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Further information on the SCNT licences
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- » What is Somatic Cell Nuclear Transfer?
- » How is the research that has been approved by the NHMRC Licensing Committee different from reproductive cloning?
- » What is the purpose of the research?
- » Where will the eggs that will be used in this research come from?
- » Why have so many eggs been authorised to be used under these Licences?
- » Some of the categories of eggs authorised to be used under the licence have been fertilised. Are these embryos?
- » What assurance is there that the research is ethical and will be properly and ethically conducted?
Q: What is Somatic Cell Nuclear Transfer?
A: Somatic cell nuclear transfer (SCNT) is a technique in which DNA from the nucleus of an unfertilised egg is removed and replaced with the nucleus of an adult cell such as a skin cell. The technique can be used to create cloned embryos in order to derive embryonic stem cells.
Q: How is the research that has been approved by the NHMRC Licensing Committee different from reproductive cloning?
A: The Prohibition of Human Cloning for Reproduction Act 2002 (PHCR Act) effectively prohibits reproductive cloning in Australia by prohibiting the placement of a cloned human embryo in the body of a human or animal. While it has been achieved in a number of animal species, the reproductive cloning of humans has never been demonstrated.
The legislation does, however, allow creation of cloned human embryos for the purposes of research. Before issuing a licence, the NHMRC Licensing Committee conducts a rigorous assessment process and ensures that the applications satisfy the stringent criteria required by the Research involving Human Embryos Act 2002 (RIHE Act). All licences issued contain specific conditions that the licence holder must comply with, including providing progress reports.
Q: What is the purpose of the research?
A: The derivation of stem cells from cloned human embryos has not yet been achieved in Australia or overseas. If the research under these licences is successful it would be a world first, significantly contributing to the field of stem cell research.
The purpose of the research proposed under these licenses is to successfully derive stem cells from human embryo clones created using the SCNT procedure. If the research is successful, it could allow this technique to be used for the generation of disease-specific and person-specific human embryonic stem cell (hESC) lines.
The availability of these hESC lines is expected to significantly contribute to the study of human diseases as well as the development of compounds to prevent or reverse the progression of the disease and may eventually be used for cellular therapies.
As part of its rigorous assessment under the RIHE Act, the NHMRC Licensing Committee considered that this research is likely to result in a significant advance in knowledge that could not reasonably be achieved by other means.
Q: Where will the eggs that will be used in this research come from?
A: Each licence authorises the use of up to 2400 clinically unusable human eggs. Human eggs are collected as part of every IVF (in vitro fertilisation) cycle. Some eggs will fail to fertilise, or will fertilise abnormally. IVF embryologists describe these eggs as “clinically unusable” and they are generally discarded. There are four main reasons why an egg is unusable:
- It is immature. All eggs are given every opportunity to do so, but some just do not make it. After around 6 hours, the embryologist would normally discard those eggs, however, they may still be brought to a point where the SCNT process can be successful.
- It fails to fertilise. Even in optimum conditions, some eggs simply don’t fertilise.
- It activates without the presence of sperm.
- More than one sperm makes it into the egg.
All of the eggs authorised to be used under these Licences have no potential for normal development, but can be used in SCNT. Egg donors must give informed consent before the eggs can be used for research, and they cannot receive any payment or inducement for their donation.
Q: Why have so many eggs been authorised to be used under these Licences?
A: The derivation of stem cells from cloned human embryos has not yet been achieved in Australia or overseas. The aim of the licences is to establish reproducible methods for the creation of cloned human embryos and to demonstrate the feasibility of deriving embryonic stem cell lines from these embryos.
The Licence Holder has estimated that the success rate for the derivation of embryonic stem cell lines from cloned human embryos will approximate 1 in 400. This estimate is based on the success rates of SCNT experiments with primates and the success rates of experiments involving the derivation of stem cell lines from human excess assisted reproductive technology (ART) embryos.
Q: Some of the categories of eggs authorised to be used under the licence have been fertilised. Are these embryos?
A: No. According to the Research Involving Human Embryos Act 2002, a human embryo exists when a human egg fertilised by a human sperm first divides. The donated eggs will not have divided and fertilisation will be incomplete. Thus, they are not considered to be embryos under the legislation.
Q: What assurance is there that the research is ethical and will be properly and ethically conducted?
A: Firstly, all applications must be assessed and approved by a Human Research Ethics Committee (HREC) before being submitted to the NHMRC Licensing Committee. The local HREC ensures that the proposed research meets the requirements of the National Statement on Ethical Conduct in Human Research (2007) and the Ethical Guidelines on the use of Assisted Reproductive Technology in Clinical Practice and Research (2007).
The NHMRC Licensing Committee then conducts a rigorous assessment of the applications in accordance with the stringent criteria required by the RIHE Act before licences are issued. They ensure that applications comply with all the relevant legislation and assess consent protocols and research procedures to make sure they are ethically and scientifically sound.
Once a licence is issued the researchers must report on how every egg and every embryo is used in the research. Inspections are also carried out at least annually to ensure compliance with the RIHE Act, PHCR Act and the licence conditions.