July 12, 2005

New science, politics muddy U.S. stem-cell debate

WASHINGTON (Reuters) - Supporters and opponents of
human-embryo research wielded politics and science on Tuesday
in last-minute battles to push some kind of stem cell
legislation through the Senate.

Scientists described different kinds of stem-cell
technology in Senate testimony, and senators threw as many as
six different bills into the mix, each backing a different
approach for making human stem cells.

"They are just muddying the water and confusing it," said
Iowa Senator Tom Harkin, a Democrat who advocates wider federal
funding of embryonic stem-cell research.

Senate Majority Leader Bill Frist said he hoped to offer
some bills for a vote within the next three weeks.

At issue is a measure to override federal restrictions on
funding human embryonic stem cell research, which scientists
believe could transform medicine by treating cancer,
Parkinson's disease and other ailments.

The issue crosses partisan and ideological lines, drawing
support from anti-abortion conservatives such as Utah
Republican Sen. Orrin Hatch and liberals such as Massachusetts
Democrat Ted Kennedy.

They back a bill sponsored by Pennsylvania Republican Sen.
Arlen Specter and Iowa Democratic Sen. Tom Harkin that would
promote federal funding of research using embryos donated by
couples attempting in-vitro fertilization, or IVF.

Opponents of the Specter-Harkin bill, who include President
Bush, say using even IVF clinic leftovers is akin to destroying
a human life.

Specter and Harkin thought they had enough votes to pass
the bill, which has passed the House. But this week some new
alternatives gained support.

Harkin accused the White House of promoting alternative
approaches to stem-cell research in order to draw support away
from his bill.

Scientists outlined some of the possible approaches at a
hearing of the Senate Health, Education, Labor and Pensions
Committee, which Specter chairs.

Specter said he could vote for any bill supporting the
other approaches as well as for his own bill.

"I will be backing all the research," Specter said.


One method, being tested in mice by Massachusetts-based
Advanced Cell Technology, would involve taking a single cell
from an embryo in a lab dish and using it to create a batch, or
line, of stem cells.

Called blastomere transfer, the procedure is already used
sometimes to test IVF embryos for severe genetic defects.

Another approach backed by the President's Council on
Bioethics would, in theory, use cells from embryos that have
stopped dividing, which the council regards as technically

The Council also backs a method in which the cell being
cloned would be genetically altered so it could never grow into
a human being.

"This is a good alternative," said Oklahoma Republican Sen.
Tom Coburn.

But Ronald Green, director of the Ethics Institute at
Dartmouth University, likened this approach to making a baby
without a brain and said other scientists may question the
health of such genetically altered cells.

Kansas Republican Sen. Sam Brownback is pushing bills to
ban all forms of human cloning and outlaw chimeras, which
contain both human and animal cells.

One anticipated bill would, like a House bill that passed
with overwhelming support, promote the banking of
umbilical-cord blood for possible future use. Such blood is
rich in so-called adult stem cells, which are different from
embryonic stem cells but also useful medically.

The ultimate approach would involve taking a normal cell
from a patient and re-programming it so that it grows into
perfectly matched tissue of the desired type.

But all scientists agree this type of work would require a
better understanding of cell biology -- an understanding many
believe can be found only by studying embryonic cells.