In stem cell biology, as in real estate, location matters.
The neighborhoods in which stem cells live and grow play a key role in the ability of those cells to regenerate and to become different types of cells. Developing drugs that target abnormal cells by attacking their environment is just one of the ways in which stem cells are finding new applications in medicine. Researchers are also exploring potential therapies that involve converting cells from one type to another, and developing stem cell-based disease models that can aid drug development.
“These are all ways in which we’ll be able to see stem cell biology have an impact on medical care in the future,” said hematologist/oncologist David T. Scadden, M.D., the Gerald and Darlene Jordan professor of medicine at Harvard University.
Scadden gave the keynote address at the UF College of Medicine’s 2011 Celebration of Research, which showcases the breadth of basic, clinical and translational science research programs within the college.
“One of the areas of focus in the College of Medicine is stem cells and regenerative medicine, so I think it’s fitting that we bring one of the country’s leading experts in this area to kick off our annual research program,” said Dean Michael L. Good, the Folke H. Peterson Dean’s Distinguished Professor.
The idea of a cell that has the ability to become all other types of cells is more than a century old. Stem cell transplantation became a reality later, but initial efforts were set back by high mortality rates that raised concerns about suitability of the procedure in humans.
Today, stem cells are used widely and successfully in skin grafting, and the idea is being explored for repairing damage to certain eye tissues. The same principles have potential in the treatment of other types of tissues such as the heart, but first, much more work is needed in that area, said Scadden, who is co-chairman of the department of stem cell and regenerative biology at Harvard University and co-founder and co-director of the Harvard Stem Cell Institute.
Going beyond the transplantation of unmodified stem cells, cultured stem cells could be introduced into wounded areas and be taught by the local environment how to grow and engraft.
Using the system that generates blood cells in the bone marrow, Scadden and other researchers demonstrated that stem cells live in specialized niches supported by a well-defined network of tissues and blood vessels, in which there also is the concentration of certain proteins and cell types that play an important role in regulating the population and activity of stem cells. Scadden’s group has applied that idea in two clinical trials, with varying levels of success. And in mouse studies, the researchers found that disruption of the stem cell niche can lead to cellular abnormalities that lead to malignancy.
“So I want us to think of not just the cells as the therapy, but actually the context in which they reside as being a potential point of intervention,” Scadden said.