Skin cells taken from patients with some eight different diseases have been reprogrammed to an embryonic-like state. These could be invaluable for studying disease and testing drugs.

Here’s the statement from the UK’s Science Media Centre, which announced the result:

‘Dr Willy Lensch from the Children’s Hospital in Boston and colleagues in his laboratory have generated stem cell lines from iPS cells with the genetic characteristics of more than six different diseases, including Huntingdon’s disease, Down’s syndrome and a type of muscular dystrophy. These can be used to study how these diseases affect fundamental development. They also can be used for surrogate testing for drug development, accelerating the development of therapies for devastating diseases.’ The announcement has been reported by the BBC. UPDATE: When I asked folks at Children’s Hospital about this, I was told that the work wasn’t ready for coverage; it had simply been mentioned at a seminar, and the fact that the UK press picked it up was surprising.

Reprogramming human cells was first reported in November, using cell cultures that could be bought commercially. Converting cells from a fresh patient biopsy was reported the following month by the lab led by George Daley and where Willy Lensch works as a senior scientist. By now, multiple labs have independently reported reprogramming cells, demonstrating that the technique is reliable and reproducible.

There are a variety of steps that will need to happen before the cells will start yielding information that will be useful for clinical applications. These are discussed in a commentary by the California Institute of Regenerative Medicine and a feature article written after mouse cells were fully reprogrammed.

The cells will need to be differentiated into the cell types that are affected in the various diseases. According to the BBC, a team at Nottingham University is already using reprogrammed cells to study heart conditions. Human cells differentiate very slowly compared to mouse cells. Turning embryonic stem cells into apparent photoreceptors, for example, took close to a year.

The first step in telling if cells are differentiating is checking out the molecules they display on their surfaces. Then comes the much more arduous task of looking at cells’ shape and function. (If it’s a nerve cell, does it release neurotransmitters? If it’s a heart cell, does it beat?) Even then scientists worry whether the cells in a dish behave like the ones in the body.

Other obstacles are getting enough of the cells and purifying the differentiated cells away from other cells growing in the dish that have not transformed fully.

Finally, drugs that are known to treat particular diseases will be tested on the differentiated cells. Results from these cell-based tests will be compared to established tests, most likely tests carried out on mice and rats.

Developing cells to become therapies (transplanting them to perk up or replace diseased hearts, brains, or other organs) will require considerably more work than developing cells to test therapies. One worry is that techniques to reprogram cells change them genetically, and clinical work in gene therapy resulted in patients’ deaths, making researchers leery of trying again.