Introduction to Stem Cells
Prepared by
the
AUSTRALIAN
STEM CELL
CENTRE
Introducing….stem cells!
What are stem cells?
• the body is made up of about 200 different kinds of
specialised cells such as muscle cells, nerve cells, fat cells
and skin cells
• all cells in the body come from stem cells
• a stem cell is a cell that is not yet specialised
• the process of specialisation is called differentiation
• once the differentiation pathway of a stem cell has been
decided, it can no longer become another type of cell on
its own
Why are stem cells special?
Stem cells can:
• self-renew to make more
stem cells
• differentiate into a
specialised cell type
Stem cells that can become many
types of cells in the body are
called pluripotent
Stem cells that can become
only a few types of cells are
called multipotent
Embryonic stem cells (pluripotent)
Tissue stem cells (multipotent)
Tissue stem cells
• often known as adult stem cells
• also includes stem cells isolated from fetal and cord blood
• reside in most tissues of the body where they are involved
in repair and replacement
Bone marrow
Kidney
Lung
• generally very difficult to isolate
• already used to treat patients (haematological malignancies,
diseases of the immune system)
Where do embryonic stem cells
come from?
• Donated excess IVF embryos
egg
Day 0
Inner cell mass
fertilised
egg
2-cell
8-cell
blastocyst
Day 1
Day 2
Day 3
Day 6
Images from www.advancedfertility.com
Embryonic stem cells
human embryonic stem cells
• derived from donated IVF
embryos
• can be grown indefinitely in
the laboratory in an
unspecialised state
• retain ability to specialise into
many different tissue types –
know as pluripotent
• can restore function in animal
models following
transplantation
Human embryonic stem cells can become any
cell in the body including these beating heart
cells
What about cloning? Has that got anything to
do with stem cell research?
Somatic Cell Nuclear Transfer – cloning to make
stem cells (therapeutic cloning)
Reproductive Cloning
Human cloning is banned in
Australia and many countries
around the world.
Dolly the Sheep
Snuppy the Puppy
Induced pluripotent stem cells
Starting cells from
donor tissue
Induced change in
gene expression
iPS Cells
pluripotent
stem cells
• derived from adult cells in
2007 - very recent discovery!
• can be grown indefinitely in
culture in an undifferentiated
state
• similar properties to
embryonic stem cells as can
differentiate into many
different tissue types –
pluripotent
• can create stem cells directly
from a patient for research
Using stem cells to conduct medical
research and treat disease is acceptable?
• Don’t know
3%
• No
5%
• Yes
92*%
Biotechnology
Australia –
Community
Attitudes to
Biotechnology
(2007)
* Compares to 80% in 2005 survey
But which type of stem cells?
- pluripotent stem cells (embryonic, SCNT, iPS stem cells)
- tissue stem cells (foetal, cord, adult)
Do you approve of the extraction of
stem cells from human embryos for
medical research?
• Don’t know
5%
• No
13%
• Yes
82%
Roy Morgan
Poll (2006)
Areas of community concern
– How come there are excess IVF embryos?
– Why do the embryos have to be destroyed for stem cell
research? Isn’t this the same as taking a life?
– Wouldn’t it be better to donate the excess IVF embryos to
other infertile couples?
– Could women be forced to sell eggs or embryos for research?
– Won’t doing therapeutic cloning lead to cloning humans?
– Why do we need to keep using embryos in research when we
have new iPS cells?
Australia has clear rules that allow embryos to be used in research
under strict conditions.
All research whether it involved embryonic, adult, cord, fetal, iPS stem
cells must have special ethics approval before research can start.
What makes stem cells so valuable?
Pluripotent
stem cells
Tissue
stem cells
Cell Therapy
Research
New Drugs
Modified from Keller & Snodgrass, Nat Med 1999
No one stem cell type fits all applications.
Research must continue using all types of stem cells.
Stem Cell Tourism
A growing concern to the stem cell community
Direct marketing to patients
promising instant results for
incurable diseases
www.stemcellcentre.edu.au
www.stemcellchannel.com.au