Transcript Embryonic Stem Cells

Embryonic Stem Cells
An introduction to the science,
ethics and legislation
What is a stem cell?
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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
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ES cells are pluripotent
AS cells found in small amounts throughout body
Most AS cells appear to be multipotent
Why all the fuss?
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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
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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
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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
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Harvesting ES cells
destroys the
blastocyst
“This is murder”
Reproduced by permission of Dave Catrow and Copley News
Service
Ethical debate, cont’d
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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
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“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
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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
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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:
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• 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
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