| Previous Section | Index | Home Page |
The first type of embryo is the cytoplasmic hybrid, which is euphemistically called a cybrid, and involves removing the nucleus from an animal egg cell and replacing it with one from a human. It is essentially a vessel to compensate for the shortage of eggs that are needed to produce embryonic stem cells. As I have said, two licences for that practice have already been granted. I am sure that the hon. Member for Norwich, North (Dr. Gibson)—a distinguished scientist—will confirm that mitochondria, which are in the area
around the cell nucleus, are neither animal nor human, but are autonomous. We need to clarify this aspect of the law, because the Human Fertilisation and Embryology Act 1990 did not foresee cybrids coming along. The Human Fertilisation and Embryology Authority has therefore granted two licences for such work to be carried out, jumping ahead of legislation. If we agree with the amendment tabled by my hon. Friend, we will go back to the days before the 1990 legislation, which would not be a positive change.
The second category of embryo is the human transgenic embryo, for which animal DNA is put into one or more cells of a human embryo. Both nuclear and mitochondrial DNA are inserted such that there will be a DNA sequence that controls the expression of the DNA already in the human sample. The hon. Gentleman made the point that DNA is not intrinsically human or animal. Sections contain proteins that are identical between animals.
The third category of embryo is the chimera, which involves adding animal cells to a human embryo; it has two or more cells from different organisms. A chimera could contain two different mouse cells, such as a mouse stem cell in a mouse embryo. Chimera are useful research tools for the observation of disease and treatments. With these, the human cells significantly outnumber those from animals.
The final category of admixed embryo is known as the true hybrid. It combines human gametes—for those who are uninitiated with the terminology, a gamete is either an egg or a sperm—with animal gametes, which are also either egg or sperm. As was pointed out earlier, the 1990 Act allows such embryos under what is called the hamster test, but they are allowed to go only to the two-cell stage and must then be destroyed. If we allow true hybrids to continue, that limit would be extended to 14 days.
Neither amendment No. 10 nor No. 11 suggests any change to the 1990 Act, which is subject to schedule 2, paragraph 1(f). Those who know about this issue will be aware that the hamster test is not used much. New technologies—specifically intracytoplasmic sperm injections—have significantly reduced the need for that type of assessment in clinics. Indeed, a distinguished stem-cell biologist, Dr. Robin Lovell-Badge, whom I shall mention again, told me in a letter only last week that the intracytoplasmic sperm injection had made the hamster test largely irrelevant.
Originally, the Government were not going to allow true hybrids up to a 50:50 genetic material mix of animals and humans. However, in response to the pre-legislative scrutiny Committee, the Government changed their mind, and I would like the Minister, in her response to the debate, to put on record why they did so. This shifting position seems to undermine any consistent ethical position on admixed embryos.
Dr. John Pugh (Southport) (LD): I am sure that the hon. Gentleman will be aware of the briefing from the Academy of Medical Sciences, the Royal Society, the Wellcome Trust and the Medical Research Council, which we have all received. It states:
“We are not aware of any current need to generate true hybrid embryos”.
Would the hon. Gentleman like to comment on that?
Mark Simmonds: If the hon. Gentleman will bear with me, I will come to that specific point in a moment. He is right to make that point, however, although there has been some dissent in the scientific community since Second Reading as to whether that is or is not the case.
So there has been a shift in the Government position, which seems to undermine the ethical situation. There was an extensive debate in the other place on the issue, but no reason seemed to be given, except that the Committee and those in another place could see no reason why true hybrids should not be included.
The HFEA, many scientists and I believe that embryonic stem-cell research is necessary. It is a research requirement that the research could not be achieved by any other means than by embryonic research. As I have said, adult stem cells are different from embryonic stem cells. When visiting Newcastle university, I saw an embryonic stem cell, created from a human embryo, under a microscope, beating like a heart muscle. That has not been done using adult stem cells. When visiting Kyoto, it was clear that embryonic stem cells were essential for benchmarking for pluripotent adult stem cells, exciting though that prospect is.
There are therefore significant differences between the different types of admixed embryos. I personally have no issue with the first three. I take issue only with true hybrids, which is what amendments Nos. 10 and 11 are about. The first reason is that, in the context of this debate, the Government have changed their position without clearly making their case. They are obviously uncertain about this.
Furthermore, the scientific community has expressed serious reservations about true hybrids, and these were quoted by other hon. Members on Second Reading. Indeed, since last Monday’s debate, the distinguished stem-cell scientist Dr. Robin Lovell-Badge has felt it necessary to clarify his position. Those who were here for the Second Reading debate will remember that he was cited as the leading scientist who felt that there was no need for human hybrid embryos to be approved under the legislation. He seems to have changed his mind, however—whether under pressure or otherwise remains unknown. During the oral evidence session of the pre-legislative scrutiny Committee, he said:
“I cannot think of a good experiment to do now”.
However, in a letter that Dr. Lovell-Badge wrote to me after the Second Reading debate last week, he confirmed that there were primarily three areas in which true hybrids could be useful. I shall outline each one quickly if I may. The first involves the hamster test, which was permitted under the 1990 Act. That would be allowed to continue if these amendments were passed today. The second area involves artificial gametes, making sperm from pluripotent cells. The Minister confirmed on Second Reading that she would not allow such a provision to be in the Bill at all. The third area involves the use of what is called somatic cell nuclear transfer to understand the mechanisms by which human somatic cells can be reprogrammed from one cell type to another. It is the rationale for the construction and study of cytoplasmic human hybrid admixed embryos, which will be allowed under the Bill even if my amendment is passed.
Even if Dr. Lovell-Badge were alone in having clarified his thoughts, there would be a serious issue to debate,
but many other scientists have also expressed significant concerns about true hybrids. Lord Winston is another example, and my hon. Friend the Member for Gainsborough was absolutely right to quote Sir Liam Donaldson’s evidence to the Committee that there was no clear scientific argument for this measure, and that it represented a step too far. Indeed, many other scientists in the stem-cell field, who do not wish to be quoted, have grave reservations. This is an anonymous quote:
“I cannot understand why anyone would want to make true hybrids”.
These are true scientists in the field.
There are significant differences between true hybrids and other hybrids. The true hybrid is not always at the human end of the spectrum. There is an ethical difference between a cell that is 99 per cent. human and one that is 50 per cent. human. Where is the principle for having a cut-off point of 50 per cent.? Should it be 50 per cent., 51 per cent., or 49 per cent.? Where will the legislation allow animal implantation if the cell is 51 per cent. animal rather than 51 per cent. human?
Dr. Evan Harris: Will the hon. Gentleman explain what the ethical difference is between 50 per cent. and 51 per cent., or between 51 per cent. and 99 per cent.?
Mark Simmonds: I think that there is a very big difference between a cell that has a 51 per cent. animal and 49 per cent. human make-up and one that has a 99 per cent. human make-up. That is, of course, what we are debating today and it is the issue on which the House must make up its mind. There is a also a significant difference between the transfer of genes and chromosomes and the mixing of gametes, which are sex cells.
I hope that the Minister will be able to clarify some of the issues we have raised. I wait to hear her response before deciding whether to put these amendments to the test later.
The Chairman: Perhaps I should remind hon. Members that we are in Committee and not in the House, so the form of address to the Chair is different from our usual practice. I apologise in that I misdirected hon. Members earlier by my own reference to the House, as opposed to the Committee.
Dr. Gibson: Sir Alan— [Interruption.] I know he is a great cricketer in the making.
It is, I think, the desire of all stem-cell scientists one day to take an adult stem cell and reprogramme it to be just like an embryonic stem cell—one that can, with growth factors, be turned into different types of tissues. That is the El Dorado and claims have been made that we are moving in that direction, particularly, as has been pointed out, on the basis of work done by Yamanaka at Kyoto university. It is important to be critical of his work and to be aware of how far it goes, as it has been used as an example to show that adult cells have something major to offer in this field.
We use viral vectors in this area; they are called retroviruses and they have a habit of carrying genes into the chromosomes of the cells where the retrovirus
is incorporated. I believe there are 20 sites in the particular cells that Yamanaka has looked at. There are 20 copies of this virus lying there, influencing how the particular genes work. It is argued by some people that the cells turn into embryonic-type cells. However, anyone who looks at Yamanaka’s paper and dissects it in detail, as I have, will see that it is nothing like that. There are many problems and flaws—and not just with the retrovirus, as it may be possible to get round that and find other ways to get the particular genes in to turn the cells back into the embryonic stage. Only very few of the colony cells that are treated develop any kind of resemblance to an embryonic cell. It is something in the region of 10 out of 50,000 cells that take on some of the properties associated with embryonic cells. Yamanaka is quite critical about it in his own paper. He says that there are
“minor genetic alterations, which could not be detected by karyo-type analyses, or epigenetic alterations”,
which may be necessary for “cell induction”. He continues:
“These issues need to be elucidated in future studies.”
He goes on to say in respect of the particular human cells influenced by the virus that it is unlikely at this stage for anyone to be able to commit to saying that these cells are very like embryonic cells. Even that work, then, leaves a lot to be desired.
We have heard about adult cord cells. It is absolutely true that they are very effective in certain haemopoietic diseases—blood diseases, anaemias and so on—but they are unable to turn into other cell types. Clearly, there is a lot yet to learn about adult cells and cord cells.
We still have the mystery of life around us. It is still possible to take a plant cell and grow the whole plant. I have always wondered about the secrets of plants without for a minute thinking of turning a plant into a human being. Gosh, we might get funding from some source to look into that! There is some magical mystery there that we have to discover, in which we can turn cells around into different tissues. Plants have something to offer in that area.
With the particular cells that would be made, we could treat single patients—that is true—but a culture of embryonic stem cells can be grown to treat lots of different patients with a particular condition. That is the El Dorado; that is the dream. Degenerative diseases can be handled in a larger arena than the single individual.
4.30 pm
Stem cells, too, are something quite new, and it is argued that we have not turned up anything yet. Stem cells were debated in this place in 2001, and were legitimised in terms of our being able to do any work with them. Their isolation was achieved in Wisconsin in the USA in 1998. The first licences in this country for doing any work with them came in 2003, so we are five years down the line and people are expecting major results that will turn the world around.
How long does it take any good company in this country or in the USA to develop a drug? It takes 20 to 40 years. Do we ever hear people being critical of drug companies being slow? They have many, many tests to go through, which we should be glad about.
Mr. Cash: In the light of what the hon. Gentleman said on Second Reading and in the light of what he is saying today about adult stem-cell research, will he not apply the same criteria to that as well, in that clearly a time will have to elapse before we can be absolutely sure about either type of research? Has not the Bill therefore been introduced too soon?
Dr. Gibson: I agree absolutely, but what we are saying here in the rational world of debate is that there are different ways to make stem cells at an early stage to use for whatever we are going to use them for—I shall return to that point in a moment—but we should be trying everything. There is no easy bet that one will be better than the other. We might need all different types for different types of disease. We should not allow ourselves to be differentiated into saying, “Adults’ are better than embryonic, and cord cells are the best of the lot.” They are very restricted in what they can do.
Lembit Öpik: On that very point, Professor Chris Shaw, professor of neurology and neurogenetics at King’s college, London and a leading motor neurone disease researcher, has said something much in line with what the hon. Gentleman is saying:
“I cannot guarantee that embryonic stem cells from hybrid embryos will lead to a breakthrough, but I do think it would be a huge mistake to slam the door on this potentially important avenue of research. I believe that every effort should be made to understand the causes of MND because this is the only way we will develop really effective treatments”.
To hold off would mean taking a precautionary principle, which, in effect, would kill all those people who could be saved if we invested now to see whether this was the right way to the cure for MND.
Dr. Gibson: I concur with that general view.
Sarah Teather: I thank the hon. Gentleman for giving way. He is arguing that we need to keep all avenues of research open, but that is not the way that we deal with licences for animal research. An application to do research on a chimpanzee would be unlikely to be granted until people had demonstrated that they were unable to do that research on something less ethically difficult—for example, a rat or a hamster. Does the hon. Gentleman not see that there is a difference here?
Dr. Gibson: I thank the hon. Lady for that intervention, but as a hard-nosed scientist, no. People work on the best organism to give them the answer that they want to see. They might not get the answer and they might even have to work on a worm to get the answer that they want. In other cases, people want to move up to the clinical situation. There, they have to go through rhesus monkeys and so on.
I know that lots of people think that using animals is ethically wrong, but I tell the House this: scientists can be fallible, but they are tightly regulated and have to go through ethical committees in much of the work that they do. They have to get permission to use certain animals and they have to deliberate on how they are going to use them. They have to prove how things will be done so that there is no cruelty appertaining to that situation. Mice, rats, guinea pigs and other animals have all featured over the history of this period, but—
Judy Mallaber (Amber Valley) (Lab): Will my hon. Friend give way?
Dr. Gibson: In a second. I want to make one point.
On Second Reading, I said that I remembered a time in the ’70s when genetic recombination was the bugbear. We were putting genes from another organism inside a bacterium or whatever. That caused trouble right across the USA. It was the scientists themselves, at a huge meeting and seminar, who disciplined themselves and ran a campaign on how to assess the dangers pertaining to such work—not just the dangers to themselves and the technicians in the lab, but the dangers to the public outside. The whole of Boston was up in arms about that kind of work being done at Harvard.
When we look back now and ask whether those scientists were right, the answer must be yes. People may not like genetically modified plants, but gosh, if they have diabetes they will all be using insulin made from GM organisms. That was the big issue in the debate about genetic modification in this place. When it led to medical improvements in our conditions it was OK, but when it involved plants it was a bit different. We know that there are many other issues involved relating to big companies and so on, but I can tell the Committee that people really do support attempts to improve their lives, and insulin is a good example. If we had banned GM completely, we would not have the human insulin that has saved so many lives.
Judy Mallaber: Will my hon. Friend clarify his exchange with the hon. Member for Brent, East (Sarah Teather)? As a scientist, can he give some examples in which adult stem cells would be of no use in advancing experimentation? I understand from some of our debates that pancreatic stem cells do not exist in adults, whereas we have heard about motor neurone stem cell lines being developed in a dish from embryonic stem cells that could be used for compounds.
Dr. Gibson: It is extremely difficult to obtain adult stem cells from the human body, although there are instances in which some stem cells are in better condition than others. The longer a stem cell stays in the body, the more likely it is that an ageing effect will lead to mutations, while an embryonic cell at the start of a process does not show any of the changes in DNA that we call mutations.
It has been said that no tests are in progress. That is untrue: tests have started in the United States. Experiments have begun using human embryonic cells to deal with spinal cord injuries. Neuronal cells have been placed in people, and it has been shown that they repair spinal damage. I have not yet confessed today that I am a member of the Stem Cell Foundation, which includes some of the most distinguished scientists in the world who are interested in stem cells. Their sole motivation is not to be uncritical about stem cells, but to ensure that when the stem cell flood happens—if it does happen in the next few years—we in this country develop the technology.
| Next Section | Index | Home Page |