Ouah, quel boulot...merci! Bon petit bemol, si les mots-clés et équations correspondantes sont bonnes, on aurait voulu voir quelques tentatives de recherche dans des bases de données bibliographiques scientifiques autres que Pubmed, comme par exemple Scopus, Web of Science, en identifiant des bonnes reviews!
2/2 A. les mots-clés sont pertinents
2/2 B. La grammaire des équations correspondant aux mots-clés est bien maîtrisée. Les équations sont pertinentes par rapport à l'outil sélectionné.
2/2C. Outils: le type de documents trouvés dans divers outils de recherche est bien maîtrisé. Les outils sont multiples et complémentaires.
2/2 La restitution de la méthodologie documentaire (mots-clés/équations/ types de documents/choix outils de recherche est riche et très appréciée!
2/2 D. Les références bibliographiques sont correctes, et mentionnent bien avec quel outil elles ont été trouvées
2/2 E.Les éléments de réponse à la question sont pertinents, et correctementréférencés.
2/2 F. La restitution écrite qui montre la méthode de recherche d'information est bonne. Parfois, cependant, elle est un peu touffue et maladroite (attention au soin de la rédaction)
Pour information, on peut utiliser des textes intégraux avec guillemets et source, ou des idées empruntées avec paraphrase et source (droit d'auteur). Mais la reproduction par copié collé d'image, de tableau, de dessin, de graphique, de statistiques, n'est pas possible, même en citant la source! Pour une reproduction, il faut demander aux auteurs et à l'éditeur la permission de reproduction (droit de diffusiont). Parfois, il faut payer pour obtenir ce droit. Autrement dit, le droit d'utilisation des "images" n'est pas le même que les idées sous forme écrite!
7.2 Equations testées dans quel outil de recherche documentaire
Nous avons commencé par une recherche des plus générale sur le site wikipédia en tapant: "thérapie génique" AND rétrovirus pour arriver à ce site concernant les méthodes les plus employées en thérapie génique: http://fr.wikipedia.org/wiki/Th%C3%A9rapie_g%C3%A9nique
Nous avons continué notre recherche en allant sur NEBIS, google scholar ou pubmed en tapant: "gene therapy" AND retroviruses pour obtenir quelques articles généraux concernant notre sujet.
Pour obtenir des informations plus particulières, nous avons choisi pubmed comme base générale et avons tapé "gene therapy" AND retroviruses AND "adverse effects" ou encore "gene therapy" AND retroviruses AND "clinical trials" pour arriver à des articles plus spécifiques concernant les accidents survenus lors de l'emploi de cette technique de thérapie.
Nous allons par la suite expliquer les résultats en mettant notre démarche à chaque étape.
7.3 Résultats
7.3.1 Introduction et exemples de recherche générale
a) en tapant sur pubmed: "gene therapy" AND retroviruses:
"Viruses have evolved to become highly efficient at nucleic acid delivery to specific cell types while avoiding immunosurveillance by an infected host. These properties make viruses attractive gene-delivery vehicles, or vectors, for gene therapy. Several types of viruses, including retrovirus, adenovirus, adeno-associated virus (AAV), and herpes simplex virus, have been modified in the laboratory for use in gene therapy applications. "1
"Because these vector systems have unique advantages and limitations, each has applications for which it is best suited. Retroviral vectors can permanently integrate into the genome of the infected cell, but require mitotic cell division for transduction. Adenoviral vectors can efficiently deliver genes to a wide variety of dividing and nondividing cell types, but immune elimination of infected cells often limits gene expression in vivo. Herpes simplex virus can deliver large amounts of exogenous DNA"1
b) en tapant sur sciencedaily: "gene therapy" AND retrovirus AND "adverse effects":
Gene therapy can cause leukemia in large animals. "Individuals with a number of life-threatening genetic diseases of the immune system have been successfully treated by gene therapy -- that is, they were infused with early precursors of immune cells that had the correct form of the defective gene delivered into them by agents known as retroviral vectors. However, some patients later developed leukemia."2
c) Sur google scholar: "gene therapy" AND retrovirus AND "adverse effects" AND leukemia
"Recently, unusual forms of leukemias have developed as complications following retroviral transfer of potentially therapeutic genes into hematopoietic cells. A crucial component in the pathogenesis of these complications was the upregulation of a cellular proto-oncogene by random insertion of the retroviral gene transfer vector. These findings have great implications for the genetic manipulation of somatic stem cells in medicine."3
"Specific pathophysiology of a gene therapy side effect. The lymphoproliferations (LP) observed in SCID-X1 patients following retroviral vector-mediated upregulation of LMO2 show some similarity with T-ALLs due to LMO2 translocations, but are unusual with respect to the presence of a mature fully rearranged T cell receptor (TCR)/CD3 complex."3
7.3.2 Les accidents:
Nous avons commencé une recherche générale sur google en tapant: "patient's death" retrovirus "gene therapy" et sommes tombés sur des cas très intéressants de la thérapie génique utilisant des rétrovirus sur des sujets ayant une arthrite.
"In July 2007 a subject died while enrolled in an arthritis gene therapy trial."4
"Attention has focused on retroviruses and adeno-associated virus (AAV), which offer the prospect of long-term expression. Most retrovirus vectors are derived from the Moloney murine leukemia virus, and were the first to be developed for human use. The viruses integrate their genetic material into the chromosomal DNA of the cells they infect, thereby providing a basis for long-term expression of the transgene."4
Seulement, les recherches ont été abandonnées avec les rétrovirus pour des questions de fonds et la base du travail a été reconstruite avec les AAV, donc nous ne prendrons pas ce cas comme un accident basé sur la thérapie génique à l'aide de rétrovirus.
Par la suite, nous avons concentré notre recherche sur la leucémie et particulièrement dans les patients de type SCID-X1. Cela nous donne en recherchant bien spécifiquement sur pubmed: "gene therapy" AND retrovirus AND leukemia AND SCID-X1 l'article en référence 5 qui nous dit:
"Several individuals with X-linked SCID (SCID-X1) were treated by gene therapy to restore the missing IL-2 receptor γ (IL2RG) gene to CD34+ BM precursor cells using gammaretroviral vectors. While 9 of 10 patients were successfully treated, 4 of the 9 developed T cell leukemia 31–68 months after gene therapy."5
"In patient 4 and patient 5 (P4 and P5, respectively), the first 2 cases initially described in 2003, the gammaretroviral vector used for transduction integrated near the LIM domain–only 2 (LMO2) proto-oncogene and activated its transcription, thereby promoting clonal T cell proliferation."5
"In all 4 adverse events, proto-oncogenes were activated as a consequence of vector integration. Activation of LMO2 was involved in 3 of 4 cases. The role of LMO2 in oncogenesis has been well established from analysis of primary T cell leukemia and murine models. In P10, 2 insertions were found, one in LMO2 locus and the other in BMI1. The Bmi1 gene was first identified in mice as a target of retroviral insertional activation in B cell lymphoma in association with c-Myc mutation"5
L'article nous donne une expérience s'étant déroulé sur des patients ayant un défaut dans leurs récepteurs IL-2. L'insertion du transgène venant de la thérapie génique à l'aide de rétrovirus s'est mal déroulée, a provoqué la promotion de 2 proto-oncogènes (LMO2 sur les 4 patients et BMi1 pour un patient en plus de LMO2) et s'en est suivi la prolifération non contrôlée des T-cells provoquant ainsi une leucémie.
Pour approfondir plus spécifiquement les accidents et trouver des sujets concrets à notre étude, nous avons recommencé avec une recherche générale dans wikipédia. L'article "gene therapy" obtenu grâce à l'équation gene AND therapy nous a permis de prendre comme base de travail cinq incidents répertoriés avec des vecteurs rétroviraux. Quatre incidents ont eu lieu en France, et un en Grande-Bretagne. Un fait important est l'effet secondaire du traitement est la leucémie, ce qui nous permettra de spécifier nos recherches.
"To date, four children in the French trial and one in the British trial have developed leukemia as a result of insertional mutagenesis by the retroviral vector"
Wikipedia. Gene Therapy [en ligne]. Disponible sur <http://en.wikipedia.org/wiki/Gene_therapy> (consulté le 01.11.08)
Une recherche lexisnexis avec les équations suivantes gene AND therapy AND france, gene AND therapy AND frenchpermet d'obtenir un article parlant de l'arrêt des essais cliniques et permet en plus d'obtenir le nom de la personne conduisant les essais cliniques : A. Fischer.
"The treatment was pioneered by a team led by Dr. Alain Fischer of the Necker Children's Hospital, Paris. The French scientists removed bone marrow stem cells from the child, and used a retrovirus to carry corrective genes into the cells. Once done the bioengineered cells were injected back into the patient."
Biotechnology Newswatch. Bubble boy blood cancer setback for gene therapy [en ligne]. Disponible sur : <http://www.lexisnexis.com/fr/business/results/docview/docview.do?docLinkInd=true&risb=21_T5077388436&format=GNBFULL&sort=RELEVANCE&startDocNo=1&resultsUrlKey=29_T5077388439&cisb=22_T5077388438&treeMax=true&treeWidth=0&csi=7921&docNo=1> (consulté le 08.11.08)
Une recherche avancée avec pubmed, en recherchant avec le nom d'autheur Fisher et en limitant les publications aux essais cliniques avec l'équation (fischer[Author]) AND (fischer) Limits: Clinical Trial permet d'obtenir un article récent traitant de l'état des patients en France5.
Le dernier incident s'est produit en Angleterre. Une recherche google avec les équations suivantes : leukemia AND after AND gene AND therapy AND great AND britain, leukemia AND after AND gene AND therapy AND england
permet d'obtenir les noms des personnes menant les essais cliniques : Professor Adrian Thrasher and professor Bobby Gaspar.
"Bobby Gaspar and Adrian Thrasher, who treated the boy, said in a statement: “Our first thoughts are to secure the best treatment for this child and to support his family."
Timesonline. Boy gets leukaemia after gene treatment to cure ‘bubble baby syndrome’ [en ligne]. Disponible sur : <http://www.timesonline.co.uk/tol/news/uk/science/article3068051.ece> (consulté le 08.11.08)
Ces deux noms permettent avec une recherche avancé de pubmed avec l'équation suivante : Gaspar or Thrasher[Author] Limits: Clinical Trial d'obtenir des détails biologiques de l'incident.6
7.3.2.1 Gravité des incidents
La littérature scientifique au sujet de ces deux cas permet de répondre à cette question. Quatre patients ont développé une leucémie. Les quatre ont été traités par chimiothérapie. Ce traitement a été
efficace sur 3 patients, le quatrième patient est décédé. Le tableau extrait de l'article 5 résume la situation
Salima Hacein-Bey-Abina et al., Insertional oncogenesis in 4 patients after retrovirus-mediated gene therapy of SCID-X1, The Journal of Clinical Investigation, 2008, vol. 118, 9, pp 3132-3142
Le patient anglais a développé lui aussi une leucémie. Il a été traité par chimiothérapie et est considéré comme en rémission
"The patient was in clinical and molecular remission 4 months after commencement of therapy"
Steven J. Howe et al., Insertional mutagenesis combined with acquired somatic mutations causes leukemogenesis following gene therapy of SCID-X1 patients, The Journal of Clinical Investigation, 2008, vol. 118, 9, pp 3143-3150
7.3.2.2 Quand ?
Pour répondre à cette question, il est nécessaire cibler à nouveau la recherche. L'utilisation de google est suffisante pour obtenir des informations.
L'équation fischer AND gene AND therapy AND leukemia dans Google
"[...] This clinical trial, which included 11 patients, was put on hold in October 2002 (see press release October 3rd 2002), after a first notification of a complication in one of the patients had been observed, consisting in an uncontrolled T-lymphocyte proliferation. The same complication has been reported for a second patient at the end of 2002 (see Afssaps Press release dated 15 January 2003). The hold was maintained until analysis and identification of the mechanism(s) responsible. One of the patients died last October, the other is progressively recovering."
Agence française de sécurité sanitaire des produits de santé. 3rd complication case in DICS X gene therapy clinical trial [en ligne]. Disponible sur : <http://afssaps.sante.fr/htm/10/filcoprs/050103en.htm> (consulté le 08.11.08)
L'équation fourth AND leukemia AND after AND gene AND therapy AND fischer dans google permet de trouver la date : mars 2007.
"As reported by Professor Alain Fischer at 33rd Annual Meeting of the European Group for Blood and Marrow Transplantation (EBMT) in Lyon, France on March 25-28, 2007, a fourth case of a malignant cell expansion has been observed in the clinical phase 1 trial" European Society of Gene and Cell Therapy (ESGCT). Fourth case of leukaemia in the first SCID-X1 gene therapy trial, and the diversity of gene therapy [en ligne]. Disponible sur : <www.esgct.org/upload/4th_CaseofLeukemial.pdf> (consulté le 8.11.08)
Le patient anglais se trouve avec l'équation suivante : leukemia AND after AND gene therapy thrasher great britain en décembre 2007.
"December 19, 2007
Boy gets leukaemia after gene treatment to cure ‘bubble baby syndrome’"
Timesonline. Boy gets leukaemia after gene treatment to cure ‘bubble baby syndrome’ [en ligne]. Disponible sur : <http://www.timesonline.co.uk/tol/news/uk/science/article3068051.ece> (consulté le 08.11.08)
7.3.2.3 Où ?
L'endroit où se sont produits les incidents n'a pas causé de difficultés, car ils sont déjà mentionnés dans la partie 7.3.2.2.
"By the end of August 2002 a serious adverse event was notified in a patient included in the first gene therapy clinical trial, aimed at correcting the X-linked severe combined immuno-deficiency (X-SCID), conducted by professors Marina Cavazzana-Calvo and Alain Fischer at Necker-Enfants Malades hospital in Paris, France (see Afssaps press release, October 3rd 2002)."
Agence française de sécurité sanitaire des produits de santé. Severe Combinated Immuno-Deficiency[en ligne]. Disponible sur : <http://agmed.sante.gouv.fr/htm/10/filcoprs/030101en.htm> (consulté le 08.11.08)
"Two years ago the boy became the eighth patient to be treated in London on Great Ormond Street Hospital’s gene therapy programme"
Timesonline. Boy gets leukaemia after gene treatment to cure ‘bubble baby syndrome’ [en ligne]. Disponible sur : <http://www.timesonline.co.uk/tol/news/uk/science/article3068051.ece> (consulté le 08.11.08)
7.3.2.4 Erreurs, sanctions, mesures préventives
Une recherche extensive de google, puis lexisnexis n'a pas permis de découvrir d'erreurs commises par les les deux groupes qui ont menés les essais cliniques. Néanmoins, certaines mesures ont été prises
suite à l'apparition des leucémies chez les premiers patients en 2002. Les agences de régulation françaises, puis américaines et britanniques ont suspendu les essais pour examiner les accidents.
Un communiqué de presse de l'Agence française de sécurité sanitaire des produits de santé, ainsi que une news de Science résume les décisions prises par différentes autorités de régulation :
Recherche google : gene AND therapy AND clinical AND trial AND fischer
"By the end of August 2002 a serious adverse event was notified in a patient included in the first gene therapy clinical trial, aimed at correcting the X-linked severe combined immuno-deficiency (X-SCID),
conducted by professors Marina Cavazzana-Calvo and Alain Fischer at Necker-Enfants Malades hospital in Paris, France (see Afssaps press release, October 3rd 2002).
Upon notification of this event, the clinical trial was put on hold by the sponsor, in agreement with the French Medical products Safety agency (Afssaps). Since then no other patients have been included in
the trial and the first eight patients, who had received the gene therapy product, have been subject to an intensive clinical and biological follow-up.
Very recently, the principal investigators have detected, in a second patient, an abnormal and monoclonal proliferation of T-lymphocytes, characteristics of which are very close to the case reported in the
first young patient.
As for the first case, the patient is receiving a chemotherapy; a satisfactory clinical response has been so far obtained for the two patients.
Further investigations, have been initiated in an attempt to better explain the mechanism of the adverse event, so as to develop methods able to prevent this risk."
Agence française de sécurité sanitaire des produits de santé. Severe Combinated Immuno-Deficiency[en ligne]. Disponible sur : <http://agmed.sante.gouv.fr/htm/10/filcoprs/030101en.htm> (consulté le 08.11.08)
Recherche google : gene AND therapy AND clinical AND trial AND fischer
"In May 2004, the French Health Product Safety Agency (Afssaps) authorised the restart of the gene therapy clinical trial conducted by Prof. Alain Fischer and Marina Cavazzana-Calvo, in Necker-Enfants-
Malades hospital in Paris.[...] The same complication has been reported for a second patient at the end of 2002 (see Afssaps Press release dated 15 January 2003). The hold was maintained until analysis and
identification of the mechanism(s) responsible. One of the patients died last October, the other is progressively recovering.
The clinical trial has been authorised to resume after the investigators proposed several protocol modifications (number of administrated cells, inclusion criteria, age of the patients to be enrolled, etc. )
aimed at reducing the risk of insertional oncogenesis. Since the restart of the clinical trial, one new patient has been treated.
On January 18th, 2005, a new complication was notified to Afssaps. It concerns a third child who was 9 months old when receiving the treatment in April 2002. This complication is also a T-lymphocytes
proliferation, which characteristics are still under investigation.
Following this information, and in agreement with Afssaps, the investigators and promoter decided to put on hold the clinical trial again, and wait for further investigations in an attempt to better explain
the mechanism of the adverse event."
Agence française de sécurité sanitaire des produits de santé. 3rd complication case in DICS X gene therapy clinical trial [en ligne]. Disponible sur : <http://afssaps.sante.fr/htm/10/filcoprs/050103en.htm>
(consulté le 08.11.08) (google)
Recherche google : gene AND therapy AND clinical AND trial AND fischer
"For the second time in 4 months, a child has developed a leukemia-like disease after receiving gene therapy at the Necker Hospital for Sick Children in Paris. Concerned about the safety of such trials, the
panel that monitors U.S. research in the field scheduled a public meeting this week to review the clinical data and weigh its next steps.
The news of a second case of cancer in the French trial reached the U.S. Food and Drug Administration (FDA) on 20 December and quickly spread to other gene-therapy researchers. FDA responded by putting a
"clinical hold" on U.S. studies that, like the French trial, use retroviruses to shuttle therapeutic genes into the chromosomes of target cells; most were already on pause for a safety review (see table).
Meanwhile, the Necker Hospital's lead investigator, Alain Fischer, asked colleagues around the world to keep the information confidential until after he had spoken with the families of the 10 children in the
experiment. At press time, Fischer had not gone public and declined to discuss the details. He said that he intended to present his data on 17 January to the Recombinant DNA Advisory Committee (RAC) of the
U.S. National Institutes of Health (NIH).[...]
FDA ordered a pause in all three U.S. clinical trials using retroviruses. The only trial of this type not to pause for review was one run by Adrian Thrasher at the Institute of Child Health in London. It suspended therapy this week.
When the first adverse event appeared last fall, FDA and RAC sought outside advice on whether to suspend similar trials in the United States or to impose new reporting requirements. Some experts warned
officials not to overreact, saying that the cancer might have been triggered by a harmful genetic mutation not related to the therapy. They noted that two other people in the child's family also had
developed cancer at an early age. Others, however, felt that the clinical data strongly suggested that the gene therapy itself had triggered the dangerous T cell proliferation. In the end, U.S. authorities
decided to allow the potentially risky trials to continue, with closer monitoring (Science, 18 October 2002, p. 510). But none actually resumed.[...]"
Eliot Marshall, GENE THERAPY: Second Child in French Trial Is Found to Have Leukemia, Science, 2003, vol. 299, no. 5605, p. 320
Recherche google : gene AND therapy AND clinical AND trial AND (England OR Great Britain)
"One of the first children in Britain to receive gene therapy for an immune system disorder has developed leukaemia as a result of his treatment.[...] The trial has now been closed to new patients, but Dr Gaspar and Professor Thrasher plan to start another programme using a slightly different technique next year. They have already completed successful animal trials of a viral vector that can carry new DNA into cells without the risk of inadvertently switching on a cancer gene.[...]"
Timesonline. Boy gets leukaemia after gene treatment to cure ‘bubble baby syndrome’ [en ligne]. Disponible sur : <http://www.timesonline.co.uk/tol/news/uk/science/article3068051.ece> (consulté le 08.11.08)
En tapant l'équation suivante sur pubmed ou google scholar: prevention AND "gene therapy" AND retrovirus AND leukemia, on tombe sur différentes mesures préventives:
"When the first case of leukemia resulting from the French gene therapy trial was announced, US, French and British agencies halted trials temporarily, but then allowed them to continue, believing that the case was isolated (43). However, the announcement of the second case and the identification of the frequency of viral insertion at the LMO2 locus in these children prompted US agencies to stop 27 trials using retroviral gene transfer."7
"New technologies that do not rely on random viral integration may one day be developed for the treatment of X-SCID. For example, site-specific integration may permit introduction of the wild-type gc gene at genomic locations known to be void of genes or regulatory elements (50,51). Alternatively, the endogenous gc gene may be corrected ex vivo by means of homologous recombination promoted by engineered zinc-finger proteins, avoiding the need for viral integration"7
"Other viral vectors may also be explored to deliver the gc gene. Adenovirus would not be an appropriate choice since this vector does not provide long-term stability or sustained transgene expression. Adeno-associated virus is being considered for hematopoietic targets, though viral insertion events have been noted in hemophilia patients in a gene therapy trial"7
Avec l'article de googl scholar, on en tire les informations suivantes:
"The possible use of pig organs and tissues as xenografts in humans is actively being considered in biomedical research. Cell-free retrovirus produced by the PK-15 kidney cell line (PERV-PK) infected pig, mink and human kidney 293 cell lines and co-cultivation of X-irradiated PK-15 cells with human cells resulted in a broader range of human cell infection, including human diploid fibroblasts and B- and T-cell lines."8
Attention: à la fin d'une référence, mentionnez l'outils de recherche qui l'a trouvé!)
1. Paul D. Robbins and Steven C. Ghivizzani, Viral Vectors for Gene Therapy, Department Of Molecular Genetics And Biochemistry, University Of Pittsburgh, School Of Medicine, W1246 Biomedical Science Tower, Pittsburgh, Pa 15261, USA, 1999 (pubmed)
2. Journal of Clinical Investigation, High incidence of leukemia in large animals after stem cell gene therapy with a HOXB4-expressing retroviral vector [en ligne], , disponible sur <http://www.sciencedaily.com/releases/2008/03/080320173632.htm> (consulté le 7 novembre 2008) (sciencedaily)
3. Christopher Baum et al., Chance or necessity? Insertional Mutagenesis in Gene therapy and Its consequences, Department of Hematology and Oncology, Hannover Medical School, Hannover, Germany, 2003 (google scholar)
4. Christopher H. Evans et al, Arthritis gene therapy's first death, Center for Molecular Orthopaedics, Harvard Medical School, 221 Longwood Avenue, BLI-152, Boston, MA 02115, USA, 2008 (google)
5. Salima Hacein-Bey-Abina et al., Insertional oncogenesis in 4 patients after retrovirus-mediated gene therapy of SCID-X1, The Journal of Clinical Investigation, 2008, vol. 118, 9, pp 3132-3142(pubmed)
6. Steven J. Howe et al., Insertional mutagenesis combined with acquired somatic mutations causes leukemogenesis following gene therapy of SCID-X1 patients, The Journal of Clinical Investigation, 2008, vol. 118, 9, pp 3143-3150(pubmed)
7. B.E. Strauss et al., Combating oncogene activation associated with retrovirus-mediated gene therapy of X-linked severe combined immunodeficiency, Setor de Vetores Virais, Laboratório de Genética e Cardiologia Molecular, Faculdade de Medicina, Brasil, 2007 (pubmed)
8. Clive Patience, Yasuhiro Takeuchi & Robin A. Weiss, Infection of human cells by an endogenous retrovirus of pigs, Chester Beatty Laboratories, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK, 1999 (google scholar)
Ce wiki
, LMO2....
