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Sandro Rusconi 1972-75 1975-79 1979-82 1982-84 1984-86 1987-94 1994-today 1996-02 Fribourg 06.11.2003 SSMI Colloque Médecins-chefs Primary school teacher (Locarno, Switzerland) Graduation in Biology UNI Zuerich, Switzerland PhD curriculum UNI Zuerich, molecular biology Research assistant UNI Zuerich Postdoc UCSF, K Yamamoto, (San Francisco) Group leader, UNI Zuerich (mol. bio., PD) Professor Biochemistry UNI Fribourg Director Swiss National Research Program 37 'Somatic Gene Therapy' 2002-today Swiss Natl. Res. Program 50 'Endocrine disruptors' 2002-03 Sabbatical, Tufts Med. School Boston and Univ. Milano, Pharmacology Department 2002-05 President Union of Swiss Societies for Experimental Biology (USGEB) UNIFR Rusconi 2003 Doping sportif avec transfert de gènes: mythe ou réalité? Schedule Basic understanding of 'genes': what is a gene, how many genes, molecular biology dogma genetic diseases, environmental factors, ageing Essential concepts on 'molecular medicine' & molecular doping: applications and problems, Techniques of gene transfer (Gene Therapy) problems and solutions, vectors, clinical achievements Gene-based doping applications, comparison with other doping, detection Conclusions plausibility table UNIFR Rusconi 2003 UNIFR 1 gène-> 1 ou plusieures fonctions Rusconi 2003 DNA RNA(s) Protein(s) Transcription / translation Gene expression GENE 2-5 FUNCTIONS 100 ’000 genes (50 ’000 genes?) >300 ’000 functions (>150 ’000 functions) Un gène c'est quoi? une nanomachine pour la production de UNIFR Rusconi RNA gravée sur un segment de DNA 2003 DNA GENE RNA Protein Transcription / translation FUNCTION Ergo pour un transfert génique efficace il faut transférér aussi les RNA séquences de régulation apprpriées DNA spacer regulatory coding spacer UNIFR 1 Organisme -> 1013 cellules, spécialisées et organisées en tissus et organes Rusconi 2003 2 mm 2m 0.2mm 0.02mm 0.001mm DNA RNA Protein 1 Cm3 de tissu 1'000'000'000 cellules ! UNIFR Le paradigme réductionniste du biologiste moléculaire Rusconi 2003 DNA GENE GENE OK GENE KO GENE transfer Protein FUNCTION(s) le transfer génique impliquera: transfert d'une fonction FUNCTION OK nouvelle , ou transfert d'une fonction compensatrice , ou transfert d'une fonction qui interfère FUNCTION KO FUNCTION transfer L'état de santé/maladie ou des différences individuelles ne dépend pas seulement du génome genetics Muscle distrophy Familial Breast Cancer Sporadic Breast Cancer Lung Cancer Obesity Artherosclerosis also acquired conditions may have a genetic component that modulates their healing/improvement Alzheimer trauma Parkinson ’s fractures burns Drug Use/Abuse infections Sexual orientation behaviour UNIFR Rusconi 2003 environment Les manipulations de base pour obtenir de DNA récombinant sont relativement simples segments of genomic DNA can be specifically cut and isolated isolated segment can be recombined with a plasmid vector Science-grade material can be essentially prepared in your cellar plasmid vector is transferred into bacteria where it can multiply ...not so clinical-grade material! isolated recombinant DNA can be further recombined to obtain the final desired molecule Final molecule is transferred into cells or organisms UNIFR Rusconi 2003 UNIFR Les quatres ères de la médecine moléculaire Rusconi 2003 Eighties Genes as probes Nineties Genes as factories Y2K Genes as drugs 1 2 3 4 5 ok ** ok ** ** 50 10 3000 80 85 90 95 99 1000technologies Y2K+n Post-genomic improvements of former 80 85 90 95 00 voilà que l'on est prêts pour parler de thérapie génique somatique Definition of GT: 'Use genes as drugs': Correcting disorders by somatic gene transfer NFP37 somatic gene therapy www.unifr.ch/nfp37 Chronic treatment Acute treatment Preventive treatment Hereditary disorders Acquired disorders Loss-of-function Gain-of-function UNIFR Rusconi 2003 UNIFR Pouquoi 'somatique'? Rusconi 2003 Germ Line Cells: the cells (and their precursors) that upon fertilisation can give rise to a descendant organism Ergo: le transfert génique somatique courant cherche à éviter les cellules germinales il ne porte pas à une trasmission héréditaire de la modification Somatic Cells: all the other cells of the body Les quatre questions fondamentales dans le transfert génique somatique Efficiency of gene transfer Specificity of gene transfer Persistence of gene transfer Toxicity of gene transfer UNIFR Rusconi 2003 Remember! les questions pharmacologiques: différent niveau de réversibilité Classical Drugs Mw 50- 500 Daltons Synthetically prepared Rapid diffusion/action Oral delivery possible Cellular delivery: - act at cell surface - permeate cell membrane - imported through channels Can be delivered as soluble molecules Ångstrom/nm size rapidly reversible treatment Protein Drugs Mw 20 ’000- 100 ’000 Da Biologically prepared Slower diffusion/action Oral delivery not possible Cellular delivery: - act extracellularly Can be delivered as soluble molecules nm size rapidly reversible treatment UNIFR Rusconi 2003 Nucleic Acids Mw N x 1’000’000 Da Biologically prepared Slow diffusion Oral delivery inconceivable Cellular delivery: - no membrane translocation - no nuclear translocation - no biological import Must be delivered as complex carrier particles 50-200 nm size slowly or not reversible Thérapie avec DNA: requère une formulation en particules est plus complexe que l'administration d'autres médicaments a un niveau inférieur de réversibilité Trois classes de transfert anatomique Ex-vivo In-vivo topical delivery UNIFR Rusconi 2003 In-vivo systemic delivery V Examples: - bone marrow - liver cells - skin cells Examples: - brain - muscle - eye - joints - tumors Examples: - intravenous - intra-arterial - intra-peritoneal Deux classes de 'vecteurs': non-virales et virales Non-viral transfer (transfection) Viral gene transfer (Infection) UNIFR Rusconi 2003 a b Nuclear envelope barrier! see, Nature Biotech December 2001 Transfection (transfert non-viral) comparée à infection (transfert viral) UNIFR Rusconi 2003 Transfection exposed to 106 particles/cell 12 hours Infection exposed to 3 particle/cell 30 min UNIFR Rusconi 2003 Popular vectors for gene transfer: r-Adenovirus (30 kb) Naked r-plasmid DNA r-Adeno-associated V. ( 4 kb) Liposomes & Coformulated r-plasmid DNA r- Retrovirus (incl. HIV)(10 Kb) Oligonucleotides Recap: current limitations of popular gene transfer vectors Adenovirus - no persistence - limited packaging - toxicity - immunogenicity Retrovirus (incl. HIV) - limited package - random insertion - unstable genome General - antibody response - limited packaging - gene silencing Solutions: - synthetic viruses (“Virosomes”) UNIFR Rusconi 2003 Biolistic bombardment or local direct injection - limited area Electroporation - limited organ access Liposomes, gene correction & Co. - very inefficient transfer General - low transfer efficiency 1/10’000 of viruses’ in vivo Solutions: - improved liposomes with viral properties (“Virosomes”) UNIFR Thérapie génique dans la clinique Rusconi 2003 trials patients As of Sept. 2003: 100 80 610 registered protocols 1500 ~4000 treated patients cancer 60 hered. 40 86% phase I 13% phase II 1 % phase III 500 vasc. 21% overall still pending Infect. or not yet Initiated ! 20 www.wiley.com 1990 1992 1000 1994 1996 1998 2000 Faits marquants: anecdotiques mais importants UNIFR Rusconi 2003 Anderson, 1990 1990, 1993, 2000 // ADA deficiency Isner, 1998 Dzau, 1999 F Anderson, M Blaese // C Bordignon Kmiec, 1999 Fischer, 2000 1997, 2000, Critical limb ischemia Dickson, 2000 J Isner († 4.11.2001), I Baumgartner, Circulation 1998 Aebischer, 2000 Kirn, 2001 1998, Restenosis V Dzau, HGT 1998 1999, Crigler Njiar (animal) C Steer, PNAS 1999 Clinical trials with ONYX-015, 2000, Hemophilia what we learned? M Kay, K High 2000, SCID (Review) A Fischer, Science April 2000 Bordignon, 2000 (ESGT, Stockholm) 2000, correction Apo E4 (animal model) proves efficacy of the same protocol G. Dickson, ESGT congress, 7.10.2000 Stockholm 2000, correction Parkinson (animal model) P Aebischer, Science, Nov 2000 2001, ONYX oncolytic Viruses D Kirn (Gene Ther 8, p 89-98) Les effets secondaires plus redoutés dans le transfert génique somatique Immune response to vector immune response to new or foreign gene product General toxicity of viral vectors Adventitious contaminants in recombinant viruses Random integration in genome -> insertional mutagenesis (-> cancer risk) side effects of newly acquired gene product Contamination of germ line cells Ergo beaucoup de ces effets sont liés au niveau prototypique de la tecnologie de transfert génique couramment les risques associés limitent l'indication de la TGS pour de maladies graves UNIFR Rusconi 2003 Quatre leçons amàres mais un seul cas de décès causé directement par la Thérapie génique UNIFR Rusconi 2003 NY May 5, 1995, R. Crystal: in a trial with adenovirus mediated gene transfer to treat cystic fibrosis (lung) one patient developed a mild pneumonia-like condition and recovered in two weeks. The trial interrupted and many others on hold. UPenn, Sept. 19, 1999, J. Wilson: in a trial with adenovirus mediated gene transfer to treat OTC deficiency (liver) one patient (Jesse Gelsinger) died of a severe septic shock. Many trials were put on hold for several months (years). Paris, Oct 2, 2002, A Fischer: in a trial with retrovirus mediated gene transfer to treat SCID (bone marrow) one patient developed a leukemia-like condition. The trial has been suspended to clarify the issue of insertional mutagenesis, and some trials in US and Germany have been put on hold. !! Most Recent Paris, Jan 14, 2003, A Fischer: Paris' Trial News www.unifr.ch/nfp37/adverse.html a second patient of the cohort of 9 comes up with a similar disease than the one reported in october 2002. 30 trials in USA are temporarily suspended les hauts et les bas dans la thérapie génique: comme les montagnes russes UNIFR Rusconi 2003 A. Fischer M. Kay high lentivectors in clinics? R. Crystal V.Dzau Adeno I C Bordignon J. Isner ADA mood NIH Motulski report Ergo Low 90 chaque fois qu'on était convaincu avoir atteint une 'vitesse de croisière', un évènement négatif a baissé les enthousiasmes 91 92 93 94 95 AAV germline in mice? Adeno III Lentivectors in pre-clinic J. Wilson J. Gelsinger 96 97 98 99 00 01 Adverse events in Paris 02 03 Finalement, doping 'génique':... possible? UNIFR Rusconi 2003 vu les difficultés de la thérapie génique on pourrait imaginer qu'il est bien trop tôt pour se précoccuper des applications possibles au doping sportif, cependant... UNIFR Rusconi 2003 Les trois niveaux de doping + Before the competition (anabolic enhancers) 'Molecular treatments Application of the know-how in molecular genetics to doping + During the competition (performance enhancers) + After the competition (repair enhancers) Quels transfert géniques seraient envisageables pour des stratégies de dopage ex vivo, hematopoietic tissue: pro hematopoietic (Epo receptor, oxygen transport...) in vivo local (example muscle): metabolic enhancers, growth factors, muscular fiber changers, cardio-modulators (glucose/oxygen, MGF, IGF, anti-myostatin,...) in vivo local (example joints): pain reducers, inflammation inhibitors, recovery and repair factors (anti-TNF, BMPs, ...) in vivo systemic: anabolic enhancers, endocrine factors, pain killers, vascular controllers, (hormone metabolising enzymes, proenkephalins, ...) UNIFR Rusconi 2003 Quels effets secondaires pourrait-on craindre lors de dopage avec transfert génique? UNIFR Rusconi 2003 Short -mid term Autoimmunity Hyperimmunity Toxic shock Long term dangers d'une attitude 'casse-cou' Fibrosis malpractice (unsuitable vector/administration route) Cancer non-clinical grade material conventional side- effects of administered factors (pathogens or allergens) Inaccessibility to future gene lack of follow-up therapy interventions (immunity) Quelles seraient les limitations objectives dans des stratégies de dopage avec transfert génique Viral gene transfer immune problems limited readministration possibilities general toxicity, genotoxicity Nonviral gene transfer generally inefficient lack of persistence, requires readministration Strategy-independent problems laborious, not readily available long term gene expression difficult to control irreversible effects or permanent tagging UNIFR Rusconi 2003 Méthodes de détection plausibles pour le dopage avec transfert génique UNIFR Rusconi 2003 Antibody detection (viral antigens) r-nucleic acids detection (PCR) recombinant protein / post-translational modification detection (MALDI-TOF ) Anatomically difficult to detect Ergo (if locally administered) TG pas toujours analysable dans -> but leaves permanent genetic marking le sang ou l'urine, mais identifiable indéniablement dans de biopsies Detection of nucleic acids cannot be performed in body fluids même longtemps après le traitement (except in early phase after systemic administration) -> might require specific tissue biopsy Comparaison directe des 'avantages' / 'désavantages': dopage 'génique' versus dopage conventionnel Category Ergo: Drug/protein Gene-based Les chances parlent objectivement plutôt en défaveur Rapidity of effectsavec rapid du dopage transfert génique slow mais: Reversibility rapid slow ces considérations se basent sur le bon sens, qui semble être très straightforward carent dans le secteur du dopage Dosage difficult et aussi: simple complex ...il y a plusieurs disciplines sportives (ou niveaux de sport) dans lesquelles le dopage n'est pas vérifié Associated risks depends high le liaisons dangereuses: ... professionnelspossible du dopage qui sedifficult mettent en Concealability /impossible contact avec des chercheurs sans scrupules Complexity of treatm. UNIFR Rusconi 2003 Le transfert génique dans le dopage: conclusions UNIFR Rusconi 2003 somatic gene transfer has been originally developed for the treatment of diseases (genetical orergo: acquired) le dopage ne serait has the potential to be applied for pre- duringandgénétique postni plus dangereux ni plus moralement performance enhancement condannable du dopage conventionnel currently dedicated to theapy, still experimental and not mature for applications in non-serious conditions le danger majeur n'est pas major risk in doping linked with improperleapplication dopage génique en soi (GCP non-compliant or non-clinical-grade materials) mais l'ambition humaine incontrôlée qui porte à répéter les même erreurs ! Has already raised the interest in the doping field In spite of premature status is likely to be attempted in the next years (perhaps already?) the CIO and the WADA have already officially included gene-based doping in the list of banned practices (ww.wada.org) starting 1.1.2003 QuickTime™ et un décompresseur None sont requis pour visualiser cette image. ... MERCI et espérons que le sport puisse rester un spectacle d'émotions et de fairplay SSMI, Prof C. Regamey My collaborators at UNIFR Swiss National Research Foundation NFP37 if you are too shy to ask send an e-mail to: [email protected] or visit: www.unifr.ch/nfp37 UNIFR Rusconi 2003 UNIFR Rusconi 2002