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Appendix 4 - Stem cells, cloning and related issues
National Health and Medical Research Council, Australia
What are stem cells?
- Stem cells are ‘unspecialised’ cells that
have the unique potential to develop into ‘specialised’ cell types in the body
(for example blood cells, muscle cells or nerve cells). This can be either for
growth and development, or for replenishment and repair.
- Stem cells occur at all stages of human
development, from embryo to adult— but their versatility and numbers tend to
decrease with age.
- Given the right conditions in the body or
the laboratory, stem cells (unlike muscle cells, nerve cells and or blood
cells) can replicate themselves many times over.
- When a stem cell replicates, the resulting
cells can either remain as stem cells or can become specialised cells.
Why is stem cell research important?
Doctors and scientists believe that stem cell research has the
potential to revolutionise medical treatment in two main areas:
- Better understanding of diseases such as
cancer. By understanding
how stem cells transform into the specialised cells that make us what we are,
we can better understand and cure diseases such as cancer. Cancer is a major example
of where this process has gone wrong.
- Making cells and tissues to replace or
regenerate tissues that are either diseased or have been destroyed. Organ transplants can be used for this in some
cases, but the demand for suitable donated organs exceeds supply. Stem cells
offer the possibility of a source of replacement cells that could be used to treat
diseases and conditions from Parkinson’s disease to heart disease, spinal cord
injury, diabetes and arthritis.
What are embryonic stem cells and adult
stem cells?
Embryonic stem cells
- Embryonic stem cells, as their name
suggests, are derived from human embryos. They have the potential to develop
into all cell types in the body.
- In Australia, embryonic stem cells are
derived from human embryos that are left over from assisted reproductive
technology (ART) treatment programs and have been donated to research by the
couple for whom they were created. They are not derived from eggs
fertilised in a woman’s body.
- As part of a couple’s
infertility treatment these ART embryos would have been placed in cold
storage within 2–6 days of fertilisation.
Adult stem cells
- Adult stem cells (often called somatic
stem cells) are found in many organs and tissues of the body, where their
main function is to replace cells that have died in the tissue or organ where
they are located.
- In certain circumstances,
adult stem cells may “transdifferentiate” into othercell types.
- Adult stem cells extracted from the bone
marrow of patients or compatible donors are used routinely in treating diseases
such as leukaemia. (All blood cells in the body are manufactured in the bone
marrow).
- Umbilical cord blood, extracted from the
umbilical cord and placenta when a baby is born, is a rich source of adult stem
cells. These cells may be useful for medical research or therapeutic use in the
future. In the USA in particular, a whole industry has
developed where people are having cord blood frozen for possible use later in
life.
Embryonic and adult stem cells in medical
research
- Most experts think that research involving
both embryonic and adult stem cells will lead to a new understanding of, and
new therapeutic treatments for, injury and disease.
- The advantages of embryonic stem cells are
that they can be grown in the laboratory for long periods and be made to change
into most types of tissue found in the human body.
- Some people have genuine and strongly held
views against the use of embryonic stem cells in research. This is because
deriving stem cells from embryos destroys the embryo.
- Adult stem cells are present in the body
in low numbers, and, with the exception of bone marrow, are difficult to
obtain.
- Although adult stem cells are currently
difficult to grow in the laboratory and may not develop into every kind of
cell, recent developments in this field are promising.
What about cloning?
- The Prohibition of Human Cloning Act 2002 does not permit
the creation of human embryo clones for any purpose (see next section on
Current Guidelines and Laws in Australia).
- The scientific technique through which human embryo clones can be
created is called somatic cell nuclear transfer, or SCNT. This was the
technique used to create the first cloned mammal, ‘Dolly’ the sheep.
- SCNT involves obtaining a woman’s egg cell in the same way
eggs are obtained for ART treatment, then removing the genetic material (DNA)
from it and replacing it with DNA from a cell of a person’s body (e.g. a skin
cell). With the right triggers this new cell can be turned into an embryo.
- SCNT is controversial for two reasons:
- The resulting embryo
could, in theory, lead to cloned human beings. If a cloned embryo is placed into a
woman’s uterus, and it implants and develops to birth, a new human being will
be created whose nuclear DNA will be identical to the person who donated the
original body cell. There is no scientific evidence that a human being has ever
been cloned, and attempts to clone other primates have been unsuccessful. This
possibility is referred to as ‘reproductive cloning’, which many people
find completely unacceptable.
- Stem cells could be
harvested from the cloned embryo, which would destroy the embryo. If a cloned embryo is grown in the
laboratory for a few days, stem cells could be harvested from it to form a new
embryonic stem cell line. This possibility is often referred to as ‘therapeutic
cloning’, since the embryonic stem cells could be encouraged to develop into
human tissue or (possibly in the future) a complete organ for transplant.
Because the stem cells from a cloned embryo have identical nuclear DNA to the
person who donated the original body cell, this theoretically overcomes the
‘rejection’ hurdle that exists with current organ or tissue transplants or with
stem cells derived from embryos left over from IVF treatment programs.
- The Prohibition of Human Cloning Act
2002 does not distinguish between ‘reproductive’ and ‘therapeutic’ cloning.
- It has also been suggested
that so-called ‘therapeutic cloning’ could be achieved by transferring human
DNA into animal eggs (such as rabbit eggs), as a way of reducing the demand for
human egg donations.
- The technique would be illegal in Australia under the Prohibition of Human Cloning Act 2002 because
it could result in the creation of a hybrid embryo.
Current guidelines and laws in Australia
Use of cell lines in research
- The use of human or animal cell lines in
health and medical research is covered by guidelines and other statements
issued by the National Health and Medical Research Council (NHMRC).
- Researchers should abide by the provisions
of the National Statement on Ethical Conduct in Human Research (1999,
under review).
[http://www.nhmrc.gov.au/publications/synopses/e35syn.htm]
- The NHMRC has also prepared a supplement
to the National Statement, on preparation and review of research
protocols relating to the use of embryonic and non-embryonic human stem cells. [http://www.nhmrc.gov.au/ethics/human/issues/stemcell.htm]
Use of human embryos to derive embryonic
stem cell lines
Research Involving Human Embryos Act
Assisted Reproductive Technology (ART) guidelines
- ART includes techniques such as IVF (in-vitro fertilisation, or
fertilisation in an artificial environment such as a test tube).
- ART itself is subject to ethical guidelines on ART, and supplementary statements on the use of human tissue in
research, issued by the NHMRC.
[http://www.nhmrc.gov.au/ethics/human/issues/art.htm]
- The ethical guidelines on ART outline the comprehensive consent process for couples who wish to
declare embryos as excess to their requirements, and to allow the embryos to be
used for research purposes.
Embryo Research Licensing
Human cloning
More information and advice on the
regulatory framework
- More information and advice on the
regulatory framework relating to human cloning and research involving human
embryos, and Commonwealth and State and Territory legislation, is available on
the NHMRC’s Policy and Guidance web page. [http://www.nhmrc.gov.au/embryos/information/index.htm]
The Lockhart Review
- The Legislation Review Committee
established to review the Prohibition of Human Cloning Act 2002 and the Research
Involving Human Embryos Act 2002, reported to Parliament and the Council of
Australian Governments on 19 December 2005. The review is known as the Lockhart
Review, after its Chair, the late Justice John Lockhart.
- The Review Committee’s reports cover areas
involving difficult ethical issues, about which people have divergent and
deeply held views.
- The Committee endorsed the
strong regulatory framework which regulates research involving excess assisted
reproductive technology embryos, and prohibits human cloning.
- The Review Committee made 54
recommendations, many of which are interlinked. These recommendations are
explained briefly below (the groupings are not related to any perceived merits
or otherwise of the recommendations):
– (a)
Maintaining the existing legislative framework, including the ban on
reproductive cloning
These recommendations provided strong support for the current
regulatory framework, including the use of excess assisted reproductive technology
(ART) embryos in research.
Recommendations
1 to 14; 31; 33, 34; 37; 38; 40; 43, 44; 46.
– (b) Development of advice, guidance and
infrastructure within the existing regulatory framework:
These recommendations are of an administrative nature and are directed
at the NHMRC, government and other parties. For example, recommendation 18
recommends the NHMRC develop a pro-forma licence application. Other
recommendations relate to advice and criteria for licensing the use of fresh ART embryos that are unsuitable for implantation into a woman. There
are also recommendations that a national Australian stem cell bank and a
national register of donated excess ART embryos be
established.
Recommendations
18, 20, 21, 22, 29, 30, 32, 36, 45, 46, 47, 48, 49, 54.
– (c)
Allowing ‘therapeutic cloning’ and other currently prohibited techniques:
Recommends that so-called ‘therapeutic cloning’ be permitted using
a technique known as somatic cell nuclear transfer (SCNT).
Recommends allowing creation of other
types of embryos whose creation is currently prohibited by the Prohibition
of Human Cloning Act 2002, including through SCNT using animal eggs (to
reduce the demand for human eggs), and cytoplasmic transfer (creation of human
embryos using the genetic material from more than two people).
Recommends extending the role of the NHMRC
Embryo Research Licensing Committee to include licensing these additional
activities.
Recommendations 23, 24, 25, 26, 27, 35,
42.
– (d)
Amending the definition of human embryo:
Recommendation that the definition of
human embryo be amended. The proposed definition starts at the point of the
first cell division after ertilisation of a human egg by a human sperm.
Recommendation 28.
– (e) Allowing
research on fertilisation up to the point of the first cell division:
These recommendations are linked to the
recommended change to the definition of a human embryo and are aimed at
facilitating research into fertilisation, testing of eggs for maturity, and
cytoplasmic transfer up to, but not beyond, the point of the first cell
division.
Recommendations
15, 16, 17, 19.
– (f)
Provide additional powers to NHMRC inspectors:
Recommendation that inspectors be given
powers of entry, inspection and enforcement in relation to non-licensed
facilities.
Recommendation
39.
– (g)
Removing restrictions on the import and export of human embryos:
Recommendation for streamlining provisions
relating to a patient’s reproductive material (including ART embryos), for that person’s ongoing ART treatment.
Recommendation
41.
– (h)
NHMRC Embryo Research Licensing Committee rulings:
Recommendation that the legislation be amended to give the
Licensing Committee the power to make binding rulings in relation to
interpretation of the legislation, in order to provide greater regulatory
flexibility in this fast-moving field.
Recommendations
50 to 52.
– (i)
Provide for further review of national legislation:
In view of the fast-moving developments in
the field the two Acts should be subject to a further review either six years
after Royal Assent to the current Acts or three years after Royal Assent to any
amended legislation.
Recommendation
53
Facts and figures on embryos, licences and
funding
Number of embryos and licences
- There were 104,830 embryos in frozen storage in 2003. Almost all of
these were embryos intended to be used to achieve a pregnancy.
- Very few ART embryos in storage have been declared to
be excess to ART requirements.
- At 31 March 2006:
– 170 excess ART embryos had been used in licensed research in Australia
– the NHMRC Embryo
Research Licensing Committee had issued 9 licences authorising the use of up to
1,735 excess ART embryos
– 4 of the 9 licences
authorised the use of up to 550 excess ART embryos for
the derivation of human embryonic stem cells.
– under
the 4 licences, 122 excess ART embryos had been used.
Australian Government funding for stem
cell research
NHMRC funding
- Around $40 million of NHMRC funding in
2006 is committed to research that involves the use of animal or human stem
cells. This is approximately 9% of NHMRC research expenditure in 2006 ($435
million).
- Approximately $1.8 million in research
funding involves use of human embryonic stem cells.
- A complete breakdown of NHMRC funding in
2005 and 2006 for research involving stem cells is available at http://www.nhmrc.gov.au/publications/_files/stemcell_funding.pdf
Other Australian Government funding
Australian Stem Cell Centre, Melbourne
- In 2002 the Australian Government provided
the Australian Stem Cell Centre in Melbourne with a competitively awarded grant
of $43.55 million through the Government’s Backing Australias Ability, Biotechnology Centre of Excellence Program (Backing Australias Ability is coordinated across five principal
portfolio Departments).
- In May 2004, the Prime Minister announced
a further $55 million grant under Backing Australias Ability II, to support the Australian Stem Cell
Centre’s activities from 2006 to 2011.
- The Australian Stem Cell Centre is a key
driver and catalyst in developing world-class capability in biotechnology
research, and its application for the economic and social benefit of Australia.
- More information on the Australian Stem
Cell Centre is available at http://www.stemcellcentre.edu.au/ascc_home.html
Adult Stem Cell Research Centre, Brisbane
- On 2 May 2006 the Government announced
that it had decided to provide $22 million over four years to fund an Adult
Stem Cell Research Centre at Griffith University in Queensland.
- This Centre is funded through the
Commonwealth Department of Health and Ageing, and will complement the work of
the Australian Stem Cell Centre.
- More information on the Adult Stem Cell Centre is available
at http://www.griffith.edu.au//centre/eskitis/home.html
International website links
The following websites provide useful and
authoritative information on stem cells, cloning and related issues
Source: http://www.nhmrc.gov.au/publications/_files/stemcells.pdf [accessed 30.10.06]
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