Adult Stem Cells Engineered to Make Insulin

In a fundamental discovery that someday may help cure type 1 diabetes by allowing people to grow their own insulin-producing cells for a damaged or defective pancreas, medical researchers at the University of Texas have reported that they have engineered adult stem cells derived from human umbilical cord blood to produce insulin.

The researchers announced their laboratory finding, which caps nearly four years of research, in the June 2007 issue of the medical journal Cell Proliferation, posted online this week. Their paper calls it "the first demonstration that human umbilical cord blood-derived stem cells can be engineered" to synthesize insulin.

"This discovery tells us that we have the potential to produce insulin from adult stem cells to help people with diabetes," said Dr. Randall J. Urban, senior author of the paper, professor and chair of internal medicine at the University of Texas Medical Branch at Galveston and director of UTMB's Nelda C. and Lutcher H. J. Stark Diabetes Center. Stressing that the reported discovery is extremely basic research, Urban cautioned: "It doesn't prove that we're going to be able to do this in people — it's just the first step up the rung of the ladder."

The lead author of the paper, UTMB professor of internal medicine/endocrinology Larry Denner, said that by working with adult stem cells rather than embryonic stem cells, doctors practicing so-called regenerative medicine eventually might be able to extract stem cells from an individual's blood, then grow them in the laboratory to large numbers and tweak them so that they are directed to create a needed organ. In this way, he said, physicians might avoid the usual pitfall involved in transplanting cells or organs from other people — organ rejection, which requires organ recipients to take immune-suppressing drugs for the rest of their lives.

Huge numbers of stem cells are thought to be required to create new organs. Researchers might remove thousands of donor cells from an individual and grow them in the laboratory into billions of cells, Denner explained. Then, for a person with type 1 diabetes, researchers might engineer these cells to become islets of Langerhans, the cellular masses that produce the hormone insulin, which allows the body to utilize sugar, synthesize proteins and store neutral fats, or lipids. "But we're a long way from that," Denner warned.

Denner said this research, which reflects a fruitful collaboration with co-authors Dr. Colin McGuckin and Dr. Nico Forraz at the University of Newcastle-Upon-Tyne in the United Kingdom, used human umbilical cord blood because it is an especially rich source of fresh adult stem cells and is easily available from donors undergoing Caesarian section deliveries in UTMB hospitals.