People With Type 1 Diabetes May Eventually Be Able To Grow Their Own Insulin-Producing Cells, Research Indicates.

Researchers Say Advancement May Lead to Cure for Type 1 Diabetes

By Denise Mann
WebMD Health News

Dec. 13, 2010 -- New research suggests it may be possible for people with type 1 diabetes to grow their own insulin-producing cells -- an advancement that could lead to a cure for this form of diabetes.

The preliminary findings are slated to be presented at the American Society of Cell Biology 50th annual meeting in Philadelphia.

“The goal here is to cure diabetes, not to treat it,” says study author G. Ian Gallicano, PhD, an associate professor in the department of biochemistry and molecular and cellular biology and the director of the Transgenic Core Facility at Georgetown University Medical Center in Washington, D.C.

Islet cells in the pancreas are responsible for producing insulin, but these cells are destroyed in people with type 1 diabetes.

Of Mice and Men

In the new study, however, researchers were able to take cells from men’s testicular tissue, isolate stem cells, and turn them into insulin-secreting islet cells. These islet cells were then re-injected into mice with diabetes.

And it worked. “These cells behave a lot like beta-islet cells,” Gallicano says. “They secrete insulin in response to glucose, and we were able to secrete insulin in mouse models to reduce high blood sugar or glucose levels.” The effects lasted for one week.

The next step is to see if these cells can produce enough insulin to cure diabetes in people. If this occurs, clinical trials in humans can begin, he says.

Today, islet cells can be transplanted from donors into people with diabetes, but there is the risk of rejection. This risk is eliminated when the islet cells are derived from the recipient. There is also a shortage of available islet cell donors.

Gallicano says there are many unanswered questions, such as how to best deliver these bioengineered cells back into the body, and whether it will work in women.

Advanced Cell Technology seeks to test embryonic stem cells to treat blindness.

From the Los Angeles Times:
November 19, 2009 10:00 am

Stem cells could be used to remedy

formerly incurable eye defects which

cause blindness.

Patients with a rare eye disease could be the first to be treated with human embryonic stem cells.
Advanced Cell Technology Inc., a Santa Monica-based biotech company with labs in Massachusetts, announced today that it has asked the U.S. Food and Drug Administration for approval to test retinal cells grown from stem cells in 12 people with Stargardt’s macular dystrophy.
The disease is a childhood version of macular degeneration and affects about one in 10,000 kids. Patients typically begin to lose their central vision between the ages of 6 and 20. As SMD progresses, things may look blurry and distorted, and patients may have trouble adjusting to low light. About half of victims are legally blind by age 50. There is no cure.
Most cases occur when children inherent a faulty version of the ABCA4 gene or the CNGB3 gene from both parents. As a result, the photoreceptor cells in the retina don’t get enough fuel, and they atrophy.
ACT hopes to reverse this by supplying patients with new retinal pigment epithelium cells derived from human embryonic stem cells. The RPE cells have been shown to improve vision in animals, with one study restoring eye function in sick rats and mice to “near-normal” levels. Another study boosted rats’ vision to 70% that of healthy animals. No adverse side effects were found in any of the company’s pre-clinical studies, Dr. Robert Lanza, ACT’s chief scientific officer, said in an interview.
ACT proposes a Phase I/II trial designed to assess the safety and tolerability of its RPE cells. The company and its collaborators would like to recruit a dozen patients with advanced SMD at three sites: the Casey Eye Institute in Portland, Ore.; the University of Massachusetts Memorial Medical Center in Worcester; and the UMDNJ – New Jersey Medical School in Newark.
Amid much fanfare, Geron Corp. received FDA approval in January to use specialized nerve cells made out of human embryonic stem cells to treat a handful of patients paralyzed by spinal cord injuries. Those plans are on hold while the company conducts pre-clinical studies to address some safety concerns about its cells, known as GRNOPC1. Last month, Geron said it expected to initiate its clinical trial in the third quarter of 2010.
Since their creation in 1998, human embryonic stem cells have been a highly controversial area of medical research. The cells are derived from days-old human embryos, which gives them the ability to grow into any type of cell in the body. Some scientists – like those at ACT and Geron – envision using them to grow replacement tissues to treat sick patients. But many people are troubled by the fact that the stem cells are typically made by dismantling and destroying human embryos.
ACT has tried to sidestep the ethical debate by using a different method to create its stem cell lines. Instead of using an entire embryo, the company figured out a way to remove only a single blastomere cell from a three-day-old embryo and turn it into a cell line. Such single-cell biopsies are routinely performed in fertility clinics to screen embryos for devastating genetic diseases, and the procedure leaves the embryo intact. The RPE cells that would be used in the clinical trial were grown from one of the company’s single-blastomere cell lines, Lanza said.
The company is also making and testing RPE cells derived from induced pluripotent stem cells. So-called iPS cells behave like embryonic stem cells but are made by reprogramming mature cells taken from children or adults, not from embryos. However, the reprogramming process currently involves viruses and genetic manipulation techniques that make the cells unsuitable for human therapies.
Lanza said ACT decided to target Stargardt’s macular dystrophy first because it has been designated an “orphan disease” and could benefit from a faster regulatory review. The FDA has 30 days to respond to the company’s filing, made Wednesday, and the clinical trial could begin early next year.
If all goes well, the company plans to seek permission to use its RPE cells to treat age-related macular degeneration, Lanza said. That disorder is much more common, and it destroys the central vision of an estimated 1.75 million Americans.
-- Karen Kaplan
Photo: Scientists from Advanced Cell Technology remove a single cell from a days-old embryo, which was used to create a line of human embryonic stem cells. Stem cells made this way were grown into eye cells that the company hopes will treat patients with Stargardt's macular dystrophy. Credit: Associated Press photo/Advanced Cell Technology