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.
STILL VITAL
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.
[to top of second column] |
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."
RENEWED ATTACKS
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.
(Reporting by Julie Steenhuysen; Editing by Eric Effron and Sue
Horton)
[© 2015 Thomson Reuters. All rights
reserved.] Copyright 2015 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed. |