Thank you for considering to present your work as a poster at Aptamers 2019.
Please prepare your poster in A1 portrait format (59cm wide x 84cm long). Please do not laminate your poster or use heavy printing material. Further information about poster sizes can be found on the following link:
Posters larger than A1 will only be displayed subject to the availability of space.
Maximum capacity 30 A1 posters
Please ensure you have appropriate permissions for the publication of your abstract from the original copyright holders. Should you wish your abstract not to be published, please notify us in writing at the time of abstract submission.
Invitation to submit an article to the journal AptamersWe invite you to submit your research to the journal Aptamers (ISSN: 2514-3247), which is a new official open-access journal of the International Society on Aptamers, dedicated to publishing peer-reviewed research and reviews on all aspects of aptamer research.
We are happy to waive basic open access publication fee until 30 September 2019 for Aptamers 2019 delegates, as long as the manuscripts are prepared according to the guidelines for authors.
If your abstract has been accepted for presentation but it does not appear in the list below, please let us know as soon as possible by email on aptamersoxford@gmail.com.
(Presenter in bold)
Selective Targeting of Melanoma Biomarkers with DNA Aptamers (+F)
Shujaat Ali1, Aya Abouhammoud2, Frédéric Saltel2, Jean J Toulmé1 and Laurent Azéma1
1 ARNA Laboratory, Inserm U1212, CNRS UMR5320, University of Bordeaux, Bordeaux, France
2 Univ. Bordeaux, Inserm U1053, Bat 1A, 146 rue Léo Saignât, 33076 Bordeaux, France
Aptamers are oligonucleotides obtained by a powerful combinatorial method known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX), with high affinity and specificity towards its target with KD in low nanomolar range. Aptamers are generated against a wide variety of targets. It binds to its targets through 3D conformational structural forms with high affinity and specificity. Discoidin Domain Receptors(DDR) has been proposed as a marker of tumor proliferation and invasion in melanoma. Our collaborators demonstrated that DDR1 and DDR2 are over-expressed in A375 cells (melanoma cells) in comparison to primary human melanocytes…
Development of a LSPR apatasensor for the Detection of β-lactoferrin allergens
Jon Ashley1, Marta Prado1
1 Food Quality and Safety Research group, Nano4Food Unit, Department of Life Sciences, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
The prevalence of individuals sensitised to food allergies has become a major health concern worldwide over the last few decades. Within a food manufacturing environment, the effective control of food allergen containing ingredients can be difficult due to large number of ingredients handled, and multiple food batches made on each line which has led to an increased risk of cross contamination of food allergens. As a result, food manufacturers have adopted precautionary labelling to warn sensitised individuals that food products may contain or may have come into contact with allergen containing ingredients. Therefore, more reliable and robust analytical methods for the detection of allergens in food products as well as reliable methods for the validation of food processing equipment needs to be adopted. Biosensors have shown great potential as analytical devices for food monitoring due to their low cost, potential for miniaturization and versatility…
Aptamers as diagnostic probes for precision oncology
Michelle L Bauer, Alister C Ward, Sarah L Shigdar
School of Medicine, Centre for Molecular and Medical Research, Deakin University, Geelong, VIC, 3216, Australia
Recent years have seen intense appreciation for the heterogeneous and dynamic nature of solid tumours. Consequently, the field of therapeutic oncology has seen a swift evolution away from a ‘one-size-fits-all’ approach, toward the relatively tailor-made approach that is precision oncology. However, in order to realise the full potential of individualised treatment strategies, there is urgent need for sensitive, specific and precise methods of sampling tumour heterogeneity at the molecular level. Aptamers represent a promising alternative to traditional antibodies for the detection of clinically-relevant tumour biomarkers due to their relatively small size, ease of functionalisation and low batch-to-batch variability. Using aptamers against the cancer stem cell-associated membrane proteins, EpCAM and CD133, we utilised ‘aptahistochemistry’ to identify this highly invasive subpopulation of tumour cells by a chromogenic, sequential double-staining technique in FFPE colorectal carcinoma xenografts…
Generation of Aptamers Using SELEX for Detection of Lucentis on Microfluidic Chip
Tanu Bhardwaj, Sandeep K Jha
Centre for Biomedical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi-110016, India
In this work, we are reporting a low-cost disposable microfluidic chip with SELEX(Systematic evolution of ligands by exponential enrichment) generated aptamer as biorecognition molecule for inline monitoring of lucentis in fermentors. Lucentis is a therapeutic protein injected as a drug into eye of a patient to treat a disease called age related macular degeneration. Presently, the available techniques for detection of lucentis in fermentors are offline monitoring techniques like HPLC(High pressure liquid chromatography), protein-L assays and chromatography. Due to longer detection time and higher expense of HPLC, and non-specificity of protein-L methods, there is a huge demand of a low cost device for inline monitoring of lucentis specifically in fermentors. For this, we generated a specific aptamer for lucentis using SELEX. In SELEX, for binding step, we immobilised lucentis on sepharose beads as matrix in a glass column and performed affinity chromatography with random ssDNA sequences. Then, for elution, combination of various techniques like salting out, pH change and heat were applied to get a pool of specific aptamers for lucentis…
Development of Plant Cell-Internalizing Aptamers by Cell-SELEX (+F)
Federico Bosetto, Pierfrancesco del Mestre, Laura Pagliari, Marta Martini, Giuseppe Firrao
Department of Agricultural, Food, Environmental and Animal Sciences (DI4A), University of Udine, Udine, Italy
Cell-SELEX is a method with widespread applications in the human health field such as targeted therapy, detection and diagnosis. Conversely, as little work has been done in developing aptamers for applications in the plant field, Cell-SELEX has never been applied to plant cells to our knowledge. In this work, starting from a DNA library with a random region of 20 nucleotides, we used Cell-SELEX to select cell-internalizing aptamers, with Arabidopsis thaliana mesophyll protoplasts as target. A first step was dedicated to adapt the buffers used to sustain the protoplasts, to fulfil the SELEX requirements as washing and binding buffers. The Cell-SELEX protocol was designed to recover potential aptamers either binding the protoplast membrane or internalizing into cell cytoplasm. Five rounds of Cell-SELEX were performed and the selection was monitored using a combined strategy dependent on quantitative polymerase chain reaction (qPCR) amplification curve and high resolution melting (HRM) curve analysis: an actual aptamer class selection…
Development of Aptamer-Field-Effect Transistor Sensors: Towards Point of Care
Kevin M Cheung,1,2 Nako Nakatsuka,1,2 Kyung-Ae Yang,3 Chuanzhen Zhao,1,2 Hongyan Yang,5 Paul S Weiss,1,2 Milan N Stojanović,3,4 and Anne M Andrews1,2,5
1 California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, United States
2 Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, United States
3 Division of Experimental Therapeutics, Department of Medicine, Columbia University, New York, New York, United States
4 Biomedical Engineering and Systems Biology, Columbia University, New York, New York, United States
5 Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, and Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, California, United States
We have designed and developed ultrathin-film field-effect transistors (FETs) coupled to rationally designed and chemically synthesized oligonucleotide sequences with molecular recognition capabilities, termed aptamers, for the detection of a diverse range of biologically important small-molecule targets (e.g., neurotransmitters, amino acids, sugars, lipids). Upon target capture, aptamers undergo conformational changes that redistribute charge densities on FET surfaces resulting in measurable changes in conductance. We demonstrate detection of targets in full ionic strength biological fluids, with high specificity and selectivity, over a dynamic range of concentrations with ultra-low detection limits. Using this platform, we are developing sensors for the direct detection of the amino acid phenylalanine for potential point-of-care use for patients with phenylketonuria (PKU), a common genetic disorder that results in elevated and potentially harmful levels of phenylalanine in the blood and brain. Three phenylalanine-specific DNA sequences were investigated to determine sensor responses contingent on different primary base sequences, secondary structures, and target affinities…
Selection and structural analysis of cubane-modified aptamers for targeting Plasomdium vivax lactate dehydrogenase
Yee-Wai Cheung1, Pascal Röthlisberger2, Ariel Mechaly2, Alvin Wai-Chung Wong1, Patrick Weber, Fabienne Levi-Acobas2, Achmed Haouz2, Paul Savage2, Marcel Hollenstein2 and Julian A. Tanner 1*
1School of Biomedical Sciences, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong
2Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris CEDEX 15, France
Incorporating unnatural nucleobases to aptamer evolution significantly enlarge the chemical and structural diversities of the evolved DNA aptamers. Previously, we have identified and structural elucidated a DNA aptamer that specifically target Plasmodium falciparum lactate dehydrogenase (PfLDH), a biomarker for diagnosing malaria. However, the identification of P. vivax LDH specific aptamer still remains a major challenge due to the similarity between the structures of PvLDH and other Plasomdium LDHs. Herein, we demonstrate the evolution of aptamer that consists of cubane-modified deoxyuridine triphosphate (dUcTP) instead of deoxythymidine triphosphate (dTTP), and coined this “cubamer”. The specificity of the identified cubamer was determined by using surface plasmon resonance and electrophoretic mobility shift assay…
Characterization of the Ochratoxin-A-binding aptamer and binding to its ligand
Zachary R Churcher, Sladjana Slavkovic, Aron A Shoara, Philip E Johnson
NMR spectroscopy, isothermal titration calorimetry (ITC), and UV-Vis spectroscopy are being used to investigate the interaction between the ochratoxin-A-binding aptamer (OTA) and its ligand ochratoxin-A. Ochratoxin A is a mycotoxin produced by certain types of Penicillium and Apsergillus fungi. Found in grain, pork and a number of other sources, Ochratoxin-A is one of the most abundant food contaminating mycotoxins. Ochratoxin-A is a strong neurotoxin thought to deplete dopamine levels in brain and may be weakly mutagenic causing oxidative damage to DNA. The OTA aptamer is predicted to be a monomolecular antiparallel G-quadruplex with a two G-tetrad core, and two tails extending from the same face of the quadruplex…
Magnetic sorting of tumour cells with attached magnetic nanoparticles in a microchannel
Petr Denissenko1, Ivan Denisov2,3, Vasily Kantsler1, Olga Kolovskaya2,3, Galina Zamay2,3, Sergey Zamay2, Anna Kichkailo2,3
1 University of Warwick, Coventry, CV4 7AL, UK
2 Federal Research Center ”Krasnoyarsk Science Center” SB RAS, Russia
3 Krasnoyarsk State Medical University named after prof. Voino-Yaseneckii, Russia
Biohybrid nanostructures consisting of aptamers and magnetic nanoparticles are promising tools for diagnostics and treatment of oncological diseases. It has recently been shown that gold-covered and aptamer-functionalised magnetic nanoparticles provide anti-inflammatory effect by magnetomechanic destruction of cells in low-intensity magnetic fields. For the magnetomechanic therapy to be efficient, the aptamers must possess affinity to tumour cells of the particular patient. To evaluate affinity of the aptamers, we use microfluidic chips in which cells with attached magnetic nanoparticles are being sorted in gradients of magnetic field…
Aptamer-mediated targeted treatment of human glioblastoma xenotransplanted in immunocompromised mice
Arsenii Bashkov3, Anna Blagodatova3, Petr Denissenko1, Evgeniy E. Erakhtin4, Yury E. Glazyrin2,3, Igor Grinev4, Anna Kichkailo2,3, Andrey K. Kirichenko3, Olga Kolovskaya2,3, Maria Komarova3, Evgenii Morozov2, Andrey Narodov3,4, Dmitry V. Veprintsev2, Galina Zamay2,3, Tatiana Zamay2,3
1 School of Engineering, University of Warwick, Coventry, CV4 7AL, UK
2 Federal Research Center ”Krasnoyarsk Science Center” SB RAS, Russia
3 Krasnoyarsk State Medical University named after prof. Voino-Yaseneckii, Russia
4 Krasnoyarsk Inter-District Ambulance Hospital named after N.S. Karpovich, Krasnoyarsk, Russia
Glioblastoma is a primary brain tumour with a high mortality rate due to its malignancy. High invasion of tumour cells into the surrounding tissues makes complete resection of this tumour impossible. Chemo and radiation therapy are inefficient for glioblastoma treatment. Despite immunotherapy with the antibodies However, it turned out that, in some cases, antibodies are toxic, do not reach adequate specificity, and have low permeability across the blood-brain barrier. All mentioned above stimulated the search for new alternative methods and means of targeted glioblastoma therapy. In this work as an alternative to protein antibodies, DNA aptamers have been used to treat glioblastoma xenotransplanted in immunocompromised mice…
Introduction of stabilizing ‘staples’ to increase robustness of aptamer sequences (+F)
Anne-Mare de Vries1,2, Lars Verdonck2, Dieter Buyst1,3, Annemieke Madder2, José C. Martins1
1 NMR and structure analysis group, Ghent University, Krijgslaan 281 S4 9000 Ghent, Belgium
2 Organic and biomimetic research group, Ghent University, Krijgslaan 281 S4 9000 Ghent, Belgium
3 NMR Expertise Centre, Ghent University, Krijgslaan 281 S4 9000 Ghent, Belgium
Our long term research goal is to evaluate if the introduction of covalent or non-covalent ‘staples’ in DNA-aptamers can be used as a strategy to make ligand detection more robust to destabilizing environmental conditions. More specifically, judicious introduction of one or more such staples in DNA duplex regions should stabilize the binding competent state, while avoiding negative impact on binding affinity. As a proof-of principle, we demonstrate the introduction of a non-covalent staple to a model DNA aptamer system, the L-argininamide binding aptamer (1OLD). This non-covalent staple consists of an imidazole-modified thymine (TImH+), that, when introduced into a specific 3 bp cassette, constitutes a stabilizing motif, as previously published by our group…
Aptamer-based Biomarker Assay for Cancer Detection (+F)
Nico Dreymann1, Julia Wünsche2, Anja Klevesath1, Denise Czepluch1, Wiebke Sabrowski1 and Marcus Menger1
1 Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Functional Nucleic Acids – Aptamers, Am Mühlenberg 13, D-14476 Potsdam, Germany
2 3B Pharmaceuticals GmbH, Magnusstraße 11, D-12489 Berlin, Germany
Bladder cancer is one of the most frequently occurring tumour diseases worldwide with an estimated 30,000 new cases diagnosed each year, especially in men. The current diagnostic gold standard methods are cystoscopy and biopsy of the tumour tissue. Non-invasive alternatives such as urine cytology are also expensive methods and inadequate for early detection. Further, superficial tumours of the bladder wall have a high risk of relapse that necessitates regular monitoring by cystoscopy. Therefore, we work on the development of a non-invasive and less expensive alternative that is suitable for early detection of bladder cancer using DNA-aptamers. These highly specific recognition elements will be used for the detection of tumour-specific markers in urine samples…
The Impact of Ions on RNA Aptamer Aminoglycoside Interactions (+F)
Muslum Ilgu1, Rezzan Fazlioglu2
1 Biology Department, Middle East Technical University (METU), Ankara, Turkey
2 Biotechnology Department, Middle East Technical University (METU), Ankara, Turkey
Aptamers are nucleic acid molecules and used for both diagnostic and therapeutic purposes. In order to have the best performance out of these aptamers there is a need for understanding their structural dynamics. In doing this, many studies have shown that aptamer structures are affected by the ion concentrations of the surrounding media. Generally, sodium, potassium and magnesium ions are present with the aptamers and often used to increase structural stability. So, changes in the concentrations of these ions may alter the three-dimensional structure of aptamers and consequently affect their binding characteristics. In our study, we investigated the effects of magnesium and potassium ions on aptamers that bind to aminoglycosides…
Improved aptasensor performance for the detection of PfLDH malaria biomarkers in human serum
Gabriela Figueroa-Miranda1, Young Lo2, Yee-Wai Cheung2, Julian Alexander Tanner2, Andreas Offenhäusser1 and Dirk Mayer1
1Institute of Complex Systems (ICS-8), Forschungszentrum Jülich GmbH, Jülich, Germany 2School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region Detection of biomarkers in complex matrices like human serum or blood by biosensors is still a challenge due to high non-specific binding of matrix species. The function of the blocking molecule in a biosensor is important because it fills those spaces not covered by receptor molecules and avoids non-specific adsorption of molecules on the surface of the sensing electrode. Polyethylene glycol (PEG) has been reported to have the ability to prevent protein absorption when immobilized on different substrates. In this work we have optimized and characterized the detection performance of a newly developed electrochemical aptasensor in human serum for malaria detection by implementing PEG as blocking molecule…
Transferrin receptor aptamer mediated delivery of siRNA
Robert L. Hale, Ching-Hsuan Tsai, Caitlin G. Vestal Tibbetts, Christine P. Donahue
GlaxoSmithKline, 200 Cambridgepark Drive, Cambridge, MA, USA
Targeted delivery of therapeutic oligonucleotides, small molecules, and biologics can be used to improve their therapeutic efficacy and safety. We are using the method of systematic evolution of ligands by exponential enrichment (SELEX) for the discovery of aptamers that mediate targeted delivery. Aptamer libraries are oligonucleotides containing random sequences that fold into complex three-dimensional structures. Aptamer selections to targets enrich molecules based on ligand affinity. Here we describe the discovery of an aptamer that was coupled to a small interfering RNA (siRNA) to create a chimera that is capable of inducing RNAi in cells. The aptamer portion of the chimera binds the transferrin receptor (TfR) and the siRNA targets luciferase. Application of the chimera, but not the siRNA alone,
Targeted glioblastoma treatment with an EGFR aptamer
Emma M Hays1, Aaron Schultz2, Sarah Shigdar1
1Molecular Medicine Research Facility, School of Medicine, Deakin University, Geelong
2School of Life and Environmental Sciences, Deakin University, Geelong
Glioblastoma is a highly malignant primary brain tumour, which is currently incurable despite advances in anti-cancer therapies. The current standard treatment includes surgery, radiotherapy and chemotherapy. However, these are associated with severe off-target effects, and poor quality of life. Targeted therapeutics have potential to provide effective treatment against glioblastoma, without harming the healthy brain tissue, or the rest of the body. Despite this, the use of antibodies to treat glioblastoma has proven clinically unsuccessful, and is associated with immunotoxicity in some patients. Therefore, an alternative targeting modality is required. Aptamers, also known as ‘chemical antibodies’, function similarly to antibodies by binding to their target via shape recognition. They can be modified to carry drug compounds, and their small size, specificity and low immunogenicity make them ideal drug delivery candidates…
Simultaneous selection of DNA aptamers against estradiol, progesterone and testosterone steroids
Miriam Jauset-Rubio1, Mary Luz Botero1, Gülsen Betül Aktas1, Vasso Skouridou1, Markéta Svobodová1, Mohammad S. El-Shahawi2, Abdulaziz S. Bashammakh2, Abdulrahman O. Al-Youbi2, Ciara K. O’Sullivan1,3
1 INTERFIBIO Consolidated Research Group, Department of Chemical Engineering, Universitat Rovira I Virgili, 43007 Tarragona, Spain
2 Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Kingdom of Saudi Arabia
3 Institució Catalana de Recerca I Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
Recently there has been an increased interest in the detection of small molecules, including toxins, antibiotics, molecular markers, drugs, heavy metals and ions for monitoring of human and animal health. Aptamer-based analytical platforms present a promising alternative to the expensive and elaborate conventional detection methods such as chromatographic separation or antibody-based assays. However, the small molecular weights of these targets, as well as the high degree of similarity in their structures, poses a challenge, not only for their selection, but also for their characterization and application for detection. In the work reported here, the simultaneous selection of DNA aptamers against estradiol, progesterone and testosterone steroids is detailed. Using next-generation sequencing, the sequences found in the positive selection (estradiol selection) and in each of the counter selections (progesterone and testosterone selections) were compared to identify common and individual sequences as a means to simultaneously select aptamers against all three targets…
Center of Aptamer Research and Development (CARD): Fully automated selection of RNA aptamers for small molecules
Tjaša Legen1, Stefan Künne1, Günter Mayer1,2
1The Center of Aptamer Research and Development (CARD), Life and Medical Sciences Institute (LIMES), Bonn, Germany
2Clickmer Systems company in foundation, Gerhard-Domagk-Str. 1, 53121 Bonn
Aptamers are a promising tool for small molecules detection due to their small size, chemical stability, and cost-effectiveness over conventional bioreceptors such as antibodies. Sensors developed with such technology (Aptasensors) are usually selected in an in vitro process named Systematic evolution of ligands by exponential enrichment (SELEX). In the conventional SELEX approach, the target is immobilized onto the matrix to carry on the separation step between bound and unbound sequences. However, the lack of functional groups makes small molecules not preferable for the immobilization. Hence, a Capture-SELEX approach was developed, where the library is immobilized onto the matrix through an oligo. Here we show that with using Capture-SELEX approach on our platform, we can fully automatedly select RNA aptamers for small molecules only in a few days. We established the method in the way that there is no need for interference through the whole selection process. Aptamers were first selected for a model target Neomycin B, as well as for some other small molecules. We are a non-profit institution, which allows scientists to access aptamers as research tools for a wide range of applications. Besides the performance of the automated Capture-SELEX, we are offering the selection of RNA and 2’-Deoxy-2’-fluoro pyrimidine modified RNA aptamers for different protein targets…
Isolation of RNA aptamers against Rickettsia rickettsii
Febe Morales1, Ana Andrade1, Manuel Meza1, Javier González2, Jesús Machado1, José Vázquez1, Rafael Martínez1, Julia Estrada1, Nicolás Serafín2, Gabriela Leija1,2
1Facultad de Medicina, Universidad Autónoma de Baja California. Mexicali, BC, México
2Unidad de Ciencias de la Salud, Universidad Autónoma de Baja California. Mexicali, BC, México
Rickettsia is a genus of obligate intracellular bacteria; the pathogenic species of rickettsia are divided into the typhus group (TG) and the spotted fever group (SFG). Rocky Mountain spotted fever (RMSF) caused by Rickettsia rickettsii (R. rickettsii) is the most severe SFG rickettsiosis. Although there is a treatment available to RMSF, it is frequently fatal for persons who do not receive the therapy during the first five days of illness, the case fatality rate from outbreaks of RMSF ranges from approximately 30% to 80% according to the geographical area. Thus, an accurate and early diagnosis is important to initiate a specific treatment, but the diagnosis is challenging due to in the early stages of illness the symptoms are non-specific and similar to many other common infectious diseases that include fever, headache and muscle pain. Progressing damage to the vascular endothelium can result in organ failure, cutaneous necrosis, and death. Therefore, the aim of this study was to isolate RNA aptamers against R. rickettsii whole cell antigens to develop a potential diagnostic tool to SFG in early stage…
Development of Aptamer Inhibitors against ADAMTS-5 for Osteoarthritis Diseases
Meng P Liu, Yuan Y Yu, Yee W Cheung, Vanessa Choi and Julian A Tanner
School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Pokfulam, Hong Kong, China
Thrombospondin motifs 5 (ADAMTS-5), an aggrecanase from the ADAMTS protein family, is involved in the pathogenesis of osteoarthritis and proposed to be a potential target for the therapy of human osteoarthritis. Various chemical inhibitors have been developed to suppress the function of ADAMTS-5. Although most chemicals show strong functional inhibition of ADAMST-5 and can relive osteoarthritis symptoms, their clinical applications are mainly limited by their low specificities and cellular toxicities, which therefore leads us to develop alternative aptamer therapeutics for osteoarthritis treatments. Aptamers are single-stranded oligonucleotides and are termed as “chemical antibodies” due to their tailored binding specificities and affinities in molecular recognition application. Here, we discovered two guanine-rich aptamer inhibitors, apt21 and apt25, against ADAMTS-5…
Applications of aptamers in detection of small molecules in agro-products and environment (+F)
Hongmei Liu, Yunxia Luan
Beijing Research Center for Agricultural Standards and Testing, Agricultural Product Quality and Safety Risk Assessment Laboratory of the Department of Agriculture, Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing 100097 China
With the development of new type of modern agriculture, paying attention to farmland ecological environment and guaranting the quality and safety of agricultural products is playing a more and more important role in the upgrading of agricultural industrialization. For the detection of toxic hazard factor, higher requirements are puting forward. A rapid method with high sensitivity, high throughput and simple operation, low cost is more in line with the requirements of rapid screening at the grass-roots. Aptamers was single oligonucleotide sequences that can strongly bind to their targets with high affinity and specificity, having a series of virtues such as high detection sensitivity, low cost, easy synthesis modification. Aptamers have a big field of application in basic research, molecular diagnosis, and the pollution of agricultural products and agricultural environmental pollution monitoring are showing broad application prospect, providing a new, efficient and fast detection platform for detecting chemical residues, biological toxins, heavy metals, pathogenic microorganisms and industrial pollutants in agricultural products, food and farmfield, which have great potential, especially, in the detection of small molecule targets…
Developing RNA Aptamers from SELEX to Therapeutic
Alex Martin, Helen Lavender, Chris Pickford, Mike Westby
Centauri Therapeutics, Discovery Park, Sandwich, Kent, CT13 9ND
Nucleic acid aptamers have demonstrated potential as therapeutic agents. We are engaged in selecting RNA aptamers as the targeting component of a novel immunotherapeutic platform, designated ‘Alphamers’. Alphamers recruit natural immunity and can be designed to target specific pathogens or clinically important cell surface receptors. In vitro studies have demonstrated proof of principle in microbiology and oncology indications. We employ SELEX methodologies to rapidly screen for novel aptamer sequences and focus on fully modified RNA compositions that deliver nuclease stable compositions. Successful Aptamer Discovery campaigns need to deliver multiple, diverse, lead families with differentiated properties. Selected oligonucleotide sequences must possess high affinity (Kd <10nM), target selectivity…
A “Swiss Army Knife” Approach Using Aptamers and Nanopores
Rhushabh Maugi 1, Mark Platt 1
1 Department of Chemistry, Loughborough University. Leicester. UK LE11 3TU
Resistive pulse sensing (RPS) is an electrochemical nanopore sensing platform that characterises nanoparticles that range from sub 100nm to micrometer sized particles. A RPS nanopore sensor creates a “swiss army knife” multi-use platform to analyse ions, particles and biological targets in solution. Measuring the interaction between aptamers and small molecules, proteins, cells, virus etc. is well suited to a nanopore platform. The aptamer adopts a tertiary structure in the presence of the target and this results in a change in charge density around the particle which is measured as a change in translocation speed on the RPS platform…
A DNA-based surface biosensor for the kinetic characterization of aptamer folding and interactions
Irene Ponzo, Nena Matscheko, Friederike M Möller
Dynamic Biosensors GmbH, Lochhamer Str. 15, 82152 Martinsried, Germany
Therapeutic and diagnostic nucleic acid aptamers are designed to bind tightly and specifically to their target. To obtain a deeper understanding of the binding behavior of aptamers, structural and kinetic analyses of aptamer interactions gain more and more importance. Here, we show how the DNA-based switchSENSE surface biosensor enables the detailed kinetic characterization of aptamer folding and interactions with proteins, small molecules and even ions (kon, koff, KD) using the well-characterized thrombin-binding-aptamer (TBA) as a model system. We find, that thrombin binds to its aptamer with an extremely fast on-rate and a KD in the pM range (kon = 4´107 M-1s-1, koff = 5´10-2 s-1, KD = 117 pM). Thereby, we achieve an unprecedented fit quality by applying very fast flow rates and low surface densities, which prevents artefacts from mass-transport limitation. In agreement with expectations from literature, we observe a strong dependence of the kinetics on type and concentration of the present cations…
Structural and functional studies of aptamers to influenza virus hemagglutinin (+F)
Anastasia A Novoseltseva1, Nikita M Ivanov1, Roman A Novikov2, Valeria A Legatova1, Alexandra S Gambaryan3, Alexander M Arutyunyan4, Elena G Zavyalova1, and Alexey M Kopylov1
1Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
2Engelhardt Institute of Molecular Biology, Moscow, Russia
3Chumakov Federal Scientific Centre for Research and Development of Immune-and-Biological Products RAS, Institute of Poliomyelitis, Moscow, Russia
4Belozersky Institute of Physical and Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
Influenza virus is a widespread pathogen that causes epidemics of flu. The World Health Organization mentioned influenza pandemic as one of ten threats to global health in 2019. The hemagglutinin (HA) is the most presented protein on the surface of influenza virus particle. HA is responsible for recognition and attachment to the mammalian cell, which makes HA a potential target for antiviral agents. In this study the structural and functional characteristics of some aptamers to HA are given. The non-canonical DNA structures of RHA0385 and BV42 aptamers to HA were firstly studied with nuclear magnetic resonance (NMR) method and spectroscopy of circular dichroism (CD). Aptamers’ affinity to recombinant HAs and the influenza viruses of different strains was determined by different methods: surface plasmon resonance (SPR), biolayer interferometry (BLI) and enzyme-linked aptamer assay (ELAA)…
Understanding Functional DNA in Non-Conventional Solvents for Bioseparation and Biosensing (+F)
Beñat Olave1, Thomas Schäfer1
1POLYMAT, University of the Basque Country, Av. Tolosa 72, 20018 Donostia-San Sebastián, Spain
Since the last decade a novel type of non-aqueous media has been used for biotechnological applications, such as enzymatic biotransformations. They are known as “non-conventional” solvents and comprise ionic liquids (ILs) and deep eutectic solvents (DESs). ILs and DESs are non-volatile and can be fine-tuned as regards their chirality, polarity, viscosity or conductivity, and furthermore allow controlling water activity and reduce hydrolytic reactions. These unique characteristics make them highly attractive alternative solvents also for applications involving functional DNA. In this work, the function and properties of DNA were studied in these non-conventional solvents with a reduced presence of water. By combining in vitro characterization and the use of molecular dynamics we expected to establish a basis for predicting DNA behaviour in these media differing significantly from physiological conditions. We performed our fundamental studies changing systematically short DNA sequences
Bioinspired Aptamers for Healing Damaged Tissues
Nuria Oliva1,2, Benjamin D. Almquist1
1Bioengineering Department, Imperial College London, London SW7 2AZ, UK
2Grup d’Enginyeria de Materials (GEMAT), Institut Quimic de Sarria, Universitat Ramon Llull, Barcelona 08017, Spain
Historically, therapeutic aptamers have served as inhibitors of protein activity for treating various pathological conditions. However, their ability to specifically bind molecules such as growth factors with high affinities presents intriguing opportunities for facilitating the controlled release of growth factors to heal damaged tissues. Recently, we have developed a bioinspired aptamer-based platform that harnesses cellular traction forces to activate growth factors, called Traction-Activated Payloads (TrAPs). We have shown that this aptamer-based approach enables various cells (primary human dermal fibroblasts, HMEC‐1 endothelial cells, primary human smooth muscle cells) to pull on aptamers, unfolding them and releasing and activating various growth factors. We demonstrate that the TrAP technology is easy to integrate within a variety of cell culture systems and biomaterials that span both 2D (glass coverslips, polyacrylamide gels) and 3D (collagen scaffolds), enabling the addition of cell-activated growth factors to virtually any existing biomaterial of interest…
Developing aptamers against melanoma cell surface markers for enhanced uptake of cytotoxic drugs
Amy Oxlade1, Rasika Samarasinghe1, Sarah Shigdar1,2
1School of Medicine, Deakin University, Geelong, VIC 3128, Australia
2Centre for Molecular and Medical Research, Deakin University, Geelong, VIC 3128, Australia
Melanoma is considered a dangerous cancer due to its likelihood to metastasize, with approximately 40% of patients developing metastases to distant organs, especially the brain. With a mean survival time of 9.2 months and a 5-year survival rate of 5-19% after the onset of distant metastasis, the prognosis for metastatic melanoma patients is very poor. Conventional therapies, such as chemotherapy and radiotherapy, are very toxic to patients due to their off-target effects, and generally cannot eradicate tumours due to a build-up of resistance to the treatments. Major breakthroughs in melanoma treatment occurred with the development of immunotherapy and antibodies such as ipilimumab and nivolumab. However, clinical studies showed that antibodies are limited due to their high immunogenicity, large size and lack of tissue penetration. Alternatively, other agents such as nanoparticles and aptamers may provide alternative methods for directed drug delivery with minimum off target effect…
Light-dependent induction of translation
Sebastian Pilsl1, Anna Maria Weber1, Andreas Möglich2 and Günter Mayer1,3
1University of Bonn, LIMES – Institute, Gerhard-Domagk-Straße 1, 53121 Bonn
2University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth
3Center of Aptamer Research and Development, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn
MicroRNAs (miRNAs) are regulators of gene expression in mammalian cells. Controlling miRNA allows for artificial regulation of target gene expression. This can be achieved through a protein-aptamer interaction. A RNA aptamer was recently developed that binds photoreceptor protein PAL in a light dependent manner. The aptamer consists of 19 nucleotides making it easy to be implemented into the RNA sequence of choice. Incorporation of the aptamer into the loop region of pre-miR-21 upregulates a miRNA21 dependent reporter gene 3.5-fold in the presence of blue light.
A novel light-induced protein-RNA interaction conditionally activates gene expression
Christian Renzl1, Anna Maria Weber1, Andreas Möglich2 and Günter Mayer1
1Life and Medical Sciences (LIMES), University of Bonn, Gerhard-Domagk-Str. 1, Germany
2Bayreuth Center for Biochemistry & Molecular Biology, Universität Bayreuth, 95447 Bayreuth
Optogenetic tools are central for the discovery of new insights into biological and cellular processes with unrivaled spatio-temporal precision. Transcription activation systems based on CRISPR/Cas9 in combination with activators such as p65 or HSF1 were shown to greatly alter gene expression. However, current optogenetic dCas9-based transcription activation systems are bulky in size and can suffer from homodimerization of their effector fusion proteins, resulting in a decrease of efficiency in these systems and lack encodability in a single virus genome, which is a disadvantage in terms of scalability. Here, we use a 19 nt hairpin RNA-aptamer capable binding to a novel LOV protein with 20 nM affinity in blue light and weaker than 1 μM in darkness, which enables precise light-dependent control of dCas9-based transcription activation targeting user-defined genes…
Development of specific DNA aptamers against the enzyme 1-deoxy-D-xylulose-5-phosphate reductoisomerase from Plasmodium falciparum
Carlota Roca1,2, Xavier Fernàndez-Busquets2, Santiago Imperial1
1Department of Biochemistry and Molecular Biomedicine, School of Biology, University of Barcelona. Av. Diagonal 643, ES08028-Barcelona, Spain
2Nanomalaria Joint Unit. Institute for Bioengineering of Catalonia (IBEC) and Barcelona Institute for Global Health (ISGlobal). Centre Esther Koplowitz, planta 1, ISGlobal, Rosselló 149-153, ES08036 Barcelona, Spain
Malaria is a disease caused by parasites of the genus Plasmodium and transmitted by female Anopheles mosquitoes. Although malaria can be prevented and treated, it continues to have devastating effects on the health and lifestyle of people around the world. According to the most recent data, it is estimated that 219 million new cases of malaria occurred in 2017, which led to 435,000 deaths. Due to the resistance acquired by Plasmodium to antimalarial drugs, the global technical strategy against malaria (World Health Organization, strategic plan 2016-2030) contemplates the search for solutions to the threat of the emerging resistance to antimalarials…
Generation of DNA aptamers against small molecules using Capture-SELEX (+F)
Wiebke Sabrowski, Anja Klevesath, Denise Czepluch, Nico Dreymann and Marcus Menger
Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Functional Nucleic Acids – Aptamers, Am Mühlenberg 13, D 14476 Potsdam, Germany
Micropollution of aquatic systems is an environmental challenge of major concern. 17-ß-estradiol is an endocrine disrupting chemical frequently found in wastewater treatment plant effluents worldwide. The effects of exposure to 17-ß-estradiol have been extensively studied inter alia in fish and include impaired reproduction, changes in sex ratio and intersexuality. However, detection of 17-ß-estradiol is mostly limited to well-equipped facilities with well-trained personnel. Therefore, the development of on-site detection platforms is highly desirable. Aptamers are promising molecules for the development of biosensors. However, using conventional SELEX methods, the selection of aptamers against small molecules is challenging. Such targets are not likely to induce major changes in characteristics of the aptamer-target complex when compared to the aptamer alone, nor are they suitable for immobilization…
Robotic Aptamer-Enabled Electrochemical Reader (RAPTER) – Diagnosing Reproductive Disorders from the Laboratory to the Clinic
Shaolin Liang1,2,3, Andrew B. Kinghorn1, Margaritis Voliotis4, Julia K. Prague2, Johannes D. Veldhuis5, Simon Chi-Chin Shiu1, Krasimira Tsaneva-Atanasova4, Craig A. McArdle6, Raymond H.W. Li7, Anthony E.G Cass3, Waljit S. Dhillo2 & Julian A. Tanner1
1School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
2Section of Endocrinology and Investigative Medicine, Imperial College London, London, SW7 2AZ, UK.
3Department of Chemistry, Imperial College London, London, SW7 2AZ, UK.
4Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, EX4 4QD, UK.
5Endocrine Research Unit, Mayo School of Graduate Medical Education, Mayo Clinic, Rochester, MN 55905, MN, USA.
6Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK.
7Department of Obstetrics and Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Despite the great promise, there are few studies reporting clinical application of aptamers in diagnostics. Aptamers hold particular promise in continuous sensing applications where antibodies have numerous drawbacks – pulsatile hormone patterns are an ideal potential application. Luteinising hormone (LH) pulsatility dysfunction is a common yet difficult to diagnose cause for common reproductive disorders such as polycystic ovary syndrome and hypothalamic amenorrhoea. Here, we report DNA aptamers against LH which we integrate into a Robotic Aptamer-Enabled Electrochemical Reader (RAPTER) for rapid, sensitive and repeatable determination of LH concentrations in serum. Bayesian Spectrum Analysis is applied to determine LH pulsatility. The system is applied to diagnose reproductive disorders in three distinct patient cohorts…
Aptamer based label free fluorescent sensor for nucleic acid sensing (+F)
Rashi Soni, Deepti Sharma, Ashwani Sharma
Department of Chemistry, Indian Institute of Science Education and Research, Tirupati 517507, India
Nucleic acid sensing holds great potential in disease diagnosis, gene expression profiling and personalized therapeutic approaches. Several fluorescence based hybridization probes for the detection of nucleic acid has been reported in literature. Most of them, for instance, molecule beacons require chemical labelling followed by purification, and are also not cost effective. Light-up aptamer based sensors have recently shown great potential and has emerged as a promising platform for designing biosensors for small molecule as well as nucleic acid detection. Many of these sensors takes the advantage of a RNA mimic of green fluorescent protein often termed as spinach aptamer that has been shown to activate the fluorescence of otherwise non-fluorescent small-molecule DFHBI (3,5-difluoro-4-hydroxybenzylidene imidazolidinone). Using a miniature variant of spinach aptamer…
Molecular tools for the rapid and cost-effective detection of Tetrodotoxin
Xhensila Shkembi1, Marketa Svobodova1, Ciara K. O´Sullivan1,2
1Interfibio,Nanobiotechnology and Bioanalysis Group, Departament d’ Enginyeria Química, Universitat Rovira i Virgili, Avinguda Paisos Catalans 26, Tarragona, Spain
2Institució Catalana de Recerca I Estudis Avancats (ICREA), Passeig Lluís Companys 23, Barcelona 08010, Spain
Tetrodotoxin (TTX) is a potent neurotoxin that acts as a sodium channel blocker. Some symptoms of poisoning are tingling of the tongue and lips, headache, vomiting, muscle weakness, ataxia and even death. TTX-group toxins are usually found in puffer fish, and are produced by endo-symbiotic bacteria that naturally inhabit the gut of the animal. TTX has been responsible for many human fatalities, most commonly following the consumption of puffer fish originating from warm waters. The availability of new analytical methods for their detection in different matrices would facilitate improved management and risk assessment, as well as assisting in the screening for intoxication cases after undesired poisoning incidents. Currently, existing biosensors for TTX detection are based on the use of specific antibodies as bio-recognition molecules…
Analysis of Ligand-Induced Structure Switching in Cocaine-Binding Aptamer Using Fluorescence Kinetics of Stilbene Photoisomerization (+F)
Aron A Shoara1, Logan W Donaldson2, Philip E Johnson1
1Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, ON, M3J 1P3 Canada
2Department of Biology, York University, Toronto, ON, M3J 1P3 Canada
Fluorescent biosensors are in-demand techniques for their sensitivity, robustness and cost effectiveness. Conventional fluorescence sensing of aptamers depends on emission measurements by comparing signals in the presence and absence of analytes. However, conventional techniques do not provide information on whether an aptamer is undergoing a structure-switching binding mechanism. Photoisomerization reaction mechanisms are powerful means in the development of aptamer sensors, where the absorption or emission of light is converted to detectable electrical signals. We utilized the cis-trans photoisomerization of 4-acetamido-4′-isothiocyanato-2,2′-stilbenedisulfonic acid (SITS) conjugated with two constructs of cocaine-binding aptamer (MN19 and MN4)…
Developing and characterization of chemically modefied RNA aptamers for targeting wild type and mutated c-KIT receptor tyrosine kinases
Ala’a S. Shraim1, Walhan Alshaer2, Nidaa A. Ababneh2, Bashaer Abu-Irmaileh3, Abdelrahim Hunaiti4, Abdalla Awidi2, Fadwa Odeh5, Said Ismail6
1Department of Biological Sciences, University of Jordan, Amman, Jordan.
2Cell Therapy Center, University of Jordan, Amman, Jordan.
3Hamdi Mango Center for Scientific Research, University of Jordan, Amman, Jordan.
4 Department of Clinical Laboratory Sciences ,University of Jordan, Amman, Jordan.
5 Department of Chemistry, University of Jordan, Amman, Jordan.
6 Qatar Genome Project, Qatar Foundation, Doha, Qatar.
c-KIT is a transmembrane tyrosine kinase that plays a crucial role in cancer progression. Deregulation of c-KIT, including overexpression and gain of function mutations, has been detected in several human cancers. Particularly, the point mutations D816V and D816H in the kinase domain which induce ligand-independent activation of the kinase activity and cause acquired drug resistance. Therefore, c-KIT represents an attractive target for cancer therapy. Aptamers are emerging as a new promising and innovative class of nucleic acid therapeutic agents that can be selected to discriminate and interfere with the biological activity of both wild type and mutant drug-resistant isoforms such as a c-KIT kinase. The aims of our study are developing and characterization of chemically modified RNA aptamers that can bind to the kinase domain of c-KIT proteins (c-KIT WT, c-KIT D816V, and c-KIT D816H) with high affinities and can selectively interfere with their kinase activities. We have successfully selected chemically modified RNA aptamers that bind with high affinity to the kinase domain of c-KIT proteins. The selected candidate aptamers show nanomolar KD values.
Structure-switching aptamers binding the steroid hormone testosterone
Vasso Skouridou1, Mohammad S. El-Shahawi2, Abdulaziz S. Bashammakh2, Abdulrahman O. Alyoubi2, Ciara K. O’Sullivan1,3
1Interfibio Consolidated Research Group, Department of Chemical Engineering, Universitat Rovira i Virgili, Av. Paı̈sos Catalans 26, 43007 Tarragona, Spain
2Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah, Saudi Arabia
3Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain
Since their discovery almost thirty years ago, aptamers have been widely exploited for the detection of a variety of targets ranging from small molecules to whole cells. The classic SELEX strategy typically used is suitable for many targets but there are many challenges associated with the discovery and validation of aptamers binding small molecules. The immobilization of these small molecules to facilitate the selection process can lead to significant structural changes of the targets, thus hindering the detection of the native, unmodified molecules. On the other hand, even when the selection is successful, there are limited assays which are suitable for the characterization of potential aptamer candidates, whereas the development of assays compatible with these targets is also quite challenging. One of the approaches used to overcome these limitations is the Capture-SELEX strategy. Using the library immobilized via DNA hybridization and the unmodified target in solution, it is possible to promote significant structural changes of the ssDNA sequences forcing them to displace to enable target binding.
Antimalarial Compounds: Cocaine-Binding Aptamer Specific or Generic DNA Binders (+F)
Sladjana Slavkovic and Philip E Johnson
Department of Chemistry, York University, Toronto, ON, M3J 1P3, Canada
Aptamers have generated great interest as biosensors as their selection process allows them to bind a wide variety of ligands, often with high affinity and specificity. An aptamer that is an exception is the cocaine-binding aptamer as one of the unique features of this aptamer is its ligand-binding promiscuity. Despite being selected for cocaine, the cocaine-binding aptamer binds quinine and quinine-based antimalarial compounds (amodiaquine, chloroquine and mefloquine) with much higher affinity than cocaine. A second unique feature of this aptamer is having a salt-controlled two-site binding mechanism. Our recent study shows that the cocaine-binding aptamer also binds two copies of artemisinin, a non-quinine based antimalarial compound, about 100-fold tighter than cocaine. We used isothermal titration calorimetry (ITC) to determine whether quinine, amodiaquine, chloroquine, mefloquine and artemisinin are specific to the cocaine binding aptamer or if they are generic DNA binders…
Target Validation Using Modified RNA Aptamers in Early Drug Discovery
Kevin Spielberger
GlaxoSmithKline, Cambridge, Massachusetts, USA
The aptamer platform within GSK continues to advance and is focused on finding DNA and modified RNA aptamers for use as affinity reagents, therapeutics of skin drug delivery, and tool compounds. The aptamer library chemical composition impacts nuclease stability of output aptamers, so nucleic acid-derived libraries with various chemical compositions are used for SELEX. We utilize the Y639 and H784 in T7 RNA polymerase (T7P) that allows for efficient transcription with 2’-modified NTPs. GSK utilizes Next Generation sequencing techniques, and moving towards deep sequencing, to obtain greater coverage of the enriched aptamer library. Here we show two case studies. The first example is for an aptamer that penetrates the skin for drug delivery. The aptamer binding IL23 shows dermis penetration as a prospective treatment for psoriasis. The second example might solve an issue for crystallography by co-crystalizing an aptamer with a protein to understand protein interactions. This presented example shows the potential for an aptamer to serve as a chaperone to a protein alone or as a multi-domain complex by competing away the co-purifying RNA.
Selection of aptamers against fragments of ciguatoxin for the development of aptamer based sandwich assay
Marketa Svobodova1, Miriam Jauset Rubio1, Mònica Campàs, Takeshi Tsumuraya, Ciara O´Sullivan1, 3
1Interfibio Group, Departament d’ Enginyeria Química, Universitat Rovira i Virgili, Avinguda Països Catalans 26, Tarragona, 43007, Spain
2IRTA, Carretera Poble Nou km 5.5, 43540 Sant Carles de la Ràpita, Tarragona, Spain
3 Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Osaka 599-8531, Japan
4Institució Catalana de Recerca i Estudis Avancats, Passeig Lluis Companys 23, Barcelona 08010, Spain
Ciguatera is a human intoxication caused by the ingestion of a variety of reef fish. The disease is characterized by severe neurological, gastrointestinal, and cardiovascular disorders. Globally, more than 50,000 people are estimated to suffer annually from this type of poisoning, making it one of the largest scale food poisonings of nonbacterial origin.Whilst the gold standard for the detection of ciguatoxinis is mouse bioassay of lipid extracts of potentially contaminated fish, an immunoassay kit was recently launched for the detection of ciguatoxin. Aptamers have emerged as versatile molecular recognition agents offering a very attractive alternative to antibodies. The extremely low levels of ciguatoxin found in contaminated fish, coupled with an extremely laborious and inefficient extraction methods, as well as a lack of any commercial source of ciguatoxin, has hampered the development of aptamers against this important target…
RNA and DNA aptamers against hepatitis C virus core protein (+F)
Beatriz Torres-Vázquez1, Miguel Moreno1, Carlos Briones1,2
1Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, Madrid, Spain
2Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd), Spain
Aptamers constitute promising alternatives to antibodies as biological recognition elements for biosensing, as well as for diagnostic and therapeutic applications. Hepatitis C virus (HCV) is the major etiological agent of chronic hepatitis, which can progress to fibrosis, cirrhosis and hepatocellular carcinoma. It is estimated that HCV infects more than 170 million people worldwide, including injecting drugs users, recipients of blood products and patients on hemodialysis. Current diagnostic tests are mainly based on serological assays that detect HCV-specific antibodies, as well as on molecular assays that quantify HCV RNA in plasma or serum samples. However, rapid, inexpensive and more sensitive analytical tools are still essential for viral diagnostics and treatment monitoring. HCV core is a multifunctional protein that forms the viral capsid. Being the least variable of all the HCV proteins, it has been proposed as an attractive target for the development of new HCV-specific binding molecules, including aptamers….
A light dependent aptamer-photoreceptor system for the control of RNA function in cells
Anna M Weber1, Thea Ziegler2, Jennifer Kaiser2, Sebastian Pilsl1, Christian Renzl1, Georg Pietruschka1, Ankana Kakoti1, Andreas Möglich2 & Günter Mayer1
1Life and medical sciences institute (LIMES), University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
2Department of Biochemistry, University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
Optogenetic makes use of light to control cellular behaviour in a spatial and temporal manner. Several processes, such as channel conformation, enzymatic activity or DNA binding have been shown to be compatible with light regulation. Photoreceptor proteins, e.g. LOV (light, oxygen, voltage)-domain containing proteins play an important role in developing those processes since they are able to reversibly change their conformation upon light absorption and therefore convert the incoming signal into a specific output. However, until now it is difficult to apply optogenetic control to RNA biochemistry, e.g. RNA localization or function. We applied a light dependent selection strategy to develop aptamers specific for binding a LOV…
Aptamer-based cell-targeted delivery facilitates translational research in orthopedics: Our research trip (+F)
Yuanyuan Yu1,2, Chao Liang1,2, Jin Liu1,2, Fangfei Li1,2, Jun Lu1,2, Zhenjian Zhuo2,3, Bao-Ting Zhang2,3*, Aiping Lyu1,2*, Ge Zhang1,2*
1Law Sau Fai Institute for Advancing Translational Medicine in Bone & Joint Diseases,
Hong Kong Baptist University, HKSAR, China
2Guangdong-Hong Kong-Macau Greater Bay Area International Research Platform for Aptamer-based Translational Medicine and Drug Discovery, HKSAR, China
3 School of Chinese Medicine, The Chinese University of Hong Kong, HKSAR, China
Our group has been working on aptamer-based translational theranostics for almost 10 years. We have a series of research focusing on aptamer-based translational medicine and drug discovery, including aptamer selection, aptamer structural biology, aptamer for targeted delivery, therapeutic aptamer, aptamer-drug conjugates and diagnostic aptamer. We will firstly introduce our research and the translational application of the aptamer-based cell-targeted delivery, including osteoblasts, osteoclasts and osteosarcoma for disease therapy in orthopedics. We will present our research progress on therapeutic aptamer against sclerostin for reversing osteoporosis, as well as the next generation of smart anti-tumor drug based on Aptamer-Drug Conjugate (ApDC).
