bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of Signal Transducers and Activators of Transcription by Src Family Kinase in AML.
Authors: Ozawa Yukiyasu , Williams Ann H. , Estes Myka , Sokol Lubomir , Jove Richard , List Alan F. 
Published: April 2020

Abstract
Specific Signal Transducers and Activators of Transcription (STAT) family members are constitutively activated in leukemia where they contribute to leukemia self-renewal and apoptosis resistance. STAT5 activation in chronic myeloid leukemia (CML) is driven by the Bcr-Abl and Lyn kinases, whereas in acute myelogenous leukemia (AML), STAT5 and STAT3 activation is demonstrable under the control of as yet undefined upstream regulators. To investigate the regulation of STAT activation in AML, we evaluated the role of Src family kinases in AML cell lines and primary patient specimens. Inhibition of leukemia cell prolifaration by Src inhibitors was evaluated in 7 cell lines (U937, HEL, KG-1a, THP-1, OCI-AML3, HL-60 and NB-4). Treatment with either PD180970 or SKI-606 significantly suppressed proliferation and decreased viability in a concentration-dependent manner in two cell lines. U937 cells displayed sensitivity comparable to K562 CML cells, whereas KG-1a cells demonstrated moderate inhibition. Corresponding DNA-STAT5 binding activity assessed by electrophoretic mobility shift assay (EMSA) showed constitutively STAT5 activation in 3 cell lines (U937, HEL and KG-1a), with inhibition of STAT5 DNA binding By Src inhibitors in U937 and KG-1a cells, while STAT5 activity was not impaired in HEL cells. STAT5 protein phosphorylation assessed by immunoblot was suppressed by the Src inhibitors in the sensitive cell lines. Moreover, Src inhibition decreased Bcl-XL expression, a transcriptional target of STAT5, and induced apoptosis in U937 cells. Immunoblot assessment of phosphorylation of the activation loop tyrosine in the two major src kinases, c-Src and Lyn, confirmed inhibition of autophosphorylation in U937 cells and K562 cells by PD180970 and SKI-606, while phosphorylation was unchanged in HEL cells. Inhibition of src kinases was rapid (&lt; 30 min), and preceeded inhibition of STAT5 activation. Analysis of primary AML patient cells revealed that 29 % (5 of 17) of patient cells have constitutively-activated STAT5, and 47 % (8 of 17) have constitutively-activated STAT3. More importantly, some primary AML patient cells were sensitive to Src inhibitor. These data suggest that Src activation of STAT5 has a pathogenetic role in AML cells. Investigation of Src inhibitors merits clinical investigation in patients with AML.
Thromboprophylaxis after Orthopaedic Surgery with an Oral, Direct Factor Xa Inhibitor: Pooled Results of Two Phase Iib Clinical Trials.
Authors: Turpie Alexander G.G. , Bauer Kenneth Alan , Borris Lars , Dahl Ola E. , Fisher William D. , Gent Michael , Haas Sylvia , Huisman Menno V. , Kakkar Ajay K. , Kälebo Peter , Kwong Louis M. , Homering Martin , Misselwitz Frank , Eriksson Bengt I. 
Published: April 2020

Abstract
Thromboembolic events, such as deep vein thrombosis (DVT) and pulmonary embolism (PE), are a serious risk after surgical procedures, such as major orthopaedic surgery. BAY 59-7939 is an oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic disorders. The efficacy and safety of BAY 59-7939 for thromboprophylaxis have been determined relative to enoxaparin in two clinical trials, one after elective total hip replacement surgery, and one after elective total knee replacement surgery. Both trials were multicenter, multinational, double-blind, dose-ranging studies; the hip surgery trial was performed in Europe, and the knee surgery trial in North America. This pre-specified analysis combines data from both trials. Patients (n=1343) were randomized to oral BAY 59-7939 at 2.5, 5, 10, 20, or 30 mg twice daily (bid), or subcutaneous enoxaparin (40 mg once daily starting 12 hours before hip surgery, or 30 mg bid starting 12 hours after knee surgery). Treatment continued until mandatory bilateral venography was performed 5–9 days after surgery. The primary efficacy endpoint was a composite of DVT, PE, and all-cause mortality, and was analyzed in 914 per-protocol patients. The secondary efficacy endpoint was major venous thromboembolism (VTE) - proximal DVT, PE, and VTE-related death. The primary safety endpoint was major, post-operative bleeding, and was analyzed in 1317 patients. Observed pooled event rates are shown in the table. No significant dose-response relationship for efficacy was observed with BAY 59-7939 (P=0.39 and P=0.46 for primary and secondary endpoints, respectively) in logistic regression models using total daily dose and adjusting for study, age and gender effects; this was potentially due to the efficacy achieved with the lower BAY 59-7939 doses. A significant dose-response relationship was observed for major, post-operative bleeding with BAY 59-7939 (P&lt;0.001). In conclusion, this analysis showed that for the prevention of VTE following major orthopaedic surgery, BAY 59-7939 has a wide therapeutic window and, at doses of 2.5 to 10 mg bid, has similar efficacy and safety to the enoxaparin regimens.
BAY 59-7939 (mg bid) Endpoint 2.5 5 10 20 30 Enoxaparin DVT, PE, all-cause mortality 36/167 (21.6%) 38/166 (22.9%) 26/161 (16.1%) 38/156 (24.4%) 17/88 (19.3%) 49/176 (27.8%) Major VTE 5/167 (3.0%) 4/166 (2.4%) 5/161 (3.1%) 5/156 (3.2%) 1/88 (1.1%) 8/176 (4.5%) Major, post-operative bleeding 2/232 (0.9%) 3/238 (1.3%) 5/236 (2.1%) 9/232 (3.9%) 10/143 (7.0%) 4/236 (1.7%)
NF Kappa B as a Therapeutic Target in AML.
Authors: Jenkins Christopher , Pepper Christopher J. , Mills Ken I. , Burnett Alan K. 
Published: April 2020

Abstract
NF Kappa B is an inducible eukaryotic transcription factor, which is highly conserved throughout nature, and regulates a large number of genes which are essential for immune and inflammatory responses. Inappropriate expression has been implicated in a number of inflammatory and malignant conditions. We have investigated the expression of NF Kappa B in normal mobilised peripheral blood cells, AML cell lines (HL60, NB4, K562, U937) and 27 primary AML cells, with a view with it being a target for NF Kappa B inhibition. The cells were also treated with a range of doses of LC1 (Leuchemix Inc) which includes NF-KB inhibition in its activity profile. The expression of NF Kappa B was determined by Affymetrix Gene Chip Array (22,283 genes) and confirmed by RT-PCR. Overall the leukaemic cells had a greater than a two-fold expression compared with normal cells. Expression was significantly greater in the FAB M2 and M4 subgroups and tended to increase with the degree of morphological differentiation, and with poor risk cytogenetics. There was no relationship between expression age, gender or FLT3 mutation status. Since increased NF Kappa B expression confers resistance to apoptosis, the level of spontaneous apoptosis of cells after 24 hours in vitro was assessed by annexin V expression. Apoptosis was inversely correlated with expression.
LC1 (Leuchemix Inc) is a novel agent with NF Kappa B inhibition among its properties. Cells were treated with LC1 in a dose range of 0.002 to 20μmol, and the LC50 determined in an MTS assay. For the cell lines HL60, NB4 and U937 the average LC50 was 6.1μmol. K562 cells have a lower expression of NF Kappa B (40%) compared with the other cell lines and this was reflected in a lower in vitro sensitivity (LC50 &gt; 100μmol). The LC50s for the 27 primary AML stem cell samples ranged from 0.61μmol to &gt; 100μmol with a mode of 7.1μmol. The majority of the cases (24/27) were between 0.61 and 13.2μmol with a mean of 5.9μmol while the 3 outliers have an LC50 which was 4–10 fold higher. In order to assess whether LC1 enhance the cytotoxicity of Ara-C co-incubation experiments were undertaken using the MTS assay. Significant synergy was observed in 8 or 27 cases, and antagonism in 12 of 27 cases.
These data suggest that NF Kappa B inhibition with LC1 merits further evaluation as targeted treatment alone, or in combination, in AML.
Phase II Clinical Trial of Flavopiridol (FL) Followed by ara-c and Mitoxantrone (AM) for Adults with Relapsed and Refractory Acute Leukemias.
Authors: Karp Judith E. , Smith B. Douglas , Greer Jacqueline , Briel Janet , Levis Mark J. , McDevitt Michael A. , Gore Steven D. , Colevas A. Dimitrios 
Published: April 2020

Abstract
The cell cycle inhibitor FL targets cyclin-dependent kinases, induces checkpoint arrest and interrupts transcriptional elongation. We demonstrated in an in vitro model that F causes apoptosis in leukemic blasts and increases A cytotoxicity in remaining blasts (Clin Cancer Res9: 307–315, 2003). Based on these observations, we have conducted a Phase II trial of timed sequential therapy (TST) with FL 50 mg/m2 daily x 3 days followed by A 2 gm/m2/72 hr infusion beginning day 6 and M 40 mg/m2 day 9 (FLAM). A total of 42 adults (median age 50, range 23–75) received FLAM for acute myelogenous leukemia (AML, 37 pts) or acute lymphoblastic leukemia (ALL, 5 pts). Four pts had new AML (myelodysplasia- or treatment-related), 19 were in relapse after first complete remission (CR; median duration 8 mos, range 1.5 – 20), and 19 had refractory leukemia (9 primary). Four pts had prior allo- or auto-stem cell transplants, 13 (31%) had secondary AML and 25 (60%) had adverse cytogenetics, including 2 with Ph+ ALL. FLAM was well-tolerated with death occurring in only 3/42 (7%, fungemia, respiratory distress, multi-organ failure). Grade ≥ 3 non-hematologic toxicities consisted of oral mucositis (2/42, 5%), diarrhea (1/42, 2%), cardiac arrhythmia or decreased ejection fraction (3/42, 7%). F induced tumor lysis in 14 (33%) within 24 hrs of first F dose and a ≥ 50% fall in WBC after 2 F doses in 18 (43%). Median time to neutrophils ≥ 500/mm3 was day 30 day (range 24–46) and platelets ≥50,000/mm3 was day 35 (range 24 – 55). CR was achieved after 1 course of FLAM in 15/37 (41%) AML: 3/4 new patients (including complex cytogenetics), 11/19 relapse and 1/9 primary refractory. CR was achieved in 1/5 (20%) ALL in a patient with relapsed Ph+ ALL. Two of 4 with prior transplant achieved CR, while no patient who was refractory to multiple chemotherapies achieved CR. Of the 15 achieving CR, 13 received additional therapy. Eight pts (7 CR, 1 partial response; median age 45, range 26–62; 1 new diagnosis, 6 relapse, 1 primary refractory) went on to receive allo-transplant in second CR, with CR 2 durations 4.5–12+ mos. An additional 2 pts (ages 45, 46) who had relapsed after allo-transplant in CR1 were able to receive donor lymphocyte infusions (DLI) after FLAM and remain in CR2 of 8+ mos duration. Three pts over age 65 received a second cycle of FLAM in CR, with CR durations of 8.5+, 10, and 10.5 mos. Induction chemotherapy with FLAM yields a significant CR rate in pts with newly diagnosed poor-risk AML or in pts with short CR1, and allows eligible pts to proceed to allo-transplant in CR2.
Differentiation Therapy for Poor Risk Myeloid Malignancies: Results of a Dose Finding Study of Bryostatin-1 (BRYO) + GM-CSF.
Authors: Smith B. Douglas , Matsui William H. , Gladstone Douglas E. , Karp Judith E. , Gore Steven D. , Huff Carol Ann , Vala Milada , Baker Sharyn , Zhao Ming , Piantadosi Steven , Jones Richard J. 
Published: April 2020

Abstract
Clinically effective differentiating therapy has been limited to the use of all-trans-retinoic acid in patients (pts) with acute promyelocytic leukemia. We recently demonstrated that the in vitro activity of many pharmacologic differentiating agents, including the protein kinase C agonist bryo, was dependent on their ability to block cell cycle and maximized by the addition of growth factors. We studied the safety and efficacy of continuous infusion bryo in combination with GM-CSF (125 ug/m2/day SC) in patients (pts) with refractory and poor risk myeloid malignancies. Bryo was dose escalated using the Continual Reassessment Method from 6ug/m2/day to 20ug/m2/day for 14 days monthly and followed by 16ug/m2/day to 20ug/m2/day over 21 days each month. The treatment plan called for 2 cycles of combination therapy prior to response evaluation. A total of 32 patients with refractory or poor risk myeloid malignancies (9 relapsed or refractory AML, 1 therapy-related AML, 2 poor risk AML age &gt;70, 19 poor risk MDS, 1 progressive PNH) were treated. The median age of subjects was 65 (range 23–75) yrs and a total of 73 (58 full + 15 partial) cycles were administered. The dose-limiting toxicity of the combination mirrored results from previous trials of bryo; grade 3–4 myalgias and arthralgias were observed in 12 of 14 pts at the highest dose levels (18 and 20ug/m2/day x 14 days, 16ug/m2/day x 21 days). Three pts discontinued therapy within a week of cycle 1 and were not considered evaluable for response. Eighteen (62%) pts responded (2 CRs and 16 PRs), 6 (21%) had stable disease, and 5 (17%) progressed. The PRs included 15 lineage responses and 1 bone marrow response (&lt;5% blasts) with persistent cytopenias. The 2 CRs included a 59 yr old with poor risk MDS treated @ 20ug/m2/day x 14 days followed by a 2nd cycle @ 18ug/m2/day x 14 days (dose-reduced due to toxicity) who achieved a CR and continues to show improving cytogenetics at 11 mos and a 74 year old with newly diagnosed primitive leukemia (&gt;50% marrow blasts) who received a single cycle @ 16ug/m2/day x 21 days and remains in CR at 5 mos. Both pts refused further courses due to myalgias and arthralgias, and interestingly, the CRs were not achieved until 4–6 weeks after completion of therapy. Our newly developed assay (sensitivity 50 pg/ml) detected measurable bryo only at the highest doses which supported the correlative in vitro assays that detected in vivo differentiation at the same doses. Bryo + GM-CSF has remarkable clinical activity in refractory myeloid malignancies, but is intolerable at biologically active doses. These results do suggest that strategies utilizing differentiating agents in conjunction with growth factors warrant further investigation.
Treatment of Patients with Refractory AML with SU5416 Downregulates VEGF-A, STAT5 and Akt Expression in Leukemic Blasts.
Authors: Loges Sonja , Tinnefeld Heike , Metzner Anja , Jucker Manfred , Butzal Martin , Bruweleit Melanie , Fischer Uta , Draab Elena , Schuch Gunter , O’Farrell Anne M. , Hossfeld Dieter K. , Bokemeyer Carsten , Fiedler Walter 
Published: April 2020

Abstract
Autocrine or paracrine activation of receptor tyrosine kinases are important pathogenetic factors in AML. Signal transduction via c-kit and FLT3 increase proliferation and apoptosis resistance of leukemic blasts. Additionally bone marrow angiogenesis plays a significant role in disease progression.
This provided the rationale for a multicenter clinical trial in patients with refractory AML with SU5416, a small molecule kinase inhibitor which blocks phosphorylation of c-kit, FLT3, VEGFR-1, VEGFR-2 (KDR) and VEGFR-3.
In the study presented here, we analysed expression levels of VEGF and the downstream signal transduction intermediates STAT5 and Akt in patients before and during treatment with SU5416.
The levels of VEGF mRNA expression were investigated in peripheral blood leukemic blasts by means of quantitative Real-Time PCR. 74% (14 of 19) of analyzed patients had rapid and persistent down regulation of VEGF during therapy. Patients initially expressing high VEGF-levels had a stronger down regulation and a higher clinical response rate (mean 865-fold, n=9) than patients initially expressing low VEGF-levels (mean 4-fold, n=8). These results suggest that downregulation of high pretherapeutic VEGF expression by SU5416 treatment may serve as an early surrogate marker of therapeutic response to anti-angiogenetic therapy.
Additionally, protein expression of STAT5 and Akt was assessed by Western blotting. Incubation of the leukemic cell line M-07e in-vitro with SU5416 using concentrations which are achievable in patients was used as a model system. In the AML patient samples parallel downregulation of both STAT5 and Akt was observed in several cases (STAT5 in 4 of 15, Akt in 3 of 6 examined patients). Decreased intracellular levels of STAT5 and Akt were also found in the line M-07e after incubation with SU5416 in vitro.
In summary, our data provide evidence for suppression of expression of VEGF and of the key signal transduction intermediates STAT5 and Akt in AML blasts in-vivo during treatment with SU5416.
Prevention of Venous Thromboembolism after Total Hip Replacement with Once-Daily BAY 59-7939 - An Oral, Direct Factor Xa Inhibitor.
Authors: Eriksson Bengt I. , Borris Lars , Dahl Ola E. , Haas Sylvia , Huisman Menno V. , Kakkar Ajay K. , Misselwitz Frank , Muehlhofer Eva , Kälebo Peter 
Published: April 2020

Abstract
Venous thromboembolism is a serious risk after major surgery, and significant research is underway to develop novel, convenient anticoagulants. Patients undergoing hip replacement surgery are a suitable population for the study of novel anticoagulants because of a high rate of silent deep vein thromboses (DVTs), and the ability to quantify bleeding in a controlled environment. BAY 59-7939 is an oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic disorders. Dose-finding studies in hip and knee replacement patients showed that twice-daily, oral BAY 59-7939 initiated post-operatively had a wide therapeutic window, with similar efficacy and safety to enoxaparin (30 mg twice-daily or 40 mg once-daily) for the prevention of venous thromboembolism (VTE), and was unlikely to require monitoring. This European, randomized, double-blind, double-dummy, dose-finding study was performed to compare the efficacy and safety of once-daily, oral BAY 59-7939 with subcutaneous enoxaparin for VTE prevention in patients undergoing total hip replacement. Males over the age of 18 and postmenopausal females undergoing elective total hip replacement were randomized to oral BAY 59-7939 5, 10, 20, 30, or 40 mg once daily, or subcutaneous enoxaparin 40 mg once daily. Patients received enoxaparin on the evening before surgery and at least 6–8 hours after surgery, or BAY 59-7939 6–8 hours after surgery. Study drugs were then given every 24±2 hours. Each treatment group was to include 135 patients: a total of 810 patients. Mandatory bilateral ascending venography was performed 6–10 days after surgery; the last dose of study drug was given on the day before venography. Patients were followed for 30–60 days after the last study treatment. The primary efficacy endpoint was a composite of any DVT, objectively confirmed non-fatal pulmonary embolism (PE), and all-cause mortality; the secondary efficacy endpoint was major VTE - proximal DVT, PE, or VTE-related death. The primary safety endpoint was the incidence of major, post-operative bleeding not later than 2 days after the last intake of study drug; secondary safety endpoints included clinically relevant, non-major bleeding, and minor bleeding. An in-depth analysis of the study results will be presented here. Based on the study findings, the potential clinical impact of oral BAY 59-7939 administered once-daily for thromboprophylaxis in orthopaedic surgery will be discussed.
Valproic Acid as Adjunct to Induction Therapy in Patients with Acute Myeloid Leukemia: First Results of Two Randomized Studies of the AMLSG.
Authors: Schlenk Richard F. , Bommer Martin , Schmid Mathias , Fröhling Stefan , Lehmann Katrin , Groner Silja , Hann Rainer , Krauter Jürgen , Döhner Konstanze , Ganser Arnold , Göttlicher Martin , Döhner Hartmut 
Published: April 2020

Abstract
Differentiation arrest in acute myeloid leukemia (AML) results in part from dysregulation of histone acetylation and deacetylation, leading to transcriptional repression of differentiation-inducing genes. Transcriptional repression can be returned by histon deacetylation inhibitors, such as valproic acid (VPA). In September 2004, we initiated two randomized trials [AMLSG 07-04 (age 18–60 yrs), AMLSG 06-04 (age &gt;60yrs)] to evaluate the impact of VPA as adjunct to standard induction therapy (idarubicin and cytarabine; additional etoposide in pts. &lt;60 yrs) in combination with all-trans retinoic acid (ATRA). This report focuses on serum-levels of VPA achieved by mid-fast saturation, correlation between total and free unbound serum levels of VPA, and influence on hematological reconstitution and morphological abnormalities at remission control induced by VPA. Dose schedule of mid-fast saturation is VPA i.v. 400mg bid. day 1+2, followed by serum level adapted p.o. treatment with retard formulation 4 times a day with a target serum level of 50 to 150mg/l. Data on serum levels in correlation to VPA-dose from 42 patients are available. Median serum level after 2 days of intravenous treatment was 34 mg/l (range 1 to 80mg/l). Median serum level at day 10 of induction therapy was 57mg/l (range 1 to 135mg/l) with 65% of patients having a minimum serum level above 50mg/l. Side effects induced by VPA were tremor, confusion and fatigue necessitating dose reduction of VPA in 5 (12%) cases. A linear regression model revealed high correlation between the free unbound fraction of VPA, total VPA-serum level (coef. 0.19 p&lt;0.0001) and albumin serum level (coef. −0.30, p&lt;0.0001). Other variables such as creatinine or total protein serum levels as well as age did not show significant influence on the free unbound fraction of VPA. High total VPA-serum levels during and after induction therapy were associated with morphological particularities at the time of morphological bone marrow assessment between day 21 to 28. In these cases there was morphological synchronization predominantly at the promyelocyte stage and a slightly but not significantly delayed reconstitution of peripheral blood values. In conclusion, VPA as adjunct to intensive induction therapy is feasible and has possible influence on the kinetics and morphology during hematological regeneration.