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Stem cells, cloning and related issues

An overview of stem cells, the regulation of human embryo research and the prohibition of human cloning in Australia.

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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.

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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.

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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 almost 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.
  • Embryonic stem cells can also be derived from embryos created by somatic cell nuclear transfer (see section below ‘What about cloning?’).

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 other cell 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.

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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 cannot develop into every kind of cell, recent developments in this field are promising.

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What about cloning?

  • The Prohibition of Human Cloning for Reproduction Act 2002 prohibits human cloning for reproductive purposes.  However, it is permitted to apply for a licence to create human embryo clones for stem cell research. Reproductive cloning is illegal in Australia and can not be carried out under any circumstances.
  • 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:
  1. 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.
  2. 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.

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Current guidelines and laws in Australia

Use of cell lines in research

Use of human embryos to derive embryonic stem cell lines

Research Involving Human Embryos Act

  • The use of human embryos to derive human embryonic stem cell lines for research is governed by the Research Involving Human Embryos Act 2002. The Act allows the use under licence of embryos created through ART that are no longer required by the couples or that are unsuitable for implantation. The Act also allows the creation and/or use of certain other types of embryos for research under licence. http://www.nhmrc.gov.au/publications/synopses/embryactsyn.htm

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 the requirements of the National Statement (see above), issued by the NHMRC. http://www.nhmrc.gov.au/health_ethics/ahec/history/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.
  • The ethical guidelines also outline the consent process for people giving consent to the use of their reproductive or genetic material or cells in the creation or use of embryos for research.

Embryo Research Licensing

More information and advice on the regulatory framework

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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 2007:
    • 329 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 1,915 excess ART embryos
    • 4 of the 9 licences authorise the use of up to 550 excess ART embryos for the derivation of human embryonic stem cells.
    • under these 4 licences, 197 excess ART embryos had been used.
  • More information on embryo and licence numbers is available at
    http://www.nhmrc.gov.au/research/embryos/information/faqs.htm

Australian Government funding for stem cell research

NHMRC funding

  • Around $49 million of NHMRC funding in 2007 is committed to research that involves the use of animal or human stem cells. This is approximately 9% of NHMRC research expenditure in 2007 ($539 million).
  • Approximately $976,000 in research funding involves use of human embryonic stem cells.
  • A breakdown of NHMRC funding for research involving stem cells since 2000 is available at www.nhmrc.gov.au/grants/dataset/issues/stem.php

Other Australian Government funding
Australian Stem Cell Centre, Melbourne

  • The ASCC is headquartered in Melbourne with two nodes based at Monash University and the University of Queensland.
  • The vision of the Australian Stem Cell Centre (ASCC) is to undertake research of the highest quality in the stem cell field in order to discover and ultimately commercialise new therapies for human disease.

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/science/national-centre-adult-stem-cell-research

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International website links

The following websites provide useful and authoritative information on stem cells, cloning and related issues

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