A political battle over the use of fetal tissue in medical research has been reinvigorated by the release of undercover videos targeting Planned Parenthood officials. But the controversy comes just as interest in the use of fetal tissue is dwindling, scientists said.
Newer, less-controversial technologies, including the “reprogramming” of adult skin cells to create specific types of stem cells, have rendered fetal tissue less central - though still important - to medical research, they said.
Dr. Robert Lanza, chief scientific officer of Advanced Cell Technology, said that much of tissue needed for research "can now be generated in the laboratory."
At Massachusetts General Hospital in Boston, for instance, only about 10 out of 8,000 active research protocols involve fetal tissue, according to an official at the Harvard-affiliated hospital who asked to remain anonymous.
The Alzheimer's Association, which says it supports any legitimate avenue of research that offers hope of a cure, has not received a request to fund a project involving fetal tissue in about seven years, said Maria Carrillo, the association's chief scientific officer.
"That tells us the field has really moved to [the newer reprogrammed] cells," she said.
But scientists also said that for some studies, fetal tissue remains essential, and that efforts to reduce an already-scarce supply could set back research on birth defects, spinal cord injuries, Parkinson's disease, eye diseases, and vaccines and treatments for HIV/AIDS, to name a few.
"No question fetal tissue remains an important research tool," said Sean Tipton of the American Society for Reproductive Medicine. Fetal cells have long been used in vaccine research, and are still used in toxicology studies.
Scientists say that newly developed stem cell technologies using adult cells have not yet been fully validated, and they still need to run tests with fetal cells to ensure their quality.
Research using human fetal tissue dates back to the 1930s, when fetal kidney cells were used as a medium in which to grow vaccines. Unlike embryonic stem cells, which come from days-old embryos that are capable of becoming any type of cell, fetal stem cells already contain instructions for becoming specialized cells that form organs.
Interest in fetal tissue surged in the 1990s with the hope that fetal nerve cells could treat Alzheimer's and Parkinson's. "They gave up on that," said Arthur Caplan, a bioethicist at NYU's Langone Medical Center, because it failed to work.
Some research suggests, however, that different methods involving fetal tissue transplants might be more effective.
Last year, for example, Harvard Stem Cell Institute reported that neuronal stem cells extracted from fetal tissue and transplanted into the brains of Parkinson's disease patients helped them remain healthy and functional for as long as 14 years.
Researchers have also had success using fetal stem cells to treat spinal cord injuries.
Insoo Hyun, a bioethicist at Case Western Reserve University, said the newer, lab-derived cells have not been perfected and researchers still need fetal tissue to ensure that the reprogrammed cells are of comparable quality.
"People are trying very hard to transition out of using stem cells from fetuses but to make that transition, it will take some time," Hyun said.
In a statement on behalf of its many campuses, the University of California's Office of the President defended continuing research that uses fetal and placental tissue, saying it remains "vital to finding treatments and cures for a wide variety of adult and childhood diseases and medical conditions."
One California-based regenerative medicine expert who spoke on condition of anonymity said that lab-manufactured stem cells don’t work for certain kinds of research.
The scientist, whose lab was once the subject of a bomb threat because of its research with fetal tissue, said that embryonic stem cells or reprogrammed cells can't make organs, which are needed to understand complex diseases such as multiple myeloma or ALS, commonly called Lou Gehrig's disease, which strikes motor neurons later in life.
"For us, to understand any of a number of disease states, we need organs," he said.
"If you took away this area of research, you are taking away the hopes of a lot of people who have currently incurable diseases for which this very likely will get us there."
In Washington, lawmakers led by conservative Republicans are using the controversy over the Planned Parenthood videos to renew efforts to defund the organization, which provides a wide range of women’s health services, including abortion.
The sting videos have also drawn attention to government funding for fetal tissue research. Last year, the National Institutes of Health spent $76 million for projects meeting the criteria of human fetal tissue research, about 0.2 percent of the overall NIH budget. But officials say that figure might exaggerate the amount of funding going to fetal tissue because grants overlap, and cover multiple aspects of research.
Many researchers said they look forward to a time when fetal tissue will be unnecessary.
Hyun said that in addition to other concerns, scientists are hampered by the unpredictability of supply when working with fetal tissue.
“You have to wait around for someone to donate, and you have to use the tissue right away. It's hard to plan your studies,” he said.