In vivo targeting leukaemic fusion genes with siRNAs

Lead Research Organisation: Newcastle University
Department Name: Northern Institute for Cancer Research

Abstract

A research team based at Newcastle University working with a co-investigator at the University of Stuttgart aim to develop a non-toxic therapeutic drug to treat a specific type of leukaemia prevalent in children. Leukaemia occurs due to a genetic change (mutation) within the DNA of bone marrow cells. This results in a mutant RNA transcript which produces an improperly functioning protein. The result is failure of the normal control mechanism for cell development and the uncontrolled growth of white blood cells. The current treatment is chemotherapy with highly toxic and non-specific drugs. Chemotherapy can affect all cells in the body leading to side effects ranging from general ill health during treatment but also, often life-threatening long term damage to organs and unfortunatly imparement or even loss of fertility. The proposed novel therapeutic approach comprises a tiny particle which specifically recognises and attaches to leukaemic cells and then delivers a unique genetic component (so-called short interfering RNAs or siRNAs) into the leukaemic cell. This siRNA adds a second degree of specificity as it recognises and binds only to the unique mutant RNA in the leukaemic cells. This prevents production of the mutant protein and so stops the aberant excessive cell division characteristic of the disease. The particle itself is a mix of fats and protein combined with the siRNA, so the therapy is non toxic to normal cells but lethal to leukaemic cells.

Technical Summary

Fusion oncogenes and their encoded products provide ideal targets for leukaemia-specific therapeutic strategies because of their exclusive expression in leukaemic cells. However, the majority of these fusion proteins are transcription factors, which are difficult to target with conventional small molecule-based approaches. Using RNA interference (RNAi) with small inhibitory RNA (siRNA), we have demonstrated that several fusion proteins are indispensable for the maintenance of leukaemic growth both in vitro and in vivo. We propose a therapy based on a targeted siRNA delivery system which provides a highly selective approach towards the transformed cells but will not affect healthy haematological cells. We have developed antibody-conjugated nanoparticles which efficiently deliver siRNAs to leukaemic cells subsequently causing a knock-down of the targeted fusion gene. This has been demonstrated as a potential target specific siRNA therapy for Acute Myeloid Leukaemia (AML) in cell culture and murine transplantation models. In the proposed project, we will determine if this Antibody Targeted Nanoparticle (AnTaNa) approach overcomes the problem of delivering sufficient siRNA to be therapeutically effective by assessing the in vivo efficacy, toxicity, pharmacokinetics and -dynamics in murine xenotransplantation models. A specific and efficient antileukaemic effect in these model systems would provide a strong impetus for progressing to clinical studies.

Publications

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Omedes Pujol M (2013) Determination of key structure-activity relationships in siRNA delivery with a mixed micelle system. in Journal of controlled release : official journal of the Controlled Release Society

 
Description A polymer nanoparticle platform for siRNA-based therapies for Leukaemia
Amount £46,410 (GBP)
Funding ID JAG/ML/0612 
Organisation Newcastle upon Tyne Hospitals NHS Foundation Trust 
Sector Public
Country United Kingdom
Start 08/2012 
End 03/2013
 
Description EPSRC KTA
Amount £32,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 01/2010 
End 09/2011
 
Description EPSRC MRes/PhD
Amount £71,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 01/2011 
End 09/2015
 
Title Nanoparticles 
Description Particle formulations used to targeted delivery of siRNAs in leukaemia 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact None yet 
 
Description Peptide-mediated siRNA delivery 
Organisation Radboud University Nijmegen
Country Netherlands 
Sector Academic/University 
PI Contribution Physicochemical characterisation of CPPs and their in vitro and in vivo testing
Collaborator Contribution New delivery approach providing its implementation into the currently pursued strategy.Provision of new CPPs
Impact BSc thesis at Nijmegen University Manuscript in preparation Multidisciplinary approach between peptide chemistry (Stockholm), cell biology (Nijmegen) and molecular oncology (Newcastle)
Start Year 2010
 
Description Peptide-mediated siRNA delivery 
Organisation Stockholm University
Department Department of Neurochemistry
Country Sweden 
Sector Academic/University 
PI Contribution Physicochemical characterisation of CPPs and their in vitro and in vivo testing
Collaborator Contribution New delivery approach providing its implementation into the currently pursued strategy.Provision of new CPPs
Impact BSc thesis at Nijmegen University Manuscript in preparation Multidisciplinary approach between peptide chemistry (Stockholm), cell biology (Nijmegen) and molecular oncology (Newcastle)
Start Year 2010
 
Description Self-organising micelles for siRNA delivery 
Organisation Newcastle University
Department School of Chemistry
Country United Kingdom 
Sector Academic/University 
PI Contribution Strategic design of polymeric micelles, physicochemical characterisation
Collaborator Contribution new composite polymers for delivery of siRNAs
Impact Successful EPSRC KTA application Successful EPSRC MRes/PhD application Multidisciplinary collaboration between polymer chemistry and molecular oncology
Start Year 2010
 
Description preparation of liposomes for siRNA delivery 
Organisation Gottfried Wilhelm Leibniz Universität Hannover
Department Medical School Hanover
Country Germany 
Sector Academic/University 
PI Contribution provision of lipid and siRNAs, physicochemical, biological and pre-clinical testing
Collaborator Contribution generation of liposomes using a microfluidics device
Impact none yet
Start Year 2013
 
Description targeted siRNA delivery 
Organisation University of Stuttgart
Department Institute of Cell Biology and Immunology
Country Germany 
Sector Academic/University 
PI Contribution Provision of siRNA, cell and animal models; development of detection method
Collaborator Contribution Knowledge and know how of nanoparticle and scFv production
Impact none yet
Start Year 2010