Company's stem cells treat diabetes in mice
By Maggie Fox, Health and Science Editor
WASHINGTON (Reuters) - Human stem cells transformed into nearly normal insulin-producing cells when implanted into mice, possibly offering a way to treat diabetes long-term, researchers at a U.S. company reported on Wednesday.
The researchers used human embryonic stem cells -- the most powerful but the most controversial source of stem cells.
Writing in the journal Nature Biotechnology, the team at San Diego, California-based Novocell Inc said their work showed that human embryonic stem cells might fulfill the promise of treating or perhaps even curing diabetes.
"Our data provide the first compelling evidence that human embryonic stem cells can serve as a renewable source of functional insulin-producing cells for diabetes cell replacement therapies," said Emmanuel Baetge, chief scientific officer of Novocell.
At least 170 million people globally have diabetes, with numbers expected to double by 2030. Five percent to 10 percent have type 1 diabetes, caused when the immune system mistakenly destroys the insulin-producing cells in the pancreas.
In both types 1 and 2 diabetes, the body cannot use insulin properly or make enough of it to regulate glucose in the blood. Patients must monitor their blood sugar and often must take insulin as needed.
One hope for human embryonic stem cells is to use them to replace insulin-producing cells. Transplants from cadavers help, but there are nowhere near enough available.
Baetge's team used embryos discarded from fertility clinics, growing their own batches, or lines, of cells in other human cells -- a system Baetge hopes can more easily be tested in humans than cells grown using animal products.
Embryonic stem cells are master cells, producing all the other cells and tissues in the body. They can live virtually forever in lab dishes, producing generations of new cells.
But controlling them is very difficult.
Baetge's team got hormone-producing or endocrine cells. But each cell produced a mishmash of hormones, instead of specializing into insulin-producing and other types of cells as they should.
So they took a step back, and implanted immature cells into mice, under the skin and in other areas.
Something in the living mouse directed the cells to mature properly, Baetge said. "They are producing all the right enzymes and release insulin in response to glucose," Baetge said in a telephone interview.
He says his company also has technology to encapsulate cells, protecting them from the immune system rejection response. He hopes that would mean patients could use donations of stem cells from other people without taking immune-suppressing drugs.
"It won't get to the underlying cause of the autoimmune disease. It is only going to allow us to transplant the cells without giving immunosuppression," Baetge noted.
The company is now looking for a large pharmaceutical company to partner with for further development.
In the past year, four labs have reported they made, from ordinary human skin, cells that look and act like embryonic stem cells, just by tweaking a few genes.
These induced pluripotent stem cells or iPS cells may be quicker and easier to work with, Baetge said.
"It is still an art to make a human embryonic stem cell from frozen embryos," he said.
On Tuesday, researchers at Stanford University reported they used human embryonic stem cells to treat stroke damage in the brains of rats.
(Editing by Julie Steenhuysen and David Storey)