Sak 03807 O Vedlegg Fagleg Rapportering 2006 - Helse Vest

408Forskerutdanning - postdoc 911182:In vivo modeller for utvikling av ny leukemibehandlingProsjektansvarlig: Emmet McCormack (emmet.mc.cormack@biomed.uib.no), Universitetet i BergenIn Vivo Imaging of AMLEmploying novel technology, researchers at the institute of internal medicine canaccurately determine disease progression in animal models of GFP-AML, and anlaysetherapeutic effect employing in vivo optical imagingThe evaluation of new therapeutic strategies or novel compounds in animals and, in particular, humanxenograft animal models of disease is the cornerstone of pharmaceutical and biomedical drugdevelopment. These models serve as critical translational tools between; in vitro hypothesis andclinical application. However, use of animal models, and especially models of leukaemia, is frustratedby disease states that cannot be quantified during disease progression. Additionally, diseasedevelopment is not uniform in all animals and they exhibit differing disease latencies making it difficultto decide treatment point. Thus, to obtain statistically meaningful data in preclinical models scientistsmust use large numbers of animals in their research. This has both serious ethical and financialimplications, and with more drug candidates failing early in clinical evaluation one must reflect on theaccuracy of current preclinical evaluation.Nevertheless, the development of genomic strategies whereby cancer cells can be encoded withfluorescent proteins (FP) such as; green fluorescent protein from the jellyfish, have enabled thedevelopment of systems which can detect the emitted light in living animals. By inoculating mice withthese cells, one can illuminate the mice and detect FP fluorescence and accordingly, where the cellsare and quantify tumour burden in each animal. Theoretically, these systems enable the developmentof more accurate disease models by permitting researchers to decide therapeutic intervention time ona per animal basis, and to follow therapeutic effect on the FP cell population. One of the majorobstacles in employing these techniques, particularly with green fluorescent proteins (GFP) is thatmouse tissue also fluoresces at the same wavelength as GFP, making it difficult to distinguish betweenGFP fluorescence and animal auto-fluorescence. We have developed a novel method to discriminatebetween GFP and auto-fluorescence based on the differing times that the fluorophores spendfluorescing (known as “fluorescence lifetime”). Using this method we have been able to accuratelyquantify GFP cell burden for the first time in animal models of acute myelogeneous leukaemia (AML).Additionally, by analysing the properties of GFPs fluorescence lifetime we have been able to determinedepth of the GFP cells allowing us to examine the pathology of AML disease progression moreaccurately than possible previous. We also outlined the application of this technique to severaldifferent body compartments including the brain and lung.Labeling potential drug candidates with fluorescent dyes also, allows tracking of the drugs in vivo,permitting evaluation of the drugs pharmaco-kinetics, -dynamics and compartmentalisation. Also, byusing labeled proteins such as Annexin V-Cy5.5, which detects apoptotic cell death followingtherapeutic intervention, one can precisely determine the efficacy of a drugs therapeutic potential.Thus, we presented (SMI, 2006) that by treating such tumours with therapeutic drugs we couldanalyse apoptotic cell death and thus drug efficacy, in vivo. So by using these technologies one canobtain more statistically significant results, using considerably fewer animals in much shorter timeperiods, enabling more accurate preclinical development and faster decisions on potential therapeuticdrugs. Further development of this project will focus on employing these novel strategies in drugdevelopment for AML.2 vitenskapelige artikler er publisert i 2006:Bruserud Ø, McCormack E, Gjertsen BT"Immunotherapy in chronic lymphocytic leukemia."Cancer Immunol Immunother. 2006;55(2):185-7PMID: 16001162Translasjonsforskning - Hematology