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Embryonic Stem Cells An introduction to the science, ethics and legislation What is a stem cell? Stem cells can become other types of cells Stem cells can also divide indefinitely stem cell line Pluripotent vs multipotent stem cells Reproduced by Permission of Professor Rathjen of the University of Adelaide Embryonic vs adult stem cells ES cells come from ICM of blastocyst Reproduced by permission of the NIH ES cells are pluripotent AS cells found in small amounts throughout body Most AS cells appear to be multipotent Why all the fuss? Stem cells may be able to replace damaged cells in the body Today: lymphoma, leukemia Future? Parkinson’s, Alzheimer’s, diabetes... Promising animal studies Courtesy of The Michael J. Fox Foundation for Parkinson’s Research Reproduced by permission of The Providence Journal Sources of ES cells ES cell lines Excess embryos from IVF clinics Embryos created for research by IVF Therapeutic cloning Reproduced by permission of the NIH Cloning Reproduced by permission of the NIH Purpose of therapeutic cloning is to harvest ES cells for treatment blastocyst destroyed Purpose of reproductive cloning is to make new person blastocyst implanted in uterus Ethical debate Harvesting ES cells destroys the blastocyst “This is murder” Reproduced by permission of Dave Catrow and Copley News Service Ethical debate, cont’d Courtesy of Kevin Siers, The Charlotte Observer © 2001 ES cell research requires human cells Could create a commercial market for human cells “This devalues life” Ethical debate, cont’d “If excess IVF embryos are being discarded anyway, they should be put to good use” Reprinted by permission of Chip Bok and Creators Syndicate, Inc. Ethical debate, cont’d Reproduced by permission of Gary Markstein and Copley News Service “Therapeutic cloning is a slippery slope it will lead to reproductive cloning” Governing ES cell research Country UK US Canada Germany Therapeutic cloning Creation of embryos for research Use of excess embryos from IVF clinics Use of existing ES cell lines √ √ √ √ ? X X √ X X √ √ X √ √ √ What Bill C-13 says about ES cells Activity Use of existing ES cell lines Legal Status Condition Punishment unrestricted blastocyst must be destroyed after 14 days of development Use of excess embryos from IVF clinics controlled written consent from donors required no sale of human cells Up to $250,000 fine and/or 5 yrs imprisonment donor must be at least 18 yrs old Creation of embryos by IVF for ES cell research prohibited Up to $500,000 fine and/or 10 yrs imprisonment Therapeutic cloning prohibited Up to $500,000 fine and/or 10 yrs imprisonment Current Clinical Uses of Adult Stem Cells: • Cancers—Lymphomas, multiple myeloma, leukemias, breast cancer, neuroblastoma, renal cell carcinoma, ovarian cancer • Autoimmune diseases—multiple sclerosis, systemic lupus, rheumatoid arthritis, scleroderma, scleromyxedema, Crohn’s disease • Anemias (incl. sickle cell anemia) • Immunodeficiencies—including human gene therapy • Bone/cartilage deformities—children with osteogenesis imperfecta • Corneal scarring-generation of new corneas to restore sight • Stroke—neural cell implants in clinical trials • Repairing cardiac tissue after heart attack—bone marrow or muscle stem cells from patient • Parkinson’s—retinal stem cells or patient’s own neural stem cells • Growth of new blood vessels—e.g., preventing gangrene • Gastrointestinal epithelia—regenerate damaged ulcerous tissue • Skin—grafts grown from hair follicle stem cells, after plucking a few hairs from patient 13