Stem cells and medicine Repairing broken hearts {project to repair spinal cords is being shelved}

[xchrom]

http://www.economist.com/node/21538657

IT HAS been a mixed week for proponents of regenerative medicine. This is the idea that worn-out organs might be repaired—or even replaced—using stem cells. A stem cell is one that, when it divides, spins off some offspring that remain as stem cells while others turn into functional tissue. Stem cells found in embryos can spin off a wide range of tissue types. Those found in adults are more limited: turning into blood cells, say, or muscle cells.

The bad news for those who have hopes of the field is that Geron, an American firm that was a pioneer of the therapeutic use of stem cells, is pulling out of the business. It is ending (or selling, if it can find a buyer) a project that was testing embryonic stem cells as a treatment for people paralysed by injuries to their spinal cords. The reason, it said, is financial. At a time when it is hard to raise new capital, the firm has decided to concentrate on anticancer therapies that, it hopes, are nearer to being commercial propositions than the stem-cell study is.

The good news for the field of stem-cell therapy comes from a paper published in this week’s Lancet by Roberto Bolli of the University of Louisville and his colleagues. They have used more specialised stem cells—ones that spin off only cardiac cells—to repair the hearts of people with heart failure. If their method can be made routine, it will bring enormous benefits. Coronary heart disease is the world’s biggest killer. It ended 7.3m lives in 2008 (the most recent year for which figures are available). That is one in every eight people who died that year. A patient with heart failure (caused, for example, by a muscle-damaging heart attack) may benefit from a transplant, but there are not enough spare thumpers around for all those who need them. Hence the idea of doing running repairs on a patient’s existing organ.

Be not still, my beating heart

The participants in Dr Bolli’s study were 23 unfortunates who had each had at least one heart attack in the past, and were thus lined up for coronary-bypass surgery, in which the furred-up blood supply to the heart is replaced with an alternative artery crafted from a blood vessel taken from elsewhere—usually the leg. On average, these patients had hearts pumping out 30% of the optimal volume of blood. Seven of the 23 acted as a control group, and received no intervention from Dr Bolli after the surgery. From the other 16, the researchers collected tissue samples during surgery. They broke these up, in order to extract cardiac stem cells from them (these cells can be identified by the presence on their surfaces of a particular protein), and then bred the stem cells in tissue cultures until they numbered millions.

[trotsky]

1. So much work to be done.

We can just cheer on the progress.

[xchrom]

2. Indeed. I'm struck though by the shelving

Of the spinal cord treatment.

Very sad.