Transcript Slide 1

Stem cells through the lens of
the Korean cloning scandal
A lens through which to view
general issues of stem cell
research
•
•
•
•
Promise of embryonic stem cells to cure
disease and as a driver of a medical industry
Ethical pitfalls
Difficulty of the technique
Policy implications for Australia
Stem cells 101
Skin cell, limited proliferation
Skin stem cell (adult stem cells),
proliferates but only makes skin
cells
Embryonic stem cells proliferate
indefinitely and make all tissues
BIOLOGICAL GOLD!!!!
Making embryonic stem cells
BUT SOME TISSUES ARE
MORE DIFFICULT THAN
OTHERS
DONE
MOST
DIFFICULT
DONE
DONE
A LONG WAY TO GO
• TRAIN CELLS TO MAKE SPECIFIC
TISSUES
• ELIMINATE CANCER CELLS
• GRAFT REJECTION???
• THERAPEUTIC CLONING PROVIDES
MATCHED TISSUES, HENCE THE
GREAT PROMISE
Cattle cloning: about 10% success rate
In Feb 2004, Hwang announces first success
But it was a very qualified success:
1. Couldn't prove it was a clone
2. Only cumulus cell
3. Only if from same egg and nucleus donor?
4. 242 eggs!
Cumulus cell
Woo Suk Hwang’s group dazzle the
world
May 2005: it’s a go-er!
-Cloned from skin cells of men,
women and children
-increased success rate over 10 fold
(17 eggs per cell line), practiced
with cow eggs!
Astonishing that no-one
suspected
• Korean work ethic 24/7
• Supportive policy and funding
• Technical prowess borne of lifetime’s use
of steel chopsticks
Scientific smoking guns
• Proofs that they were embryonic stem
cells: visual appearance, marker proteins,
teratomas
Marker proteins look good
Teratomas for three of the cell lines
Spot the duplication?
Are they cloned stem cells?
• Compare DNA fingerprints of donor skin
cells and stem cell lines
DNA Fingerprints
Policy implications
• Women were exploited (suffered sideeffects; some did it for money)
• Scientists behaved dishonestly (now also
an issue of missing millions)
• Ban the technique?
Legislation that permits advance
while preventing transgressions
• TC will not be used to produce customized
tissues—its too hard
• For model diseases its still a worthy goal
Spinal Muscular Atrophy-a case in point
One in 8000 births, biggest genetic
killer of kids under 2 yo
Disease causes death of motor
neurons
Use Therapeutic cloning to make
cell lines for screening drugs
Test 100,000 compounds a day on these model patients
Put cloned cells to work tomorrow
Many diseases a mystery: genes and
environment
ALS: 95% out of the blue, MN die off
No real animal models
Cloned cells from patients could be
first real models to study the disease
ES cells (not adult stem cells) can be
made into Motor Neurons (H.
Wychterle 2002, Cell)
Unscientific debate
• “Pick and choose” notions of research are
misguided
• Furfies — adult stem cells have more runs on
the board. Only in bone marrow transplants and
skin grafts
• Novel applications remain unproven and highly
contentious.
 Common sense: in exploration success comes
from following as many paths as possible