bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Molecular Signature for a Cytokine Receptor Survival Pathway in AML Identifies Unique Prognostic Indicators and Therapeutic Targets
Authors: Thomas Daniel , Powell Jason A , Barry Emma F , To Luen Bik , Lopez Angel , Guthridge Mark A 
Published: April 2020

Abstract
The IL-3 receptor regulates myeloid cell survival and proliferation and is overexpressed on AML blasts and CD34+CD38- AML “stem-like” cells suggesting it plays a role in leukemic cell survival that could be exploited by targetted therapy. We have previously shown that Serine 585 in the cytoplasmic domain of the beta subunit of the IL-3 receptor is phosphorylated in response to sub-picomolar concentrations of cytokine, binds 14-3-3 zeta adaptor and is required for cytokine mediated survival (Guthridge et al, 2006, EMBO). We wished to examine the phosphorylation status of this receptor in AML blasts from patients and the expression levels of downstream Ser585 target genes.
Results: We show that Ser585 of the beta common subunit is constitutively phosphorylated in the majority of leukaemic patients regardless of Flt3 status or cytogenetics (18/21 patients). In contrast, tyrosine phosphorylation of the receptor is not deregulated and remains cytokine-dependent (20/21). We have identified a panel of 139 Ser585-regulated genes by microarray (WT receptor vs Ser to Gly mutant) and show that a specific subset of these genes is deregulated in AML blasts confirmed by RT-PCR compared to normal mononuclear cells consistent with constitutive activation of this pathway in AML. We have identified a 4-gene signature that is a molecular correlate of the Ser585-survival pathway in AML. We further identify Ser585-regulated genes that are prognostic indicators of clinical outcome in a cohort of adult patients AML (n=33) independent of WCC or cytogenetic abnormalities. Targetting Ser585 survival genes using siRNA or blocking mAbs induces apoptosis in AML blasts validating Ser585-regulated genes as potential targets for therapy.
Conclusions: Given the emerging problem of resistance to tyrosine kinase inhibitors (TKI) and limited success of Flt3 inhibitors in AML, new strategies for therapy are needed. By interrogating a cytokine survival pathway that functions independently of tyrosine phosphorylation we have uncovered novel Ser585 gene targets with promising clinical utility in leukaemia.
Mechanisms of Suppression Used by Regulatory T Cells in Patients Newly Diagnosed with Acute Myeloid Leukemia
Authors: Szczepanski Miroslaw J , Szajnik Marta , Czystowska Malgorzata , Mandapathil Magis , Welsh Ann , Foon Kenneth , Whiteside Theresa L , Boyiadzis Michael 
Published: April 2020

Abstract
An elevated frequency of CD4+CD25high regulatory T cells (Treg) has been reported in the peripheral blood in patients with various solid tumors and hematologic malignancies. Although the increase in Treg seems to be a characteristic feature of most tumors, the functional role of Treg and the mechanisms of suppression, especially in patients with hematologic malignancies, have been less well defined. We investigated Treg-mediated suppression and the responsible mechanisms in thirty newly diagnosed acute myeloid leukemia (AML) patients prior to any treatment and twenty five healthy donors (NC). The percentage of circulating CD4+ CD25high Treg was higher (p &lt;0.0001) in the AML patients (4.5 ±0.2%, range 1.7–8.2%) compared to NC (1.5 ± 0.08%, range 0.9–3.1 %). To evaluate the suppressive function, CD4+CD25high T cells (S) were co-cultured with sorted, CFSE-labeled autologous CD4+CD25high T cells (R) at different S/R ratios. Suppression mediated by Treg co-incubated with proliferating autologous responders was significantly higher (p&lt;0.001) in AML than that mediated by control Treg. To evaluate the role of cytokines produced by Treg in suppression and a need for cell-to- cell contact, transwell analysis of S/R co-cultures was performed. Co-incubation in the presence of transwell inserts (TRI) resulted in significant reduction of suppression (p&lt;0.05), and the addition of neutralizing antibodies to IL-10 and TGF-β1 in the presence of TRI further decreased suppression mediated by Treg. These data suggest that both immunoinhibitory cytokine production and cell-to-cell contact are necessary for suppression. To explore other potential mechanisms of Treg suppression, we evaluated the expression by Treg of ectonucleotidases CD39 and CD73 and the capability of Treg to produce adenosine. CD4+CD25high T cells of AML patients had higher expression (p&lt;0.01) of CD39 and more efficiently hydrolyzed ATP to adenosine relative to Treg in NC. These data indicate that various mechanisms of suppression may be utilized by Treg in patients with AML. The increase frequency of Treg mediating potent suppression by various mechanisms is likely to play a role in host anti-tumor immune responses. Therefore, modulation of the frequency and functions of Treg might provide new immunotherapeutic approaches in AML.
Activation of p53 Signaling Is Synergistically Enhanced by Bcl-2 Inhibition through Induction of Noxa and Bak/Bax Heterodimers Resulting in Apoptosis of AML Stem Cells
Authors: Konopleva Marina , Tsao Twee , Ling Xiaoyang , Kojima Kensuke , Watt Julie , Mak Duncan H. , Verhaegen Monique , Bornmann William , Soengas Maria , Andreeff Michael 
Published: April 2020

Abstract
Disruption of Mdm2-p53 interaction by the small molecule Nutlin-3a activates p53 signaling and induces apoptosis in acute myeloid leukemia (AML) (Kojima et al., Blood 2005). ABT-737 binds to the hydrophobic BH3-binding groove of the Bcl-2 family members Bcl-XL, Bcl-2, Bcl-w but not Mcl-1 and exerts its pro-apoptotic function by preventing anti-apoptotic Bcl-2 family members from sequestering activating BH3 proteins (Konopleva et al., Cancer Cell 2006). We have recently reported that Nutlin-3a and ABT-737 induced Bax conformational change and mitochondrial apoptosis in AML cells in a strikingly synergistic fashion (Kojima et al., Cell Cycle 2006). In this study, we investigated molecular mechanisms of this synergism. Nutlin-3a and ABT-737 synergistically induced apoptosis in OCI-AML3 and MOLM13 cells with wt-p53, but not in p53-null HL-60 cells or in OCI-AML3 stably transfected with p53 shRNA. Both, Nutlin-3a and ABT-737 induced Noxa protein levels resulting in Noxa/Mcl-1 heterodimers and therefore inactivation of Mcl-1. Lentiviral transfection of MOLM13 cells with Noxa shRNA protected cells from ABT-737/Nutlin-induced apoptosis. As reported by us, ABT-737 disrupted Bcl-2/Bak leading to formation of pro-apoptotic Bak/Bax heterodimers. Despite increased p53 levels there was no change in p53/Bcl-2 or p53/Bak association; however, combined exposure of cells to Nutlin-3a/ABT-737 induced massive Bak/Bax heterodimers and facilitated direct binding of p53 to Bax. HCT-116 cells deficient in Bax were largely protected from pro-apoptotic effects of the Nutlin-3a/ABT-737 combination. Taken together, these findings indicate that in leukemic cells p53-dependent apoptosis is executed through pro-apoptotic Bcl-2 family proteins, which are also targeted by BH3 mimetics. Bcl-2 is critical for AML leukemogenesis (Padua et. al., ASH 2008) and is overexpressed in AML stem cells. In primary AML samples, the Nutlin-3a/ABT-737 combination synergistically depleted CD34+CD38−CD123+ AML stem cells (combination index 0.5). Since high Bcl-2 and increased Bcl-2/Bax ratios are associated with poor clinical response in AML, the combination strategy proposed here may have considerable therapeutic promise in targeting AML stem cells.
Trib1 and Trib2 but Not Trib3 Degrade C/EBPá and Induce Acute Myelogenous Leukemia
Authors: Dedhia Priya , Keeshan Karen , Vega Maria , Uljon Sacha , Xu Lanwei , Shestova Olga , Romany Candice , Blacklow Stephen C , Pear Warren S. 
Published: April 2020

Abstract
Trib1, Trib2, and Trib3 are mammalian homologues of the Tribbles protein family, an evolutionarily conserved group of proteins that can mediate proteasome-dependent degradation. Evidence suggests that these proteins function as adapters, where they recruit E3 ligases and enhance ubiquination of the target protein in order to promote its degradation. To date, increased Trib1 and Trib2 mRNA expression has been shown to correlate with acute myelogenous leukemia (AML) in humans and induces AML in mice; whereas Trib3 has not been associated with AML. In order to understand the effects of Trib family members in hematopoietic cells, we reconstituted mice with hematopoietic progenitors retrovirally expressing Trib1, Trib2, or Trib3. Trib1 and Trib2 mice developed AML whereas Trib3 mice did not. Our previous data suggested that Trib2-mediated degradation of the transcription factor, C/EBPα, is important for leukemogenesis. We now show that Trib1, like Trib2, strongly binds C/EBPα and induces its degradation. In contrast, Trib3 weakly binds C/EBPα and fails to induce its degradation. Consistent with the ability to strongly bind and degrade C/EBPα, Trib1 and Trib2, but not Trib3, block differentiation of myeloid cells. We are currently mapping the domains that account for the differences between Trib1/Trib2 and Trib3 in leukemogenesis. Together, our results strengthen the correlation between Trib-induced C/EBPα degradation and induction of AML. Furthermore, our data show that different Tribbles family members have distinct targets and understanding this specificity may provide opportunities to therapeutically target Tribbles.
Outcome of First Salvage Therapy in Core Binding Factor Associated Acute Myelogenous Leukemia Is Less Than Optimal
Authors: Fava Carmen , Blamble Deborah , O’Brien Susan , Garcia-Manero Guillermo , Pierce Sherry , Kantarjian Hagop , Borthakur Gautam 
Published: April 2020

Abstract
Background: Core binding factor (CBF) associated acute myelogenous leukemia (AML) is considered to have a better prognosis compared to that of other patients with AML. Reinduction with cytarabine based therapy followed by allogeneic stem cell transplant is a standard salvage approach.
Method: We performed a retrospective analysis of outcome in patients with CBF AML.
Results: Between the years 1992 and 2005, 107 patients with CBF AML were treated at M.D. Anderson Cancer Center. Sixty-six (62%) patients had inv 16 abnormality and 41 (38%) had t(8;21) abnormality. Induction chemotherapy regimens included fludarabine and cytarabine with or without granulocyte colony stimulating factor (G-CSF) (66 patients) or idarubicin and cytarabine with/without G-CSF (41 patients). One hundred and one (94%) patients achieved complete remission (CR). After a median CR duration of 159 weeks, 37 (37%) patients relapsed. Relapse rate was 26/66 (39%) among patients with inv 16 abnormality and 11/41 (27%) among those with t (8;21) abnormality. Higher WBC count predicted for relapse (p=.001) and relapse rate did not differ among induction regimens (p=0.1).
Salvage chemotherapy included cytarabine based regimen in 22 (59%) patients, clofarabine and idarubicin (2 patients), topoisomerase inhibitor (5 patients), histone deacetylase inhibitor (2 patients) and miscellaneous regimens (6 patients). Sixteen (43%) of the patients with relapsed CBF AML achieved CR after first salvage therapy. Eleven of 26 (42%) patients with inv 16 and 7/11 (64%) of patients with t (8;21) were resistant to first salvage therapy. Thirteen patients (10 in CR) underwent allogeneic stem cell transplant and 12 of them remained in CR post-transplant. Overall survival was significantly worse among patients who relapsed compared to the ones who did not (p=.001).
Conclusion: A significant proportion of patients with CBF AML relapse and second remissions can be achieved in less than half the patients. This highlights the need for better induction/consolidation regimens in this group of patients with ‘good-risk’ AML.
Hypomethylating Therapy in Patients with AML and High-Risk MDS and Chromosome 5 and 7 Abnormalities Is Associated with An Improved Outcome Compared to Conventional Chemotherapy
Authors: Ravandi Farhad , Issa Jean-Pierre , Garcia-Manero Guillermo , O’Brien Susan , Pierce Sherry , Shan Jenny , Verstovsek Srdan , Faderl Stefan , Cortes Jorge , Kantarjian Hagop 
Published: April 2020

Abstract
Outcome of patients with AML and high-risk MDS with chromosome 5 and 7 abnormalities [excluding del 5(q)] has been poor with fewer than 10% of patients alive at 2 years. We investigated whether the use of hypomethylating agents, 5-azacytidine and decitabine, is associated with an improved outcome. Between January 2004 and December 2007, a total of 81 pts [including 37 (46%) with AML (≥ 20% blast) and 44 (54%) with high-risk MDS] with chromosome 5 and 7 abnormalities were treated with hypomethylating agents as their initial therapy. This included 68 patients with complex abnormalities and 13 with less than 3 aberrations. During the same period, 151 patients (126 AML, 25 MDS) with chromosome 5 and 7 abnormalities (128 complex, 23 noncomplex) were treated with intensive cytotoxic chemotherapy (including cytarabine based regimens in 72% and other regimens in 28%). The median age for the two groups was 66 and 61 years, respectively [(ranges (37–85) and (19–89)]. Thirty three (41%) pts in the hypomethylating group achieved CR versus 53 (35%) pts in the chemotherapy group (p=0.395). With a median follow up of 51 weeks (range 12–101) and 40 weeks (range, 5–128), 22/33 pts in the hypomethylating group and 33/53 pts in the chemotherapy group have relapsed giving median CR duration of 45 weeks for the hypomethylating group and 23 weeks for the chemotherapy group (p=0.153). The overall survival was superior for the hypomethylating group as compared to the chemotherapy group (Figure). We conclude that treatment with hypomethylating agents may be superior to chemotherapy in patients with chromosome 5 and 7 abnormalities who are traditionally resistant to cytotoxic agents.
Figure Figure
Alternate Donor HCT for Fanconi Anemia (FA): Results of a Total Body Irradiation (TBI) Dose De-Escalation Study
Authors: MacMillan Margaret L. , Blazar Bruce R. , DeFor Todd , Ma Linan , Tolar Jakub , Zierhut Heather , Wagner John E. 
Published: April 2020

Abstract
FA is the most common heritable marrow failure syndrome with a high predisposition to myelodysplastic syndrome and leukemia. Great strides have been made in optimizing the conditioning regimen and GVHD prophylaxis, necessarily tailored to these patients as a result of their underlying defect in DNA repair. Prior to 1995, survival rates after alternate donor hematopoietic cell transplantation (AD-HCT) were exceptionally poor (&lt;20%). After 1999, the addition of fludarabine (FLU) significantly improved engraftment and survival. However, risks of infection and late effects remained important challenges. Seeking to reduce these risks, we conducted a single center, single arm, TBI dose deescalation trial designed to determine the lowest possible dose of TBI required for engraftment in recipients of T cell depleted AD marrow (TCD BM). All patients received cyclophosphamide (CY) 10 mg/kg × 4 days, FLU 35 mg/m2 × 4 days, ATG 30 mg/kg ×5 days and a single fraction of TBI with CT guided thymic shielding (TS). TBI dose deescalation strata were: TBI 300 cGy (cohort 1); TBI 150 cGy (cohort 2); no TBI (cohort 3). All patients received CSA and methylprednisolone as GVHD prophylaxis and G-CSF 5 ug/kg/day until engraftment. The decision to proceed with each stepwise decrease in TBI was based upon achieving primary neutrophil engraftment in 10 of 10 patients at each dose level, or 14 of 15 patients if one graft failure is observed in any of the first 10 patients. More than 1 graft failure in 15 patients was considered unacceptable and the next higher TBI dose level was then considered the optimal dose. Between July 2006-May 2008, 19 FA patients were enrolled with 17 in cohort 1 and 2 in cohort 2. Five patients received 5–6/6 unmanipulated UCB because a marrow donor could not be identified. All patients achieved primary engraftment at a median of 11 days after AD-HCT. However, 2/2 patients who received TBI 150 developed secondary graft failure at 76 and 114 days after HCT. The dose de-escalation was stopped with TBI 300 cGy identified as the lowest possible dose in the context of FLU/CY given concomitantly. Thus far, 17 patients have been treated with TBI 300. As shown, results compare favorably with prior regimens using TBI 450 with and without TS (table).
Outcomes after AD-HCT in Standard Risk FA Patients
N Neutrophil Engraftment Acute GVHD Chronic GVHD 1 Year Survival TS = thymic shielding TBI 450 no TS 21 95% 24% 19% 67% TBI 450 +TS 12 92% 42% 8% 83% TBI 300 +TS 17 94% 25% 0% 92%
Our results demonstrate that TBI 300 cGy is sufficient for consistent engraftment in recipients of CY-FLU-ATG and HLA matched or mismatched TCD AD BM or UCB and represents a new standard of care for this patient population. Longer follow up is needed to quantitate the impact of lower dose radiation on immune recovery, risks of infection, cancer risk and other therapy-related late effects.
Improvement of Thrombolysis by Rivaroxaban, An Anti Xa Inhibitor. Potential Therapeutic Importance in Patients with Thrombosis
Authors: Varin Remi , Mirshahi Shasultan , Mirshahi Pehzman , Lu-Hong Li , Kierzek Gerald , Vigneau Jean-Francois , Marie Jean-Pierre , Perzborn Elisabeth , Mirshahi Massoud , Soria Claudine , Soria Jeannette 
Published: April 2020

Abstract
Background and objective Rivaroxaban – an oral, direct Factor Xa inhibitor – inhibits thrombus formation and growth in animal models. We have investigated the effects of rivaroxaban on thrombolysis because impaired fibrinolysis is a risk factor for venous thrombosis and it occurs more often in patients who had a myocardial infarction. As the propensity of a clot to be degraded depends on its structure, we tested the effects of rivaroxaban on clot structure and degradability by tissue plasminogen activator (t-PA). This was done in the absence and presence of thrombomodulin because the thrombin - thrombomodulin complex is the activator of TAFI (thrombin-activatable fibrinolysis inhibitor), a potent inhibitor of fibrinolysis.
Methods Clots were formed in a microchamber in the presence or absence of rivaroxaban at pharmacological concentrations (0.15 and 0.25 μg/ml). Clot structure was analyzed by confocal microscopy, and permeability calculated by measuring flow rates. Degradation was evaluated by the amount of D-dimers in the eluate of clot perfused with t-PA, in the presence or absence of thrombomodulin.
Results Microscopy showed that clots formed in the presence of rivaroxaban had thicker fibers and a looser fibrin structure with larger pores than controls, leading to increased permeation rate (Darcy constant 2.16-fold and 2.45-fold higher than controls with rivaroxaban at 0.15 μg/ml and 0.25 μg/ml, respectively). This clot structure modification renders the clots more susceptible to fibrinolytic enzymes. The degradation of clots containing 0.15 μg/ml of rivaroxaban was 3.6-fold higher than that of control clots, after 90 minutes perfusion with t-PA. In addition, when clots are formed in the presence of thrombomodulin, the degradability is decreased in control, while In the presence of rivaroxaban, fibrin degradation remains enhanced.
Conclusion Rivaroxaban increased thrombolysis by t-PA. This was due to a decrease in thrombin generation. Two mechanisms are involved:
modification of clot structure, which makes it more accessible to thrombolytic enzymes; and decrease in TAFI activation by the thrombomodulin–thrombin complex. This property of rivaroxaban may contribute to its antithrombotic effect.
Fatal Disseminated Intravascular Coagulation and Autoimmune Hemolytic Anemia Due to Anti-Ena
Authors: Klapper Ellen B , Xie Joanna J , Garratty George , Pepkowitz Samuel , Arndt Patricia 
Published: April 2020

Abstract
Background: Autoimmune hemolytic anemia (AIHA) caused by warm IgG antibodies is usually characterized by IgG-mediated extravascular hemolysis and anemia that develops slowly. We report a case of AIHA presenting with sudden massive intravascular hemolysis and disseminated intravascular coagulation (DIC), similar to that seen following an ABO incompatible transfusion reaction.
Case Report: A 71-year-old female had a 4-year history of immune thrombocytopenic purpura requiring splenectomy 1 ½ years ago. Six weeks prior to admission, in association with a viral infection, her platelet (plt) count fell from 350,000/mm3 to 150,000/mm3 over 2 weeks. She was treated with oral prednisone, and one week prior to admission her platelet count was 200,000/mm3. Two days before admission she noted reddish urine. Laboratory studies at her doctor’s office showed hemoglobin (Hb) 9 g/dL (had been 13 g/dL 1 week earlier) and bilirubin (bili) 9 mg/dL. On the day of admission, in the emergency department, she complained of generalized weakness, jaundice, and near-syncope. She became increasingly agitated and dyspneic and was intubated. At that time laboratory studies showed Hb 4.5 g/dL, LDH &gt;2,500 U/L, haptoglobin 7 mg/dL, total bili 13.0 mg/dL, indirect bili 11.8 mg/dL, D-dimers &gt;10,000 ng/dL, plts 139,000/mm3, prothrombin time 18.3 seconds, fibrinogen 166 mg/dL, fibrin monomers were positive. She was admitted to the medical intensive care unit with a diagnosis of DIC and hemolysis. The patient’s RBCs were coated with IgG (4+) and C3 (3+); IgM and IgA were not detected. Her plasma and an eluate contained an antiglobulin test reactive autoantibody with anti-Ena specificity (anti-Pr and -Wrb were excluded), an antibody directed at epitopes on glycophorin A. No alloantibodies were detected in the patient’s plasma. The patient was treated with IV steroids and received multiple RBC transfusions over the first few hospital days. Her Hb stabilized at 10 g/dL. The day after admission, she became oliguric and required dialysis throughout her hospital course. Over the next several days, additional signs and symptoms of DIC were noted: ischemic digits and toes, elevated Troponin I, partial thromboplastin time, D-dimers and decreased plt count. She was placed on intravenous heparin. Gastrointestinal bleeding developed and heparin was discontinued on hospital day 9. One week later, the onset of abdominal pain necessitated exploratory laparotomy which revealed ischemic bowel with perforation; vessels showed organized thrombi with recanalization. She remained critically ill and died on hospital day 25.
Conclusion: Complement-mediated intravascular hemolysis in a patient with AIHA due to anti-Ena was associated with renal failure and DIC leading to death of the patient. All of these, even separately, are unusual in warm AIHA. We know of no reports where all 5 events (intravascular lysis, anti-Ena, renal failure, DIC, and death) occurred in one patient.