October 1, 2022

Yamanaka expands on ethical implications of stem cell discovery

Dangers in fertility methods and shonky cures

Shinya Yamanaka
The Japanese scientist who created pluripotent stem cells without
destroying embryos, Shinya Yamanaka, of Kyoto University, has expanded upon the ethical implications of his
discovery in a recent issue of New Scientist (subscription required). Here are some brief

Fertility technology: "I can make eggs as well as sperm
from my own male iPS [induced pluripotent stem] cells. What if somebody took those sperm and
eggs from a single person and fertilised them? The result would not
be a clone because of the way cells divide during sexual reproduction
– the fertilised egg would not be genetically identical to the
original iPS cells – but it would be something very strange and

Unproven cures: "It’s possible that scientists
in less regulated countries will offer these cells to people as a
therapy for spinal cord injuries, for example. The patients may say
they don’t care about the risk of tumours and I am very afraid of
that. In a sense I would feel responsible [if something went wrong]
because we started this technology."

Who decides what is ethically acceptable?: "These are
very difficult decisions, and I think that society should make them.
It should not be scientists. They can find it difficult to think like
the person on the street, and instead may see it simply as a good
opportunity. We scientists can be involved in the decision-making
process, but I think unless society is comfortable with the therapy
it should not go ahead."

The future of embryonic stem cell research: " I do want
to avoid the use of embryos if possible. Ultimately I think that
patients’ lives are more important than embryos, but I do appreciate
that embryos can become beautiful babies as well." ~ New Scientist, Dec 15