CRISPR-Cas: ‘The Multipurpose Molecular Tool’ for Gene Therapy and Diagnosis

Since the discovery of the CRISPR-Cas engineering system in 2012, several approaches for using this innovative molecular tool in therapeutic strategies and even diagnosis have been investigated. The use of this tool requires a global approach to DNA damage processes and repair systems in cells. The diversity in the functions of various Cas proteins allows for the use of this technology in clinical applications and trials. Wide variants of Cas12 and Cas13 are exploited using the collateral effect in many diagnostic applications. Even though this tool is well known, its use still raises real-world ethical and regulatory questions

Identification et caractérisation d'aptamères ciblant le biomarqueur du cancer de l'ovaire Human Epididymis Protein 4 pour l'application dans l'urine

International audienceOvarian cancer is the deadliest gynecological cancer. With non-specific symptoms of the disease and the lack of effective diagnostic methods, late diagnosis remains the crucial hurdle of the poor prognosis. Therefore, development of novel diagnostic approaches are needed. The purpose of this study is to develop DNA-based aptamers as potential diagnostic probes to detect ovarian cancer biomarker Human epididymis protein 4 (HE4) in urine. HE4 is a protein overexpressed in ovarian cancer, but not in healthy or benign conditions. With high stability and diagnostic value for detection of ovarian cancer, urine HE4 appears as an attractive non-invasive biomarker. The high-affinity anti-HE4 DNA aptamers were selected through 10 cycles of High Fidelity Systematic Evolution of Ligands by EXponential enrichment (Hi-Fi SELEX), a method for aptamer selection based on digital droplet PCR. The anti-HE4 aptamers were identified using DNA sequencing and bioinformatics analysis. The candidate aptamer probes were characterized in urine for binding to HE4 protein using thermofluorimetry. Two anti-HE4 aptamers, AHE1 and AHE3, displayed binding to HE4 protein in urine, with a constant of dissociation in the nanomolar range, with Kd (AHE1) = 87 ± 9 nM and Kd (AHE3) aptamer of 127 ± 28 nM. Therefore, these aptamers could be promising tools for application in diagnostics and future development of urine tests or biosensors for ovarian cancer.Le cancer de l'ovaire est le cancer gynécologique le plus mortel. Avec des symptômes non spécifiques de la maladie et le manque de méthodes de diagnostic efficaces, le diagnostic tardif reste l'obstacle crucial du mauvais pronostic. Par conséquent, le développement de nouvelles approches diagnostiques est nécessaire. Le but de cette étude est de développer des aptamères à base d'ADN comme sondes diagnostiques potentielles pour détecter le biomarqueur du cancer de l'ovaire, la protéine 4 de l'épididyme humain (HE4) dans l'urine. HE4 est une protéine surexprimée dans le cancer de l'ovaire, mais pas dans des conditions saines ou bénignes. Avec une grande stabilité et une valeur diagnostique pour la détection du cancer de l'ovaire, l'HE4 urinaire apparaît comme un biomarqueur non invasif attractif. Les aptamères d'ADN anti-HE4 de haute affinité ont été sélectionnés par 10 cycles d'évolution systématique haute fidélité des ligands par enrichissement EXponentiel (Hi-Fi SELEX), une méthode de sélection des aptamères basée sur la PCR numérique en gouttelettes. Les aptamères anti-HE4 ont été identifiés par séquençage de l'ADN et analyse bioinformatique. Les sondes aptamères candidates ont été caractérisées dans l'urine pour la liaison à la protéine HE4 par thermofluorimétrie. Deux aptamères anti-HE4, AHE1 et AHE3, ont montré une liaison à la protéine HE4 dans l'urine, avec une constante de dissociation dans la gamme nanomolaire, avec Kd (AHE1) = 87 ± 9 nM et Kd (AHE3) aptamère de 127 ± 28 nM. Par conséquent, ces aptamères pourraient être des outils prometteurs pour une application dans le diagnostic et le développement futur de tests urinaires ou de biocapteurs pour le cancer de l'ovaire

Detection of the ovarian cancer biomarker in body fluids using nucleic acid aptamers as diagnostic probes

EACR 2022 - Innovative Cancer Science: Translating Biology to MedicineInternational audienc

Detection of the ovarian cancer biomarker in body fluids using nucleic acid aptamers as diagnostic probes

EACR 2022 - Innovative Cancer Science: Translating Biology to MedicineInternational audienc

Analysis of Microbial Communities: An Emerging Tool in Forensic Sciences

International audienceThe objective of forensic sciences is to find clues in a crime scene in order to reconstruct the scenario. Classical samples include DNA or fingerprints, but both have inherent limitations and can be uninformative. Another type of sample has emerged recently in the form of the microbiome. Supported by the Human Microbiome Project, the characteristics of the microbial communities provide real potential in forensics. They are highly specific and can be used to differentiate and classify the originating body site of a human biological trace. Skin microbiota is also highly specific and different between individuals, leading to its possibility as an identification tool. By extension, the possibilities of the microbial communities to be deposited on everyday objects has also been explored. Other uses include the determination of the post-mortem interval or the analysis of soil communities. One challenge is that the microbiome changes over time and can be influenced by many environmental and lifestyle factors. This review offers an overview of the main methods and applications to demonstrate the benefit of the microbiome to provide forensically relevant information

Evaluation of DNA Methylation-Based Age-Prediction Models from Saliva and Buccal Swab Samples Using Pyrosequencing Data

In forensic genetics, the identification of an individual is often carried out by comparing unknown DNA profiles obtained in a case against databases or references. When no match is found, investigators need new tools in order to obtain additional leads. The latest technical advances now make it possible to predict externally visible characteristics. With this objective, predicting the age of an individual through DNA methylation analysis remains one of the last challenges. The prediction models have to account for the specific constraints of this field, including tissue specificity and DNA availability (i.e., low DNA amounts or low-quality DNA). Jung and colleagues have recently produced models from blood, saliva and buccal cells by using a single base extension sequencing method. With the goal of evaluating these models in our own analytical conditions, saliva and buccal cell samples from 115 French individuals between the ages of 0 and 88 years old were collected and analyzed. After having determined the optimal analysis conditions, including the DNA quantity for bisulfite conversion (75 ng), some differences were highlighted in the measured methylation rates between the two studies. Despite these discrepancies, the prediction performance levels remain very similar, our study showing mean absolute errors of 3.5 years, 3.9 years and 3.2 years, respectively, for the saliva, buccal swab and multitissue model, with limitations observed for the oldest and youngest individuals. Furthermore, we propose the use of a prediction interval with an error dispersion and correct prediction rate at ±5 years and ±10 years, respectively

Innovations in Forensic Sciences for Human Identification by DNA in the French Gendarmerie during the Last 10 Years

The IRCGN (Institut de Recherche Criminelle de la Gendarmerie Nationale) is a forensic science institute built by the French Gendarmerie which has the ability to exploit crime scene evidence. Any piece of evidence, anywhere in the world, in any environment, can be examined by IRCGN teams deployed in just a few hours. During the past 10 years, experts specializing in genetics have developed innovative genetic engineering technologies for application in forensic sciences. In this review, we highlight the main innovations and the creation of new tools for human identification, which are fully suited to the French Gendarmerie’s needs. Devices developed by the IRCGN are specific to the Gendarmerie’s purposes

juillet-août 2017

La médiation numérique dans les institutions muséales Les outils numériques sont devenus les compagnons indispensables de la médiation culturelle mais leur usage ne manque pas de questionner les professionnels des musées, notamment sur la place des publics, le profil des utilisateurs, le rôle dévolu à ces outils… Ainsi, la première contribution de ce nouveau numéro de La Lettre de l’Ocim montre comment l’institution muséale peut mettre en place une démarche pour appréhender le public qui fréquente le musée sur Internet, observer et comprendre les pratiques des internautes, tenter de mesurer la réception de ses actions en dehors de l’établissement. Par ailleurs, à travers l’analyse de l’utilisation d’une table tactile interactive restituant l’évolution dans le temps et l’aménagement d’un site archéologique, une seconde contribution s’interroge sur la place de cet outil numérique dans la médiation, relevant l’importance de la transmission humaine des savoirs et du patrimoine. Enfin ce numéro propose une nouvelle rubrique « Une collection – Un objet de musée » qui désormais présentera un objet d’un musée thématique, d’un muséum, d’un CCSTI, d’un centre d’interprétation… Cet objet qui a une histoire particulière au sein d’une collection ou qui pose une problématique inédite en terme de conservation, d’exposition, d’interprétation, de réception… sera choisi et commenté par l’institution concernée. Serge LOCHOT, rédacteur en che

A mobile DNA laboratory for forensic science adapted to coronavirusSARS-CoV-2 diagnosis

International audienceThe Forensic Science Institute of the French "Gendarmerie Nationale" (IRCGN™) developed in 2015 an ISO 17025 certified mobile DNA laboratory for genetic analyses. This Mobil'DNA laboratory is a fully autonomous and adaptable mobile laboratory to perform genetic analyses in the context of crime scenes, terrorism attacks or disasters.To support the hospital taskforce in Paris during the peak of the COVID-19 epidemic, we adapted this mobile genetic laboratory to perform high-throughput molecular screening for coronavirus SARS-CoV-2 by real-time PCR. We describe the adaptation of this Mobil'DNA lab to assist in Coronavirus SARS-CoV-2 diagnosis

MicroFLOQ® Direct: A Helpful Tool for the Coronavirus SARS-Cov-2 Rapid Detection without RNA Purification

International audienc