Re: What is your view on obtaining stem cells from aborted tissue?

Hi Matthew

Hmmm... an interesting and thorny question with no simple answer, however 
I will try so here goes.

Firstly I would say that scientists will have a range of views just like 
any other group of people, so I can only provide MY opinion. Maybe of more 
use is the ethical considerations used to formulate an opinion (note that 
ethics can be defined as 'the systematic study of moral choices' and is 
therefore not exactly the same as 'morality').

Now, the motivation behind this use of stem cells is in therapeutic 
cloning in order to clone healthy copies of damaged or malfunctioning 
tissues as stem cells are capable of developing into many different types 
of 'self' cell. This would allow transplants without rejection 
problems, ,and also might solve the problem of shortages of donor 
organs/tissues - a patient might just have a small piece of themselves 
cloned and cultured. There have already been attempts to use this new 
technology with a trial on patients with Parkinson's Disease although the 
results weren't particularly conclusive other than indicating more work 
would be needed. So, we have a new technique with the potential to provide 
significant medical benefits, but of course there are ethical problems, 
the main two being;

1. It involves killing the embryo. The arguements for and against abortion 
are well-known and often vociferous, and are relevant here as an embryo is 
after all a potential person. The problem here is where to draw the line 
and decide that the embryo is an individual and therefore has the right 
not to be killed. Is an embryo an individual from the moment of 
conception? If not, what about at implantation in the uterus (7 days after 
fertilisation), primitive streak formation (14 days, when the nervous 
system begins to form), quickening (16 weeks, when autonomous movement 
begins) or viability outside the womb (22 weeks, the abortion limit in the 
UK)? Up to 14 days, twinning can still occur and thus the embryo is not 
biologically a definite individual, but could be more than one. This is 
however the limit for stem cell experiments - much earlier than for 
abortion. Why is this, do you think?

2. It is linked to human cloning. This is because, to create the required 
tissues, an early cloned embryo has to be allowed to divide in vitro, and 
then used to set up stem cell cultures. The ethical problems are not the 
same as for cloning a complete individual human, but they do exist, for 
example (although there are others);

a. Cloning produces a high rate of spontaneous abnormalities and many 
clones fail, leading to a high rate of wastage of embryos - which brings 
us back to point 1 above.
b. Some people consider cloning to be intrinsically wrong for religious or 
other reasons. Others belive that it is an affront to human dignity to use 
embryos simply as a source of cells.
c. There are unknown risks, including the fact that there are potentially 
problems with cloned cells being effectively as old as the donor when 
created (due probably to shortening of telomeres, the end-pieces of 
chromosomes that stop them unravelling and killing the cell), and so may 
age prematurely and cause unpredictable medical conditions.

So, you can see that this is a complex issue - it is quite possible to see 
the potential medical benefits but also to have ethical difficulties with 
one or more of the associated issues. This is why informed bioethical 
decision-making is so important, if not easy. Personally, I don't like the 
idea of using embryos as nothing more than a source of cells, plus I 
perceive technical difficulties with the technology, such as premature 
cell aging. Then again, I also understand the need for more transplant 
material as there is always a shortage, especially given the difficulties 
surrounding tissue rejection.

Anyhow, I hope this somewhat complex answer is useful and helps to explain 
the decision-making process involved in such issues from a scientist's 
point of view.

Yours,

Dr David Hubble, UK