Capsule of a cell
Fourteen years ago, during the darkest moments of the “stem-cell wars” pitting American scientists against the White House of George W. Bush, one group of advocates could be counted on to urge research using cells from human embryos: parents of children with type 1 diabetes. Motivated by scientists who told them these cells would lead to amazing cures, they spent millions on TV ads, lobbying, and countless phone calls to Congress.
Now the first test of a type 1 diabetes treatment using stem cells has finally begun. In October, a San Diego man had two pouches of lab-grown pancreas cells, derived from human embryonic stem cells, inserted into his body through incisions in his back. Two other patients have since received the stand-in pancreas, engineered by a small San Diego company called ViaCyte.
It’s a significant step, partly because the ViaCyte study is only the third in the United States of any treatment based on embryonic stem cells. These cells, once removed from early-stage human embryos, can be grown in a lab dish and retain the ability to differentiate into any of the cells and tissue types in the body. One other study, since cancelled, treated several patients with spinal-cord injury (see “Geron Shuts Down Pioneering Stem-Cell Program” and “Stem-Cell Gamble”), while tests to transplant lab-grown retina cells into the eyes of people going blind are ongoing (see “Stem Cells Seem Safe in Treating Eye Disease”).
Type 1 diabetes is especially hard on children. If they don’t manage their glucose properly, they could suffer nerve and kidney damage, blindness, and a shortened life span.
Type 1 patients must constantly monitor their blood glucose using finger pricks, carefully time when and what they eat, and routinely inject themselves with insulin that the pancreas should make. Insulin, a hormone, triggers the removal of excess glucose from the blood for storage in fat and muscles. In type 1 diabetics, the pancreas doesn’t make it because their own immune system has attacked and destroyed the pancreatic islets, the tiny clusters of cells containing the insulin-secreting beta cells.