Staff Writer
Using stem cells to spark the body's own repair system after a heart attack or stroke could be the fastest way to first accessing the cells' potential, researchers said Tuesday.
They gathered at Medical College of Georgia for the quarterly meeting of the 2-year-old Georgia Stem Cell Initiative, a consortium of researchers from the state's universities and biotech companies. Stem cells, whether derived from unwanted embryos or from bone marrow or umbilical cord blood, have long tantalized scientists because of their ability to replicate themselves and evolve into other cell types, and are seen as a potential source of cell repair.
Several early studies under way or planned, including a clinical trial in heart attack patients by Athersys of Cleveland, Ohio, use stem cells derived from bone marrow. The company has collaborated in the past with MCG, and David Hess, the chairman of the Department of Neurology, is hoping to get funding for an early study using those cells in stroke patients.
It appears that the cells' greatest effect comes not as replacement heart cells, however, but from releasing growth factors that seem to improve blood flow to the damaged area and may be rallying stem cells already in the body to help repair damage, said Anthony Ting, the director of regenerative medicine for Athersys.
"Basically, your heart wants to repair itself," Dr. Ting said, and there are mechanisms there to do it. "It's the (stem) cells telling the donor, hey, this is an area that's damaged; let's make new blood vessels."
The company is still in the first phase of showing that the MultiStem stem cells are not toxic but is hoping that if all goes well it can apply for approval from the Food and Drug Administration in 2011, Dr. Ting said. The cells have so far shown a few advantages -- they don't need to be tissue-matched with the recipient, don't require immunosuppression and so far have not produced a tumor.
Working with embryonic stem cells that can be induced to become progenitor cells for different cell types in the heart, University of Georgia researcher Stephen Dalton said they might prove useful in finding a drug that can work in a similar cell type that is already in place.
"We actually do have an adult stem cell population in the heart," Dr. Dalton said. "What if we could activate this adult stem cell to generate cardiomyocytes to do tissue repair?"
In fact, embryonic stem cells might first prove more useful in providing cellular models for high-volume testing for new drugs, said Steven L. Stice, the director of the Regenerative Bioscience Center at UGA .
"The lowest-hanging fruit is using stem cells to find" new drug treatments, Dr. Stice said.
Reach Tom Corwin at (706) 823-3213 or tom.corwin@augustachronicle.com.
WHAT STEM CELLS DO
Stem cells are active in development and in replacing cells in the adult body, and scientists are looking at using different kinds in repairing or even regenerating tissue. Many researchers work with adult stem cells, often derived from bone marrow, and early clinical trials are under way to test their ability to make repairs after a stroke, heart attack or traumatic brain injury.
FDA APPROVAL: The Food and Drug Administration recently approved the first trial in embryonic stem cell therapy. Embryonic cells are thought to have greater potential to replicate and generate new cell types, but they also are more likely to form a tumor. Embryonic stem cell lines, created from unwanted and unusable embryos, raise ethical and religious issues for many people.
FEDERAL FUNDING: President Bush limited federal funding for embryonic stem cell research to those cell lines that were already created in August 2001, which left a limited pool available. That is likely to change under President Obama. As a U.S. senator, he was a co-sponsor of the Stem Cell Research Enhancement Act of 2007, according to the White House Web site. A policy paper posted there notes that both the president and Vice President Joe Biden "believe that we owe it to the American public to explore the potential of stem cells to treat the millions of people suffering from debilitating and life-threatening diseases."