April 21, 2024

Stunning discovery creates ethical stem cells

Immersing cells in acid creates pluripotent stem cells? Who could believe that? But it could be the future.

It’s the ultimate confirmation of the notion that stress is good for you. A team of researchers from Japan and Boston have discovered that subjecting ordinary cells to stress will make them revert to a state in which they can make any cell in the body. It is an astonishingly simple door to the promise of personalised medicine which has obsessed scientists for the last 15 years.

“It’s a startling result that makes you stand up and go, ‘Wow!’” says George Q. Daley, a leading stem cell researcher at the Harvard Stem Cell Institute. “With an equal dose of amazement and skepticism.”

And colleague Douglas Melton, says, “It’s just a wonderful result; it’s almost like alchemy. It says one has found a way to reveal the hidden potential of cells with a relatively straightforward method.”

The bombshell research was published in the journal Nature this week. The researchers claim that their method of reprogramming cells to pluripotent state – which they have dubbed stimulus-triggered acquisition of pluripotency (STAP) bypasses both cloning and the use of chemicals. It has been proven with mouse cells; experiments with human cells are under way.

Stem cell reprogramming is one of the hottest areas of biology and Japanese researcher Shinya Yamanaka won a Nobel Prize in 2012 for discovering “induced pluripotent stem cells”. This discovery, because of its simplicity, could be even more momentous.

Surprisingly the central figure in the discovery, Dr Charles Vacanti, of a tissue engineer at Brigham and Women’s Hospital in Boston, is not even a stem cell scientist. In 2001 he published an article in which he claimed that he had discovered a new type of stem cell which he called a “spore-like cell.” But other scientists were sceptical. “Our lab was pretty ridiculed,” he told the Boston Globe.

But by reflecting on his results, Dr Vacanti realised that the stem cells might have emerged as a result of stress, as part of the body’s repair kit, and did not reside in the tissue itself. Together with a Japanese research fellow in anaesthesiology, Haruko Obokata, of the RIKEN Center for Developmental Biology in Kobe, his team pursued this avenue.

They found that after bathing mature cells in acid or growing them in a low-oxygen environment, some of them reverted to a pluripotent state – STAP cells. If they were then placed in a growth medium, they became just like embryonic stem cells — totipotent. In other words, they can also produce the cells which create the placenta as well as the embryo. The new method is far simpler and quicker than Yamanaka’s method.

However, the results were so counter-intuitive that other scientists refused to believe them until the accumulation of data was overwhelmingly convincing.

For years many stem cell scientists have insisted that ethical barriers to destructive research on embryos had to be dismantled because they are the best source of pluripotent stem cells. Persuaded by their arguments, many governments relaxed legislation on destructive embryo research. But if the STAP cells prove to be viable, both scientists and politicians will be looking rather silly.

Unfortunately, this discovery could give rise to its own ethical debate. New Scientist points out that if STAP cells are totipotent, they could become induced to become embryos. “The word totipotent brings up all kinds of issues,” Robert Lanza ,of Advanced Cell Technology, told the magazine. “If these cells are truly totipotent, and they are reproducible in humans then they can implant in a uterus and have the potential to be turned into a human being. At that point you’re entering into a right-to-life quagmire” 

In other words, the STAP cells could lead to a new debate about cloning. “Clones like Dolly are not actually a perfect copy,” says Dr Vacanti. “When you clone a cell using our technique, there is no egg, so there’s no additional mitochondrial DNA. There’s an embryo and a placenta which is a perfect copy of the original.”

Michael Cook
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