Embryonic stem cells: Advance in medical human cloning

Early embryo An embryo at the blastocyst stage

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Human cloning has been used to produce early embryos, marking a "significant step" for medicine, say US scientists.

The cloned embryos were used as a source of stem cells, which can make new heart muscle, bone, brain tissue or any other type of cell in the body.

The study, published in the journal Cell, used methods like those that produced Dolly the sheep in the UK.

However, researchers say other sources of stem cells may be easier, cheaper and less controversial.

Opponents say it is unethical to experiment on human embryos and have called for a ban.

Stem cells are one of the great hopes for medicine. Being able to create new tissue might be able to heal the damage caused by a heart attack or repair a severed spinal cord.

There are already trials taking place using stem cells taken from donated embryos to restore people's sight.

However, these donated cells do not match the patient so they would be rejected by the body. Cloning bypasses this problem.

The technique used - somatic cell nuclear transfer - has been well-known since Dolly the sheep became the first mammal to be cloned, in 1996.

Dolly the sheep Dolly's birth in 1996 was seen as a major scientific breakthrough

Skin cells were taken from an adult and the genetic information was placed inside a donor egg which had been stripped of its own DNA. Electricity was used to encourage the egg to develop into an embryo.

However, researchers have struggled to reproduce the feat in people. The egg does start dividing, but never goes past the 6-12 cell stage.

'Real deal'

A South Korean scientist, Hwang Woo-suk, did claim to have created stem cells from cloned human embryos, but was found to have faked the evidence.

Now a team at the Oregon Health and Science University have developed the embryo to the blastocyst stage - around 150 cells - which is enough to provide a source of embryonic stem cells.

Cloned babies?


Could scientists fully clone a person? It's an interesting question that emerges from this research.

These researchers have certainly developed a cloned embryo further than anyone else.

But producing a five-day-old embryo is a world away from a woman giving birth to the first human clone.

The embryo would need to be implanted as per IVF, but primate research shows that things often go wrong before the clone is born.

Prof Robin Lovell-Badge of the UK National Institute for Medical Research said: "It is an unsafe procedure in animals and it will similarly be an unsafe procedure in humans. For this reason alone it should not be attempted."

It would also be illegal in some countries, such as the UK, which differentiate between "therapeutic" and "reproductive" cloning.

Dr Shoukhrat Mitalipov said: "A thorough examination of the stem cells derived through this technique demonstrated their ability to convert just like normal embryonic stem cells, into several different cell types, including nerve cells, liver cells and heart cells.

"While there is much work to be done in developing safe and effective stem cell treatments, we believe this is a significant step forward in developing the cells that could be used in regenerative medicine."

Chris Mason, a professor of regenerative medicine at University College London, said this looked like "the real deal".

"They've done the same as the Wright brothers really. They've looked around at where are all the best bits of how to do this from different groups all over the place and basically amalgamated it.

"The Wright brothers took off and this has actually managed to make embryonic stem cells."

The ethical rival

Embryonic stem cell research has repeatedly raised ethical concerns and human eggs are a scarce resource. This has led researchers to an alternative route to stem cells.

The technique takes the same sample of skin cells but converts them using proteins to "induced pluripotent" stem cells.

However, there are still questions about the quality of stem cells produced using this method compared with embryonic stem cells.

Prof Mason said the field was leaning towards induced pluripotent stem cells: "It has got a lot of momentum behind it, a lot of funding and a lot of powerful people now."

Dr Lyle Armstrong, at Newcastle University, said that the study "without doubt" marked an advance for the field.

Dr Lyle Armstrong, Newcastle University: "They can become any of the cells or tissues"

But he warned: "Ultimately, the costs of somatic cell nuclear transfer-based methods for making stem cells could be prohibitive."

Opponents of the new technique argue that all embryos, whether created in the lab or not, have the potential to go on to become a fully-fledged human, and as such it is morally wrong to experiment on them.

They strongly advocate the use of stem cells from adult tissue.

Dr David King, from the campaign group Human Genetics Alert, warned that: "Scientists have finally delivered the baby that would-be human cloners have been waiting for: a method for reliably creating cloned human embryos.

"This makes it imperative that we create an international legal ban on human cloning before any more research like this takes place. It is irresponsible in the extreme to have published this research."

However advocates of the new technique say that the embryos created from this technique could never become viable human beings.


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  • rate this

    Comment number 456.

    @46 "How are human eggs a scarce resource? Half of the worlds population has hundreds of them."

    Good point, but wrong! You should have said;

    ""How are human eggs a scarce resource? Half of the worlds population has hundreds of thousands of them."

  • rate this

    Comment number 455.


    Hich is your right of course - just so long as you don't try and force your views onto those who would gladly make use of this technology.

    After all this isn't an embryo concieved naturally, it one one made in the lab using an unwanted egg that has never been near a sperm & some skin cells from the person invloved.

    So it barely even qualifies as embryonic......

  • rate this

    Comment number 454.

    At present we butcher a dead body or a living one (kidneys etc) which is much more invasive or worthy of blasphemy than the harmless growing of spare parts.
    The faster this is seen as normal the faster we will be able to beat old age and move forward with living without fear of premature death.

  • rate this

    Comment number 453.

    The world is going to be a far better place when they make millions of clones of me!!

  • rate this

    Comment number 452.

    MRR there is really no real fundamental difference between a human embryo and that of any other animal. At the stage we are talking about it has yet to have a backbone, a brain, I don't think it even has a heart. It has the theoretical potential to become a person but only if implanted in a womb. Every sperm and egg has the same potential yet we let most of them die. :)

  • rate this

    Comment number 451.

    Reality, DownWithTheEBC , etc

    It is possible to identify pretty much exactly how people get their moral codes. We mostly learn them as small children as a reflection of the people and culture around us especially our parents, & today the TV and media.
    The brain constructs itself by self-evolving and has an initial inbuilt programming but in humans this can be made to adapt to almost any point.

  • rate this

    Comment number 450.

    This kind of research always claims in justification that it will cure all sorts of diseases.Personally, if I was suffering from an incurable disease, I'd rather die than be saved by embryonic cells. I'd feel too guilty about the life that was sacrificed for mine.

  • rate this

    Comment number 449.

    The big difference today between the Wright brothers and cloning?
    If the Wright brothers were trying to make their first flights today leaving the ground would no doubt be technically illegal as a 'threat' to mankind.

    We live in a cowardly bureaucratic age that doesn't trust in the future or science or technology. An age that puts the opinions of the incompetent and the ignorant over everyone.

  • rate this

    Comment number 448.

    The future may be a bright one but "The way to Hell is paved with good intentions".

    We are unable to see the future.
    If we were able could we avert disasters like Chernobyl ?
    Short sighted scientists tend to believe that everything will turn out rosy but make the future unpredictable, and worse than it should be.

    If nobody ever dies, ever wondered what happens IF the population IS too high?

  • rate this

    Comment number 447.

    It does not matter if a subject is banned as "immoral" "unethical" or "evil".

    In the name of science some clinician will achieve human cloning even if it has the same imperfections that plagued Dolly the Sheep.

    I think the slippery slopers are rather alarmist

    An embryo is implicit - that if implanted could grow into a living being. The slope starts right there with intrinsic fact!

  • rate this

    Comment number 446.

    I don't think it is alarmist to say that a line should not be crossed in our research. When you talk about embryonic stem cells you are destroying an entity with all the structural characteristics of a human being. It only lacks the environmental support to become a person like you or I. Anyone who does not see this is kidding himself

  • rate this

    Comment number 445.

    I hope they go on with this important research. I might give new life to injured vets and millions of other folks around the globe that are forced to spend their lives in wheelchairs. Can you imagine a person that has a spinal injury that this could help.

  • rate this

    Comment number 444.

    404 "Your morality may have been "handed down" to you, mine most certainly was not."

    Yes it most certainly was. Morality does not develop in a vacuum. Even if you rejected the morality of your parents or peers, your sense of morality ultimately has been influenced by others in society either directly or indirectly. Your "experience and reason" comes from social exposure, not thin air.

  • rate this

    Comment number 443.

    Human cloning is unethical and against Divine plan. Encroaching on the Almighty's territory may boomerang into unchartered waters causing irreversible damage. It amounts to challenging God's will. Scientists should restrict themselves to medical research for betterment of human health and cure for what is incurable.

  • rate this

    Comment number 442.

    It is an extreme view to brand all skeptics as 'zealots'. As a Christian, I welcome the research and can understand how beneficial it can be to those in need. However, I have concerns, both moral and ethical, and it would be vitally important that all concerns are addressed in a logical and scientific manner and not 'swept under the carpet' by science extremists.

  • rate this

    Comment number 441.

    I think I've made my position clear on this; I think it's a good thing and welcome it. Lets trust in those that provide governance and oversight; and hopefully reassure those that oppose or fear it.

    Hopefully this will lead to good for all; and will help the thousands that suffer everyday with debilitating illness.
    Night all
    (inc DownWithTheEBC.. good chatting with you)

  • rate this

    Comment number 440.

    Both sides of the argument have a point. The gains we get from this are great, and they are needed. But unfortunately, humans have a tendency to mess up the best of intentions, and reduce it to a mere shell of what it was intended to do. I expect that we will see both sides played out... the good and the bad... as per usual.

  • rate this

    Comment number 439.

    @435. Reality

  • rate this

    Comment number 438.

    The reason why there's no real agreement over religions role in morality is because, in many ways religion is a codification of laws and morals that were already in position.

    Religion does reflect the morals at the time of its creation, but like the rules regarding wife-beating, not all morals that were deemed 'acceptable' then are as such now. Inflexibility is the real risk of hardline religion.

  • rate this

    Comment number 437.

    @431 As an atheist on a sinking ship..
    Being alone in the middle of the ocean after my ship's sinking, I would welcome death.
    This is something you death-fearing believers-in-an-afterlife will never understand!
    I don't envy you, you must be so afraid...


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