Medical milestone in human cloning

OREGON, United States, Wednesday May 22, 2013 – Human cloning has been used to produce early embryos, marking a “significant step” for medicine, according to a study published in the journal Cell.

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.

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, noted BBC News’ Health and Science reporter James Gallagher, who added that trials are already underway using stem cells taken from donated embryos to restore people’s sight.

These donated cells do not match the patient, however, so they would be rejected by the body – a problem bypassed by cloning.

According to Gallagher’s report, the technique used – somatic cell nuclear transfer – has been well-known since 1996, when Britain’s trailblazing Dolly the sheep became the first mammal to be cloned.

In Dolly’s case, 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.

Researchers have nevertheless struggled to reproduce the feat in people. While the egg does start dividing, it never goes past the 6-12 cell stage.

Now, a team at the Oregon Health and Science University has developed the embryo to the blastocyst stage — around150 cells – which is enough to provide a source of embryonic stem cells.

“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,” said Dr Shoukhrat Mitalipov.

“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,” he added.

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.

Questions nevertheless still arise about the quality of stem cells produced using this method compared with embryonic stem cells.

Chris Mason, a professor of regenerative medicine at University College London, 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, but 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.”

Advocates of the new technique nevertheless maintain that the embryos created from this technique could never become viable human beings. (Excerpted from “Embryonic stem cells: Advance in medical human cloning” by James Gallagher, Health and Science reporter, BBC News) Click here to receive free news bulletins via email from Caribbean360. (View sample)