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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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What are embryonic stem cells ?

  • Embryonic stem cells, as their name suggests, are derived from the early embryo. They have the potential to develop into cell types in the body.
  • In Australia, human embryonic stem cells are derived from human embryos that are excess to the needs of patients undergoing 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 'Cloning' section below).

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What are Adult stem cells?

  • Adult stem cells (often called somatic stem cells) are found in many organs and tissues of the body. Their main function is to replace cells that have died in the tissue or organ where they are located.
  • 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.

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What are induced pluripotent stem (iPS) cells?

  • Adult cells can be reprogrammed into cells that have similar properties to embryonic stem cells – these are termed induced pluripotent stem (iPS) cells.
  • Reprogramming can be induced through expression of a small group of proteins in the adult cells.
  • iPS cells were first generated in 2006. Many research groups have now produced iPS cells, including in Australia.
  • A number of methods can be used to produce iPS cells. Some alter the DNA sequence of the cells, such as the use of retroviruses.
  • Some researchers have shown that the genes that induce reprogramming can be removed once the iPS cells are produced. Others groups have used purified proteins to induce reprogramming, avoiding the use of DNA such as retroviruses.
  • Research on iPS cells may eventually lead to the development of patient-specific stem cell lines which could be used clinically without the need to use human eggs or embryos. However, additional research is required to establish whether iPS cells are sufficiently similar to embryonic stem cells to substitute for them.

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What are the potential uses for stem cells?

Researchers and clinicians are developing stem cell technologies to:

  • improve our understanding of fundamental processes in biology
  • contribute to novel treatment methods in the health care setting, by producing:
    • models of diseases – for example, stem cells can be derived from patients with known genetic disorders, allowing researchers to study the disease process
    • models for drug screening – novel compounds to treat diseases can be tested using cell lines derived from stem cells
    • personalized therapeutics – stem cells may be a source of replacement cells that could be used to treat disease

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Cloning?

  • "Cloning" is an umbrella term traditionally used by scientists to describe different processes for duplicating biological material.
  • The possibility of human cloning arose when Scottish scientists at the Roslin Institute created the much-celebrated sheep 'Dolly' (Nature 385, 810-13, 1997)
  • Reproductive cloning is banned in Australia under the Prohibition of Human Cloning for Reproduction Act 2002
  • Therapeutic cloning, also known as somatic cell nuclear transfer (SCNT) is permitted in Australia under licence issued by the NHMRC Embryo Research Licensing Committee.
  • SCNT was the technique used to create the first cloned mammal, 'Dolly' the sheep. SCNT involves isolating a somatic cell from an adult body, often a skin cell, and transferring the nucleus from that cell to an egg from which the nucleus has been removed. This new cell is then stimulated to begin embryonic growth.
  • Presently, no human stem cell lines have been derived from SCNT research.

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Regulatory framework

Use of human embryos to derive embryonic stem cell lines

Research Involving Human Embryos Act 2002

  • 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 on Ethical Conduct in Human Research 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

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 (2007; National Statement)

More information and advice on the regulatory framework

Facts and figures on embryos, licences and funding

What are the licence holders hoping to achieve through the use of human embryos for research?

  • Melbourne IVF is licensed to develop tests to improve IVF success rates for couples with specific types of infertility.
  • In collaboration with Stem Cell Sciences Pty Ltd, Melbourne IVF is licensed to develop improved and defined culture conditions for establishing embryonic stem cell lines.
  • The licences issued to Sydney IVF will enable them to undertake research leading to improved IVF success rates; gain a better understanding of embryo metabolism; undertake specialised work to derive embryonic stem cells and to attempt to create embryos by somatic cell nuclear transfer and then, if successful, to attempt to derive embryonic stem cells from the embryos.

Number of embryos and licences

  • There were 118700 embryos in frozen storage in 2006 (the most recent time for which data are avaiable). Almost all of these were embryos were 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 2009:
    • 573 excess ART embryos had been used in licensed research in Australia
    • the NHMRC Embryo Research Licensing Committee had issued 10 licences authorising the use of up to 2165 excess ART embryos
    • 5 of the 10 licences authorise the use of up to 800 excess ART embryos for the derivation of human embryonic stem cells.
    • 334 excess ART embryos had been used under these 5 licences.
    • 3 licences had expired or been surrendered. 2 of those licences authorised the derivation of human embryonic stem cells. The total number of embryos authorised to be used under the remaining licences is 1690.
    • 3 additional licences had been issued authorising the attempted creation of embryos by somatic cell nuclear transfer. Only eggs which are considered to be unsuitable for use in clinical treatment are permitted to be used under the licences.
  • More information on embryo and licence numbers is available at
    http://www.nhmrc.gov.au/research/embryos/information/faqs.htm
  • Information about the results of the licensed research is available in the NHMRC Embryo Research Licensing Committee Reports to Parliament at http://nhmrc.gov.au/research/embryos/information/reports/index.htm.

How many excess ART embryos or eggs will be used in the licensed activities?

There are currently 9 active licences issued by the NHMRC Embryo Research Licensing Committee:

Sydney IVF

Licence 309701 up to 670 embryos
Licence 309702A up to 170 embryos
Licence 309702B 220 embryos (170 of these must have been used in 309701 first and then transferred to 309702B) *.
Licence 309703 200 embryos
Licence 309710 100 embryos
Licence 309712 2400 eggs
Licence 309713 2400 eggs
Licence 309714 2400 eggs

Note: (*) This Licence was granted on the condition that suitable embryos used in 309701 must then be used for 309702B. This is to ensure a minimum number of embryos are used in the research authorised in these licences.

Melbourne IVF

Licence 309704 up to 300 embryos
Licence 309709 up to 200 embryos (surrendered 16 November 2009)

These details are included in the information on each licence that is provided on the NHMRC website.

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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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