I think the greatest challenge of stem
cell research is to take a stem cell
that can become anything in your body
and make it become one single cell type
in large number high-purity my recent
research is really targeting the
development of a treatment for spinal
muscular atrophy a my atrophic lateral
sclerosis and chronic spinal cord injury
all three injury and disease types
rolled into one because all three are
characterized by the loss of motor
neurons those cells that control all the
moving parts in your body from your the
movement of your internal organs to your
arms eyes blinking and mouth everything
now those diseases have a deficit of
motor neurons so we've identified a
therapeutic target motor neurons the
path to the clinic really begins with
pre clinical efficacy work do your stem
cells actually effectively treat an
animal model of human disease so we have
to pick that animal model find an animal
model or developed an animal model that
mirrors in some way the human condition
we can never do that never ever has
there been an animal model that
perfectly reflects the human condition
of a disease State so all of our models
are imperfect which means that we have
to use two or three so once we find the
two or three that are closest to the
human condition then we transplant our
cells in there and decide on dosing on
timing the quantity of
volume that we're putting into the
disease state in addition we've got to
determine what we're going to look for
what are the outcome measures are we
going to look for leg function after
spinal cord injury
or are we going to look for bladder
function bowel functions sexual function
motor control sensory control any
portion thereof the point here is that
we don't want to miss an effect so we
have to have multiple outcome measures
we often have to design those outcome
measures talk to the field and pick
methods that others can follow and
others can replicate so that one
laboratory can back up the work of
another
after we've got this thing working we
then have to show that it's safe so
again we have to pick the right animal
models to look for safety do these cells
cause tumors do they cause pain
we recently designed a safety study that
contains some 160 outcome measures 160
analyses of a single rat 60 to 80 rats
in each group that's a lot of time it's
a lot of students it's a lot of weekends
it's a lot of birthdays it's a lot of
time to determine if these things are
safe if they're working and now in
spinal muscular atrophy some very smart
people have developed a mouse model of
that disease but it dies within 14 days
of birth that's not so bad if you're
transplanting Mouse motor neurons into a
mouse because everything moves fast in a
mouse they live and die within two years
but to transplant our human cells into
the mouse we have human motor neurons to
take months to grow from the spinal cord
to their targets yet we only have two
weeks to test their function in this
animal model a very appropriate animal
model for this clinical disease so you
see every model is flawed it means that
we need a multiplicity of approaches
sometimes we have to develop those
animal models and then we need other
laboratories to be able to replicate our
work using those very same models so
there has to be a continuity across labs
Ken stem-cell technologies reasonably be
applied to the human condition in the
foreseeable future well it was only 1998
where that human embryonic stem cells
were first isolated in a few short years
thereafter methods of differentiating
them became known just two years ago we
had our first high purity derivation
from human embryonic stem cells done in
a clinically viable manner in my
laboratory here at UCI now we're
starting to see the derivation of
multiple high purity human cell
populations heart cells have been made
pancreatic islet cells have been made
oligodendrocytes motor neurons retinal
tissue we're starting to see the
derivation of useful products and their
application to animals so now what the
field is trying to do is figure out how
we design the preclinical work what do
we have to do by way of efficacy and
safety in order to get these into humans
but we have developed the technologies
that's very very impressive in a few
short years so stem cell technologies
will be applied in the very near future
to human conditions it's no doubt
you