One DLT (grade 3 fatigue) occurred in 6 patients treated at dose level 2 of the concurrent schedule. Most common drug-related non-hematological toxicities of any grade (all CTCAE grades 1 or 2) were nausea (71%), fatigue (54%), diarrhea (54%), vomiting (42%), anorexia (25%), constipation (13%), abdominal pain (13%), dehydration (13%), and headache (13%). No other non-hematological grade 3 or 4 toxicities were observed. Of the 25 evaluable patients, one patient achieved an incomplete CR (without neutrophil recovery), one a morphologic leukemia-free state (without blood count recovery), and three partial remissions (1 achieved red cell transfusion independency and a second normalization of platelet counts). Seven of these patients remain on study for 2.7 to 13.5+ months. Correlative studies examining histone acetylation and gene promoter methylation in leukemic cells at baseline and after treatment, as well as plasma pharmacokinetic levels for both decitabine and vorinostat are being evaluated.
Conclusions: The combination of decitabine and vorinostat is safe, well-tolerated, and has clinical activity in patients with AML. Enrollment is ongoing.
Antisense Strategies to Specifically Deplete Levels of Factors II, VII and IX in Mice To Assess Their Potential as Targets for Anticoagulation.
Authors: Zhang Hong , Zhao Chenguang , Crosby Jeff , Siwkowski Andy , Freier Sue , Witchell Donna , Monia Brett P. 
Published: October 2019

Abstract
Numerous potential intervention points exist within coagulation pathways for development of novel anticoagulant agents. To help determine the most suitable target for the discovery of novel antithrombotic agents, we have implemented an antisense strategy to specifically deplete levels of various coagulation factors in mice. Here we report the effects of antisense oligonucleotides (ASOs) targeting factors II, VII, and IX on target RNA and protein levels in mice, as well as PT/aPTT. ISIS 401025 targeting factor II, ISIS 403102 targeting factor VII, and ISIS 402618 targeting factor IX dose-dependently suppressed their respective target transcript levels in a specific manner in primary mouse hepatocytes. Following subcutaneous administration to mice, each ASO reduced target RNA levels in liver and target protein levels in plasma in a specific and dose-dependent fashion (ED95 of approximate 25 mg/kg for each ASO). In conjunction with these effects, clotting times were also prolonged in a similar dose responsive fashion. Both PT and aPTT were increased following factor II inhibition and a PT-INR of 2.5 was achieved at 25 mg/kg, corresponding to a reduction in prothrombin transcript of 95%. As expected following factor VII ASO treatment, PT was significantly increased, while aPTT was unchanged. Conversely, following factor IX ASO treatment, aPTT was marginally but significantly prolonged, while PT was unchanged. These results demonstrate the capability of ASOs to dose-dependently and specifically modulate coagulation factor activity depletion and support the ASO approach as a novel strategy for the discovery of novel anticoagulation agents. Studies are in progress to assess relative safety and to expand the anticoagulation profile in mice for each of the factors under study.