A breakthrough in stem cell research

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Scientists in Japan have shown that it is possible to create stem cells simply by dropping blood cells into acid.

This discovery has the potential to unlock a new era in personalised medicine, and could lead to therapies and cures for a huge number of diseases.

Stem cells are undifferentiated cells that can be made to transform into any other type of cell – a feature termed pluripotency. This gives them a huge potential for use in regenerative medicine since, if entire organs can be grown for transplants, there will no longer be a need for human donors.

There is also hope that they can be used to provide cures for cancer, heart disease, type I diabetes and neurological diseases such as Parkinson’s, Alzheimer’s and Huntington’s disease by providing new and healthy cells for the patient which can be grown for them specifically, meaning rejection by the immune system will no longer be a problem.

This massive potential is why stem cell research is such an exciting topic in modern biology.

Unfortunately, it is also surrounded by controversy, because the one way in which stem cells can be obtained is from human embryos.

A breakthrough came in 2012 when Sir John B. Gurdon and Dr Shinya Yamanaka won the Nobel Prize in Physiology or Medicine for their discovery that skin cells could be genetically reprogrammed to become pluripotent (termed ‘induced pluripotent stem cells’ or ‘iPS cells’) reducing the need for embryonic stem cells.

However, this method has been shown to cause mutations that could lead to cancer so it is not yet entirely ethically sound.

This new method of creating stem cells could, then, revolutionise the field of stem cell biology. It is a major breakthrough because of its simplicity – it will make producing stem cells faster, cheaper and safer.

The cells (termed ‘stimulus-triggered acquisition of pluripotency’ or ‘STAP’ cells) simply need to be placed in a stressful (for example, acidic) environment and they will return to their pluripotent state.

This technology has been observed before in plants. Severe environmental stress can cause an adult plant cell to transform into an immature one from which an entire new plant can arise. Similar processes have also been seen in some types of adult cell in reptiles and birds.

“a very exciting, but surprise, finding … almost too good to be true”

The goal was to see if this technology was reproducible in mammals. The researchers took a blood sample from mice which had had a gene introduced into their DNA that caused their cells to fluoresce green in the presence of Oct-4, a protein only found in pluripotent cells.

White blood cells were isolated from the sample and exposed to various physical and chemical stresses which included placing them in an acidic environment with a pH value of 5.7 for thirty minutes.

The cells were then left and observed and by the next day some had begun to glow green, showing they were producing the pluripotency marker, Oct-4. After a week, over two-thirds of the sample were showing this fluorescence. To contrast, it would take four weeks for induced pluripotent stem cells to reach the same stage.

There is much research still to be carried out on this new technology – principally if it can be reproduced safely in humans.

Concern has already been raised over the possibility that the process could lead to human cloning – if the researchers have been able to make ‘totipotent’ cells (which are even more versatile than pluripotent cells, as a single cell can go on to produce an entire embryo), then this would mean a single blood cell could be transformed into a STAP cell, implanted into a human uterus, and develop into a clone.

As it stands at the moment, the technology is a long way off this possibility and it is unknown whether a human clone would be able to be produced this way in practice.

Despite these fears, the amazing medical opportunities offered by stem cells, that have for so long only been possibilities, are now much closer to becoming realities.

The discovery has been met with astonishment and excitement throughout the scientific community. Robert Lanza, chief scientific officer at Advanced Cell Technology, Massachusetts, commented, “if this can be reproduced in humans, it will be a paradigm changer”, while Chris Mason, Professor of Regenerative Medicine at University College London, described the discovery as being “a very exciting, but surprise, finding” and almost “too good to be true.”

Photograph: Tareq Salahuddin on Flickr

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