Los aptámeros como novedosa herramienta diagnóstica y terapéutica y su potencial uso en parasitología / Aptamers as a novel diagnostic and therapeutic tool and their potential use in parasitology

Los aptámeros son secuencias de ADN o ARN de cadena sencilla que adoptan la forma de estructuras tridimensionales únicas, lo cual les permite reconocer un blanco específico con gran afinidad. Sus usos potenciales abarcan, entre otros, el diagnóstico de enfermedades, el desarrollo de nuevos agentes terapéuticos, la detección de riesgos alimentarios, la producción de biosensores, la detección de toxinas, el transporte de fármacos en el organismo y la señalización de nanopartículas. El pegaptanib es el único aptámero aprobado para uso comercial por la Food and Drug Administration (FDA). Otros aptámeros para el tratamiento de enfermedades están en la fase clínica de desarrollo. En parasitología, se destacan los estudios que se vienen realizando en Leishmania spp., con la obtención de aptámeros que reconocen la proteína de unión a poliA (LiPABP) y que pueden tener potencial utilidad en la investigación, el diagnóstico y el tratamiento de la leishmaniasis. En cuanto a la malaria, se han obtenido aptámeros que permiten identificar eritrocitos infectados e inhiben la formación de rosetas, y otros que prometen ser alternativas para el diagnóstico al detectar de forma específica la proteína lactato deshidrogenasa (PfLDH). Para Cryptosporidium parvuum se han seleccionado aptámeros que detectan ooquistes a partir de alimentos o aguas contaminadas. Para Entamoeba histolytica se han aislado dos aptámeros llamados C4 y C5, que inhiben la proliferación in vitro de los trofozoítos y tienen potencial terapéutico. Los aptámeros contra Trypanosoma cruzi inhiben la invasión de células LLC-MK2 (de riñón de mono) en un 50 a 70 % y aquellos contra T. brucei transportan moléculas tóxicas al lisosoma parasitario como una novedosa estrategia terapéutica. Los datos recopilados en esta revisión destacan los aptámeros como una alternativa para la investigación, el diagnóstico y el tratamiento contra parásitos de interés nacional.

Aptamers are single-stranded DNA or RNA sequences that adopt unique three-dimensional structures that allow them to recognize a specific target with high affinity. They can potentially be used for the diagnosis of diseases, as new therapeutic agents, for the detection of food risks, as biosensors, for the detection of toxins, and as drug carriers and nanoparticle markers, among other applications. To date, an aptamer called pegaptanib is the only aptamer approved by the Food and Drug Administration (FDA) for commercial use. Other aptamers are in different clinical stages of development for the treatment of different diseases. In parasitology, investigations carried out with parasites such as Leishmania spp. allowed the acquisition of aptamers that recognize the polyA-binding protein LiPABP and may have potential applications in research and diagnosis and even as therapeutic agents. Regarding malaria, aptamers have been obtained that allow the identification of infected erythrocytes or inhibit the formation of rosettes, along with those that provide promising alternatives for diagnosis by specifically detecting the protein lactate dehydrogenase (PfLDH). In Cryptosporidium parvum allow the detection of oocysts in contaminated food or water. In Entamoeba histolytica, two aptamers called C4 and C5, which inhibit the proliferation of trophozoites in vitro and have potential use as therapeutic agents, have been isolated. Aptamers obtained against Trypanosoma cruzi inhibit the invasion of LLC-MK2 (from monkey kidney) cells by 50-70%, and in T. brucei, aptamers with the potential to transport toxic molecules to the parasitic lysosome were identified as a novel therapeutic strategy. The data collected in this review highlight aptamers as a novel alternative in the research, diagnosis, and treatment of parasites of national interest.

Aptamers selection for tumor based on cell-SELEX and its application in tumor diagnosis and treatment / 国际肿瘤学杂志

Aptamers have shown great potential in early diagnosis,treatment of tumor because of its high specificity and affinity.The aptamers selected by cell-SELEX can identify tumor cells through target molecular changes,and then realize the prevention and treatment of tumors.At present,researchers have successfully selected a number of aptamers by using cell-SELEX technology combined with flow cytometry.To make up for the deficiencies and exert the advantages of aptamers can make aptamer technology really apply to clinical diagnosis and treatment.

Application of aptamer in the study of cancer stem cells / 国际肿瘤学杂志

Cancer stem cells have self-renewal and multilineage differentiation potentials,which play important roles in tumorigenesis,metastasis,recurrence and resistance to chemical therapy and radiotherapy,and so on.It is the hotspot of tumor research recently.Aptamer is a small molecular oligonucleotide with high targeting ability and affinity,which is a new type of nucleic acid in the diagnosis and treatment of cancer.Now more and more research is being done on the aptamer is applied in the diagnosis and treatment of cancer stem cells,which provides a new research tool for the diagnosis and treatment of cancer stem cells.

Expanding targets for systematic evolution of ligands by exponential enrichment (SELEX) / 第二军医大学学报

The continuous expanding of targets is a distinct character of systematic evolution of ligands by exponential enrichment (SELEX) technique and other random library technologys (such as phage display technology). Over the past 20 years the targets of SELEX have expanded to various metal ions, organic molecules, drugs, proteins and biomacromolecules, pathogenic bacteria, live cells and tissue slide. The SELEX screenings using live cells and tissue slide as targets have been preliminarHy applied for studying targeted diagnosis and treatment of cancers. This paper reviews the expansion of the targets of SELEX technique.

Application of aptamers in the study of autoimmune diseases / 中华检验医学杂志

Aptamers are oligonucleotides or peptides those are able to bind tightly,by their specific three-dimensional shapes,to a variety of targets.Because of numerous merits ( high affinity,high specificity,small size,little immunogenicity,stable structures,and ease of synthesis),aptamers represent a valid alternative to antibodies and become a valuable research tool and show great application to fundamental research,drug selection and clinical diagnosis and therapy.The review describe the applications and the possible applications of aptamers in the diagnosis,treatment and pathogenesis of autoimmune diseases.

An aptamer-based biosensor for colorimetric detection of Enteropathogenic Escherichia coli / 中华检验医学杂志

Objective To develop and evaluate an aptamer based biosensor (aptasensor) for rapid colorimetric detection of enteropathogenic Escherichia coli (EPEC). Method The aptasensor was fabricated by modifying the truncated LPS-binding aptamer on the surface of nanoscale polydiacetylene vesicles using peptide bonding between the carboxyl group of the vesicle and the amine group of the aptamer. Molecular recognition between EPEC and aptamer at the interface of the vesicle led to blue-red transition of polydiacetylene which was readily visible to the naked eyes and could be quantified by colorimetric responses (CR). Transmission electron microscopy (TEM) was used to confirm the specific interactions between EPEC and polydiacetylene vesicles. Result Truncated aptamer showed the similar LPS-binding activity. The aptasensor could detect the target bacteria in a range of 105-108 colony-forming units (CFU)/ml within less than 30 minutes and its specificity was 100% for detection of EPEC O111. The sensor reproducibiliry obtained at 106 CFU/ml was 6. 08% R. S. D. The results of TEM confirmed that the specific interactions between EPEC and polydiacetylene vesicles. Conclusion A new aptasensor was developed successfully for rapid colorimetric detection of EPEC.