Stem cell research: 15 years on

Fifteen years ago, the first permit for human embryonic stem cell research was granted in Germany.

Stem cell research: 15 years on
dpa

Berlin (dpa) - The police guard is no longer a fixture of daily life for German scientist Oliver Bruestle, and the threatening telephone calls stopped long ago.

Fifteen years ago, on December 19, 2002, Bruestle was granted the first permit to research human embryonic stem cells in Germany.

To opponents, that sounded like a licence to experiment Frankenstein-style on embryos, while to supporters, it raised hopes of finding the cures to diseases such as Parkinson's. 

Bruestle, 55, who lives in the western city of Bonn, never expected miracles, even back then. Still, his research has come a long way since then.

But some say Germany's strict laws on stem cell research mean the country's scientists are being left behind internationally.

Bruestle, a neuropathologist, was looking for ways to replace worn-out cells in the nervous system by using brain cells created in the laboratory from embryonic stem cells.  

Embryonic stem cells are taken from embryos that are a few days old and which have been left over from in vitro fertilization.

The embryos, made up of just a few cells, are destroyed in the process.

In the 15 years since Bruestle began, the procedures for extracting replacement cells from human stem cells have developed at enormous speed.

Today, Bruestle and his international colleagues can create all kinds of brain cells from stem cells with incredible precision.

They have also been used successfully in experiments involving animals.

Since 2002, 132 permits for research involving human embryonic stem cells have been given out in Germany. Acquiring one is a time-consuming process.

Applications are first examined by a commission made up of scientists, doctors and ethics experts, and then once again by the Robert Koch Institute (RKI), Germany's public health institute.

"You don't all of a sudden decide to apply," says Peter Loeser, a cell biologist who helps the RKI examine applications. "It's all very thought-out."

Bruestle believes that he is now closer to being able to use his replacement cells in humans, but he is still cautious.

"There are still a few difficulties to overcome," he says.

In 2006, scientists discovered another way to extract stem cells.

Japanese researcher Shinya Yamanaka - who won the 2012 Nobel Prize for Medicine for his efforts - developed revolutionary technology that enabled scientists to convert mature skin and blood cells back to stem cells.

The process creates pluripotent stem cells (iPS cells), which are very similar to embryonic stem cells (ES). Its greatest advantage, however, is that no embryos are needed to create them.

For most of his research, Bruestle now uses both types, and his laboratory has even come up with a third way of creating stem cells: the direct conversion of blood cells into brain cells without first turning them into iPS cells.

"There is no ideal stem cell. ES cells, iPS cells and direct cell conversion will be used in parallel for different biomedical purposes according to need," he predicts.

But will that really be the case in Germany?

Bruestle is careful in how he answers.

"The restrictive regulations here have meant that comparatively fewer scientists are working on the therapeutic uses of ES cells," he says.

And because many methods are transferable from ES to iPS cells, German teams have had a more difficult start in research relating to therapeutic use of iPS cells compared to those from countries such as the United States, Britain, France and Sweden.

Patients in the US, Britain and Japan have, for example, already taken part in studies on age-related eye disease (macular degeneration) with ES and iPS cells. 

German scientists have made significant contributions to stem cell research, but now they're taking a back-seat role.

While Bruestle's team cooperates with European colleagues, "the first clinical studies won't take place in Germany," he says.