Download `Humanised` Organs Can Be Grown In Animals

'Humanised' Organs Can Be Grown In Animals
New Scientist; Boston; December 17, 2003; by Sylvia Pagan Westphal
A Position Paper
Ever since stem cell research has been discovered there has been many controversial
arguments discussing whether or not this method is okay to use when dealing with patients.
Research on stem cells is advancing knowledge about how an organism develops from a single
cell and how healthy cells replace damaged cells in adult organisms. Since it was discovered,
stem cell research is coming a very long way, even though these processes probably won’t be
experimented in humans years for decades. Right now in stem cell research we are extracting
stem cells from humans bone marrow and inserting them into animal fetus's before the immune
system can learn the difference between it's own cells and foreign cells. The plan is to grow more
human stem cells in animal organs than animal cells so we can perform organ transplants to
replace damaged organs with the animal's organs. The only problem about this, is a rejection of
the animal portion of cells in the human body. This means that the cells in our body could attack
this new organ.
Although, this therapy is still years away, the beginning processes have been started by a
team led by Esmail Zanjani at the University of Nevada. Zanjani’s team hopes that the animalhuman organs they are working on will have compatible new cells that are exactly the same as a
patient’s organs for fixing damaged organs. With the new research they have found, it could be
possible that they replace whole organs. The only problem about animal-human organs is that
people could get viruses from animals that humans don’t normally acquire
The original plan of Zanjani’s was to see prevent birth defects in unborn babies by
injecting healthy stem cells into the fetus but in the process of doing this, he found that in doing
this process, it could also be used to grow “humanized” organs. This idea came from the work of
Flake. He found that the human cells develop into part of the heart, skin, muscle, fat, and other
tissues when stem cells are taken out of bone marrow and injected into sheep fetuses.
Stem cells have two important characteristics that distinguish them from other types of
cells. First, they are unspecialized cells that renew themselves for long periods through cell
division. The second is that under certain physiologic or experimental conditions, they can be
induced to become cells with special functions such as the beating cells of the heart muscle or the
insulin-producing cells of the pancreas.
In some cases, stem cells in the human liver can cluster together to make functional,
human liver units. Then these human liver units can be transplanted at whole auxiliary organs.
The exciting thing about this is that a blood protein produced by the liver has been detected in the
host animals' blood. This could open the door to creating fetal heart cells for therapy. For
example, a kind of fetal heart cell called a cardiomyocyte has been shown to be especially good
at repairing hearts in rats or mice, but there is one big obstacle: at the moment the only source of
human fetal heart cells is human fetuses.
Zanjani says it could be likely to grow a large variety of other tissues, like insulinproducing islet cells for treating diabetes. Now the team is trying to identify subpopulations of
stem cells that could improve producing one organ to another. They also said that the timing and
site of the injection of the stem cells makes a big difference.
I believe that this is a great discovery in the field of genetic engineering. If Zanjani can
make all of this work, we can save so many lives. Extracting stem cells from humans and
injecting them in to sheep fetus’s to make organs that contain our identical cells would be a
miracle. We wouldn’t need people to wait for organ transplants until they die. I think that it is
amazing to look at how far medical science has come, and how much we have accomplished, in
this field. To think of all the different methods we have today that help save lives is astonishing.
It’s crazy to think that we have come this far in only the last decade, I wonder how long it will
take before this research will be perfected so we can start using it on humans.
We also could be able to fix birth defects even before the babies are born also by injecting
healthy stem cells in the fetus. It also states in the article that, “it might also be possible to grow
a wide range of other tissues, such as insulin-producing islet cells for treating diabetes.” This
means that those with diabetes could be cured by having certain stem cells injected in that area so
that they can make insulin for themselves. This will not only end up saving them money, but will
prevent them from having to inject insulin into themselves daily.
The only problem I see with this type of genetic engineering is that being able to replace
organs and fixing people with diabetes will cause people to live longer. I’m not saying having
people live longer is a bad thing, but having parts our world already over-populated, this could
create a big dilemma. Charles Darwin, in his studies, discussed the possibility of “Survival of
the Fittest” and by allowing people to replace their organs, suggests that the human race has now
taken over mother nature. Charles Darwin believed that it is important for all species to go
through the cycle of life in order for only the stongest to survive, by allowing doctors to cure all
diseases suggests that we are allowing the sick and the weak to continue to live. This might only
cause further problems in the future if we continue to live as if normal population rules do not
apply to our species.
The author, Sylvia Pagan Westphal, does not state a clear opinion about her standing,
although, she does state that, “Some people oppose the creation of all human-animal chimeras
(organs) on religious grounds, and many more would join them if there were the slightest chance
that sheep with human brain cells might be more than just sheep.” Zanjani also says that at the
level he is working with the animal, it’s still a sheep. This opinion only has to do with dealing
with the animals.
As for stem cell research, Zanjani is still searching for the right method that will produce
normal human cells, that would not be rejected and hope that any stray animal cells would be
destroyed by the patient’s immune system. He is also working on trying to increase the
proportion of human cells in organs.