Entecavir maleate versus entecavir in Chinese chronic hepatitis B predominantly genotype B or C: Results at week 144

Reports on the efficacy and safety of long-term entecavir treatment in chronic hepatitis B (CHB) predominantly genotype B or C are insufficient. This study presents the efficacy and safety of entecavir maleate in Chinese CHB patients. Patients were randomly assigned to receive 48-week treatment with either 0.5 mg/day entecavir (group A) or 0.5 mg/day entecavir maleate (group B), and then all patients received treatment with 0.5 mg/day entecavir maleate from week 49. Two hundred and seventy-five patients with CHB (HBeAg-positive: 218) were analysed, predominantly (98.5%) with genotype B or C. Baseline characteristics were balanced. For the HBeAg-positive CHB patients, the mean HBV DNA level decreased similarly (A: by 6.36 log₁₀ IU/mL vs B: by 6.31 log₁₀ IU/mL) between groups at week 144. The percentages of patients who achieved undetectable HBV DNA were similar (A: 70.59% vs B: 66.67%) between groups. Similar HBeAg loss rates (A: 43.53% vs B: 40.23%; P>.05) and HBeAg seroconversion rates (A: 21.52% vs B: 21.18%) were achieved. For the HBeAg-negative CHB patients, similar reductions in HBV DNA levels from baseline (A: by 6.13 log₁₀ IU/mL vs B: by 5.65 log₁₀ IU/mL) and percentages of patients who achieved undetectable HBV DNA (A: 100% vs B: 100%) were achieved. The overall incidence of adverse events was comparable between groups. In conclusions, 48-week administration of entecavir maleate and entecavir showed similar efficacy and safety in Chinese patients with CHB. Long-term entecavir maleate treatment was effective and safe in CHB patients.

Determination of the Spin and Parity of the Z_{c}(3900)

The spin and parity of the Z_{c}(3900)^{±} state are determined to be J^{P}=1^{+} with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the process e^{+}e^{-}→π^{+}π^{-}J/ψ. We use a data sample of 1.92  fb^{-1} accumulated at sqrt[s]=4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z_{c}(3900)^{±} with a Flatté-like formula, we determine its pole mass M_{pole}=(3881.2±4.2_{stat}±52.7_{syst})  MeV/c^{2} and pole width Γ_{pole}=(51.8±4.6_{stat}±36.0_{syst})  MeV. We also measure cross sections for the process e^{+}e^{-}→Z_{c}(3900)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-} and determine an upper limit at the 90% confidence level for the process e^{+}e^{-}→Z_{c}(4020)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-}.

Overlapping roles for PARP1 and PARP2 in the recruitment of endogenous XRCC1 and PNKP into oxidized chromatin

A critical step of DNA single-strand break repair is the rapid recruitment of the scaffold protein XRCC1 that interacts with, stabilizes and stimulates multiple enzymatic components of the repair process. XRCC1 recruitment is promoted by PARP1, an enzyme that is activated following DNA damage and synthesizes ADP-ribose polymers that XRCC1 binds directly. However, cells possess two other DNA strand break-induced PARP enzymes, PARP2 and PARP3, for which the roles are unclear. To address their involvement in the recruitment of endogenous XRCC1 into oxidized chromatin we have established ‘isogenic’ human diploid cells in which PARP1 and/or PARP2, or PARP3 are deleted. Surprisingly, we show that either PARP1 or PARP2 are sufficient for near-normal XRCC1 recruitment at oxidative single-strand breaks (SSBs) as indicated by the requirement for loss of both proteins to greatly reduce or ablate XRCC1 chromatin binding following H₂O₂ treatment. Similar results were observed for PNKP; an XRCC1 protein partner important for repair of oxidative SSBs. Notably, concentrations of PARP inhibitor >1000-fold higher than the IC50 were required to ablate both ADP-ribosylation and XRCC1 chromatin binding following H₂O₂ treatment. These results demonstrate that very low levels of ADP-ribosylation, synthesized by either PARP1 or PARP2, are sufficient for XRCC1 recruitment following oxidative stress.

Systematic influences on the areas of peaks in gamma-ray spectra that have a large statistical uncertainty

A method is presented for calculating the expected number of counts in peaks that have a large relative peak-area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculated peak areas to their expected values decrease with an increasing relative peak-area uncertainty. The accuracy of taking the systematic influence inducing the correction factors into account is given by the dispersion of the correction factors corresponding to specific peaks. It was shown that the highest accuracy is obtained in the peak analyses with the GammaVision and Gamma-W software.

High-throughput profiling of signaling networks identifies mechanism-based combination therapy to eliminate microenvironmental resistance in acute myeloid leukemia

The bone marrow microenvironment is known to provide a survival advantage to residual acute myeloid leukemia cells, possibly contributing to disease recurrence. The mechanisms by which stroma in the microenvironment regulates leukemia survival remain largely unknown. Using reverse-phase protein array technology, we profiled 53 key protein molecules in 11 signaling pathways in 20 primary acute myeloid leukemia samples and two cell lines, aiming to understand stroma-mediated signaling modulation in response to the targeted agents temsirolimus (MTOR), ABT737 (BCL2/BCL-XL), and Nutlin-3a (MDM2), and to identify the effective combination therapy targeting acute myeloid leukemia in the context of the leukemia microenvironment. Stroma reprogrammed signaling networks and modified the sensitivity of acute myeloid leukemia samples to all three targeted inhibitors. Stroma activated AKT at Ser473 in the majority of samples treated with single-agent ABT737 or Nutlin-3a. This survival mechanism was partially abrogated by concomitant treatment with temsirolimus plus ABT737 or Nutlin-3a. Mapping the signaling networks revealed that combinations of two inhibitors increased the number of affected proteins in the targeted pathways and in multiple parallel signaling, translating into facilitated cell death. These results demonstrated that a mechanism-based selection of combined inhibitors can be used to guide clinical drug selection and tailor treatment regimens to eliminate microenvironment-mediated resistance in acute myeloid leukemia.

Characterization of retroviral infectivity and superinfection resistance during retrovirus-mediated transduction of mammalian cells

Retroviral vectors including lentiviral vectors are commonly used tools to stably express transgenes or RNA molecules in mammalian cells. Their utilities are roughly divided into two categories, stable overexpression of transgenes and RNA molecules, which requires maximal transduction efficiency, or functional selection with retrovirus (RV)-based libraries, which takes advantage of retroviral superinfection resistance. However, the dynamic features of RV-mediated transduction are not well characterized. Here, we engineered two murine stem cell virus-based retroviral vectors expressing dual fluorescence proteins and antibiotic markers, and analyzed virion production efficiency and virion stability, dynamic infectivity and superinfection resistance in different cell types, and strategies to improve transduction efficiency. We found that the highest virion production occurred between 60 and 72 h after transfection. The stability of the collected virion supernatant decreased by >60% after 3 days in storage. We found that RV infectivity varied drastically in the tested human cancer lines, while low transduction efficiency was partially overcome with increased virus titer, prolonged infection duration and/or repeated infections. Furthermore, we demonstrated that RV receptors PIT1 and PIT2 were lowly expressed in the analyzed cells, and that PIT1 and/or PIT2 overexpression significantly improved transduction efficiency in certain cell lines. Thus, our findings provide resourceful information for the optimal conditions of retroviral-mediated gene delivery.

Combined inhibition of β-catenin and Bcr-Abl synergistically targets tyrosine kinase inhibitor-resistant blast crisis chronic myeloid leukemia blasts and progenitors in vitro and in vivo

Tyrosine kinase inhibitor (TKI) resistance and progression to blast crisis (BC), both related to persistent β-catenin activation, remain formidable challenges for chronic myeloid leukemia (CML). We observed overexpression of β-catenin in BC-CML stem/progenitor cells, particularly in granulocyte–macrophage progenitors, and highest among a novel CD34⁺CD38⁺CD123^hiTim-3^hi subset as determined by CyTOF analysis. Co-culture with mesenchymal stromal cells (MSCs) induced the expression of β-catenin and its target CD44 in CML cells. A novel Wnt/β-catenin signaling modulator, C82, and nilotinib synergistically killed KBM5^T315I and TKI-resistant primary BC-CML cells with or without BCR–ABL kinase mutations even under leukemia/MSC co-culture conditions. Silencing of β-catenin by short interfering RNA restored sensitivity of primary BCR–ABL^T315I/E255V BC-CML cells to nilotinib. Combining the C82 pro-drug, PRI-724, with nilotinib significantly prolonged the survival of NOD/SCID/IL2Rγ null mice injected with primary BCR–ABL^T315I/E255V BC-CML cells. The combined treatment selectively targeted CML progenitors and inhibited CD44, c-Myc, survivin, p-CRKL and p-STAT5 expression. In addition, pretreating primary BC-CML cells with C82, or the combination, but not with nilotinib alone, significantly impaired their engraftment potential in NOD/SCID/IL2Rγ-null-3/GM/SF mice and significantly prolonged survival. Our data suggest potential benefit of concomitant β-catenin and Bcr–Abl inhibition to prevent or overcome Bcr–Abl kinase-dependent or -independent TKI resistance in BC-CML.

Observation of Λ_{c}^{+}→nK_{S}^{0}π^{+}

We report the first direct measurement of decays of the Λ_{c}^{+} baryon involving the neutron. The analysis is performed using 567  pb^{-1} of e^{+}e^{-} collision data collected at sqrt[s]=4.599  GeV with the BESIII detector at the BEPCII collider. We observe the decay Λ_{c}^{+}→nK_{S}^{0}π^{+} and measure the absolute branching fraction to be B(Λ_{c}^{+}→nK_{S}^{0}π^{+})=[1.82±0.23(stat)±0.11(syst)]%. A comparison to B[Λ_{c}^{+}→p(K[over ¯]π)^{0}] provides an important test of isospin symmetry and final state interactions.

Precise Measurement of the e^{+}e^{-}→π^{+}π^{-}J/ψ Cross Section at Center-of-Mass Energies from 3.77 to 4.60 GeV

The cross section for the process e^{+}e^{-}→π^{+}π^{-}J/ψ is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9  fb^{-1} of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of (4222.0±3.1±1.4)  MeV/c^{2} and a width of (44.1±4.3±2.0)  MeV, while the second one has a mass of (4320.0±10.4±7.0)  MeV/c^{2} and a width of (101.4_{-19.7}^{+25.3}±10.2)  MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the Y(4260) resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in e^{+}e^{-}→π^{+}π^{-}J/ψ for the first time. The statistical significance of this resonance is estimated to be larger than 7.6σ. The mass and width of the second resonance agree with the Y(4360) resonance reported by the BABAR and Belle experiments within errors. Finally, the Y(4008) resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data.

Evidence of Two Resonant Structures in e^{+}e^{-}→π^{+}π^{-}h_{c}

The cross sections of e^{+}e^{-}→π^{+}π^{-}h_{c} at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e^{+}e^{-}→π^{+}π^{-}J/ψ and e^{+}e^{-}→π^{+}π^{-}ψ(2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e^{+}e^{-}→π^{+}π^{-}h_{c} cross sections around 4.22 and 4.39  GeV/c^{2}, which we call Y(4220) and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4_{-4.5}^{+5.5}±0.9)  MeV/c^{2} and a width of (66.0_{-8.3}^{+12.3}±0.4)  MeV for the Y(4220), and a mass of (4391.5_{-6.8}^{+6.3}±1.0)  MeV/c^{2} and a width of (139.5_{-20.6}^{+16.2}±0.6)  MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10σ over one structure assumption.

Baseline hepatitis B core antibody predicts treatment response in chronic hepatitis B patients receiving long-term entecavir

Studies regarding the clinical significance of quantitative hepatitis B core antibody (anti-HBc) in patients with chronic hepatitis B receiving first-line nucleos(t)ide analogues is limited. The aim of this study was to determine the performance of anti-HBc as a predictor for hepatitis B e antigen (HBeAg) seroconversion in HBeAg-positive CHB patients treated with entecavir. This was a retrospective cohort study consisting of 139 Chinese patients enrolled in a multicenter clinical trial treated with entecavir or entecavir maleate for up to 240 weeks. Anti-HBc evaluation was conducted for all the available samples using a newly developed double-sandwich anti-HBc immunoassay. At week 240, 35 (25.2%) patients achieved a serological response (HBeAg seroconversion) and these patients at week 240 had significantly higher levels of anti-HBc (P<.01). We defined 4.65 log₁₀  IU·mL^-1 , with a maximum sum of sensitivity and specificity, as the optimal cut-off value of baseline anti-HBc level to predict seroconversion. Patients with baseline anti-HBc ≥4.65 log₁₀  IU·mL^-1 had 28.0% (26/93) and 35.5% (33/93) chance of seroconversion at weeks 144 and 240, respectively. The baseline anti-HBc level was the strongest predictor for seroconversion at week 144 (OR: 5.78, 95% confidence interval [CI]: 2.05-16.34, P=.001). The baseline anti-HBc level was a strong predictor for seroconversion at week 240 (OR: 5.36, 95% CI: 2.17-13.25, P<.001). Hence, baseline anti-HBc titre is a useful predictor of long-term entecavir therapy efficacy in HBeAg-positive CHB patients, which could be used to optimize antiviral therapy.

Rifampicin pre-treatment inhibits the toxicity of rotenone-induced PC12 cells by enhancing sumoylation modification of α-synuclein

Our previous research revealed that rifampicin could protect PC12 (pheochromocytoma 12) cells from rotenone-induced cytotoxicity by reversing the aggregation of α-synuclein. Furthermore, increasing evidence indicated that the misfolded α-synuclein with SUMOylation, an important protein posttranslational modification, was easier to solubilize and was less toxic. Here, we investigated whether rifampicin could stabilize α-synuclein and prevent rotenone-induced PC12 cells from undergoing apoptosis by enhancing SUMOylation of α-synuclein. The expression of SUMO1 and SUMO2/3, the two main proteins responsible for the SUMOylation modification in PC12 cells, were detected by western blotting. Co-immunoprecipitation was performed to compare qualitatively the SUMOylation modification of α-synuclein. The cell viability and apoptosis rate were measured by a CCK-8 assay kit and flow cytometry, respectively. We targeted Ubc9 as a key enzyme in the SUMOylation modification pathway and knocked down the UBC9 gene using a short interfering RNA. Treatment with 150 μmol/L rifampicin, increased the expressions of SUMO1 and SUMO2/3 in cells by 1.5 times compared with the control group; meanwhile, the cell viability of rotenone-induced cells increased from 20 to 80% (P < 0.05). In addition, the increased SUMOylation activity in the cells stimulated by rifampicin was observed 18 h earlier compared with cells treated by rotenone alone. SUMOylation of α-synuclein was more significant in rifampicin-treated cells and Ubc9 upregulated cells. However, the same phenomenon and the protective effect of rifampicin were reversed after UBC9 knockout. In conclusion, rifampicin might reduce the cytotoxicity of rotenone-induced PC12 cells by promoting SUMOylation of α-synuclein.

Amplitude Analysis of the Decays η^{'}→π^{+}π^{-}π^{0} and η^{'}→π^{0}π^{0}π^{0}

Based on a sample of 1.31×10^{9}  J/ψ events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays η^{'}→π^{+}π^{-}π^{0} and η^{'}→π^{0}π^{0}π^{0} is performed. A significant P-wave contribution from η^{'}→ρ^{±}π^{∓} is observed for the first time in η^{'}→π^{+}π^{-}π^{0}. The branching fraction is determined to be B(η^{'}→ρ^{±}π^{∓})=(7.44±0.60±1.26±1.84)×10^{-4}, where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant S-wave component, there is a significant σ meson component. The branching fractions of the combined S-wave components are determined to be B(η^{'}→π^{+}π^{-}π^{0})_{S}=(37.63±0.77±2.22±4.48)×10^{-4} and B(η^{'}→π^{0}π^{0}π^{0})=(35.22±0.82±2.54)×10^{-4}, respectively. The latter one is consistent with previous BESIII measurements.

XRCC1 mutation is associated with PARP1 hyperactivation and cerebellar ataxia

XRCC1 is a molecular scaffold protein that assembles multi-protein complexes involved in DNA single-strand break repair. Here we show that biallelic mutations in the human XRCC1 gene are associated with ocular motor apraxia, axonal neuropathy, and progressive cerebellar ataxia. Cells from a patient with mutations in XRCC1 exhibited not only reduced rates of single-strand break repair but also elevated levels of protein ADP-ribosylation. This latter phenotype is recapitulated in a related syndrome caused by mutations in the XRCC1 partner protein PNKP and implicates hyperactivation of poly(ADP-ribose) polymerase/s as a cause of cerebellar ataxia. Indeed, remarkably, genetic deletion of Parp1 rescued normal cerebellar ADP-ribose levels and reduced the loss of cerebellar neurons and ataxia in Xrcc1-defective mice, identifying a molecular mechanism by which endogenous single-strand breaks trigger neuropathology. Collectively, these data establish the importance of XRCC1 protein complexes for normal neurological function and identify PARP1 as a therapeutic target in DNA strand break repair-defective disease.

First-principles investigation of the orientation influenced He dissolution and diffusion behaviors W surfaces

He-induced vacancy formation aggravates He accumulation on the W(111), W(112), and W(100) surfaces and hinders He escaping from the W(111) surface.

Buparlisib, a PI3K inhibitor, demonstrates acceptable tolerability and preliminary activity in a phase I trial of patients with advanced leukemias

Phosphatidylinositol-3-kinase (PI3K) signaling plays a crucial role in oncogene-mediated tumor growth and proliferation. Buparlisib (BKM120) is an oral pan-class I PI3K inhibitor. This phase I study was conducted to determine the dose limiting toxicity (DLT) and maximum tolerated dose (MTD) of BKM120 in patients (pts) with relapsed/refractory acute leukemias. Fourteen pts (12 acute myeloid leukemia, 1 acute lymphoblastic leukemia, and 1 mixed phenotype leukemia) were enrolled. Twelve pts received BKM-120 80 mg/day and two 100 mg/day. The MTD was 80 mg/day. Of the 14 patients treated, the best response was stable disease in one patient that lasted 82 days. The median survival for all patients was 75 days (range 10-568). Three patients with a 3q26 chromosome abnormality had a significantly improved median survival of 360 days (range 278-568) as compared to a median survival of 57 days (range, 10-125) among the 11 other patients. The most frequent drug-related toxicities included confusion, mucositis, dysphagia, and fatigue. Western blot profiling revealed a decrease in p-pS6K/total pS6K in 5/7 (71%) available patient samples with a mean quantitative inhibition of 65% (range, 32-100%) and a decrease in p-FOXO3/total FOXO3 in 4/6 (67%) samples with a mean quantitative inhibition of 93% (range, 89-100%). BKM120 administered at 80 mg/day showed modest efficacy and was tolerable in advanced acute leukemias. Am. J. Hematol. 92:7-11, 2017. © 2016 Wiley Periodicals, Inc.

Measurement of Singly Cabibbo Suppressed Decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}

Using 567  pb^{-1} of data collected with the BESIII detector at a center-of-mass energy of sqrt[s]=4.599  GeV, near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold, we study the singly Cabibbo-suppressed decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. By normalizing with respect to the Cabibbo-favored decay Λ_{c}^{+}→pK^{-}π^{+}, we obtain ratios of branching fractions: [B(Λ_{c}^{+}→pπ^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(6.70±0.48±0.25)%, [B(Λ_{c}^{+}→pϕ)/B(Λ_{c}^{+}→pK^{-}π^{+})]=(1.81±0.33±0.13)%, and [B(Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(9.36±2.22±0.71)×10^{-3}, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Λ_{c}^{+}→pπ^{+}π^{-} is observed for the first time, and the precision of the branching fraction for Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-} and Λ_{c}^{+}→pϕ is significantly improved.

Comparison of coronary heart disease risk among four diagnostic definitions of metabolic syndrome

PURPOSE

Metabolic syndrome (MetS) is now well known as one of the major risk factors for coronary heart disease (CHD). Currently, there are several methods used to define MetS. The aim of this study was to determine to what extent current MetS definition reflects CHD risk using the probability of CHD in 10 years based on Framingham risk score algorithms.

METHODS

A total of 7575 adults, aged 16-93 years (2532 men and 5043 women), were recruited. We conducted a cross-sectional health survey in China using MetS criteria from four different definitions: modified National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III), International Diabetes Federation (IDF), Chinese and Japanese.

RESULTS

Differences in the prevalence of MetS by each definition were small in males (22.9-25.9 %), whereas in females, MetS was three times more prevalent using the IDF definition (29.1 %) versus the Japanese definition (9.7 %). Framingham risk scores in participants with MetS were significantly higher than in those without MetS by all definition criteria (p < 0.001). The CHD risk scores for participants with MetS by each definition showed similar values in males (range 11.5-12.1 %) with no significant differences among definitions. Conversely, in females with MetS the risk score for CHD was low (range 3.5-4.3 %) by each MetS definition.

CONCLUSIONS

These findings suggest that further studies are required to establish appropriate criteria of MetS in females.

PARP3 is a sensor of nicked nucleosomes and monoribosylates histone H2B(Glu2)

PARP3 is a member of the ADP-ribosyl transferase superfamily that we show accelerates the repair of chromosomal DNA single-strand breaks in avian DT40 cells. Two-dimensional nuclear magnetic resonance experiments reveal that PARP3 employs a conserved DNA-binding interface to detect and stably bind DNA breaks and to accumulate at sites of chromosome damage. PARP3 preferentially binds to and is activated by mononucleosomes containing nicked DNA and which target PARP3 trans-ribosylation activity to a single-histone substrate. Although nicks in naked DNA stimulate PARP3 autoribosylation, nicks in mononucleosomes promote the trans-ribosylation of histone H2B specifically at Glu2. These data identify PARP3 as a molecular sensor of nicked nucleosomes and demonstrate, for the first time, the ribosylation of chromatin at a site-specific DNA single-strand break.

Observation of an Anomalous Line Shape of the η^{'}π^{+}π^{-} Mass Spectrum near the pp[over ¯] Mass Threshold in J/ψ→γη^{'}π^{+}π^{-}

Using 1.09×10^{9} J/ψ events collected by the BESIII experiment in 2012, we study the J/ψ→γη^{'}π^{+}π^{-} process and observe a significant abrupt change in the slope of the η^{'}π^{+}π^{-} invariant mass distribution at the proton-antiproton (pp[over ¯]) mass threshold. We use two models to characterize the η^{'}π^{+}π^{-} line shape around 1.85  GeV/c^{2}: one that explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatté formula), and another that is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85  GeV/c^{2} with strong couplings to the pp[over ¯] final states or a narrow state just below the pp[over ¯] mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a pp[over ¯] moleculelike state or bound state with greater than 7σ significance.

Observation of h_{c} Radiative Decay h_{c}→γη^{'} and Evidence for h_{c}→γη

A search for radiative decays of the P-wave spin singlet charmonium resonance h_{c} is performed based on 4.48×10^{8} ψ^{'} events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels h_{c}→γη^{'} and γη are observed with a statistical significance of 8.4σ and 4.0σ, respectively, for the first time. The branching fractions of h_{c}→γη^{'} and h_{c}→γη are measured to be B(h_{c}→γη^{'})=(1.52±0.27±0.29)×10^{-3} and B(h_{c}→γη)=(4.7±1.5±1.4)×10^{-4}, respectively, where the first errors are statistical and the second are systematic uncertainties.

Paediatric liver re-transplantation after primary partial liver graft transplantation: a report of four cases

OBJECTIVE

To discuss rules of anatomic shifting of the porta hepatis structures of the original graft and dissection techniques for the portal vein (pull-out technique) in pediatric liver re-transplantation.

METHOD

We summarized four cases of paediatric liver re-transplantation. The main donor type is partial liver graft especially using the left lateral lobe.

RESULT

In paediatric liver re-transplantation, gross morphological changes were observed in the liver, and the spatial position of the porta hepatis structures was shifted clockwise (with the anastomosis of the hepatic vein as the origin). Preoperative three-dimensional imaging showed that segment 3 of the liver graft increased in a compensatory manner. The pull-out technique could expose the surgical field without dissection and separation, and reduce the technical difficulty of identifying and dissociating the anatomical structures.

CONCLUSION

Changes in the spatial location and structure of the liver portal anatomy increase the difficulties and risks of surgery. We can reduce the difficulty of surgical anatomy, and the risk of bleeding and injury and increase the safety of paediatric liver re-transplantation by evaluation and the application of special techniques.

The regulation of Sema4D exodomain shedding by protein kinase A in platelets

We have previously shown that Sema4D expressed on the platelet plasma membrane can be cleaved by the metalloprotease ADAM17, producing a 120-kDa exodomain fragment that retains biological activity and remnant fragments of 24-28 kDa that remain associated with the platelet membrane. This process is modulated by calmodulin. Here we investigated the potential role of protein kinase A (PKA) in these events. Using a pharmacological approach, we now show that inhibition of PKA by H89 is sufficient to induce Sema4D exodomain shedding, while activation of PKA inhibits agonist-initiated shedding. Studies on the regulatory mechanism show that the shedding induced by PKA inhibition is mediated by ADAM17, but, unlike agonist-induced shedding, does not involve the dissociation of calmodulin from the Sema4D cytoplasmic domain. In attempt to identify the cleavage sites for shedding, we found that ADAM17 mediates variable cleavages in the juxtamembrane region. Therefore, our data reveal a potential regulatory mechanism for the shedding of Sema4D in platelets.

Observation of the Singly Cabibbo-Suppressed Decay D^{+}→ωπ^{+} and Evidence for D^{0}→ωπ^{0}

Based on 2.93  fb^{-1} e^{+}e^{-} collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D^{+}→ωπ^{+} and D^{0}→ωπ^{0}. A double tag technique is used to measure the absolute branching fractions B(D^{+}→ωπ^{+})=(2.79±0.57±0.16)×10^{-4} and B(D^{0}→ωπ^{0})=(1.17±0.34±0.07)×10^{-4}, with statistical significances of 5.5σ and 4.1σ, where the first and second uncertainties are statistical and systematic, respectively.

ATF4 induction through an atypical integrated stress response to ONC201 triggers p53-independent apoptosis in hematological malignancies

The clinical challenge posed by p53 abnormalities in hematological malignancies requires therapeutic strategies other than standard genotoxic chemotherapies. ONC201 is a first-in-class small molecule that activates p53-independent apoptosis, has a benign safety profile, and is in early clinical trials. We found that ONC201 caused p53-independent apoptosis and cell cycle arrest in cell lines and in mantle cell lymphoma (MCL) and acute myeloid leukemia (AML) samples from patients; these included samples from patients with genetic abnormalities associated with poor prognosis or cells that had developed resistance to the nongenotoxic agents ibrutinib and bortezomib. Moreover, ONC201 caused apoptosis in stem and progenitor AML cells and abrogated the engraftment of leukemic stem cells in mice while sparing normal bone marrow cells. ONC201 caused changes in gene expression similar to those caused by the unfolded protein response (UPR) and integrated stress responses (ISRs), which increase the translation of the transcription factor ATF4 through an increase in the phosphorylation of the translation initiation factor eIF2α. However, unlike the UPR and ISR, the increase in ATF4 abundance in ONC201-treated hematopoietic cells promoted apoptosis and did not depend on increased phosphorylation of eIF2α. ONC201 also inhibited mammalian target of rapamycin complex 1 (mTORC1) signaling, likely through ATF4-mediated induction of the mTORC1 inhibitor DDIT4. Overexpression of BCL-2 protected against ONC201-induced apoptosis, and the combination of ONC201 and the BCL-2 antagonist ABT-199 synergistically increased apoptosis. Thus, our results suggest that by inducing an atypical ISR and p53-independent apoptosis, ONC201 has clinical potential in hematological malignancies.

Measurements of Absolute Hadronic Branching Fractions of the Λ_{c}^{+} Baryon

We report the first measurement of absolute hadronic branching fractions of Λ_{c}^{+} baryon at the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold, in the 30 years since the Λ_{c}^{+} discovery. In total, 12 Cabibbo-favored Λ_{c}^{+} hadronic decay modes are analyzed with a double-tag technique, based on a sample of 567  pb^{-1} of e^{+}e^{-} collisions at sqrt[s]=4.599  GeV recorded with the BESIII detector. A global least-squares fitter is utilized to improve the measured precision. Among the measurements for twelve Λ_{c}^{+} decay modes, the branching fraction for Λ_{c}^{+}→pK^{-}π^{+} is determined to be (5.84±0.27±0.23)%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other 11 Cabibbo-favored hadronic decay modes are significantly improved.

Bifidobacteria possess inhibitory activity against dipeptidyl peptidase-IV

The incretin hormones are extremely rapidly metabolized by the ubiquitous enzyme dipeptidyl peptidase IV (DPP-IV). Therefore, DPP-IV inhibitors which can prolong the incretin effect are the newest and promising drugs for management of type 2 diabetes. In this study, we investigated whether Bifidobacteria colonizing the human gut possess DPP-IV inhibitory activity. Cell-free intracellular extracts of 13 Bifidobacterium strains isolated from breast-fed infant faecal samples were prepared and screened for DPP-IV inhibitory activity, and two Bifidobacterium strains-Bif. longum BBMN68 and Bif. lactis Bb12-were used as reference strains. Most of the strains showed varying levels of DPP-IV inhibitory property (7-27%). Strains of Bifidobacterium adolescentis IF1-11 and Bifidobacterium bifidum IF3-211 showed the greatest DPP-IV inhibitory activity (27 and 25%) as well as good in vitro probiotic properties. This initial finding suggested that new beneficial function of Bifidobacteria is strain-dependent and the strains or their components may have the potential application for management of type 2 diabetes via inhibiting gastrointestinal DPP-IV activity. Further investigations into the isolation and identification of the bioactive components of Bifidobacteria are warranted.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results show that Bifidobacteria isolated from breast-fed infants' faecal samples possess DPP-IV inhibitory activity. Strains of Bifidobacterium bifidum IF3-211 and Bifidobacterium adolescentis IF1-11, which showed excellent DPP-IV inhibitory properties as well as good in vitro probiotic properties, are expected to be beneficial for application as anti-diabetic probiotics.

Sn doping induced intermediate band in CuGaS2

As an intermediate band material, the dynamical and phase stability and optoelectronic properties of Sn doped CuGaS₂ are systematically investigated, and suggest that CuGaS₂ that is moderately doped with Sn can be a potential candidate for photovoltaic applications.

mTOR kinase inhibitors synergize with histone deacetylase inhibitors to kill B-cell acute lymphoblastic leukemia cells

High activity of the mechanistic target of rapamycin (mTOR) is associated with poor prognosis in pre-B-cell acute lymphoblastic leukemia (B-ALL), suggesting that inhibiting mTOR might be clinically useful. However, emerging data indicate that mTOR inhibitors are most effective when combined with other target agents. One strategy is to combine with histone deacetylase (HDAC) inhibitors, since B-ALL is often characterized by epigenetic changes that silence the expression of pro-apoptotic factors. Here we tested combinations of mTOR and pan-HDAC inhibitors on B-ALL cells, including both Philadelphia chromosome-positive (Ph+) and non-Ph cell lines. We found that mTOR kinase inhibitors (TOR-KIs) synergize with HDAC inhibitors to cause apoptosis in B-ALL cells and the effect is greater when compared to rapamycin plus HDAC inhibitors. The combination of TOR-KIs with the clinically approved HDAC inhibitor vorinostat increased apoptosis in primary pediatric B-ALL cells in vitro. Mechanistically, TOR-KI and HDAC inhibitor combinations increased expression of pro-death genes, including targets of the Forkhead Box O (FOXO) transcription factors, and increased sensitivity to apoptotic triggers at the mitochondria. These findings suggest that targeting epigenetic factors can unmask the cytotoxic potential of TOR-KIs towards B-ALL cells.

Observation of a Neutral Structure near the DD[over ¯]^{*} Mass Threshold in e^{+}e^{-}→(DD[over ¯]^{*})^{0}π^{0} at sqrt[s]=4.226 and 4.257 GeV

A neutral structure in the DD[over ¯]^{*} system around the DD[over ¯]^{*} mass threshold is observed with a statistical significance greater than 10σ in the processes e^{+}e^{-}→D^{+}D^{*-}π^{0}+c.c. and e^{+}e^{-}→D^{0}D[over ¯]^{*0}π^{0}+c.c. at sqrt[s]=4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as Z_{c}(3885)^{0}. Assuming the presence of a resonance, its pole mass and width are determined to be [3885.7_{-5.7}^{+4.3}(stat)±8.4(syst)]  MeV/c^{2} and [35_{-12}^{+11}(stat)±15(syst)]  MeV, respectively. The Born cross sections are measured to be σ[e^{+}e^{-}→Z_{c}(3885)^{0}π^{0},Z_{c}(3885)^{0}→DD[over ¯]^{*}]=[77±13(stat)±17(syst)]  pb at 4.226 GeV and [47±9(stat)±10(syst)]  pb at 4.257 GeV. The ratio of decay rates B[Z_{c}(3885)^{0}→D^{+}D^{*-}+c.c.]/B[Z_{c}(3885)^{0}→D^{0}D[over ¯]^{*0}+c.c.] is determined to be 0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process, Z_{c}(3885)^{0}→DD[over ¯]^{*}.

Measurement of the Absolute Branching Fraction for Λ_{c}^{+}→Λe^{+}ν_{e}

We report the first measurement of the absolute branching fraction for Λ_{c}^{+}→Λe^{+}ν_{e}. This measurement is based on 567  pb^{-1} of e^{+}e^{-} annihilation data produced at sqrt[s]=4.599  GeV, which is just above the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold. The data were collected with the BESIII detector at the BEPCII storage rings. The branching fraction is determined to be B(Λ_{c}^{+}→Λe^{+}ν_{e})=[3.63±0.38(stat)±0.20(syst)]%, representing a significant improvement in precision over the current indirect determination. As the branching fraction for Λ_{c}^{+}→Λe^{+}ν_{e} is the benchmark for those of other Λ_{c}^{+} semileptonic channels, our result provides a unique test of different theoretical models, which is the most stringent to date.

Abstract 1391: Single cell analysis of Lin-CD34-CD45- cells from primary AML samples reveals leukemia clones with stem cell-like properties distinct from CD34+CD38-CD123+ LSC

Phenotypically characterized Lin-CD34+CD38-CD123+ AML cells (leukemia stem cells, LSC) are believed to contain leukemia initiating cells (LIC). In the normal hematopoietic developmental hierarchy, CD34- cells are primitive hematopoietic stem cells that occupy the apex of the hematopoietic tree (Cell Stem Cell. 2013 Aug 1;13(2):161-74). A subpopulation of cells from normal individuals that lack cell surface markers (Lin-CD34-CD45- phenotype) were previously shown to have hematopoietic (and endothelial) potential (Blood. 2011 Aug 25;118(8):2105-15). Lin-CD34-CD45- cells from AML patient samples have also been shown to have LIC capacity in limited experiments (J Clin Invest. 2011 Jan;121(1):384-95). We investigated samples from 40 AML patients with active disease to determine the prevalence and frequency of Lin-CD34-CD45- cells, and determined that Lin-CD34-CD45- cells comprise 0.18 ± 0.07% of mononuclear cells in AML patients, comparable to the frequency found in normal samples (0.35 ± 0.20%, P = 0.32, n = 10). In 15 AML samples with informative cytogenetics, Lin-CD34-CD45- subpopulation contained high percentages of leukemia cells as determined by FISH (58.5 ± 8.5%). Relapsed patients with ≥ five prior different lines of therapy had significantly higher percentages of relative leukemic Lin-CD34-CD45- cells (84.6 ± 5.4% vs. 51.0 ± 11.3%, P = 0.015), and the number of prior therapies positively correlated with the fraction of leukemic Lin-CD34-CD45- cells (r = 0.55, P = 0.032). Using conventional flow cytometry and mass cytometry we sought to determine whether individual Lin-CD34-CD45- cells contained any identifying cell surface markers. The Lin-CD34-CD45- population was heterogeneous among and within patients, however some samples contained Lin-CD34-CD45- cells that expressed stem cell markers including CD38, CD47, CD99, CD117, CD146, or CD184. We further evaluated the Lin-CD34-CD45- population, LSC, and bulk AML by gene expression arrays using three primary AML samples. Gene set enrichment revealed that in comparison to LSC, Lin-CD34-CD45- cells have unique expression patterns similar to chemoresistant stem cells characterized by increased proliferation and oxidative phosphorylation. Single cell RNA-sequencing of Lin-CD34-CD45- cells, LSC, and bulk leukemia from one FLT3+ DNMT3A-mutated sample confirmed that individual Lin-CD34-CD45- cells had leukemia gene expression patterns. While some individual Lin-CD34-CD45- cells had gene expression similar to LSC, others possessed unique gene expression profiles. Results suggest that Lin-CD34-CD45- cells represent a putative stem cell state distinct from classically defined LSC. Investigations into alternate stem cell subpopulations that contribute to relapse and therapy resistance are warranted, and may reveal targets for eliminating LIC.

Citation Format: Christopher B. Benton, Ahmed Al Rawi, Taejin Min, Rui-Yu Wang, Wendy Schober, Zhiqiang Wang, Zhihong Zeng, Jeffrey Hokanson, Zhu Zhu, Xiaoping Su, Xiaofeng Zheng, Karen Lu, Bing Carter, Richard E. Davis, Hagop Kantarjian, Marina Konopleva, Michael Andreeff. Single cell analysis of Lin-CD34-CD45- cells from primary AML samples reveals leukemia clones with stem cell-like properties distinct from CD34+CD38-CD123+ LSC. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1391. doi:10.1158/1538-7445.AM2015-1391

Self-reported illnesses and service utilisation among migrants working in small-to medium sized enterprises in Guangdong, China

OBJECTIVES

As one of the most vulnerable populations in China, many migrants work in the small-to-medium-sized enterprises (SMEs). This study aims to describe the self-reported illnesses and service utilization of the migrants working in the SMEs in Pearl River Delta Areas (PRDA) of Guangdong province, China.

STUDY DESIGN

Cross-sectional survey.

METHODS

We interviewed 856 migrants working in the SMEs of different manufacturing industries in 2012. Descriptive analysis was employed to report self-reported illnesses and service utilisation among migrants in the last two weeks and in the last year. Statistical tests such as χ2 test were used to explore factors influencing their service utilisation.

RESULTS

In the last two weeks, 91(11%) of the respondents reported having any illness. The most reported illness was respiratory problem (69%), while 9.9%, 7.7% and 13% reported having digestive, skin and other problems respectively. The most important symptom was cough (39%). Thirty-seven percent of the respondents who reported any illness had visited health facilities. The lower income group were more likely to visit health facilities than the higher income group (P = 0.006). The most reported reason for not visiting health facilities was 'feeling not serious' (65%). In the last year, 13% reported having respiratory problems and 7.8% reported accidental injuries. Less than 3% received hospitalization care. The proportion of those without hospitalization to those who should have been hospitalized was 31%.

CONCLUSION

Underuse of the health service among migrants working in the SMEs could be associated with the 'healthy migrant' effect. However, when assessed among the ill migrants in the SMEs, the utilisation rate was still low mainly due to their poor health awareness. Improving their risk perception and integration of occupational and general health service is crucial to improve the health conditions and utilisation of service among migrants in the SMES.

Mesenchymal stem cells regulate cytoskeletal dynamics and promote cancer cell invasion through low dose nitric oxide

Bone marrow-derived mesenchymal stem cells (BMSCs) can be recruited to tumor sites and integrate into the stroma of tumors. When co-cultured with BMSCs, otherwise weakly metastatic nasopharyngeal carcinoma cells (NPC) showed improved metastatic ability. BMSCs in the tumor environment displayed the characteristics of macrophages. Nitric oxide produced by BMSCs in tumor environment could translocate caldesmon to podosome in Ca2+/calmodulin manner and promoted metastatic ability of NPC cells through invadopodia formation, with which the NPC cells degrade the extracellular matrix. Thus, we concluded that the BMSCs promoted cell migration and invasion through nitric oxide-induced paracrine signals.

Leukemia cell mobilization with G-CSF plus plerixafor during busulfan-fludarabine conditioning for allogeneic stem cell transplantation

We hypothesized that during conditioning chemotherapy for allogeneic stem cell transplant (allo-SCT), disruption of stromal-leukemia interactions using granulocyte-colony stimulating factor (G-CSF) in combination with the CXCR4-specific inhibitor plerixafor, may promote release of leukemic cells from the niche and increase tumor elimination. In a phase 1/2 investigation, we treated 45 AML/MDS/CML patients (34 AML, 7 MDS, and 4 CML) with G-CSF (10 μg/kg daily for 6 days starting on day −9) plus plerixafor (doses of 0, 80, 160 or 240 μg/kg daily for 4 days starting on day −7) along with the busulfan-fludarabine (Bu-Flu) conditioning regimen. In the phase 1 part, we determined that G-CSF plus plerixafor is safe in this setting. We compared clinical effects and outcomes of AML/MDS study patients (n = 40) to 164 patients from a historical data set who received Bu-Flu alone prior to allo-SCT by stratifying on cytogenetics and disease status to correct for bias. Study patients had increased myeloid chimerism and lower rates of GvHD. There was no significant difference in relapse free survival or overall survival. The G-CSF plus plerixafor combination increased circulating white blood cells, CD34+ cells, and CXCR4+ cells, and preferentially mobilized FISH+ leukemic cells. ClinicalTrials.gov identifier is NCT00822770.

Structural annotation of equine protein-coding genes determined by mRNA sequencing

The horse, like the majority of animal species, has a limited amount of species-specific expressed sequence data available in public databases. As a result, structural models for the majority of genes defined in the equine genome are predictions based on ab initio sequence analysis or the projection of gene structures from other mammalian species. The current study used Illumina-based sequencing of messenger RNA (RNA-seq) to help refine structural annotation of equine protein-coding genes and for a preliminary assessment of gene expression patterns. Sequencing of mRNA from eight equine tissues generated 293,758105 sequence tags of 35 bases each, equalling 10.28 gbp of total sequence data. The tag alignments represent approximately 207 × coverage of the equine mRNA transcriptome and confirmed transcriptional activity for roughly 90% of the protein-coding gene structures predicted by Ensembl and NCBI. Tag coverage was sufficient to refine the structural annotation for 11,356 of these predicted genes, while also identifying an additional 456 transcripts with exon/intron features that are not listed by either Ensembl or NCBI. Genomic locus data and intervals for the protein-coding genes predicted by the Ensembl and NCBI annotation pipelines were combined with 75,116 RNA-seq-derived transcriptional units to generate a consensus equine protein-coding gene set of 20,302 defined loci. Gene ontology annotation was used to compare the functional and structural categories of genes expressed in either a tissue-restricted pattern or broadly across all tissue samples.

Inner scale effect on scintillation index of flat-topped beam in non-Kolmogorov weak turbulence

A simpler generalized expression of irradiance fluctuation for flat-topped beams is presented based on the Born and Rytov perturbation methods. The theoretical expression of the on-axis scintillation index in non-Kolmogorov weak atmospheric optics links is developed using the generalized von Kármán spectrum model, and using the equivalent structure constant that is different for all power-law exponents. The effect of the inner scale on the on-axis scintillation index is examined comprehensively. It is observed that flat-topped beams happen to possess smaller scintillation indices at larger inner scale. The effects of the power law, flat-topped order, source size of the fundamental Gaussian beam, propagation distance, and wavelength are also analyzed.

A Phase I/II Study of the mTOR Inhibitor Everolimus in Combination with HyperCVAD Chemotherapy in Patients with Relapsed/Refractory Acute Lymphoblastic Leukemia

PURPOSE

Previous studies suggest a potential therapeutic role for mTOR inhibition in lymphoid malignancies. This single-center phase I/II study was designed to test the safety and efficacy of the mTOR inhibitor everolimus in combination with HyperCVAD chemotherapy in relapsed/refractory acute lymphoblastic leukemia (ALL).

EXPERIMENTAL DESIGN

Twenty-four patients were treated; 15 received everolimus 5 mg/day and 9 received 10 mg/day with HyperCVAD.

RESULTS

The median age of patients was 25 years (range, 11-64) and median number of prior treatments was 2 (range, 1-7). Grade 3 mucositis was the dose-limiting toxicity and the maximum tolerated everolimus dose was 5 mg/day. Responses included complete remission (CR) in 6 patients (25%), CR without platelet recovery (CRp) in 1 (4%), and CR without recovery of counts (CRi) in 1 (4%), for an overall response rate of 33%. In addition, partial response (PR) was noted in 2 patients (8%). Seven of 11 patients treated in first salvage achieved CR/CRp (64%). The median OS was 29 weeks for patients in first salvage versus 15 weeks for patients in second salvage and beyond (P ≤ 0.001). A response was noted in 5 of 10 (50%) heavily pretreated T-ALL patients (median of 4 prior salvage regimens). Everolimus significantly inhibited phosphorylation of S6RP, but this did not correlate with response. No significant decreases in p4EBP1 and pAkt levels were noted. Responders had higher everolimus dose-adjusted area under the curve (P = 0.025) and lower clearance (P = 0.025) than nonresponders.

CONCLUSIONS

The combination of HyperCVAD and everolimus is well tolerated and moderately effective in relapsed ALL, specifically T-ALL.

Single-cell mass cytometry reveals intracellular survival/proliferative signaling in FLT3-ITD-mutated AML stem/progenitor cells

Understanding the unique phenotypes and complex signaling pathways of leukemia stem cells (LSCs) will provide insights and druggable targets that can be used to eradicate acute myeloid leukemia (AML). Current work on AML LSCs is limited by the number of parameters that conventional flow cytometry (FCM) can analyze because of cell autofluorescence and fluorescent dye spectral overlap. Single-cell mass cytometry (CyTOF) substitutes rare earth elements for fluorophores to label antibodies, which allows measurements of up to 120 parameters in single cells without correction for spectral overlap. The aim of this study was the evaluation of intracellular signaling in antigen-defined stem/progenitor cell subsets in primary AML. CyTOF and conventional FCM yielded comparable results on LSC phenotypes defined by CD45, CD34, CD38, CD123, and CD99. Intracellular phosphoprotein responses to ex vivo cell signaling inhibitors and cytokine stimulation were assessed in myeloid leukemia cell lines and one primary AML sample. CyTOF and conventional FCM results were confirmed by western blotting. In the primary AML sample, we investigated the cell responses to ex vivo stimulation with stem cell factor and BEZ235-induced inhibition of PI3K and identified activation patterns in multiple PI3K downstream signaling pathways including p-4EBP1, p-AKT, and p-S6, particularly in CD34(+) subsets. We evaluated multiple signaling pathways in antigen-defined subpopulations in primary AML cells with FLT3-ITD mutations. The data demonstrated the heterogeneity of cell phenotype distribution and distinct patterns of signaling activation across AML samples and between AML and normal samples. The mTOR targets p-4EBP1 and p-S6 were exclusively found in FLT3-ITD stem/progenitor cells, but not in their normal counterparts, suggesting both as novel targets in FLT3 mutated AML. Our data suggest that CyTOF can identify functional signaling pathways in antigen-defined subpopulations in primary AML, which may provide a rationale for designing therapeutics targeting LSC-enriched cell populations.

Cluster dynamics simulation of deuterium retention behaviors in irradiated beryllium

The long-term dynamics evolution behaviors of deuterium in beryllium under different irradiation conditions are investigated using the cluster dynamics model.

Abstract 4768: Novel peptidic CXCR4 antagonist LY2510924 disrupts the SDF-1α/CXCR4 axis resulting in anti-AML efficacy in vivo

Disruption of the SDF-1α/CXCR4 axis by CXCR4 inhibitors has been proven to be an attractive investigational therapeutic approach for acute myeloid leukemia (AML). Moreover, the addition of CXCR4 inhibitor plerixafor to cytotoxic chemotherapy in a phase 1/2 study was associated with increased response rates in relapsed AML (Blood 2012:119;3917). However, plerixafor as a single agent induces only 2- to 4-fold mobilization of leukemic blasts, and this is thought to be due to incomplete inhibition of the SDF-1α/CXCR4 axis and short half-life.

LY2510924 is a selective peptidic CXCR4 antagonist that blocks SDF-1α from binding to the receptor. Flow cytometry using OCI-AML3 cells showed that LY2510924 inhibited binding of anti-CXCR4 antibody 12G5 to surface CXCR4 in a concentration-dependent fashion. LY2510924 was 100 times more potent compared to plerixafor (normalized surface expression, LY2510924 at 1 nM, 10.7±0.27%; plerixafor at 1 nM and 100 nM, 74.6±1.23% and 11.0±0.29%, respectively). The action of LY2510924 started as early as 1 minute and continued up to 72 hours at 10 nM. SDF-1α induced migration of OCI-AML3 and primary AML cells, which was abolished by 1 nM LY2510924 but not suppressed by 1 nM plerixafor. LY2510924 inhibited SDF-1α-induced AKT and/or ERK phosphorylation in AML cell lines (OCI-AML3 and U937) and primary AML cells as shown by immunoblotting and multi-parameter phospho-flow cytometry.

To test the efficacy of LY2510924 in vivo, we injected OCI-AML3/luc/mCherry cells into sub-lethally irradiated NSG mice. Twelve days after cell injection, mice were randomized into 4 groups: control, cytarabine, LY2510924, and LY2510924 plus cytarabine. On day 21 after cell injection, we observed a 3.4±1.4-fold increase of circulating leukemic cells at 3 hours and a 24.1±15.4-fold mobilization at 24 hours after LY2510924 injection. Bioluminescence imaging demonstrated that mice treated with LY2510924 had lower leukemia burden than cytarabine-treated and control mice. On day 39, the combination group showed less luciferase activity than the LY2510924 group (P=0.034). Hematoxylin-eosin and immunohistochemical staining with human CD45 antibody demonstrated that the LY2510924-treated groups had a significant decrease in leukemic infiltration of bone marrow, spleen, liver, and lung. This anti-leukemia effect translated into a significant prolongation of survival in LY2510924-treated mice (40 days vs. 26 days, P&lt;0.001).

In summary, in vitro data showed that a novel peptidic CXCR4 antagonist, LY2510924, could effectively disrupt the SDF-1α/CXCR4 axis in AML cells and was more potent than plerixafor. In vivo data showed anti-leukemia effects of LY2510924 as a single agent. LY2510924's stronger potency than plerixafor, rapidity of action, and prolonged CXCR4-inhibitory effects will likely translate into a higher anti-leukemia potency than that of plerixafor in future clinical applications.

Citation Format: Byung Sik Cho, Zhihong Zeng, Hong Mu, Teresa McQueen, Marina Protopopova, Jorge Cortes, Joe Marszalek, Sheng-Bin Peng, Donald E. Thornton, Michael Andreeff, Marina Konopleva. Novel peptidic CXCR4 antagonist LY2510924 disrupts the SDF-1α/CXCR4 axis resulting in anti-AML efficacy in vivo. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4768. doi:10.1158/1538-7445.AM2014-4768