RNA interference-mediated gene silencing approaches
RNA interference represents a promising approach towards the inhibition of gene expression not only in cell culture but also in vivo for the development of new generation biodrugs. There is a common opinion that the full potential of siRNA as a therapeutic agent will not be attained until better methodologies for its targeted intracellular delivery to cells and tissues are developed. Highly negatively charged oligonucleotides, such as naked siRNA, can barely cross the cell membrane to reach the cytoplasm where their target and their enzymatic machinery are present. (Paganin et al., PNAS 2011)
We have shown that gene expression could be modulated in vivo in muscle by different types of molecules (shRNA, siRNA). These studies have been also performed in sub-cutaneous tumors (mouse melanoma and fibrosarcoma) in vivo by using fluorescent reporter genes. The efficiency varies according to the chemical and physical properties of these molecules (charges and size). The in vitro and ex vivo findings help us to adjust the electrical parameters in order to increase the efficiency of the delivery.
Project leader : M. Golzio
LNAs electrotransfer for cancer-associated miR therapy
Micro-RNAs ( 22ntnon-coding RNAs ) play crucial roles in the control of critical biological processes and are involved in a wide variety of human diseases and so have rapidly emerged as a new class of potential therapeutic targets . An obvious miRNA inhibitor is an oligonucleotide which is complementary to its target miRNA and binds to it with high affinity and specificity. New generations of chemically modified oligonucleotides have been developed. Among them, there is the Locked Nucleic Acid (LNA) which contains a methylene bridge that connects the 2’-oxygen with the 4’-carbon of the ribose. Because of the thermal stability when hybridized with its RNA target molecule, the high resistance to nucleases degradation and the low toxicity in biological system, LNA-based molecule appears as a promising therapeutic tool to develop miRNA mimic or inhibitor.
Lectin targeting epithelial cancer cells
We develop a protein nanocontainer to deliver pharmacological drugs to epithelial cancer cells. The idea is to take advantage of three intrinsic properties of this protein which offer the opportunity to confine small drugs inside an inner cavity, to deliver them specifically to epithelial cancer cells and finally to release the drugs inside cells.
This work is realized as a maturation project with the SATT-ToulouseTechTransfer with the main goal to transfer this technology to pharmaceutical companies. Patent and PCT were deposited in 2012 and 2013.
Investigators : Technician: C. Ladurantie / Engineer: M. Coustets / Project leaders: L. Paquereau
Collaborations : A. Milon, P. Demange (IPBS, Toulouse)
We develop original approaches to select and validate DNA aptamers. These aptamers are directed against different targets (membrane proteins, soluble proteins, small molecules) for using in diagnosis and therapeutic purposes.
The selection is realized by SELEX or non-SELEX methods and with different technical approaches depending of the targets: filter binding, cell-SELEX, CE-SELEX or immobilized targets on magnetic beads.
These selections were followed by Illumina sequencing and bioinformatics analysis. We also develop imaging methods using DNA aptamers (Martínez et al. Nucleic Acids Therapeutics 2014).
Investigators : PhD students: A. Boutonnet / Technician: C. Ladurantie / Project leaders: L. Paquereau & V. Ecochard
Collaborations : B. Couderc (ICR, Toulouse), J.M. Escudier (LSPCMIB, Toulouse), D. Querleu (MD, ICR, Toulouse), Picometrics Technology (Labège)