bluuebunny/crossref_metadata_2025 huggingface dataset:
CORRELATES AND PREDICTORS OF DISABILITY RELATED TO CHRONIC LOW-BACK PAIN IN A NIGERIAN POPULATION
Authors: Maruf Fatai Adesina , Ani Kenneth , Akosile Christopher Olusanjo , Nwodo Obinna Dickson , Okonkwo Prosper Uchenna , Awhen Peter Agba
Published: June 2021

Purpose: Identifying factors related to low-back pain (LBP) can facilitate its management. However, information on how physical activity (PA) level, health-related quality of life (HRQoL) and anthropometric characteristics are related to LBP-associated health indices in individuals with chronic LBP (CLBP) is scarce. This study explored how PA level, HRQoL and anthropometric indices are related to CLBP-related disability in a Nigerian population.

Methods: This cross-sectional study involved 100 individuals with CLBP who were receiving treatment in physiotherapy out-patient clinics of selected tertiary hospitals, and 95 apparently healthy individuals. PA level, disability level and HRQoL were measured using standardized procedures.

Results: Disability level inversely correlated with physical component score (PCS) of HRQoL ([Formula: see text]; [Formula: see text]), mental component score (MCS) of HRQoL ([Formula: see text]; [Formula: see text]), pain intensity ([Formula: see text]; [Formula: see text]) and PA level ([Formula: see text]; [Formula: see text]), but positively correlated with duration of pain ([Formula: see text]; [Formula: see text]) among individuals with CLBP. PCS of HRQoL ([Formula: see text]; [Formula: see text]) solely accounted for 71% of the prediction of disability level.

Conclusion: PA level and HRQoL decrease with increasing CLBP-related disability with the PCS of HRQoL being mostly affected. Individuals with CLBP may need to be motivated against their health problem, and be encouraged to participate in PA.
Analytic view on N body interaction in electrostatic quantum gates and decoherence effects in tight-binding model
Authors: Pomorski Krzysztof
Published: June 2021

Analytical solutions describing quantum swap and Hadamard gate are given with the use of tight-binding approximation. Decoherence effects are described analytically for 2 interacting electrons confined by local potentials with use of tight-binding simplistic model and in Schroedinger formalism with omission of spin degree of freedom. The obtained results can be generalized for the case of [Formula: see text] electrostatically interacting quantum bodies confined by local potentials ([Formula: see text]-qubit) system representing any electrostatic quantum gate with [Formula: see text] inputs/outputs. The mathematical structure of system evolution with time is specified.
Numerical Study on Wave Attenuation of Tsunami-Like Wave by Emergent Rigid Vegetation
Authors: Qu K. , Lan G. Y. , Kraatz S. , Sun W. Y. , Deng B. , Jiang C. B.
Published: June 2021

The extreme surges and waves generated in tsunamis can cause devastating damages to coastal infrastructures and threaten the intactness of coastal communities. After the 2004 Indian Ocean tsunami, extensive physical experiments and numerical simulations have been conducted to understand the wave attenuation of tsunami waves due to coastal forests. Nearly all prior works used solitary waves as the tsunami wave model, but the spatial-temporal scales of realistic tsunamis differ drastically from that of solitary waves in both wave period and wavelength. More recent work has questioned the applicability of solitary waves and been looking towards more realistic tsunami wave models. Therefore, aiming to achieve more realistic and accurate results, this study will use a parameterized tsunami-like wave based on wave observations during the 2011 Japan tsunami to study the wave attenuation of a tsunami wave by emergent rigid vegetation. This study uses a high-resolution numerical wave tank based on the non-hydrostatic wave model (NHWAVE). This work examines effects of prominent factors, such as wave height, water depth, vegetation density and width, on the wave attenuation efficiency of emergent rigid vegetation. Results indicate that the vegetation patch can dissipate a considerable amount of the total wave energy of the tsunami-like wave. However, the tsunami-like wave has a higher total wave energy, but also a lower wave energy dissipation rate. Results show that using a solitary instead of a tsunami-like wave profile can overestimate the wave attenuation efficiency of the coastal forest.
Weather Differentials and Discount Rate Impact on Farmers’ Net Revenue: Modeling Results from Ghanaian Data Focusing on Different Agro-Climatic Zones
Authors: Dasmani Isaac , Dadzie Samuel K. N.
Published: June 2021

In most developing countries, climate variabilities and discount rate played an integral role in the decision-making of farmers, which mostly affect their net revenue. Our study employs Ricardian models to empirically verify this hypothesis using data collected from three major agro-climatic zones in Ghana. We particularly estimated the comparative effect of climate change variability, discount rate, and soil fertility; due to trade-off effect of certain farm practices in response to climate change across major climatic zones and also the fact that discount rate becomes an extremely critical issue in formulating and evaluating conservation and management policy to address climate change. The result indicates that discount rate has a positive and significant effect on the farmers’ net revenue. Further, effect of changes in temperature on food crop production and hence net revenue is more felt in the forest and savannah zones. On the other hand, an increase in rainfall has significant negative effects on crop net revenues and whole-farm net revenue, but a positive effect on net revenue of farmers in the savannah zone. We also found a significant increase in soil fertility to increase crop net revenues.
Observational Constraints on Black Hole Spin
Authors: Reynolds Christopher S.
Published: June 2021

The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Furthermore, spin can be a potent energy source for powering relativistic jets and energetic particle acceleration. In this review, I describe the techniques currently used to detect and measure the spins of black holes. It is shown that: ▪  Two well-understood techniques, X-ray reflection spectroscopy and thermal continuum fitting, can be used to measure the spins of black holes that are accreting at moderate rates. There is a rich set of other electromagnetic techniques allowing us to extend spin measurements to lower accretion rates. ▪  Many accreting supermassive black holes are found to be rapidly spinning, although a population of more slowly spinning black holes emerges at masses above [Formula: see text] as expected from recent structure formation models. ▪  Many accreting stellar-mass black holes in X-ray binary systems are rapidly spinning and must have been born in this state. ▪  The advent of gravitational wave astronomy has enabled the detection of spin effects in merging binary black holes. Most of the premerger black holes are found to be slowly spinning, a notable exception being an object that may itself be a merger product. ▪  The stark difference in spins between the black hole X-ray binary and the binary black hole populations shows that there is a diversity of formation mechanisms.

Given the array of new electromagnetic and gravitational wave capabilities currently being planned, the future of black hole spin studies is bright.
Effect of portable noninvasive ventilation on thoracoabdominal volumes in recovery from intermittent exercise in patients with COPD
Authors: Chynkiamis N. , Lane N. D. , Megaritis D. , Manifield J. , Loizou I. , Alexiou C. , Riazati S. , LoMauro A. , Bourke S. C. , Vogiatzis I.
Published: June 2021

Compared with the pursed-lip breathing technique, acute application of portable noninvasive ventilation during recovery from intermittent exercise improved end-expiratory thoracoabdominal dynamic hyperinflation (DH) in 50% of patients with COPD (DH responders). DH responders, compared with DH nonresponders, exhibited a reduction in end-expiratory thoracoabdominal DH predominantly driven by the abdominal compartment that effectively offset end-expiratory rib cage DH. The essential difference between DH responders and DH nonresponders was, therefore, in the behavior of the abdomen.
Segmentation Technology of Nucleus Image Based on U-Net Network
Authors: Fang Jie , Zhou QingBiao , Wang Shuxia
Published: June 2021

To solve the problems of rough edge and poor segmentation accuracy of traditional neural networks in small nucleus image segmentation, a nucleus image segmentation technology based on U-Net network is proposed. First, the U-Net network is used to segment the nucleus image, which stitches the feature images in the channel dimension to achieve feature fusion, and the skip structure is used to combine the low- and high-level features. Then, the subregional average pooling is proposed to improve the global average pooling in the attention module, and an attention channel expansion module is designed to improve the accuracy of image segmentation. Finally, the improved attention module is integrated into the U-Net network to achieve accurate segmentation of the nuclear image. Based on the Python platform, the experimental results show that the proposed segmentation technology can achieve fast convergence, and the mean intersection over union (MIoU) is 85.02%, which is better than other comparison technologies and has a good application prospect.
Decisions on the Orderliness and Collaborative Operation Mechanism of Each Subsystem under the Organizational Model of the Internet of Things
Authors: Cai Lingyi , Liu Wei
Published: June 2021

This paper analyzes the overall organic network system integrated by subnetworks, analyzes the network evolution process of the overall system of the Internet of Things (IoT) organization mode network, and analyzes the network through the network scale measurement, the node growth measurement, the node distribution measurement, and the node association measurement. We analyze the coordination mode of hardware resources, information resources, financial resources, human resources, organizations, and customer resources from the perspective of resource elements. And we analyze the vertical and horizontal work collaboration mode from the perspective of work activities. From the perspective of equity, two types of equity-based synergy and four types of contract-based synergy are proposed. It is proposed that the network stage of the IoT organization model is different from the previous stage of the important collaboration model, the platform-based collaborative model, which is analyzed from the coordination manager software platform and the IoT organization model infrastructure hardware platform. We use relevant data to construct a SIM model to measure the synergy of the development of the IoT industry system to quantify the overall collaborative development status of the IoT industry system. At the same time, the gray correlation analysis model GM (1, N) is used to correlate the complex system subsystems. The research results show that the development of the IoT industry has gone through a U-shaped development process from the uncoordinated stage to the coordinated development of the industrial system. Each subsystem has self-development capabilities and exhibits different interaction relationships with each other.
Model of Seismic Wave Field Excited by Horizontally Distributed Charge
Authors: Qian Xu , Zhong-Qi Wang
Published: June 2021

The amplitude‐frequency characteristics of seismic wave field excited by an explosive source can directly affect the accuracy of seismic prospecting. To reveal the laws by which the horizontally distributed charge excites the amplitude‐frequency characteristics, a method to calculate seismic wave field excited by horizontally distributed charge was studied in this paper. By taking the spherical cavity source model as the basis, the superposition method was applied to obtain the approach of calculating seismic wave field excited by horizontally distributed charge. Compared with numerical simulation, the error of this method was controlled under 7%. As a matter of fact, the distributive charge can effectively reduce the impact on ground vibration and increase the downward seismic wave energy. The charges that are horizontally distributed with 1 m interval can enhance the seismic wave resolution excited by explosive source. The research shows that the established theoretical model can correctly describe the amplitude‐frequency characteristics of the seismic wave field excited by horizontally distributed charges.
An Efficient Decision Support System for the Selection of Appropriate Crowd in Crowdsourcing
Authors: Huang Yongjun , Nazir Shah , Wu Jiyu , Hussain Khoso Fida , Ali Farhad , Khan Habib Ullah
Published: June 2021

Crowdsourcing is a complex task‐solving model that utilizes humans for solving organizational specific problems. For assigning a crowdsourced task to an online crowd, crowd selection is carried out to select appropriate crowd for achieving the task. The efficiency and effectiveness of crowdsourcing may fail if irrelevant crowd is selected for performing a task. Early decisions regarding selection of a crowd can ultimately lead to successful completion of tasks. To select most appropriate crowd from crowdsourcing, this paper presents a decision support system (DSS) for appropriate selection of crowd. The system has been implemented in the Superdecision tool by plotting hierarchy of goals, criteria, and alternatives. Various calculations have been done for performing the proposed research. Results of the study reveal that the proposed system is effective and efficient for selection of crowd in crowdsourcing by performing various pairwise computation of the study.
Rail Corrugation of High‐Speed Railway Induced by Rail Grinding
Authors: Du Xing , Jin Xuesong , Zhao Guotang , Wen Zefeng , Li Wei
Published: June 2021

Rail corrugation is a common railway defect that involves diverse and complex factors. Rail grinding is also the most commonly used method to address corrugations. Through numerous irregularity tests and one‐third octave frequency spectrum analyses, this study determined the characteristics and development process for rail corrugation on high‐speed rail tracks. The vibration transmission properties of the grinding train were tested using the force hammer impacting method. Thereafter, using a simulation, the influence of the vertical vibration behavior of the grinding stone and the stiffness of the hydraulics were determined. Through a series of field tests and numerical simulations, this study revealed a clear correlation between rail corrugation and rail grinding and confirmed that the technical operation of rail grinding is closely associated with regular grinding marks at a wavelength of approximately 60 mm on rail surfaces. The combination of the natural vibration of the grinding stone (frequency of 60 Hz) and an inappropriate operational process can aggravate the grinding marks on the rail surfaces, thereby forming an initial excitation of rail corrugation. Although a large number of irregularity tests are performed after rail grinding, these wavelength‐fixing grinding marks can cause the formation and development of rail corrugation. Suggestions for improving the high‐speed rail‐grinding technology are also provided.
Weighted Gene Coexpression Network Analysis to Construct Competitive Endogenous RNA Network in Chromogenic Renal Cell Carcinoma
Authors: Chen Yong-Bo , Gao Liang , Zhang Jin-Dong , Guo Jiang , You Ping-Hong , Tang Liang-You , Liu Ying-Wen
Published: June 2021

Aim. This study is aimed at constructing the competing endogenous RNA (ceRNA) network in chromophobe renal cell carcinoma (ChRCC). Methods. Clinical and RNA sequence profiles of patients with ChRCC, including messenger RNAs (mRNAs), microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), were obtained from The Cancer Genome Atlas (TCGA) database. “edgeR” and “clusterProfiler” packages were utilized to obtain the expression matrices of differential RNAs (DERNAs) and to conduct gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Weighted gene coexpression network analysis (WGCNA) was performed to screen the highly related RNAs, and miRcode, StarBase, miRTarBase, miRDB, and TargetScan datasets were used to predict the connections between them. Univariate and multivariate Cox proportional hazards regressions were performed in turn to elucidate prognosis‐related mRNAs in order to construct the ceRNA regulatory network. Results. A total of 1628 DElncRNAs, 104 DEmiRNAs, and 2619 DEmRNAs were identified. WGCNA showed significant correlation in 1534 DElncRNAs, 98 DEmiRNAs, and 2543 DEmRNAs, which were related to ChRCC. Fourteen DEmiRNAs, 113 DElncRNAs, and 43 DEmRNAs were screened. Nine mRNAs (ALPL, ARHGAP29, CADM2, KIT, KLRD1, MYBL1, PSD3, SFRP1, and SLC7A11) significantly contributed to the overall survival (OS) of patients with ChRCC (P < 0.05). Furthermore, two mRNAs (CADM2 and SFRP1) appeared to be independent risk factors for ChRCC. Conclusion. The findings revealed the molecular mechanism of ChRCC and potential therapeutic targets for the disease.
Detection of Static and Dynamic Stereopsis after Femtosecond Laser Small Incision Lenticule Extraction for High Myopia
Authors: Xiang Aiqun , Hang Chu , Wu Xiaoying , Yin Yewei , Fu Yanyan , Lu Ying , Du Kaixuan , Hu Tu , Yan Li , Wen Dan
Published: June 2021

Purpose. The purpose of this study is to test binocular visual function after femtosecond laser small incision lenticule extraction (SMILE) for high myopia. The traditional Titmus stereotest and dynamic stereotest based on the visual perception biological model were used for comparative analysis. Methods. A total of 43 patients were enrolled in this prospective study. At Week 1, Month 1, and Month 3 after surgery, the Titmus stereotest and dynamic stereotest generated by MATLAB were conducted. Dynamic stereopsis consists of randomly flickering Gabor spots and is divided into two models of high energy and low energy according to flicker frequency. Results. The preoperative manifest refraction spherical equivalent was −7.21 ± 0.70 D. The preoperative anisometropia was 0.52 ± 0.54D. The quartiles of static stereoacuity in preoperation and 3 follow-ups were as follows: 50.00 (25.00, 100.00) in preoperation, 63.00 (40.00, 63.00) at Week 1, 40.00 (32.00, 63.00) at Month 1, and 40.00 (25.00, 50.00) at Month 3. Static stereopsis improved at Month 1 and Month 3 compared with preoperation and Week 1 (

P
<
0.05

). There were statistically significant differences in high energy dynamic stereopsis at Week 1 and Month 1 compared to preoperation (

P
<
0.05

). In addition, significant differences in low energy dynamic stereopsis were detected between Month 1 and preoperation and also at Month 3 compared to Month 1 (

P
<
0.05

). Conclusion. Most high myopia patients have a dynamic stereopsis deficiency before refractive correction. SMILE surgery can improve both static and dynamic stereopsis early in the postoperation period. However, in the long term, there is no significant difference or even a decrease in dynamic stereopsis.
Reliability and Sensitivity Analysis of a Repairable System with Warranty and Administrative Delay in Repair
Authors: El-Sherbeny Mohamed S. , Hussien Zienab M.
Published: June 2021

The purpose of this study is to analyze the behavior of some industrial systems in light of the cost-free warranty policy. According to this policy, we assume that the repairman is not always present in the system. When the active unit fails, the repairman will be called to visit the system; however, administrative procedures may delay the visit for some time. Once on the system, the repairman first inspects whether the fault is caused by the user or not and whether it is repairable or not. According to product warranty laws, the repairman carries out the repair or replacement of the faulty unit. The failure time, administrative delay time, inspection time, and repair time are assumed taken as a negative exponential distribution. The system model is analyzed by the supplementary variable technique and Laplace transform, as various performance metrics of system efficiency have been obtained. The sensitivity and relative sensitivity analyses for the system parameters have also been performed. Finally, an illustrative example is taken to illustrate the efficiency of the system.
Physical Layer Secrecy Analysis of Multihop Hybrid Satellite‐Terrestrial Relay Networks with Jamming
Authors: Wang Xiaoqi , Zhang Hanwei , Hou Zheng
Published: June 2021

This paper explores the secrecy analysis of a multihop hybrid satellite‐terrestrial relay network (HSTRN) with jamming, where one satellite source is aimed at communicating with destination users via multihop decode‐and‐forward (DF) terrestrial relays, in the existence of an eavesdropper. All the destination users are deployed randomly following a homogeneous Poisson point process (PPP) based on stochastic geometry. Each relay operates not only as a conventional DF relay to forward the received signal but also as a jammer to generate intentional interference to degrade the eavesdropper link, considering shadowed‐Rician fading for legitimate link and wiretap link while Rayleigh fading for jamming link. To characterize the secrecy performance of the considered network, the accurate analytical expression for the secrecy outage probability (SOP) is derived. In order to reveal further insights on the achievable diversity order of the network, the asymptotic behavior of SOP expression at high signal‐to‐noise ratio (SNR) region is deduced. Moreover, the throughput of the system is discussed to characterize the secrecy performance. Finally, the theoretical results are validated through comparison with simulation results and show that (1) the secrecy performance of the considered network gets better with the decreasing of the hops and with the decreasing severity of the channel fading scenario, (2) the relay of the network operating as a jammer can provide better secrecy performance without extra network resources, and (3) small hops and high SNR can yield to high throughput of the system.
Capnocytophaga canimorsus Bloodstream Infection Associated with an Urticarial Exanthem
Authors: Goetzinger John C. , LaGrow Austin L. , Shibib Dena R. , Thind Sharanjeet K.
Published: June 2021

Background. Capnocytophaga canimorsus is a fastidious, slow-growing, Gram-negative rod that is a commensal bacterium in normal gingival flora of canine and feline species. Infection with the organism may cause disease ranging from flu-like symptoms to disseminated intravascular coagulation (DIC), fulminant sepsis, meningitis, and endocarditis with an overall fatality rate of 6–26%. Risk factors for infection from C. canimorsus include immunosuppression, alcoholism, and asplenia. Case Presentation. We describe an unusual case with a relatively indolent clinical course and an urticarial exanthem in an otherwise young immunocompetent patient with a history of type 1 diabetes. The patient presented to the Emergency Department (ED) with a <1-day history of rhinorrhea, fever, and dyspnea. He met sepsis criteria on initial presentation, but left against medical advice and returned to the ED the following day, with new arthralgias and a diffuse rash, multiple erythematous, tender macules scattered across his trunk and extremities, and tonsillar erythema. He had not taken the doses of the prescribed amoxicillin. Blood cultures two days later signaled positive for growth with the Gram stain showing a Gram-negative rod. Three 7-8 cm tender targetoid lesions with central clearing were identified on the patient’s back. The patient reported two nonengorged ticks crawling on his body a week prior and sustaining a dog bite to his ear three weeks before presentation. Ultimately, the organism was identified as C. canimorsus through MALDI-TOF mass spectrometry and additional biochemical testing. He was given appropriate antibiotics and improved clinically thereafter. Despite the patient’s bacteremia, he never progressed to fulminant sepsis and followed a mild clinical course with several unusual characteristics. C. canimorsus is an uncommon cause of illness in humans, but is an important pathogen to consider when evaluating a patient with a dog bite, known risk factors, and an urticarial exanthem as empiric treatment may prevent severe outcomes.
Wearable, Multimodal, Biosignal Acquisition System for Potential Critical and Emergency Applications
Authors: Lin Chin-Teng , Wang Chen-Yu , Huang Kuan-Chih , Horng Shi-Jinn , Liao Lun-De
Published: June 2021

For emergency or intensive-care units (ICUs), patients with unclear consciousness or unstable hemodynamics often require aggressive monitoring by multiple monitors. Complicated pipelines or lines increase the burden on patients and inconvenience for medical personnel. Currently, many commercial devices provide related functionalities. However, most devices measure only one biological signal, which can increase the budget for users and cause difficulty in remote integration. In this study, we develop a wearable device that integrates electrocardiography (ECG), electroencephalography (EEG), and blood oxygen machines for medical applications with the hope that it can be applied in the future. We develop an integrated multiple-biosignal recording system based on a modular design. The developed system monitors and records EEG, ECG, and peripheral oxygen saturation (SpO2) signals for health purposes simultaneously in a single setting. We use a logic level converter to connect the developed EEG module (BR8), ECG module, and SpO2 module to a microcontroller (Arduino). The modular data are then smoothly encoded and decoded through consistent overhead byte stuffing (COBS). This developed system has passed simulation tests and exhibited proper functioning of all modules and subsystems. In the future, the functionalities of the proposed system can be expanded with additional modules to support various emergency or ICU applications.
Multiplicity Solutions of Fractional Impulsive
p
-Laplacian Systems: New Result
Authors: Guefaifia Rafik , Abdalla Mohamed , Bouali Tahar , Kamache Fares , Cherif Bahri Belkacem , Mekawy Ibrahim
Published: June 2021

In this paper, the existence of multiplicity distinct weak solutions is proved for differentiable functionals for perturbed systems of impulsive nonlinear fractional differential equations. Further, examples are given to show the feasibility and efficacy of the key findings. This work is an extension of the previous works to Banach space.
Network Public Opinion Monitoring System for Agriculture Products Based on Big Data
Authors: Liu He , Yu Zekun , Zhong Xiangzhi , Yu Helong
Published: June 2021

The influence of online public opinion on agricultural product safety on the society is increasing. In order to correctly guide the direction of online public opinion on agricultural products, help the agricultural sector turn from passive to active public opinion, timely prevent the spread of negative public opinion, and reduce the negative impact on public opinion hot events, it is especially important to improve the ability of monitoring agricultural products’ network public opinion. This research is based on big data technology to develop an agricultural products’ network public opinion monitoring system that can collect, process, and analyze data in real time, discover and track hot topics, and calculate and visualize the polarity of public sentiment. The use of big data technology to increase the processing speed aims to strengthen the public’s supervision of the public opinion on the network security of agricultural products and provide an effective basis of the decision-making of relevant departments.
Abstract A37: Mapping KRAS signaling pathways using the Mammalian-Membrane Two-Hybrid (MaMTH) assay to elucidate novel therapeutic targets
Authors: Grozavu Ingrid Claudia , Snider Jamie , Lyakisheva Anna , Stagljar Igor
Published: June 2021

Background: KRAS is a well-established cancer driver. Clinically successful therapeutics have not yet been developed despite its disease burden, suggesting that KRAS-driven cancers are more complicated than previously thought.

Aim: Our goal is to identify the global changes in KRAS interaction patterns that occur in disease states. This is accomplished by mapping the dynamic interactome of both WT and oncogenic KRAS isoforms using the Mammalian Membrane Two-Hybrid (MaMTH) assay, which is suitable for identification of protein interactors of virtually any integral membrane or membrane-associated protein.

Methods: To probe the protein-protein interactions (PPIs) of KRAS, we used the Mammalian Membrane Two-Hybrid (MaMTH) assay, a split-ubiquitin-based two-hybrid system that can be applied to any cell line. This assay is suited for PPI detection using both low- to-medium throughput array and high-throughput large-scale PPI screening. We generated stably expressing “bait”-tagged KRAS constructs in HEK293T cells that contained the MaMTH reporter system. KRAS baits, namely KRAS-WT, -G12D, -G12V, and -Q61H, were characterized using signaling assays as well as within the MaMTH system using “prey”-tagged CRAF interaction control, Western blotting, and immunofluorescence techniques. Currently, we are performing unbiased screening for PPIs of KRAS using the human ORFeome (hORFeome) library consisting of approximately 13,000 fully sequenced human ORFs.

Results: We first validated compatibility of KRAS in the MaMTH assay through several means. Oncogenic KRAS variants showed increased interaction signal with CRAF (a known KRAS binding partner) compared to KRAS-WT. This corresponded with upregulated MAPK pathway activation by oncogenic KRAS, as determined from increased pERK levels via Western blotting. KRAS bait expression levels were similar across all variants, suggesting that these findings were not due to differential expression of KRAS isotypes. Additionally, we confirmed that the KRAS bait correctly localizes to the plasma membrane, consistent with previous literature. After establishing KRAS compatibility with the MaMTH assay, we have begun unbiased screening of the hORFeome against KRAS baits in the WT, G12D, G12V, and Q61H isoforms.

Conclusions: We have characterized KRAS compatibility with the MaMTH assay. Currently, we are performing large screening protocols for high-throughput detection of PPIs of KRAS using MaMTH.

Citation Format: Ingrid Claudia Grozavu, Jamie Snider, Anna Lyakisheva, Igor Stagljar. Mapping KRAS signaling pathways using the Mammalian-Membrane Two-Hybrid (MaMTH) assay to elucidate novel therapeutic targets [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr A37.
Abstract A43: Investigating novel inhibitors of the IMP-1-KRAS mRNA interaction
Authors: Liu Victor , Wang Chuyi , Lee Chow
Published: June 2021

K-Ras functionality is integral for cell growth and differentiation due its canonical role in signaling the PI3K and MAPK pathways. Genetic analysis on various cancers revealed that mutations in the K-Ras gene are responsible for 21% of all cases, which include lung, pancreatic and colorectal cancer. Prior efforts at directly targeting mutant K-Ras have been largely unsuccessful, thus creating a demand for novel therapeutic approaches. Common to the aforementioned cancers is expression of the Insulin-Like Growth Factor 2 mRNA Binding Protein 1 (IMP-1). IMP-1 is part of the VICKZ family of RNA-binding proteins known for post-transcriptional regulation, including its ability to shield its mRNA substrates from decay. One notable substrate of IMP-1 is the K-Ras mRNA, which was identified using UV-crosslinking experiments. Downregulation of IMP-1 through siRNA treatment led to a reduction of K-Ras protein by 60% in SW480 colorectal cancer cells and consequently reduced cell proliferation. The studies suggest a relationship between IMP-1 binding, mRNA turnover and the resultant protein expression of target substrates. To study the IMP-1-mRNA relationship and to help find inhibitors of such interaction, we developed a fluorescence polarization (FP) method that employed 45-nt K-Ras and 39-nt CD44 fluorescein-labeled RNA probes. Using full-length IMP1, truncated and point-mutated IMP1, we showed that the FP method faithfully recapitulated the relative affinity of recombinant proteins for both K-Ras and CD44 RNAs. The FP method was then used to find inhibitors of the IMP-1-K-Ras mRNA interaction and to elucidate potential domain target of inhibitors. We found that oligonucleotides SM6 and SM7, but not SM2, could significantly reduce the FP units, consistent with the results from electrophoretic mobility shift assay. In addition, the molecule UNBC143 was found to decrease FP units in a dose-dependent manner, suggesting its ability to inhibit IMP-1-K-Ras RNA interaction. The SM oligonucleotides and UNBC143 were also assessed on K-Ras expression in SW480 human colon cancer cells. These experiments and their results will be discussed in further detail upon presentation.

Citation Format: Victor Liu, Chuyi Wang, Chow Lee. Investigating novel inhibitors of the IMP-1-KRAS mRNA interaction [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr A43.
Abstract A45: Protective autophagy elicited by RAF→MEK→ERK inhibition suggests a treatment strategy for RAS-driven cancers
Authors: Kinsey Conan G. , Camolotto Soledad A. , Boespflug Amelie M. , Gullien Katrin P. , Foth Mona , Shea Jill E. , Seipp Michael T. , Yap Jeffrey T. , Burrell Lance D. , Lum David H. , Whisenant Jonathan R. , Gilcrease Weldon , Cavalieri Courtney C. , Rehbein Kaitrin M. , Cutler Stephanie L. , Affolter Kajsa E. , Welm Alana L. , Welm Bryan E. , Scaife Courtney L. , Snyder Eric L. , McMahon Martin
Published: June 2021

Pancreatic ductal adenocarcinoma was responsible for ~43,000 deaths in the USA in 2017 and is the epitome of a recalcitrant cancer driven by a pharmacologically intractable oncoprotein, KRAS. Although the clinical picture remains grim, the mechanisms by which key alterations in tumor suppressors and proto-oncogenes contribute to PDA have been dissected. Downstream of KRAS, the RAF→MEK→ERK signaling pathway plays a central role in pancreatic carcinogenesis. However, to date, pharmacologic inhibition of this pathway has provided no clinical benefit to PDA patients. Here we show that inhibition of KRAS→RAF→MEK→ERK signaling in PDA cell lines elicits autophagy, a process of cellular recycling that protects pancreatic cancer cells from the potentially cytotoxic effects of KRAS pathway inhibition. Furthermore, combined inhibition of MEK1/2 plus autophagy displays synergistic antiproliferative effects against PDA cell lines in vitro, and promotes regression of xenografted patient-derived PDA tumors in mice. Finally, treatment of a KRAS-mutated PDA patient on a compassionate basis with the combination of trametinib plus hydroxychloroquine resulted in a partial but nonetheless striking disease response. These data suggest that this combination therapy may represent a new strategy to target RAS-driven cancers such as PDA.

Citation Format: Conan G. Kinsey, Soledad A. Camolotto, Amelie M. Boespflug, Katrin P. Gullien, Mona Foth, Jill E. Shea, Michael T. Seipp, Jeffrey T. Yap, Lance D. Burrell, David H. Lum, Jonathan R. Whisenant, Weldon Gilcrease, Courtney C. Cavalieri, Kaitrin M. Rehbein, Stephanie L. Cutler, Kajsa E. Affolter, Alana L. Welm, Bryan E. Welm, Courtney L. Scaife, Eric L. Snyder, Martin McMahon. Protective autophagy elicited by RAF→MEK→ERK inhibition suggests a treatment strategy for RAS-driven cancers [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr A45.
Abstract B07: Inhibition of Ras signalling by targeting Son of Sevenless with Affimers
Authors: Saunders Sophie E. , Tiede Christian , Edwards Thomas , Breeze Alexander , Tomlinson Darren
Published: June 2021

Mutations in Ras result in increased signaling through the MAPK pathway, resulting in increased cell proliferation and survival. These activating mutations are found in 30% of all cancers, making inhibition of Ras a key therapeutic strategy. However, due to its lack of small-molecule binding pockets, Ras-based therapies have been difficult to develop, leading to the assumption it is “undruggable.” A novel method of inhibiting aberrant signaling through the MAPK pathway is to prevent the activation of Ras by inhibiting its guanine nucleotide exchange factor Sos. Our aim is to isolate and characterise Affimer reagents to aid the identification of druggable pockets on Sos. Affimer reagents are a nonantibody binding scaffold designed to mimic the binding properties of antibodies. Affimers present two variable regions for molecular recognition that have been used to probe for hot spot regions on protein surfaces. 57 Affimers have been isolated that bind to the catalytic domains of Sos; of these, 17 have been shown to inhibit Sos catalysed nucleotide exchange in vitro, a selection of which have IC50 values in the nano-molar range. We are currently studying the effects of expressing these Affimer reagents in mammalian cells on MAPK signaling, cell proliferation, survival and migration and have shown the Affimers are capable of inhibiting EGF-stimulated signaling through the MAPK pathway. Structural studies are also ongoing and will be used to determine the binding properties of the Affimers in the hope of identifying novel binding pockets on Sos and possible sites of allosteric regulation as demonstrated with anti-Ras Affimers.

Citation Format: Sophie E. Saunders, Christian Tiede, Thomas Edwards, Alexander Breeze, Darren Tomlinson. Inhibition of Ras signalling by targeting Son of Sevenless with Affimers [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B07.
Abstract B11: O-GlcNAcylation is required for mutant KRAS-induced lung tumorigenesis
Authors: Shiraishi Takumi , Tran Phuoc T. , Malek Reem , Lafargue Audrey , Barbhuiya Mustafa , Wang Xing , Simons Brian , Ballew Matthew , Nugent Katriana , Groves Jennifer , Williams Russell , Wang Hailun , Verdone James , Yildirir Gokben , Henry Roger , Zhang Bin , Wong John , Wang Ken , Nelkin Barry , Pienta Kenneth , Felsher Dean , Zachara Natasha , Taparra Kekoa
Published: June 2021

Mutant KRAS drives glycolytic flux in lung cancer, potentially impacting aberrant protein glycosylation. Recent evidence suggests aberrant KRAS drives flux of glucose into the hexosamine biosynthetic pathway (HBP). HBP is required for various glycosylation processes, such as protein N- or O-glycosylation and glycolipid synthesis. However, its function during tumorigenesis is poorly understood. One contributor and proposed target of KRAS-driven cancers is a developmentally conserved epithelial plasticity program called epithelial-mesenchymal transition (EMT). Here we showed in novel autochthonous mouse models that EMT accelerated KrasG12D lung tumorigenesis by upregulating expression of key enzymes of the HBP pathway. We demonstrated that HBP was required for suppressing KrasG12D-induced senescence, and targeting HBP significantly delayed KrasG12D lung tumorigenesis. To explore the mechanism, we investigated protein glycosylation downstream of HBP and found elevated levels of O-linked β-N-acetylglucosamine (O-GlcNAcylation) post-translational modification on intracellular proteins. O-GlcNAcylation suppressed KrasG12D oncogene-induced senescence (OIS) and accelerated lung tumorigenesis. Conversely, loss of O-GlcNAcylation delayed lung tumorigenesis. O-GlcNAcylation of proteins SNAI1 and c-MYC correlated with the EMT-HBP axis and accelerated lung tumorigenesis. Our results demonstrated for the first time that O-GlcNAcylation was sufficient and required to accelerate KrasG12D lung tumorigenesis in vivo, which was reinforced by epithelial plasticity programs.

Citation Format: Takumi Shiraishi, Phuoc T. Tran, Reem Malek, Audrey Lafargue, Mustafa Barbhuiya, Xing Wang, Brian Simons, Matthew Ballew, Katriana Nugent, Jennifer Groves, Russell Williams, Hailun Wang, James Verdone, Gokben Yildirir, Roger Henry, Bin Zhang, John Wong, Ken Wang, Barry Nelkin, Kenneth Pienta, Dean Felsher, Natasha Zachara, Kekoa Taparra. O-GlcNAcylation is required for mutant KRAS-induced lung tumorigenesis [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B11.
Abstract B18: Clostridium perfringens lethal toxin specifically targets RAS and disrupts RAS signaling pathway
Authors: Abreu-Blanco Maria , Yi Ming , Denson Jean-Paul , Holderfield Matthew
Published: June 2021

Clostridium perfringens lethal toxin (TpeL) belongs to the family of large clostridial glucosylating cytotoxins. Clostridial toxins are glucosyltransferases that modify and deactivate small GTPases of the RHO and RAS subfamily. TpeL mono-glucosylates in the switch I domain (Thr35) of RAC and RAS small GTPases. RAS family proteins function as key regulators of cell proliferation, differentiation, survival and gene expression. Moreover, mutations in RAS proteins are highly prevalent in human cancers. Considering the specificity of TpeL for RAS, we decided to investigate the biochemical interaction between TpeL and RAS, and potentially develop TpeL as a tool to disrupt the RAS signaling pathway in vivo. First, we used RAS-dependent MEFs expressing different KRAS mutations and BRAF V600E to assess the specificity of TpeL in vivo. We expected that proliferation should be inhibited in MEF cells expressing RAS isoforms, but MEF cells expressing BRAF V600E should not be affected. We found that TpeL treatment did not affect the viability of the BRAF V600E cells and only induced toxicity in RAS expressing cells. Consistent with this result, TpeL treatment inhibited MAPK signal transduction in the RAS expressing cells, but not in the BRAF V600E cells. Surprisingly, both cell viability as well as pERK levels remained unaffected in the KRAS Q61R MEF cells, suggesting that KRAS Q61R is resistant to TpeL. Furthermore, TpeL treatment of cancer cell lines shows significant differences in potency, with KRAS G12C cell lines being more sensitive to the toxin. Our cellular data suggest a correlation between TpeL sensitivity and intrinsic hydrolysis rate of the KRAS alleles. Biochemical assays corroborate our hypothesis that TpeL preferentially glucosylates KRAS GDP loaded in vitro. Moreover, TpeL glucosylation inhibits GEF-mediated nucleotide exchange, effectively blocking KRAS on the GDP inactive state. To further follow up the correlation between KRAS GDP levels and TpeL sensitivity, we used a combination treatment of TpeL and EGFR/FGFR inhibitors. Combination screen shows a synergistic effect; we observed increased TpeL sensitivity in combination with the inhibitors. By elucidating the mechanism of substrate binding and substrate specificity, we have gained insight into the TpeL-RAS interaction and we are working on developing the toxin as a therapeutic tool.

Citation Format: Maria Abreu-Blanco, Ming Yi, Jean-Paul Denson, Matthew Holderfield. Clostridium perfringens lethal toxin specifically targets RAS and disrupts RAS signaling pathway [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B18.
Abstract B28: Direct targeting oncogenic Ras mutants by IgG-format cytosol-penetrating antibody
Authors: Shin Seung-Min , Kim Ji-Sun , Hong Jin-Sun , Park Seong-wook , Jun Sei-Yong , Kweon Hye-Jin , Choi Dong-Ki , Kim Yong-Sung
Published: June 2021

Oncogenic Ras mutants, and most frequently KRas mutants (86% of Ras-driven cancers), are found in approximately 25% of human cancers and are high-priority anticancer drug targets. Despite 30 years of effort to develop drugs that directly target oncogenic Ras mutants, no effective pharmacologic inhibitors for these mutants are clinically available, mainly because of the lack of suitable surface binding pockets for small molecules. More than 50 therapeutic antibodies have been clinically approved against many extracellular proteins. However, such antibodies do not have the capacity to localize in intracellular cytosolic regions after receptor-mediated endocytosis, restricting their therapeutic application for targeting cytosolic proteins. Our group recently developed a platform technology of cytosol-penetrating antibody, which in the IgG format can reach the cytosolic space of living cells owing to its endosomal escaping ability after receptor-mediated endocytosis. Exploiting the cytosol-penetrating antibody technology, we have engineered a human IgG1 format antibody, named iMab (internalizing and protein-protein interaction [PPI] interfering monoclonal antibody), which internalizes into the cytosol of living cells and selectively binds to the activated GTP-bound form of oncogenic Ras mutants. iMab specifically binds to the PPI interfaces of activated Ras with effector proteins to block the associations, thereby inhibiting the Ras downstream oncogenic signaling and exerting antiproliferation effects on oncogenic Ras mutant tumor cells. For in vivo antitumor efficacy assessment, we further engineer iMab to have tumor tissue-homing ability by fusion of tumor-associated integrin αvβ3/αvβ5 binding cyclic peptide to the N-terminus of light chain. When systemically administered, the iMab variant significantly inhibited the in vivo growth of oncogenic Ras-mutated tumor xenografts in mice, but not wild-type Ras-harboring tumors. Our results demonstrate the feasibility of developing antibody therapeutics that directly target cytosolic proteins involved in disease-associated PPIs, such as oncogenic Ras mutants, by systemic administration, similar to conventional therapeutic antibody regimens. Because the oncogenic Ras targeting antibody holds many desirable features of the conventional IgG antibody, it shows great potential for development as a first-in-class anticancer antibody.

Citation Format: Seung-Min Shin, Ji-Sun Kim, Jin-Sun Hong, Seong-wook Park, Sei-Yong Jun, Hye-Jin Kweon, Dong-Ki Choi, Yong-Sung Kim. Direct targeting oncogenic Ras mutants by IgG-format cytosol-penetrating antibody [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B28.