May 24, 2013 | by Nicole White
H. Teresa Ku, Ph.D., believes adult pancreatic stem cells could hold the key to making a type 1 diabetes cure more widely available.
First, she has to prove they exist.
Transplantation of insulin-producing islet cells into the pancreas is one promising method for treating type 1 diabetes patients, particularly those with very advanced disease that can no longer be sufficiently managed with insulin shots.
But, of the 200,000 patients who fit this description, only 1 percent will be able to receive a transplant. The procedure requires two donor pancreases to gather enough healthy islet cells, and the precious organs are in short supply – with only 1,000 a year available for islet cell transplantation.
“I would argue this is a critical need,” said Ku, associate professor in the Department of Diabetes and Metabolic Diseases Research at City of Hope. “As we go through the numbers, 99 percent of those patients who are in need cannot have that beneficial transplantation.”
Ku and a team of City of Hope researchers hope to use adult pancreatic stem cells to grow islet cells that could supplement those harvested from donor organs. The stem cells would be recovered from donor pancreases after the islet cells are removed, and could potentially allow for transplants using only one donor pancreas per patient.
The search for pancreatic stem cells has been a long one, and whether or not they exist at all is hotly debated in medical literature. For now, Ku says, the tide has turned against belief in pancreatic stem cells. However, her recent National Institutes of Health-funded research shows some promising evidence that adult pancreatic stem cells not only exist but that they can be identified and analyzed.
She and her team were able to take non-islet cells from the pancreas and cultivate them into cells that responded to glucose levels – very similar to insulin-producing beta cells. The cells also self-replicated, an important hallmark of stem cells, and could duplicate more than 100,000-fold.
Ku cautions that the cells found in her recent study are “stem-cell-like,” or "progenitor-cell-like.” Like stem cells, progenitor cells can be developed into other useful cells. She’ll need more definitive research to show that such cells are bona fide stem cells or progenitor cells.
Regardless, the type of cell she found and cultivated is rare, with only about 1 percent of all pancreatic cells showing these properties. In other tissue that the body regenerates frequently, such as skin and bone marrow, stem cells are easier to find.
Ku believes that her team’s success in growing these cells is due to some changes in the method for growing them. A simple, but significant, change: Trying a semi-solid medium rather than a liquid suspension to grow the cells.
Ku’s team extracted the potential stem cells from the pancreases of adult mice, and grew them in lab dishes containing Matrigel, a gelatinous mixture of proteins that approximates the environment surrounding cells in the body. Then, they transferred the cells to a gel containing a protein called laminin. There, the cells formed colonies that produced insulin and reacted to glucose levels – in short, behaving a lot like the kind of cells that diabetes patients need.
“What we’re probably looking at is a mixture of true stem cells and progenitor cells,” Ku said.
Regardless, if the cells lead to more islet cell transplants, she’ll have plenty of believers.