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1 Senate Community Affairs Legislation Committee Inquiry Into Research Involving Embryos And Prohibition Of Human Cloning Bill 2002 Submission of Associate Professor Martin F. Pera, BA, PhD 12 September 2002 Monash Institute of Reproduction and Development Monash University 246 Clayton Road Clayton 3168 Victoria Phone 03 9594 7318 Fax 03 9594 7311 Email [email protected] Statement of professional status and disclosure: I am Associate Professor and CoDirector of the Centre for Early Human Development at the Monash Institute of Reproduction and Development, Monash University. I have over seventeen years of research experience in the field of human pluripotent stem cell biology. My laboratory conducts research on human embryonic stem cells and a closely related cell type derived from human germ cell tumours of the testis, known as embryonal carcinoma cells. I am a founding scientist of ES Cell International Pte., an Australian-Singaporean stem cell research company; I own shares in that company and receive funding from it to support research in my laboratory. Our research is also supported by the National Health and Medical Research Council, the Juvenile Diabetes Research Foundation, and the United States National Institutes of Health. My primary motivation in helping to found ES Cell International was to obtain financial backing for the research at a time when such support was not available from governmental or philanthropic bodies. 2 1. Scope of proposed legislation: The proposed legislation will allow researchers to derive new embryonic stem (ES) cell lines from embryos surplus to clinical requirement donated with informed consent by couples having undergone infertility treatment. The legislation will outlaw human cloning throughout Australia, a ban which will include prohibition of the use of somatic cell nuclear transfer methodology to create ES cell lines (therapeutic cloning). 2. No impact of the proposed legislation on the rate of production or disposal of human embryos: I fully respect the views of those who have ethical objections to human embryo experimentation, but these views must be considered in the context of a pluralistic society that has an obligation to use medical advances to provide optimal care for its sick or injured. Embryo wastage is an inevitable consequence of both natural conception and assisted reproduction. The proposed legislation will have no effect whatsoever on the rate of production and disposal of embryos associated with in vitro fertilization procedures. Our society and many others, by accepting in vitro fertilization, therapeutic abortion, and certain forms of contraception, have already assigned the human embryo and fetus a different ethical and legal status to that of a child or adult. Blocking ES cell research would not “save” embryos; it would only ensure that their disposal serves no constructive end. 3. Embryonic stem cells: ES cells are cultured cell lines derived from the early embryo prior to formation of the tissues of the body. ES cells may be grown in the laboratory indefinitely in the primitive embryonic state, and they retain a key property of the embryo cells from they originate: pluripotentiality, or the ability to give rise to any type of adult body cell. This combination of properties has not been documented in any type of adult tissue stem cell isolated to date. These two features mean that ES cells in principle represent an indefinitely renewable source of human tissue for use in research, or in transplantation therapy to correct a range of debilitating and currently intractable medical conditions characterized by cell injury or death. The potential research applications of human ES cells are equally important to their applications in transplantation, and they include: the study of early human development and its disorders, including birth defects and childhood cancers; the study of how human genes function; the discovery of novel proteins involved in tissue regeneration and repair; the discovery of new medicines. 4. Current status of human and mouse embryonic stem cell research: Human ES cells were first isolated in late 1998. Since that time a number of groups including our own have confirmed first that pluripotent stem cells can be isolated from the human blastocyst with relatively high efficiency, and second that these cells can be propagated indefinitely whilst retaining pluripotentiality. Published research has documented the production of the following array of specialised cell types from human ES cells in vitro: heart muscle, insulin producing cells, nerve cells, endothelial (blood vessel lining) 3 cells, blood forming stem cells. Nerve cell precursors derived from human ES cells have been transplanted into the brains of rodents and shown to integrate and differentiate normally in the host tissue without tumour formation (more extensive long-term study is of course required to demonstrate safety of stem cell grafts). Pre-clinical testing of ES-derived cells in animal models of disease will be underway shortly in our laboratories and is probably ongoing in others. In proof of concept experiments, mouse ES cells, or cells derived from them, have been used successfully to treat animal models of diabetes, severe immune deficiency, Parkinson’s disease, myocardial infarction, stroke, and demyelinating disorders. Mouse ES cells have of course played a revolutionary role in advancing our understanding of gene function in mammals. 5. Significance of the legislation to the future of human embryonic stem cell research: The key impact of the new legislation will be to allow the derivation of new stem cell lines from spare IVF embryos. New cell lines are essential for four reasons. First, the existing cell lines have almost all been derived using mouse helper cells or feeder cells which produce as yet unidentified substances necessary for stem cell growth. Regulatory agencies including the United States Food and Drug Administration have expressed concern over the possible transmission of pathogens, in particular viruses, from these mouse cells to human stem cells. New techniques will allow the production of safer stem cell lines without the use of animal cells. Second, clinical therapy with ES cells will have to address the possible rejection of stem cell derived grafts by the recipient’s immune system. We need the flexibility to allow us to develop larger panels of cell lines which may well required to achieve adequate tissue matching to avoid immune rejection. Third, since our understanding of human ES cells is still at an early stage, it is likely the future improvements to the methodology for initiating and growing these cell lines will enable us to produce second generation ES cells with desirable improved properties. Finally, most existing cell lines have been derived with commercial funding and have some restrictions on their use. Many investigators feel that ES cell lines should be available in the public domain to researchers without such restrictions. 6. Adult and embryonic stem cell research: During the course of this debate, some have argued that research on adult stem cells, in particular results from recent studies which demonstrate that adult stem cells are more versatile than previously expected, has already demonstrated that adult stem cells will fulfill all the potential roles in research and therapy envisioned for ES cells. Such claims are premature. While there is little scientific argument regarding the potential for ES cells to give rise to all tissues of the body, claims for pluripotentiality of adult stem cells (stem cell plasticity) remain controversial or preliminary. In some cases, the initial exciting reports have proven difficult to repeat, or alternative explanations have emerged to account for the results. In many instances where the bona fide conversion of adult stem cells to different cell types is proven, the events only occur at very low frequency in the context of severe tissue damage. Adult stem cells often represent 4 minority populations within a tissue, and unlike ES cells they may be difficult to isolate and impossible to expand in numbers outside the body. While research on adult stem cells and their plasticity is very important, it is premature to assert that adult stem cells with properties equivalent to ES cells have been identified, or to make definitive claims for the future roles of either cell type in therapy. 7. Therapeutic cloning: Therapeutic cloning combines cloning techniques with stem cell technology to produce ES cell lines which are custom made for individual patients. Grafts derived from such cell lines would in principle avoid the problem of immune rejection. Practical problems with this approach, including the requirement for large numbers of human eggs, the time delay in delivering the therapy to individual patients, and the need to evaluate the safety of the custom made cells, may severely limit its application in the clinic. However, therapeutic cloning and related techniques provide a very promising experimental approach to the study of adult cell plasticity, since the procedure effectively reprograms an adult cell back to a pluripotent state. Thus although the scientific case for the clinical application of therapeutic cloning in man is not compelling at present, basic research on reprogramming in humans may eventually be very important to successful development of adult stem cell based therapies. I therefore endorse in principle the original recommendation of the report of Mr. Kevin Andrews’ committee of inquiry for a moratorium, rather than a ban, on this area of research. 8. Importance of the legislation for Australian science: Australia is fortunate to have an outstanding group of researchers in the fields of embryonic and adult stem cell research. These research areas are complementary and synergistic; the review panel that awarded the Biotechnology Centre of Excellence grant to the National Stem Cell Centre clearly recognized the unique potential of a consortium of these workers and its high competitiveness internationally. Defeat of this legislation will severely restrict the ability of Australian scientists to remain at the forefront of embryonic stem cell research. Defeat of the legislation will return us to an unsatisfactory position in which contradictory piecemeal regulations govern embryo research in the various States and Territories. Most importantly, although some stem cell research could continue, defeat of the legislation would send a strong negative message about Australian scientific policy to the research community locally and internationally. The proposed legislation is an effective compromise between the more liberal approach taken in the United Kingdom and the more restrictive policy governing federally funded research in the United States. It is a compromise that will enable Australian embryonic stem cell research to proceed on an ethical basis. It is a compromise that will enable us to maintain our international standing in exciting new area, the potential significance of which has been repeatedly endorsed in extensive reviews conducted by scientific academies and governmental agencies throughout the world. It is a compromise that the Parliament should support.