STEM CELL RESEARCH - Basics

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STEM CELL RESEARCH - Basics

• M. Arshad Chaudhry, Ph.D.
• Michael Smith Laboratories
• UBC, Vancouver
• ma_chaudhry_at_hotmail.com

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Outline of This Presentation

• Stem cell research
• The nature and promise of stem cell research
• The ethical debate

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What Are Stem Cells?

• Stem cells are the raw material from which all of
  the bodys mature, differentiated cells are made.
  Stem cells give rise to brain cells, nerve
  cells, heart cells, pancreatic cells, etc.

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Whats So Special About Stem Cells?

• They have the potential to replace cell tissue
  that has been damaged or destroyed by severe
  illnesses.
• They can replicate themselves over and over for a
  very long time.
• Understanding how stem cells develop into healthy
  and diseased cells will assist the search for
  cures.

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Two Kinds of Stem Cells

• Embryonic (also called pluripotent) stem
  cells are capable of developing into all the cell
  types of the body.
• Adult stem cells are less versatile and more
  difficult to identify, isolate, and purify.

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Stages of Early Embryonic Development
Stages of Early Embryonic Development
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Embryonic Stem Cells
Researchers extract stem cells from a 5-7 days
old blastocyst.
Stem cells can divide in culture to form more of
their own kind, thereby creating a stem cell
line.
The research aims to induce these cells to
generate healthy tissue needed by patients.
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Two Sources of Embryonic Stem Cells

• 1. Excess fertilized eggs from IVF (in-vitro
  fertilization) clinics
• 2. Therapeutic cloning (somatic cell nuclear
  transfer)

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• Tens of thousands of frozen embryos are routinely
  destroyed when couples finish their treatment.
• These surplus embryos can be used to produce
  stem cells.
• Regenerative medical research aims to develop
  these cells into new, healthy tissue to heal
  severe illnesses.

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• Somatic Cell Nuclear Transfer
• The nucleus of a donated egg is removed and
  replaced with the nucleus of a mature, "somatic
  cell" (a skin cell, for example).
• No sperm is involved in this process, and no
  embryo is created to be implanted in a womans
  womb.
• The resulting stem cells can potentially develop
  into specialized cells that are useful for
  treating severe illnesses.

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Adult Stem Cells

• Fundamental feature of adult stem cells
• They maintain the ability to divide throughout
  life and give rise to specific cell type
• Blood vessel stem cells can not give rise to
  brain or heart muscle cells
• The fact that developmental potential of adult
  stem cells is restricted has recently been
  challenged
• Why some tissues maintain stem cells and others
  dont is not understood

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The Ethical Debate

• In favor of ESCR
• Embryonic stem cell research (ESCR) fulfills the
  ethical obligation to alleviate human suffering.
• Since excess IVF embryos will be discarded
  anyway, isnt it better that they be used in
  valuable research?
• SCNT (Therapeutic Cloning) produces cells in a
  petri dish, not a pregnancy.
• Against ESCR
• In ESCR, stem cells are taken from a human
  blastocyst, which is then destroyed. This
  amounts to murder.
• There is a risk of commercial exploitation of
  the human participants in ESCR.
• Slippery slope argument ESCR will lead to
  reproductive cloning.

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Key Ethical Issues

• The blastocyst used in stem cell research is
  microscopically small and has no nervous system.
  Does it count as a person who has a right to
  life?
• What do various religions say about when
  personhood begins? Does science have a view on
  this?
• In a society where citizens hold diverse
  religious views, how can we democratically make
  humane public policy?

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Stem Cell Research Worldwide