[extropy-chat] Stem cell breakthrough claims

[Damien Broderick]

"Scientists Clone Stem Cells Genetically Matched to Patients"

May 19, 2005; Washington, D.C. (AP and CNN) -- South Korean scientists have 
created the world's first human embryonic stem cells that are customized to 
injured or sick patients, a major step in the quest to grow patients' own 
replacement tissue to treat diseases.  These  same scientists last year 
became the first to clone a human embryo, sparking international clamor. 
But those cloned stem cells -- the building blocks that give rise to every 
tissue in the body -- were a genetic match to a healthy woman, not a sick 
person. And it wasn't easy: It took 242 donated human eggs to grow just one 
batch.

         Now the Seoul scientists have cloned patient-specific stem cells, 
important if doctors are to develop cell-based therapies that won't be 
rejected by the body's immune system. The  technique worked with males and 
females, as young as 2 and as old as 56 -- all suffering  either spinal 
cord injuries, diabetes, or a genetic immune disease, the researchers 
report in  Friday's edition of the journal Science.  And the Korean lab 
found faster and safer ways  to cull stem cells, using far fewer donated 
eggs -- about 20 per try.   They also eliminated the use of mouse "feeder 
cells" that have been used to nourish most human stem-cell lines, thus 
obviating concerns about contamination.

         But, any therapy is still years away from being tested in 
people.  "Therapeutic cloning  has tremendous, tremendous healing 
potential, but we have to open so many doors before human trials," lead 
researcher Hwang Woo-suk of Seoul National University said in a  telephone 
interview. "Our work reveals the possibility that this technology could be 
applied in the patient himself in the future."

         Stem-cell specialists called the research remarkable.  "This is a 
very important advance," said Dr. Janet Rowley of the University of 
Chicago, a genetics specialist who helped co-author recent ethics 
guidelines on stem-cell research from the Institute of Medicine. "It's 
surprising to me the amount of progress they've made in basically a year's 
time."  "This paper will be of major impact," said stem-cell researcher Dr. 
Rudolph Jaenisch of the Whitehead Institute for Biomedical Research in 
Cambridge, Mass. "The argument that it will not work in humans will  not be 
tenable after this."

         The work marks "a gigantic advance" for another reason, said 
neuroscientist Fred Gage of the Salk Institute for Biological Studies in 
San Diego. By cloning stem cells from sick patients, scientists can watch, 
in a test tube, the very earliest origins of diseases like Alzheimer's, 
insight that could point to other ways to prevent and treat illness, 
explained Gage, who plans to do some of that work. The Korean research 
"will be a tremendous boon to the investigation of the nature and biology 
of  human disease," he said.

         It's also sure to revive international controversy over whether to 
ban all forms of human cloning, as the Bush administration desires -- or to 
allow cloning for medical research, so-called therapeutic cloning that 
South Korea has committed by law to pursue.  Culling stem cells destroys 
the days-old embryo harboring them, regardless of whether that embryo was 
cloned or left over in a fertility clinic. Because opponents argue that is 
the same as destroying life, President Bush has banned Federally-funded 
research on all but a handful of old embryonic stem-cell lines and the 
South Korean work spotlights the frustration many U.S. scientists felt at 
being left behind.  "It's just going to highlight the tragedy of our 
current situation in America where there are technologies that are 
promising that are not being pursued by talented American scientists 
because of ideologic constraints," Rowley said.

         The Seoul researchers collected eggs donated by 18 unpaid 
volunteers and removed the gene-containing nucleus from them. They inserted 
into those eggs DNA from skin cells of 11 people who had spinal cord 
injuries, Type-1 Diabetes, or a congenital immune disease.  Chemicals 
jump-started cellular division, and 31 blastocysts -- early-stage embryos 
-- successfully grew. From those, the scientists were able to harvest 11 
colonies, or "lines," of stem cells, each one a genetic match to the 
patient who had donated a skin snippet.  The scientists were careful to 
explain to the research participants that getting medicine made from their 
stem cells is a long shot. They don't yet know how to control which types 
of tissues -- brain cells, bones, muscles, etc. -- the stem cells form, 
something the Korean lab is studying next.  "I didn't think they would be 
at this stage for decades, let alone within one year," said Dr. Gerald 
Schatten of the University of Pittsburgh, who acted as an adviser to the 
Korean Lab in analyzing its data for U.S. publication. "All of us in the 
biomedical communities owe our colleagues in Korea a tremendous debt of 
gratitude."

         The work raises ethical concerns, cautioned Stanford University 
bioethicists David Magnus and Mildred Cho. Scientists must ensure that 
women understand they get no benefit and can be put at some risk when they 
agree to donate eggs for medical research -- and that patients who 
volunteer also understand that it's unlikely they'll benefit from any stem 
cells they help to clone because so many years of research are yet 
required, they wrote.

__

  "Cloning of Human Stem Cells Speeds Up"
by Gretchen Vogel (Science)

May 19, 2005; Scientists have created nearly a dozen new lines of human 
Embryonic Stem (ES) cells that for the first time carry the genetic 
signature of diseased or injured patients. The breakthrough represents a 
dramatic increase in the efficiency of creating such lines and may 
eventually pave the way for treating conditions such as spinal cord injury 
with stem cell transplants.  [etc]