bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strong Therapeutic Effect Of Anti-IL1RAP Immunotherapy In a Xenograft Model Of Acute Myeloid Leukemia
Authors: Agerstam Helena , Askmyr Maria , Hansen Nils , Rissler Marianne , Juliusson Gunnar , Richter Johan , Wunderlich Mark , Järås Marcus , Mulloy James C. , Fioretos Thoas 
Published: October 2019

Abstract
Acute myeloid leukemia is a genetically heterogeneous disease characterized by expansion of immature hematopoietic cells in the bone marrow. The disease is associated with a general poor survival and thus the need for novel treatment strategies is urgent. We have previously shown that the IL1 receptor accessory protein (IL1RAP) is highly expressed on primitive chronic myeloid leukemia (CML) cells and that a polyclonal antibody against IL1RAP can direct natural killer cells to specifically target and destroy CML CD34+CD38- cells in an in vitro-based antibody dependant cell-mediated cytotoxicity (ADCC) assay (Järås et al, PNAS, 2010). We recently also demonstrated that IL1RAP is upregulated in about 80% of AML patients and that primitive AML cells can be targeted by a monoclonal antibody against IL1RAP and selectively killed by ADCC (Askmyr et al, Blood, 2013).
In this study, we applied these findings to a human AML xenograft model. NOD/SCID mice were engrafted with lethal doses of MA9Ras cells, previously generated by transformation of human umbilical cord blood CD34+ cells by retroviral integration of cDNAs directing the expression of an MLL/AF9 fusion and an activated NRAS gene. Leukemic mice were treated twice weekly with Mab81.2, a monoclonal antibody targeting IL1RAP, or a corresponding isotype control antibody. Notably, the seven mice treated with Mab81.2 displayed a significant reduction of leukemic cells in the peripheral blood 35 days after transplantation compared to the seven mice in the isotype control treated group (0.10±0.04% vs. 0.69±0.45% CD45+ cells, p=0.0043). This reduction was even more significant at 62 days (3.75±2.50% vs. 46.46±24.92% CD45+ cells, p=0.0007). Treatment with the IL1RAP-targeting antibody also resulted in an increased overall survival compared to the isotype control treated group (median survival 75 days vs 64 days, p=0.0089). Furthermore, at time of sacrifice, the Mab81.2-treated mice were shown to have significantly lower frequency of leukemic cells in the bone marrow (4.99±3.34% vs. 59.51±25.18% CD45+ cells, p=0,0001) and spleen (17.19±10.21% vs. 49.71±23.09% CD45+ cells, p=0,0052).
In conclusion, we show that in vivo delivery of the Mab81.2 monoclonal antibody results in significant suppression of human MA9Ras cells and prolongs survival in a xenograft setting, demonstrating that anti-IL1RAP immunotherapy provides a new promising treatment approach for AML.

Disclosures:
Richter: Cantargia: Consultancy, Equity Ownership. Järås:Cantargia AB: Equity Ownership, Membership on an entity’s Board of Directors or advisory committees. Fioretos:Cantargia AB: Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Research Funding.
ODE-Adefovir As Potential Therapeutic Agent In AML
Authors: Khoury Haytham , Ruijuan Hu , Schimmer Aaron , Hostetler Karl , Minden Mark D 
Published: October 2019

Abstract
Adefovir is an antiviral adenosine monophosphate analogue from the class of acyclic nucleoside phosphonate (ANP). During 0n-patent drug library screen, we discovered adefovir-dipivoxil (adefovir-DP) as potentially active against AML. Second-generation formulations Of adefovir, including ODE-adefovir and HDP-adefovir, have been designed to overcome adefovir-DP pharmacodynamic disadvantages. To characterize the activity of the above-mentioned agents in AML, we undertook this study. In AML cell lines (OCI/AML-1, -2, -3, -4 and -5) adefovir-DP appeared to be highly potent with IC50 ranging from 45.8 to 252.5 nM. ODE-adefovir was equally potent as adefovir-DP (IC50 from 51.7 nM to 205.3 nM), whereas HDP-adefovir was significantly less potent (224.8±19.6 to 956.3±14.4 nM). Similar results were obtained when we tested the activity of these agents in primary AML patient samples. Interestingly, ODE-adefovir was remarkably less toxic than adefovir-DP in normal hematopoietic cells, with IC50 at 40 and 1µM, respectively. In addition, ODE-adefovir at dose 15mg/kg/day showed potent activity against AML in NOD/SCID-mouse human-leukemia model with reduction in human leukemia in mouse bone marrow > 50%in all mice tesed within 14 days. Based on its chemical structure, we hypothesized that the plausible mechanisms of ODE-adefovir cytotoxicity in AML are cell-cycle arrest and DNA damage. Indeed, treatment of OCI/AML-2 cells with ODE-adefovir induced increase of the cells in the S phase from 9% to 30%. Moreover, ODE-adefovir increased the expression of pH2Ax, a hallmark of DNA damage, within 2h of treatment. Plus, there was increase in phosphorylation of P53; transactivation of proapoptotic genes, Puma, Noxa and BAX; and induction of the intrinsic apoptotic pathway, as shown by the cleavage of caspases 7 and 9. Further investigation unveiled strong synergism between ODE-adefovir and cytarabine, a mainstay drug in the treatment of AML, without any cross-resistance between both agents, thus making their co-administration potentially beneficial. MRP4 expression appeared to influence AML cells response to ODE-adefovir and its inhibition potentiates this response. Taken together, our findings emphasize the potential cytotoxic activity of adefovir in AML and the importance of choice of appropriate formulation for such purpose. Further, they indicate that the development of ODE-adefovir for clinical testing in AML is warranted.

Disclosures:
Off Label Use: Adefovir dipivoxil is a drug used for the treament of hepatitis B. WE found it is cytotoxic for AML.
Replacing Gemtuzumab Ozogamicin With Idarubicin In Frontline Fludarabine, Cytarabine and G-CSF Based Regimen Does Not Compromise Outcome In Core Binding Factor Acute Myelogenous Leukemia
Authors: Borthakur Gautam , Cortes Jorge E. , Ravandi Farhad , Gonzalez Graciela Nogueras , Luthra Rajyalakshmi , Jabbour Elias , Garcia-Manero Guillermo , Kadia Tapan M. , Bass Joyce , Brandt Mark , Kantarjian Hagop M. 
Published: October 2019

Abstract
A regimen comprising of fludarabine, cytarabine, G-CSF and gemtuzumab ozogamicin (FLAG-GO) has been our frontline treatment regimen for patients with core binding factor acute myelogenous leukemia (CBF-AML) and among 50 patients with median follow up of over 3 years, this regimen resulted in overall survival (OS) and relapse free survival (RFS) of 78% and 85% respectively. This is clearly better than our historical data with idarubicin and cytarabine based regimens (Borthakur et al. JCO. Vol 28, No 15 suppl; 2010:6552). After withdrawal of GO from the market, it has been substituted by low dose idarubicin at 6 mg/m2 on days 3 and 4 in induction and in one post remission cycle during cycles 3-6 (FLAG-Ida). So far 38 patients have been treated with FLAG-Ida (median follow up 1 year) with all patients achieving complete remission. The current report is part of the planned analysis to ensure that patient outcomes have not been compromised by the change in regimen.
Univariate and multivariate (MVA) Cox proportional hazards regression was used to identify association of the clinical variables with overall survival (OS), event free survival (EFS) and time to relapse (TTR). Event is defined as death from any cause or relapse. Treatment regimen (FLAG-GO or FLAG-Ida) were included as variables in the analysis. Apart from relevant clinical variables, reduction in fusion transcript ratio (in reference to ABL gene transcript compared to that at diagnosis) at time points 1 month (≥3 log reduction yes/no) and 3 month (≥3 log reduction yes/no) and presence of any mutation (RAS, KIT, FLT3 yes/no) were also added as variables. Stepwise backwards selection method was used to remove variables that did not remain significant in the multivariate model (p ≥ 0.15).
T(8;21) is the cytogenetic abnormality in 52% of all 88 patients. Median age of all patients is 51 (range, 19-78 years) and 48% are female. Median time to 3 log reduction in transcript ratio was 1 month (range, 1-22 months). Complete remission rate with or without platelet recovery has been 98% with 2 induction deaths.
Kaplan-Meier analysis showed OS (Fig.1), EFS and TTR were not significantly different FLAG-GO and FLAG-Ida regimens. By MVA, OS, EFS and TTR are not different among these regimens (p > 0.5). Three log or more reduction in transcript ration at 1 month was associated with better OS (p=.03) and EFS (p=.008) (not TTR) in MVA. Presence of KIT, RAS or FLT3 gene mutation did not impact outcomes studied.
In conclusion, replacing GO with low dose idarubicin in a front-line FLAG regimen does not seem to compromise the excellent outcomes with such a regimen in CBF AML.

Disclosures:
No relevant conflicts of interest to declare.
The Effects Of Hydrogen Sulphide On Adipocyte Viability In Human Adipocyte and Adipocyte Derived Mesenchymal Stem Cells Culture Under Ischemic Conditions
Authors: Aykan Andac , Ozturk Serdar , Avcu Ferit , Sahin Ismail , Ural Ali Ugur , Ilikci Rahsan , Isik Selcuk 
Published: October 2019

Abstract
Hydrogen Sulfide (H2S) is accepted as a gasotransmitter, which has a gaseous structure like the other two gasotransmitters; carbon monoxide and nitric oxide. It is known that H2S increases the resistance to ischemia in some tissues and decreases apoptosis, however the exact mechanism is still unclear. Morover there is no research about its effects on adipose tissue in the literature.
The aim of this study was to evaluate the in vitro effects of H2S on Adipocyte survival under ischemic conditions and to explain the possible mechanisms of its apoptotic process in details.
For this purpose mesenchymal stem cell (MSCs) culture was prepared from subcutaneous adipose tissue sample of a human donor. Adipose derived MSCs were differentiated into adipogenic direction and mature adipocyte culture was obtained. Adipose derived MSCs culture and mature adipocyte culture were divided into six groups separately. Sodium Hydrogen Sulfide (NaHS) was used as a H2S donor. After applying NaHS to all groups with a concentration of 0, 0.1, 1, 10, 100 and 1000μM, cell cultures were incubated in special gas incubator with %1 oxygen at 37°C for 24 hours. Following the ischemia period, cell culture groups were evaluated by the rates of proliferation/cytotoxicity within MTT test, apoptosis and necrosis rates with flow cytometry, apoptotic (bax, caspase3) and anti-apoptotic genes (bcl-2) expression levels within reverse transcriptase polymerase chain reaction.
Statistically significant increase in proliferation rates were found in MSCs groups which was applied low dose (0,1 and 1 μM) NaHS (p<0,05). For every different dose applications, statistically significant decrease was found in apoptosis levels on the mature adipocyte cultures (p<0,05). In both cell culture groups bcl-2 gene expression was increased and caspase-3 gene expression was decreased.
As a conclusion, H2S has protective effect on both MSCs and mature adipocytes and this effect is mediated by elevation of anti-apoptotic gene expression. Furthermore, this study suggests that, administration of H2S to fat graft before fat graft injection may be therapeutic benefit in the fat graft viability.

Disclosures:
No relevant conflicts of interest to declare.
Disease-Associated Chromatin Conformation and Therapeutic Implications In Leukemia
Authors: Cheng Jason X , Anastasi John , Vardiman James W. 
Published: October 2019

Disease- or treatment-associated chromatin conformation has yet to be illustrated. Here we first demonstrate that monocytic and erythroid leukemia cell lines have distinctly different chromatin conformation at the PU.1 locus: a looped, connected, RNA-polymerase-II-bound, active conformation in the former and a disconnected, inactive conformation in the latter. These conformations undergo opposite transformations, becoming more active in the erythroid leukemia line and less active in the monocytic leukemia line, in response to both DNA and histone hypomethylating drugs.To explore the underlying mechanisms we developed a novel method to analyze DNA modifications. We demonstrate that the erythroid leukemia line has a marked drug-responsive change in both hydroxymethyl-CpG and 5-meythyl-CpG at the promoter, whereas the monocytic leukemia line has a higher level bivalent histone/chromatin with co-localized H3K4me3 and H3K27me3 at the enhancer. Consequently, the erythroid leukemia line is more sensitive to DNA hypomethylation while the monocytic leukemia line is more sensitive to histone hypomethylation. Further studies on clinical leukemia samples confirm the findings, and demonstrate that the leukemic cells from the clinical samples have different chromatin conformations with much more bivalent chromatin and denser DNA/histone modifiers and are more sensitive to hypomethylating drugs, compared to normal controls. Different chromatin conformations dictate preferential drug responses and open new diagnostic and therapeutic avenues.

Disclosures:
No relevant conflicts of interest to declare.
Inhibition Of PI3K/mTOR Overcomes Nilotinib Resistance In BCR-ABL1 Positive Leukemia Cells
Authors: Ding Jie , Romani Julia , Zaborski Margarete , MacLeod Roderick AF , Nagel Stefan , Drexler Hans G. , Quentmeier Hilmar 
Published: October 2019

Abstract
Expression of the Philadelphia chromosome (Ph), i.e., the t(9;22) chromosomal translocation and the formation of the BCR-ABL1 fusion protein, is the hallmark of chronic myeloid leukemia (CML). Tyrosine kinase inhibitors (TKI), such as imatinib and nilotinib, have emerged as leading compounds to treat CML. Translocation t(9;22) does not only occur in CML, 20-30% of acute lymphoblastic leukemia (ALL) are also found to carry the Ph. However, TKIs are not as effective in the treatment of Ph+ ALL as in CML. In this study, the Ph+ cell lines JURL-MK2 and SUP-B15 were used to investigate TKI resistance mechanisms and sensitization of Ph+ tumor cells to TKI treatment. The annexin V/PI (propidium iodide) assay revealed that nilotinib induced apoptosis in JURL-MK2 cells, but not in SUP-B15 cells. There was no mutation in the tyrosine kinase domain of BCR-ABL1 in both cell lines. SUP-B15 cells were not generally irresponsive to TKI, evidenced by dephosphorylation of the BCR-ABL1 downstream target GAB2 (Grb-associated binder-2). The resistance to apoptosis after nilotinib treatment was accompanied by the constitutive and nilotinib irresponsive activation of the phosphoinositide 3-kinase (PI3K) pathway. Treatment of SUP-B15 with the dual PI3K/mammalian target of rapamycin (mTOR) inhibitor BEZ235 alone induced apoptosis in a low percentage of cells, combination of nilotinib and BEZ235 led to a synergistic effect. Caspase 3 and PARP (poly ADP ribose polymerase) cleavage confirmed that apoptosis was induced after combined treatment. The main role of PI3K/mTOR inhibitor BEZ235 and the reason for apoptosis in the nilotinib-resistant cells was the block of the translational machinery, leading to the rapid down-regulation of anti-apoptotic protein MDM2 (human homolog of the murine double minute 2, hMDM2). The current findings suggest that MDM2 may be a therapeutic target to increase TKI-mediated apoptosis and that the combination of PI3K/mTOR dual inhibitor and TKI inhibitor might turn out to be a novel strategy for TKI-resistant BCR-ABL1 positive leukemia.

Disclosures:
No relevant conflicts of interest to declare.
The Preparation Of PLGA-PLL-Peg Nanoparticles Simultaneously Loaded With Daunorubicin and Tetrandrine By Modified Double-Emulsion Method
Authors: Liu Ran , Wang Yonglu , Wang Liyao , Cheng Jian , Xia Guohua , Bao Wen , Zhang Xiaoping , Guo Liting , Chen Baoan , Xu Yuanlong , Chen Wei , Yin Haixiang 
Published: October 2019

Abstract
A functional polymer composed of PLGA, PLL and PEG was synthesized, which was used as carrier material for fabricating drug delivery system of nanoparticles. PLGA-PLL-PEG nanoparticles simultaneously loaded with daunorubicin (DNR) and tetrandrine (Tet) were prepared in order to inhibit MDR activity and enhance the antitumor activity of DNR. A modified double-emulsion solvent evaporation/diffusion method was used to increase the incorporation of DNR (hydrophilic) and Tet (hydrophobic) into PLGA-PLL-PEG nanoparticles (NPs). The influence of various processing parameters on particle size and drug loadings were investigated systematically, such as the molecular weight, such as the molecular weight and concentration of PLGA-PLL-PEG, volume ratio of acetone to dichloromethane, PVA concentration in the external aqueous phase, the volume ratio of internal aqueous phase to external aqueous phase and the surfactants of internal aqueous phase. The particle size of the nanoparticles produced by optimized formulation and preparation was 213.0±12 nm (n = 3) with low polydispersity index (0.075 ± 0.023, n = 3). Transmission electron microscopy (TEM) examination showed that the morphology of the prepared nanoparticles was spherical in shape with a smooth surface. The drug loadings were 3.63±0.15% for DNR and 4.27±0.13% for Tet (n = 3). The entrapment efficiencies were 70.23±1.91% for DNR and 86.5±0.7% for Tet (n = 3). The release of DNR and Tet were sustained over one week. The PLGA-PLL-PEG-NPs formulation was potentially useful for hydrophilic and hydrophobic drugs that require efficient delivery to cancer cells.

Disclosures:
No relevant conflicts of interest to declare.
Drug-sensitivity of resistant acute myeloid leukemia cell line to Doxorubicin is enhanced by Triptolide through down-regulation of HIF-1α and Nrf2
Authors: Xu Bing , Chen Feili , Liu Yuejian , Wang Shiyun , Li Rongwei , Dong Huijuan 
Published: October 2019

Abstract

Background
Relapse and treatment-related complication have been the hurdle for the cure of acute myeloid leukemia patients. Finding a new drug-sensitizer could significantly prolong the survival time of patients. Triptolide (TPL) has been shown to enhance the drug-sensitivity of a variety of cancer cells when used in a low-concentration. HL60/DOX is a kind of acute myeloid leukemia cell line which is resistant to a commonly used drug Doxorubicin. This kind of cell line is widely used in the study of drug-sensitization.

Aim
This study aims to investigate whether low-dose TPL could enhance the drug-sensitivity of resistant acute myeloid leukemia cell line HL60/DOX to Doxorubicin and related mechanism.

Method
HL60/DOX cells were subjected to different treatments and thereafter MTT assay, flow cytometry and Western blot or RT-PCR were used to determine IC50, apoptotic status and expression of Nrf2, HIF-1α and their target genes.

Results
HL60/DOX cells were exposed to increasing concentrations of Doxorubicin with TPL at a constant IC20 concentration (14nM) for 48h. In comparison with anticancer agent alone, TPL enhanced the cytotoxicity of Doxorubicin (IC50:14.36±2.23 vs. 7.9±0.33μM, 1.82 fold; P=0.008) to HL60/DOX. Results of combination index showed that TPL and anti-cancer agents had synergistic effects when fraction affected was below 60%. Flow cytometry analysis also showed that apoptoticratio of cells treated by Doxorubicin together with TPL was significantly increased compared to cell streated by Doxorubicin alone (19.55±1.70%vs. 72.62±4.83%, P<0.01). Next, we explored the underlying mechanism. Hypoxia-inducible factor- 1α (HIF-1α) is the major mediator of hypoxic responses in malignant cells. High expression of it is correlated with bad clinical outcome in patients. It is also important for the survival of leukemia stem cells which are responsible for relapse. Nrf2 is an important protective factor which is correlated with chemo-resistance in cancer cells. When combined with TPL, Doxorubicin down-regulates Nrf2 and HIF-1α expression at protein and mRNA levels. Down-stream genes of Nrf2 e.g NQO1, GSR and HO-1 as well as target genes of HIF-1α e.g BNIP3, VEGF and CAIX are also down-regulated at mRNA level.

Conclusion
Inconclusion, our study demonstrates that TPL could enhance drug-sensitivity of HL60/DOX in vitro through down-regulation of Nrf2 and HIF-1α, providing the experimental base for further study.

Disclosures:
No relevant conflicts of interest to declare.
Gamma-Tocotrienol and Simvastatin Synergistically Induce Cytotoxicity In Leukemia Cell Lines, K-562 and HL-60
Authors: Maung Ko , Palau Victoria , Lightner Janet , Brannon Marianne , Krishnan Koyamangalath 
Published: October 2019

Abstract

Introduction
Statins and tocotrienols modulate the cholesterol biosynthesis pathway by inhibiting the 3-hydroxy-3- methylglutaryl coenzyme A (HMG-CoA) reductase. Tocotrienols modulate HMG-CoA reductase by post-transcriptional downregulation. In addition, tocotrienols contain a farnesol moiety in its side-chain that triggers degradation of HMG-CoA reductase. These effects lead to suppression of cell proliferation, cell cycle arrest, and apoptosis. Several studies have shown that statins have suppressive effects in in vitro experiments on acute myelocytic leukemia cell lines. Since both statins and gamma-tocotrienol are associated with decreased cholesterol biosynthesis, we hypothesized that if the cytotoxicity of these drugs on cancer cells is related to impaired biosynthesis of cholesterol, combination of them could synergize in cytotoxicity on leukemic cells.

Materials and Methods
K-562 and HL-60 leukemia cells were grown in Iscove's Modified Dulbecco's medium with penicillin/streptomycin, 10% fetal bovine serum and 20% fetal bovine serum added respectively. K-562 and HL-60 leukemia cells were seeded in 96 well plates, grown overnight, and treated for 24, 48 and 72 hours with simvastatin in concentrations of 1,2,4, and5 µM; gamma-tocotrienol in concentrations of 20, 40, and 80 µM; and a combination of the two drugs in the same concentrations. For 24 hour dose, cells were seeded at a density of 5000/well and for 48 and 72 hour doses, at 3500/well. Following the treatment, MTS/PMS reagent (Promega, Madison, WI), [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] mixed with and an electron coupling reagent (phenazine methosulfate), was added at 40 µg/well and incubated at 37°C for 2 hours. We measured the solubilized formazan crystals at 450 nm as an indicator of cytotoxicity. The presence of ATP as an indicator of cell viability was measured with the CellTiter Glo® assay (Promega). Cells were again seeded, grown overnight, and dosed as indicated above. Following treatment, the assay was conducted as specified by the manufacturer.

Results
Both simvastatin and gamma-tocotrienol induce cytotoxicity in K-562 and HL-60 cell lines by the MTS and Cell Titer Glo Assays. The IC50 at 72 hour incubation are as follows 1) HL-60: simvastatin - 16.543 uM, gamma tocotrienol - 36.297 uM; 2) K-562: simvastatin - 5.235 uM, gamma tocotrienol - 34.947 uM. We used CompuSyn to calculate the IC50. When combined, simvastatin and gamma-tocotrienol exhibit synergy at lower concentrations when examined by isobologram analysis.

Conclusion
Gamma-tocotrienol, an isoform of vitamin E, and simvastatin, a cholesterol lowering drug exhibit synergy in induction of cytotoxicity in K-562 and HL-60 leukemia cell lines. Rescue experiments and mechanistic pathway analysis are being explored to confirm these observations.

Disclosures:
No relevant conflicts of interest to declare.