The cosmic ray energy spectrum measured with the new Tibet hybrid experiment

We have upgraded the new Tibet ASgamma experiment in China since 2014 to measure the chemical composition of cosmic rays around the knee. This hybrid experiment consist of an air-shower-core detector array (YAC-II) to detect high energy electromagnetic component, the Tibet air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD). We have carried out a detailed air-shower Monte Carlo (MC) simulation to study the performance of the hybrid detectors by using CORSIKA (version 7.5000), which includes EPOS-LHC, QGSJETII-04, SIBYLL2.1 and SIBYLL2.3 hadronic interaction models. The preliminary results of the interaction model checking above 50 TeV energy region are reported in this paper, and the primary proton and helium spectra in the energy range 50 TeV to 1015 eV was derived from YAC-I data and is smoothly connected with direct observation data at lower energies and also with our previously reported works at higher energies within statistical errors. The knee of the (P+He) spectra is located around 400 TeV. The interaction model dependence in deriving the primary (P+He) spectra is found to be small (less than 25% in absolute intensity, 10% in position of the knee), and the composition model dependence is less than 10% in absolute intensity.

Cell membrane-covered nanoparticles as biomaterials

Surface engineering of synthetic carriers is an essential and important strategy for drug delivery in vivo. However, exogenous properties make synthetic nanosystems invaders that easily trigger the passive immune clearance mechanism, increasing the retention effect caused by the reticuloendothelial systems and bioadhesion, finally leading to low therapeutic efficacy and toxic effects. Recently, a cell membrane cloaking technique has been reported as a novel interfacing approach from the biological/immunological perspective, and has proved useful for improving the performance of synthetic nanocarriers in vivo. After cell membrane cloaking, nanoparticles not only acquire the physiochemical properties of natural cell membranes but also inherit unique biological functions due to the presence of membrane-anchored proteins, antigens, and immunological moieties. The derived biological properties and functions, such as immunosuppressive capability, long circulation time, and targeted recognition integrated in synthetic nanosystems, have enhanced their potential in biomedicine in the future. Here, we review the cell membrane-covered nanosystems, highlight their novelty, introduce relevant biomedical applications, and describe the future prospects for the use of this novel biomimetic system constructed from a combination of cell membranes and synthetic nanomaterials.

[Practice of parenting and related factors on children aged 0-5 in the urban areas of China]

Objective: To characterize the relations between the practice of parenting and associated factors on children (0-5 years old) in urban areas of China, in order to provide evidence for promoting the early development of children and to provide positive guidance and service programs on parenting. Methods: A total of 4 515 parents from 15 cities (14 provinces) were surveyed with a self-administered questionnaire. Parenting and Family Adjustment Scales (PAFAS) was used, including parameters as: consistency and coercive parenting, positive encouragement, parent-child relationship and parental emotion adjustment, family relationship and parental teamwork aspects, etc. Both single factor analysis and multiple linear regression were used to examine the associations between parenting practice, individual, parental and family factors. Results: The mean score of PAFAS was 21.00 (15.00-28.00), associated with factors as children's age, only-child family, premature delivery, father's education level, confidence on parenting, problems regarding the parental mood, annual family income, family structure and behavior on seeking professional help, etc. Results showed that there were big differences on the practice of parenting in China and influenced by variety of factors. Conclusions: The general situation of parenting was well, in the urban areas of China. The practice of parenting was associated with a series of individual, parental and family factors. Programs on improving the parenting skills and promoting the early development of children, should be highlighted.

Biomorphic Engineering of Multifunctional Polylactide Stomatocytes toward Therapeutic Nano-Red Blood Cells

Morphologically discrete nanoarchitectures, which mimic the structural complexity of biological systems, are an increasingly popular design paradigm in the development of new nanomedical technologies. Herein, engineered polymeric stomatocytes are presented as a structural and functional mimic of red blood cells (RBCs) with multifunctional therapeutic features. Stomatocytes, comprising biodegradable poly(ethylene glycol)-block-poly(D,L-lactide), possess an oblate-like morphology reminiscent of RBCs. This unique dual-compartmentalized structure is augmented via encapsulation of multifunctional cargo (oxygen-binding hemoglobin and the photosensitizer chlorin e6). Furthermore, stomatocytes are decorated with a cell membrane isolated from erythrocytes to ensure that the surface characteristics matched those of RBCs. In vivo biodistribution data reveal that both the uncoated and coated nano-RBCs have long circulation times in mice, with the membrane-coated ones outperforming the uncoated stomatoctyes. The capacity of nano-RBCs to transport oxygen and create oxygen radicals upon exposure to light is effectively explored toward photodynamic therapy, using 2D and 3D tumor models; addressing the challenge presented by cancer-induced hypoxia. The morphological and functional control demonstrated by this synthetic nanosystem, coupled with indications of therapeutic efficacy, constitutes a highly promising platform for future clinical application.

Abstract GS5-05: Resistance to neoadjuvant chemotherapy in triple negative breast cancer mediated by a reversible drug-tolerant state

Approximately 50% of patients with localized triple negative breast cancer (TNBC) have substantial residual cancer burden following treatment with neoadjuvant chemotherapy (NACT), resulting in distant metastasis and death for most of these patients. While genomic and phenotypic intra-tumor heterogeneity are pervasive features of TNBCs at the time of diagnosis, the functional contributions of heterogeneous tumor cell populations to chemoresistance have not been elucidated.

To investigate tumor evolution accompanying NACT, we employed orthotopic patient-derived xenograft (PDX) models of treatment-naïve TNBC, which retain intra-tumor heterogeneity characteristic of human TNBC. We discovered that some PDX models initially exhibited partial sensitivity to standard front-line NACT (Adriamycin plus Cytoxan, AC). Following AC, residual tumors were resistant to chemotherapy but repopulated tumors with chemo-sensitive cells if left untreated, indicating that tumor cells possessed inherent plasticity. To identify the tumor cell subpopulation(s) conferring chemoresistance, we conducted barcode-mediated clonal tracking in three independent PDX models by introducing a high-complexity pooled lentiviral barcode library into PDX tumor cells which were then orthotopically engrafted into recipient mice. Strikingly, residual tumors maintained the same heterogeneous clonal architecture as naïve tumors. Concordantly, whole-exome sequencing revealed conservation of genomic subclonal architecture throughout treatment. These results were corroborated by genomic sequencing of serial biopsies pre- and post-AC obtained directly from TNBC patients enrolled on an ongoing clinical trial at MD Anderson (ARTEMIS; NCT02276443). Together, these studies revealed that genomically distinct pre-treatment subclones were equally capable of surviving AC to reconstitute tumors after treatment.

To identify functional addictions of residual tumor cells, we conducted histologic and transcriptomic profiling. Residual tumors following AC-treatment exhibited extensive fibrotic desmoplasia and tumor cell pleomorphism in both PDX models and in serial biopsies obtained from TNBC patients enrolled on the ARTEMIS trial. Strikingly, these AC-induced features were reverted upon regrowth of residual tumors in PDXs and in patients' tumors. Similarly, residual tumors exhibited unique transcriptomic features, many of which are also de-regulated in cohorts of human TNBCs undergoing chemotherapy treatment. These features were nearly completely reverted after tumors regrew, suggesting that the residual tumor state may be a unique and transient therapeutic window. Gene set enrichment analyses revealed that residual tumors had increased activation of oxidative phosphorylation and decreased glycolytic signaling. Pharmacologic targeting of oxidative phosphorylation with a small-molecule inhibitor of mitochondrial electron transport chain complex I (IACS-010759) significantly delayed the regrowth of AC-treated residual tumors in three independent PDX models. Collectively, these studies reveal that a reversible phenotypic state can confer chemoresistance in the absence of genomic selection and that the residual tumor state is a novel therapeutic window for chemo-refractory TNBC.

Citation Format: Echeverria GV, Ge Z, Seth S, Jeter-Jones SL, Zhang X, Zhou X, Cai S, Tu Y, McCoy A, Peoples M, Lau R, Shao J, Sun Y, Bristow C, Carugo A, Ma X, Harris A, Wu Y, Moulder S, Symmans WF, Marszalek JR, Heffernan TP, Chang JT, Piwnica-Worms H. Resistance to neoadjuvant chemotherapy in triple negative breast cancer mediated by a reversible drug-tolerant state [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS5-05.

Abstract P3-07-03: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Rinkenbaugh AL, Sinha VC, Zhang X, Shao J, Piwnica-Worms H. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-07-03.

Test of the hadronic interaction models SIBYLL2.3, EPOS-LHC and QGSJETII- 04 with Tibet EAS core data

A hybrid experiment has been started by the ASγ experiment at Yangbajing (4300m a.s.l.) in Tibet since May 2009, that consists of a high-energy air-shower-core array (YAC-I) and a high-density air-shower array (Tibet-III). In this paper, we report our results to check the hadronic interaction models SIBYLL2.3, SIBYLL2.1, EPOS-LHC and QGSJETII-04 in the multi-tens TeV energy region using YAC-I+Tibet-III experimental data from May 2009 through January 2010. The effective live time is calculated as 106.05 days. The results show that the description of transverse momentum, inelastic cross-section and inelasticity for the 4 hadronic interaction models is consistent with YAC-I experimental data within 15% systematic errors range in the forward region below 100 TeV. Among them, the EPOS-LHC model is the best hadronic interaction model. Furthermore, we find that the H4a composition model is the best one below the 100 TeV energy region.

On the Solar Cycle Variation of the Solar Diurnal Anisotropy of Multi-TeV Cosmic-ray Intensity Observed with the Tibet Air Shower Array

We analyze the temporal variation of the solar diurnal anisotropy of the multi-TeV cosmic-ray intensity observed with the Tibet air shower array from 2000 to 2009, covering the maximum and minimum of the 23rd solar cycle. We comfirm that a remarkable additional anisotropy component is superposed on the Compton-Getting anisotropy at 4.0 TeV, while its amplitude decreases at higher energy regions. In constrast to the additional anisotropy reported by the Matsushiro experiment at 0.6 TeV, we find the residual component measured by Tibet at multi-TeV energies is consistent with being stable, with a fairly constant amplitude of 0.041% ± 0.003% and a phase at around 07.17 ± 00.16 local solar time at 4.0 TeV. This suggests the additional anisotropy observed by the Tibet experiment could result from mechanisms unrelated to solar activities.

pH-Induced Transformation of Biodegradable Multilamellar Nanovectors for Enhanced Tumor Penetration

Herein we describe biodegradable nanovectors comprised of block copolymers of poly(ethylene glycol) and poly(trimethylene carbonate) (PEG–PTMC) that change their morphology and surface charge when exposed to tumor environment conditions. Well-defined, drug-loaded nanovectors were prepared via direct hydration using liquid oligo(ethylene glycol) as a dispersant. Systematic introduction of basic imidazole-functional TMC derivatives, through modular polymerization, resulted in polymers that self-assembled in multilamellar nanoparticles (at neutral pH) and that were loaded with hydrophobic drugs. The resultant multilamellar nanovectors demonstrated a significant size reduction and charge reversal at pH ≈ 6.5, which yielded cationic nanovectors that were tailored for tumor penetration. Invitro studies using 3D heterospheroids demonstrate that this platform has excellent potential to promote enhanced tumor penetration under physiological conditions.

A Novel Thermoresponsive Gel as a Potential Delivery System for Lipoxin

The objective of this study was to evaluate a novel thermoresponsive polyisocyanopeptide (PIC)–based hydrogel as an injectable carrier for local drug delivery for periodontal applications. Three formulations of PIC gels, 0.2%, 0.5%, and 1% w/w, were prepared. As controls, commercially available poloxamer 407 (P407) gels of 20% and 26% w/w were used. Lipoxin A₄ (LXA₄), a proresolving drug, was suspended into the gel solutions. The systems were evaluated regarding dynamic mechanical properties, injectability and stability, release and bioactivity of LXA₄, and cytocompatibility. Results showed that the gelation temperatures of PIC and P407 gels were around 13°C to 23°C. PIC gels were less viscous and mechanically weaker than P407 gels due to the low polymer concentrations. However, PIC gels kept gel integrity for at least 2 wk when incubated with phosphate-buffered saline, whereas P407 gels were disintegrated totally within 1 wk. LXA₄ was chemically stable in both neutral and alkaline medium for over 1 mo. The release of LXA₄ from either 1% PIC or 26% P407 gels depicted an initial burst release followed by a sustained release for around 4 d. The extent of burst release was negatively correlated to the polymer concentration. LXA₄ remained bioactive after release from PIC gels. No cytotoxicity was observed for 1% PIC gel. However, 26% P407 inhibited periodontal ligament cell and gingival epithelial cell growth. In conclusion, the thermoresponsive PIC gel is a potential candidate for periodontal drug delivery.

[Simultaneous determination of trichloroethylene and trichloroethanol in blood by liquid-liquid extraction-gas chromatography]

Objective: To establish a method for determing the trichloroethylene(TCE)and trichloroethanol(TCOH)in blood samples by liquid-liquid extraction-gas chromatography with electron capture detector. Methods: With this method,ether was used as extraction solvent and trichloromethane was used as an internal standard. The whole blood sample was extracted with ether, and dehydrated by anhydrous sodium sulfate. Then the analytes were separated on HP-5 capillary column(30m×0.32mm×0.15μm)and detected byECD.The retention time was for qualitative analysis and the internal standard was for quantitation. Results: The standard curves of TCE and TCOH showed significant linearity between 95.5μg/L-7640.0μg/L(r=0.9997)and 19.0μg/L-1520.0μg/L(r=0.9992). The average recovery was 95.5%-103.6%.The intra-day and inter-day precisions(RSD)were 2.5%-6.8%(n=6)and 1.6%-4.3%(n=6) respectively. The detect limit of TCE and TCOH were 2.10 μg/L and 0.56μg/L(S/N=3)respectively.The blood can be kept 7 days at-20℃ refrigerator without significantly loss. Conclusion: This method is proved to be simple,practical and highly sensitive. It can satisfy the request for the determination of blood samples of humans exposed to TCE.

Modified Model of Whole Ovary Transplantation in Rats

OBJECTIVE

A rat model of right whole ovary transplantation is difficult to establish because of an unfit location or absence of the right ovarian artery. The purpose of this study is to develop a rat model of left whole ovary transplantation.

METHODS

Two methods of whole ovary transplantation were performed. In Group A (n = 40), the rats underwent right whole ovary grafting via conventional orthotopic allotransplant, with donor abdominal aorta and inferior vena cava end-to-side anastomoses to the recipient abdominal aorta and inferior vena cava. In Group B (n = 40), the rats underwent left whole ovary graft via orthotopic allotransplant, with donor abdominal aorta and left renal vein end-to-side anastomoses to the recipient abdominal aorta and inferior vena cava. Bilateral native ovariectomy in the recipient was performed immediately in both groups. The operative times, recipient survival rates, and transplanted ovarian function were measured.

RESULTS

There was no significant difference in the success rates of transplant between the 2 groups, with 92.5% and 90% success, respectively. All the living recipients recovered ovarian function. However, the operative time for the donor, the vein anastomosis time, and the cold ischemia time decreased significantly in Group B (P < .05).

CONCLUSION

The modified method of left whole ovary transplantation is reliable and easy to perform, which could significantly shorten the times of graft harvest and cold ischemia. The method is a good supplement and improvement of the conventional model of rat whole ovary transplantation.

Erythrocyte Membrane Modified Janus Polymeric Motors for Thrombus Therapy

We report the construction of erythrocyte membrane-cloaked Janus polymeric motors (EM-JPMs) which are propelled by near-infrared (NIR) laser irradiation and are successfully applied in thrombus ablation. Chitosan (a natural polysaccharide with positive charge, CHI) and heparin (glycosaminoglycan with negative charge, Hep) were selected as wall materials to construct biodegradable and biocompatible capsules through the layer-by-layer self-assembly technique. By partially coating the capsule with a gold (Au) layer through sputter coating, a NIR-responsive Janus structure was obtained. Due to the asymmetric distribution of Au, a local thermal gradient was generated upon NIR irradiation, resulting in the movement of the JPMs through the self-thermophoresis effect. The reversible "on/off" motion of the JPMs and their motile behavior were easily tuned by the incident NIR laser intensity. After biointerfacing the Janus capsules with an erythrocyte membrane, the EM-JPMs displayed red blood cell related properties, which enabled them to move efficiently in relevant biological environments (cell culture, serum, and blood). Furthermore, this therapeutic platform exhibited excellent performance in ablation of thrombus through photothermal therapy. As man-made micromotors, these biohybrid EM-JPMs hold great promise of navigating in vivo for active delivery while overcoming the drawbacks of existing synthetic therapeutic platforms. We expect that this biohybrid motor has considerable potential to be widely used in the biomedical field.

THE CORRELATION BETWEEN NECK CIRCUMFERENCE AND UMBILICAL ARTERY BLOOD FLOW IN PHYSIOLOGIC PREGNANCIES

Objective

To study the correlation between neck circumference(NC) and umbilical artery blood flow in physiologic pregnancies.

Methods

One hundred and one healthy pregnant woman in the third trimester were enrolled. Anthropometric measurements and ultrasonic testing were done.

Results

The women with NC ≥34.7cm had a more elevated umbilical artery pulsatility index(PI) and systolic/diastolic ratio (S/D) than the women with NC <34.7cm (P<0.01). NC were positively correlated with PI(r=0.224,P=0.024) and S/D ratio(r=0.415,P=0.0001). In multivariate analysis, NC was independently associated with PI (β=0.026, P=0.016) and S/D ratio (β=0.132, P=0.0001).

Conclusions

Obesity has an adverse impact on feto-placetal vessels, and NC was superior to body mass index.

Abstract GS6-06: Identifying metastatic drivers in patient-derived xenograft models of triple negative breast cancer

Metastases are responsible for the vast majority of deaths due to breast cancer. Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high rates of metastasis and poor prognosis. We are employing patient derived xenograft (PDX) models of TNBC to identify drivers of metastasis. Tumor samples are obtained from the breast tumors of patients with TNBC and engrafted immediately into the humanized mammary fat pads of immune compromised mice. Lentiviral transduction was employed to express bioluminescent and fluorescent markers in two independent PDX models of TNBC. Using these models, we demonstrated that human breast tumors are capable of completing all stages of the metastatic cascade in mice, and metastatic lesions are observed in organs normally found in patients with metastatic breast cancer including lung, liver, bone, brain, and lymph nodes. Dynamic and reversible epithelial to mesenchymal transition (EMT) was observed as tumors metastasized to lung and were re-passaged to recipient mouse mammary glands. Lung metastases were isolated using bioluminescence imaging and lung metastasis gene expression signatures were generated. Metastasis signatures from two independent PDX models were compared to identify genes that were commonly de-regulated in lung metastases relative to corresponding mammary tumors. Comprehensive gain-of-function screens were then conducted in vivo to identify functional drivers of TNBC metastasis. Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) was identified as a metastatic driver in this screen. CEACAM5 mRNA and protein levels were elevated in lung metastases relative to corresponding mammary gland tumors in mice. In addition, we demonstrated that CEACAM5 expression was upregulated in the lung metastases of breast cancer patients, and its expression inversely correlated with patient survival. Our data indicate that the metastatic function of CEACAM5 is to promote growth of breast tumors in the lung by inducing MET (mesenchymal to epithelial transition).

Citation Format: Powell E, Shao J, Picon HM, Ge Z, Echeverria GV, Peoples M, Bristow C, Cai S, Tu Y, McCoy AM, Piwnica-Worms D, Draetta G, Edwards JR, Moulder SL, Symmans WF, Heffernan TP, Liang H, Piwnica-Worms H. Identifying metastatic drivers in patient-derived xenograft models of triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS6-06.

Abstract PD8-03: ESR1 gene fusions drive endocrine therapy resistance and metastasis in breast cancer

Background. Dysregulation of the estrogen receptor gene (ESR1) is an established mechanism of inducing endocrine therapy resistance. We previously discovered a chromosomal translocation event generating an estrogen receptor gene fused in-frame to C-terminal sequences of YAP1 (ESR1-YAP1) that contributed to endocrine therapy resistance in estrogen receptor positive (ER+) breast cancer models. This study compares functional, transcriptional, and pharmacological properties of additional ESR1 gene fusion events of both early stage (ESR1-NOP2) late stage (ESR1-YAP1 and ESR1-PCDH11x) breast cancers to gain a better understanding of therapeutic resistance and metastasis. Understanding the role of ESR1 fusions in inducing metastasis is critical, since the primary cause of death in breast cancer patients is through metastasis to distant sites.

Methods. RNA-seq screens identified ESR1 fusions from early and late stage, endocrine therapy resistant breast tumor samples. Functional experiments were conducted using ER+ breast cancer cell lines, xenograft, and PDX models to test the ability of ESR1 fusions to induce therapeutic resistance and metastasis. ChIP-seq and RNA-seq were performed to examine transcriptional properties and differential gene expression induced by the fusions which directed subsequent pharmacological experiments with a CDK4/6 inhibitor.

Results. ESR1-YAP1 and ESR1-PCDH11x promoted estrogen-independent and fulvestrant-resistant growth in vitro and induced greater tumor growth and increased metastatic capacity to the lungs of xenografted mice. In contrast, the ESR1-NOP2 fusion was sensitive to low estrogen conditions in vitro, and did not promote tumor growth. RNA-seq profiling revealed E2F targets pathway as the most highly enriched pathway induced by the ESR1 fusions. IHC revealed higher levels of pRb in ESR1-YAP1 and ESR1-PCDH11x xenograft tumors and subsequent CDK4/6 inhibition completely blocked tumor growth in an ESR1-YAP1 PDX model. Integrating RNA-seq with ChIP-seq data, we discovered a set of EMT and metastasis genes bound by all ESR1 fusions and WT-ER, but whose expression was strongly and uniquely up-regulated only by the ESR1-YAP1 and ESR1-PCDH11x fusions. These studies also revealed gained sites bound only by the ESR1-YAP1 and ESR1-PCDH11x fusions, not bound by WT-ER nor ESR1-NOP2. Genes mapping to these sites have a role in metastatic biology and were highly up-regulated by the YAP1 and PCDH11x fusions, potentially mediated by long range transcriptional activation.

Conclusion. ESR1-YAP1 and ESR1-PCDH11x are driver fusions that occur in drug-resistant, advanced stage breast cancer and are a new class of recurrent somatic mutation that can cause acquired endocrine therapy resistance, yet can be treated with CDK4/6 inhibition. These driver fusions also confer increased metastatic ability through their ability to drive expression of genes that contribute to EMT and metastasis. In contrast, ESR1-NOP2 did not produce functional protein and appears to be a passenger event. These studies may provide pre-clinical rationale for targeting ESR1 translocated breast tumors, since the presence of an ESR1 driver fusion places a patient in a therapeutic category where none of the currently available endocrine therapies are likely to be effective.

Citation Format: Lei JT, Shao J, Zhang J, Iglesia M, Chan DW, Cao J, Anurag M, Singh P, Haricharan S, Kavuri SM, Matsunuma R, Schmidt C, Kosaka Y, Crowder R, Hoog J, Phommaly C, Goncalves R, Ramalho S, Rodrigues-Peres RM, Lai W-C, Hampton O, Rogers A, Tobias E, Parikh P, Davies S, Ma C, Suman V, Hunt K, Watson M, Hoadley KA, Thompson A, Perou CM, Creighton CJ, Maher C, Ellis MJ. ESR1 gene fusions drive endocrine therapy resistance and metastasis in breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD8-03.

Polyelectrolyte multilayer-cushioned fluid lipid bilayers: a parachute model

Lipid bilayer membranes supported on polyelectrolyte multilayers are widely used as a new biomembrane model that connects biological and artificial materials since these ultrathin polyelectrolyte supports may mimic the role of the extracellular matrix and cell skeleton in living systems. Polyelectrolyte multilayers were fabricated by a layer-by-layer self-assembly technique. A quartz crystal microbalance with dissipation was used in real time to monitor the interaction between phospholipids and polyelectrolytes in situ on a planar substrate. The surface properties of polyelectrolyte films were investigated by the measurement of contact angles and zeta potential. Phospholipid charge, buffer pH and substrate hydrophilicity were proved to be essential for vesicle adsorption, rupture, fusion and formation of continuous lipid bilayers on the polyelectrolyte multilayers. The results clearly demonstrated that only the mixture of phosphatidylcholine and phosphatidic acid (4 : 1) resulted in fluid bilayers on chitosan and alginate multilayers with chitosan as a top layer at pH 6.5. A coarse-grained molecular simulation study elucidated that the exact mechanism of the formation of fluid lipid bilayers resembles a "parachute" model. As the closest model to the real membrane, polyelectrolyte multilayer-cushioned fluid lipid bilayers can be appropriate candidates for application in biomedical fields.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

[Comparative analysis of open surgical repair and endovascular aortic repair in the treatment of abdominal aortic aneurysm implicated visceral arteries]

Objective: To evaluate the value of open surgery repair and endovascular aortic repair in the treatment of abdominal aortic aneurysm which implicate visceral arteries. Methods: From January 2012 to October 2016, 26 patients were reviewed. According to the treatment, they were divided into open surgery group (n=7) and endovascular repair group(n=19). Then, the characteristics and relative data of follow-up of the two groups were analysis. Results: In open surgery group, there were 7 patients. All of them were men, median age 58(41-62) years and 1 patient were older than 75 years. And in endovascular repair group, there were 19 patients(14 men) of median age 72(66-76) years, 8 patients were older than 75 years. Patients in endovascular repair group were significantly older than who were in open surgery group (Z=-13.06, P<0.05). Complications of open surgery group and endovascular repair group were 57.14% and 15.79% respectively. There was no statistically significant difference (χ(2)=3.13, P>0.05). During follow-up, the diameters of aneurysm which planted stents were smaller than before. Conclusions: In the treatment of abdominal aortic aneurysm implicated visceral arteries, open surgery is mainly suitable for the patients with low-risk. But the rate of complications was high. By contrast, endovascular aortic repair with small trauma and high safety, has becoming the first choice.

Composites of Bacterial Cellulose and Small Molecule-Decorated Gold Nanoparticles for Treating Gram-Negative Bacteria-Infected Wounds

Bacterial infections, especially multidrug-resistant bacterial infections, are an increasingly serious problem in the field of wound healing. Herein, bacterial cellulose (BC) decorated by 4,6-diamino-2-pyrimidinethiol (DAPT)-modified gold nanoparticles (Au-DAPT NPs) is presented as a dressing (BC-Au-DAPT nanocomposites) for treating bacterially infected wounds. BC-Au-DAPT nanocomposites have better efficacy (measured in terms of reduced minimum inhibition concentration) than most of the antibiotics (cefazolin/sulfamethoxazole) against Gram-negative bacteria, while maintaining excellent physicochemical properties including water uptake capability, mechanical strain, and biocompatibility. On Escherichia coli- or Pseudomonas aeruginosa-infected full-thickness skin wounds on rats, the BC-Au-DAPT nanocomposites inhibit bacterial growth and promote wound repair. Thus, the BC-Au-DAPT nanocomposite system is a promising platform for treating superbug-infected wounds.

Structural evolution during calcination and sintering of a (La0.6Sr0.4)0.99CoO3-δ nanofiber prepared by electrospinning

Design of three-dimensional metal oxide nanofibers by electrospinning is being widely explored. However, the impacts of calcination and sintering on the resulting morphology remain unknown. For the first time, (La_0.6Sr_0.4)_0.99CoO_3-δ (LSC) nanofiber, which is among the most promising electrode materials for solid oxide fuel cells, was synthesized by sol-gel electrospinning. By elevating the temperature in oxygen using in situ transmission electron microscopy, we discovered the structural transitions from nanofibers to nanotubes and then to nano-pearl strings. This facile and up-scalable method can be widely applied to design metal oxide one-dimensional nanomaterials with precise control in both geometry (nanofiber, nanotube and nano-pearl string) and surface area (by varying grain size).

Optically efficient InAsSb nanowires for silicon-based mid-wavelength infrared optoelectronics

InAsSb nanowires (NWs) with a high Sb content have potential in the fabrication of advanced silicon-based optoelectronics such as infrared photondetectors/emitters and highly sensitive phototransistors, as well as in the generation of renewable electricity. However, producing optically efficient InAsSb NWs with a high Sb content remains a challenge, and optical emission is limited to 4.0 μm due to the quality of the nanowires. Here, we report, for the first time, the success of high-quality and optically efficient InAsSb NWs enabling silicon-based optoelectronics operating in entirely mid-wavelength infrared. Pure zinc-blende InAsSb NWs were realized with efficient photoluminescence emission. We obtained room-temperature photoluminescence emission in InAs NWs and successfully extended the emission wavelength in InAsSb NWs to 5.1 μm. The realization of this optically efficient InAsSb NW material paves the way to realizing next-generation devices, combining advances in III-V semiconductors and silicon.

Abstract PD2-03: Recurrent functionally diverse in-frame ESR1 gene fusions drive endocrine resistance in breast cancer

Background. We previously reported an alternative ESR1 somatic gain-of-function chromosomal translocation event in a patient presenting with aggressive, endocrine therapy resistant estrogen receptor (ER) positive disease, producing an in-frame fusion gene consisting of N-terminal ESR1 and the C-terminus of the Hippo pathway coactivator YAP1 (ESR1-YAP1). We recently identified another ESR1 fusion through RNA sequencing (RNA-seq) in advanced stage ER+ disease from a chest wall recurrence in a male patient that was refractory to multiple lines of treatment. Two examples of fusions discovered in primary breast cancer samples include ESR1 fused in-frame to C-terminal sequences from NOP2 (ESR1-NOP2), identified in a resistant cohort from a RNA-seq screen focused on 81 primary breast cancers from aromatase inhibitor clinical trials, and a second ESR1 fusion, fused in-frame to the entire coding sequence of POLH (ESR1-POLH), that was identified from RNA-seq analysis of 728 Cancer Genome Atlas breast samples. This current study extends our previous characterization of ESR1-YAP1 by comparing functional and pharmacological properties of these three additional ESR1 gene fusion events of both early stage and advanced breast cancers.

Methods. In vitro and in vivo experiments were conducted to test ESR1 fusions to induce therapeutic resistance, and metastasis. The transcriptional and binding properties of each fusion was also examined. Pharmacological inhibition with Palbociclib, a cyclin-dependent kinase 4/6 inhibitor, was utilized to assess drug sensitivity in ESR1 fusion containing breast cancer cells and in a patient derived xenograft (PDX) model expressing ESR1-YAP1 (WHIM18).

Results. The YAP1 and PCDH11x fusions conferred estrogen-independent and fulvestrant-resistant growth. Immunohistochemistry revealed significantly higher numbers of ER+ cells in lungs of mice xenografted with T47D cells expressing the YAP1 and PCDH11x fusions compared to YFP control, NOP2 and POLH fusions. Results from ChIP-seq and microarray studies suggest that these two fusions promote proliferation and metastasis through genomic action by binding estrogen response elements (ERE) and subsequent gene activation. We thereby define these fusions as “canonical” fusions compared to “non-canonical” NOP2 and POLH fusions, which demonstrated dramatically decreased genomic binding ability. The non-canonical fusions induced genes associated with basal-like breast cancer and promoted HER2, EGFR, and MAPK gene expression signatures in contrast to genes associated with cell cycle/proliferation induced by canonical fusions. The proliferative ability of canonical fusion-containing ER+ cells was inhibited by Palbociclib in a dose-dependent manner. In vivo WHIM18 tumors in mice fed with Palbociclib-containing chow demonstrated significantly reduced tumor volume, growth rate, and weight compared to tumors in mice on control chow.

Conclusions. In-frame ERE activating canonical fusions occur in end-stage drug resistant advanced breast cancer and can be added to ESR1 point mutations as a class of recurrent somatic mutation that may cause acquired resistance. Growth induced by these fusions can be antagonized by Palbociclib and is potentially clinically helpful.

Citation Format: Lei JT, Shao J, Zhang J, Iglesia M, Cao J, Chan DW, He X, Kosaka Y, Schmidt C, Matsunuma R, Haricharan S, Crowder R, Hoog J, Phommaly C, Goncalves R, Ramalho S, Lai W-C, Hampton O, Rogers A, Tobias E, Parikh P, Davies S, Ma C, Suman V, Hunt K, Watson M, Hoadley KA, Thompson A, Chen X, Perou CM, Creighton CJ, Maher C, Ellis MJ. Recurrent functionally diverse in-frame ESR1 gene fusions drive endocrine resistance in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD2-03.

Abstract P6-01-08: Identifying metastatic drivers in patient derived xenograft models of triple negative breast cancer

Metastases are responsible for the vast majority of deaths due to breast cancer. Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high rates of metastasis and poor response to chemotherapy. We are using patient derived xenograft (PDX) models of TNBC to identify drivers of TNBC metastasis. Using these models, we demonstrated that human breast tumors are capable of completing all stages of the metastatic cascade in mice, and metastatic lesions are observed in organs normally found in patients with metastatic breast cancer including lung, liver, bone, brain and lymph nodes. Lentiviral transduction was employed to express both bioluminescent and fluorescent proteins in three distinct PDX models of TNBC. In this way, metastatic lesions can be isolated using bioluminescent imaging and circulating tumor cells (CTCs) are isolated by flow cytometry. A lung metastasis gene expression signature was generated and comprehensive gain-of-function screens are being conducted in vivo to validate this signature and identify functional drivers of TNBC metastasis.

Citation Format: Powell E, Shao J, Tieu T, Peoples M, Bristow C, Manyam G, Cai S, Tu Y, Edwards JR, Heffernan TP, Piwnica-Worms D, Liang H, Piwnica-Worms H. Identifying metastatic drivers in patient derived xenograft models of triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-01-08.

Long noncoding RNAs as novel serum biomarkers for the diagnosis of hepatocellular carcinoma: a systematic review and meta-analysis

PURPOSE

Long noncoding RNAs (lncRNAs) are outstanding as novel cancer biomarkers with great prospects. Herein, we focused on summarizing the overall diagnostic evaluation of lncRNAs for hepatocellular carcinoma (HCC).

METHODS

Relevant literature was collected from the online databases. The Quality Assessment for Studies of Diagnostic Accuracy checklist was used to assess the quality of included studies. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were plotted using random-effects models. Summary receiver operating characteristic curve and the area under the curve (AUC) were used to estimate the overall test performance. Statistical analysis was performed by STATA 14.0 and Meta-DiSc 1.4 software.

RESULTS

Ten studies with a total of 820 HCC patients and 785 healthy controls were included. For overall lncRNAs, the pooled sensitivity, specificity, and DOR to predict HCC patients were 80% [95% confidence interval (CI) 77-82%], 79% (95% CI 76-81%), and 27.66 (95% CI 14.26-53.63), respectively, corresponding to an AUC of 0.91.

CONCLUSIONS

LncRNAs were a high diagnostic value for HCC and its expression could potentially be used as auxiliary biomarker in confirming HCC.

Cloning and expression analysis of glucose transporter 4 mRNA in the cold hardiness frog, Rana dybowskii

BACKGROUND

The Rana dybowskii distribute in northeast region of China which have seasonally cold climates. During winter they survival freezing by biosynthesizing carbohydrate cryoprotectants such as high concentrations glucose into blood and all tissues. The essential role of glucose transporter 4 is a high-affinity glucose transporter, which can increase glucose uptake in cells when it stimulated by insulin.

OBJECTIVE

In this study, we analysis the full-length GLUT4 mRNA detect the gene levels of GLUT4 in R. dybowskii main tissues by qPCR during low temperature.

RESULTS

We found in heart, fat body, skeletal muscle and skin four tissues all express GLUT4, and the levels of GLUT4 decreased on initial cold exposure stage, 8~12 hours, followed 24 hours it recovered.

CONCLUSION

This study we firstly indentified and characterized GLUT4 in amphibious, and provide a novel insight into the role of GLUT4 in cryoprotectant synthesis and cell protection in cold hardiness amphibians.

[Effects of transthyretin on biological behavior of retinal pigment epithelial cells and retinal microvascular epithelial cells]

Objective: To explore the effects of transthyretin (TTR) on biological behavior of retinal pigment epithelial cells (RPECs) and retinal microvascular epithelial cells (RMVECs). Methods: RPECs were cultured with exogenous TTR to explore the effect of TTR on the proliferation of RPECs. The expression of TTR of RPECs was silenced by TTR specific small interfering RNA and the expression of TTR was detected by using Western blotting to identify the efficacy of TTR silence. The level of vascular endothelial growth factor (VEGF) massage RNA was detected by using RT-PCR to identify the interaction between VEGF and TTR. The different proliferation and migration abilities of RMVECs with different expressions of TTR were measured by transwell system. Results: MTT assay showed that RPECs with 0 μmol/L TTR glowed faster than with 4 μmol/L TTR (t=18.08, P<0.0001). The expression level of TTR was decreased in the small interfering RNA group as compared with the negative control group (P<0.05). RT-PCR assay showed no differential expression of VEGF after the silencing of TTR (P>0.05). The transwell assay showed RMVECs with the silence of TTR proliferated more slowly than RMVECs without the treatment (t=4.901, P=0.0012), and also migrated more slowly (t=4.213, P=0.0029). Conclusions: TTR can inhibit the proliferation of RPECs and promote the proliferation and migration of RMVECs without the help of VEGF, the mechanism of which may be worth further study. (Chin J Ophthalmol, 2016, 52: 856-860).

[Current status of treatment of refractory ascites in patients with liver cirrhosis]

Ascites is a common clinical manifestation of cirrhotic portal hypertension, and about 60%-80% of cirrhotic patients develop the symptom of ascites within 10 years. Once ascites occurs, the 5-year survival rate is reduced from 80% to 50%. With the progression of liver diseases, approximately 5%-10% of patients with ascites develop refractory ascites, and the median survival time is only 6-12 months. This article reviews the definition and diagnosis of refractory ascites, evaluation of prognostic factors, and treatment regimens, including large-volume paracentesis combined with protein supplementation, transjugular intrahepatic portosystemic shunt, and liver transplantation.