Embryonic Stem Cells An introduction to the science, ethics and legislation

What is a stem cell? n Stem cells can become other types of cells n Stem cells can also divide indefinitely  stem cell line n Pluripotent vs multipotent stem cells Reproduced by Permission of Professor Rathjen of the University of Adelaide

Embryonic vs adult stem cells n ES cells are pluripotent n AS cells found in small amounts throughout body n Most AS cells appear to be multipotent  ES cells come from ICM of blastocyst Reproduced by permission of the NIH

Why all the fuss? n Stem cells may be able to replace damaged cells in the body n Today: lymphoma, leukemia n Future? Parkinson’s, Alzheimer’s, diabetes... n Promising animal studies Reproduced by permission of The Providence Journal Courtesy of The Michael J. Fox Foundation for Parkinson’s Research

Sources of ES cells n ES cell lines n Excess embryos from IVF clinics n Embryos created for research by IVF n Therapeutic cloning Reproduced by permission of the NIH

Cloning n Purpose of therapeutic cloning is to harvest ES cells for treatment  blastocyst destroyed n Purpose of reproductive cloning is to make new person  blastocyst implanted in uterus Reproduced by permission of the NIH

Ethical debate n Harvesting ES cells destroys the blastocyst n “This is murder” Reproduced by permission of Dave Catrow and Copley News Service

Ethical debate, cont’d n ES cell research requires human cells n Could create a commercial market for human cells n “This devalues life” Courtesy of Kevin Siers, The Charlotte Observer © 2001

Ethical debate, cont’d n “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 n “Therapeutic cloning is a slippery slope - it will lead to reproductive cloning” Reproduced by permission of Gary Markstein and Copley News Service

Governing ES cell research

What Bill C-13 says about ES cells

13 n Cancers—Lymphomas, multiple myeloma, leukemias, breast cancer, n neuroblastoma, renal cell carcinoma, ovarian cancer n Autoimmune diseases—multiple sclerosis, systemic lupus, n rheumatoid arthritis, scleroderma, scleromyxedema, Crohn’s disease n Anemias (incl. sickle cell anemia) n Immunodeficiencies—including human gene therapy n Bone/cartilage deformities—children with osteogenesis imperfecta n Corneal scarring-generation of new corneas to restore sight n Stroke—neural cell implants in clinical trials n Repairing cardiac tissue after heart attack—bone marrow or n muscle stem cells from patient n Parkinson’s—retinal stem cells or patient’s own neural stem cells n Growth of new blood vessels—e.g., preventing gangrene n Gastrointestinal epithelia—regenerate damaged ulcerous tissue n Skin—grafts grown from hair follicle stem cells, after plucking a few n hairs from patient Current Clinical Uses of Adult Stem Cells: