Sunday, January 20, 2008

California company sees fertile ground in stem cells

By Maggie Fox, Health and Science EditorThu Jan 17, 1:46 PM ET

A small California company set up by an unnamed investor and a top fertility doctor burst into the stem cell field on Thursday with a report that it is the first lab to clone human embryos and prove it.
Stemagen Corp. of La Jolla, California, said its scientists used cloning technology to make five early-stage embryos, called blastocysts, from donated human eggs and skin cells from two men.
While they did not make stem cells from their embryos -- they were destroyed in the process of proving they were clones -- company founder Dr. Samuel Wood says stem cells are his business plan.
"We believe that this is the future -- to create patient-specific stem cells," Wood said in a telephone interview.

Stem cells are found throughout the body, renewing tissue and blood cells. Cells taken from very early human embryos -- smaller than the head of a pin -- can give rise to all the cells and tissues found in the human body.
Scientists hope to harness their power to transform medicine, to repair devastating injuries, replace the brain cells lost in Parkinson's disease, or to cure juvenile diabetes.
The best would be tailor-made, using a patient's own DNA.
But an influential minority of people and groups oppose their use in the United States because they believe it is wrong to destroy any human embryo.
They include President George W. Bush, who has vetoed legislation from Congress that would expand federal funding of human embryonic stem cell research. That limits the work to a few academic labs that can juggle the complex requirements of the federal limits, and private companies.

EXCESS EMBRYOS
Wood came up with the idea as part of his work at a large fertility clinic.
"We had this great excess of embryos in the tank that eventually were donated to research or to other couples. But what I also noticed was that we had a great excess of eggs," Wood said.
Human eggs are needed to use cloning techniques to make embryos, and that got Wood thinking. His mother had type-2 diabetes and died after a bad fall. He knew of an investor whose mother had died from a degenerative disease.
Wood said he made his pitch in 2005 to the investor, who wants to remain anonymous, "over a martini in a local restaurant." He then recruited Andrew French, who had created animal clones while at Monash University in Australia.
Wood says the technique is only efficient if the egg is used within two hours of being taken from the woman.
Opponents of cloning technology say it is a slippery slope to using cloning to make live babies. Wood is mindful his work at a fertility clinic could raise suspicions. But he noted that cloned animals are often abnormal.
"To put any human through that just strikes me as inherently unethical," he said.
While some cloning experts support the new company's work, others are skeptical, including Dr. Douglas Melton, who helped found Harvard University's stem cell research center.
"The value, if any, will come from using the cells to discover drugs, i.e. using the cells as research tools," Melton said by e-mail.
French said his team is working to make embryonic stem cells from embryos donated at the clinic, to perfect the technique before trying to use cloning methods again to make tailored cells.
"This field has faced a lot of controversy so we wanted to be clean," French said.
Other companies in the field include Massachusetts-based Advanced Cell Technology, California-based International Stem Cell Corporation and Geron Corp..

1 comment:

D.B. said...

http://news.yahoo.com/s/nm/20080120/hl_nm/dystrophy_stemcells_dc

Stem cells help mice with muscular dystrophy: study By Julie Steenhuysen
Sun Jan 20, 1:22 PM ET


CHICAGO (Reuters) - A therapy using embryonic stem cells helped restore muscle function in mice with Duchenne muscular dystrophy, the most common form of muscular dystrophy in children, U.S. researchers said on Sunday.

They said the study is the first to show that transplanted embryonic stem cells can restore muscle in genetically engineered mice with the disease.

Stem cells are the body's master cells, acting as a source for the various cells and tissues in the body. Those taken from days-old embryos, called embryonic stem cells, can produce all of the body's cell types.

Many researchers have tried different stem cell strategies in the hopes of treating muscular dystrophy, a genetic disease that occurs when the cells can no longer regenerate after injury. These studies have often been disappointing.

And one problem with embryonic stem cells is they want to form all the tissues in the body, often in a type of tumor called a teratoma. Getting them to differentiate -- to become only certain cell types -- has been difficult.

"The problem had been that embryonic stem cells make everything," said Dr. Rita Perlingeiro of the University of Texas Southwestern Medical Center, whose study appears in the journal Nature Medicine.

"We know with embryonic stem cells you have to find a way to pull out the cells you want," Perlingeiro said in a telephone interview. "How to dig them out -- that is the problem."

Perlingeiro's team experimented with stem cells taken from mouse embryos. Mice in the study lacked dystrophin, a protein that is lacking in humans with muscular dystrophy.

Perlingeiro knew it was important to isolate just the cells that would become muscle because early transplant attempts that included other undifferentiated cells had caused the mice to develop teratomas.

GREEN DYE

Her team developed a painstaking technique using fluorescent dyes to sort through the cells, allowing them to isolate only the cells destined to become muscle.

They injected these cells into the hindquarters of mice with the disease. After a month, the dyed cells had made their way deep into the muscle, suggesting they had started to grow new muscle cells. Many muscle fibers also contained dystrophin.

At three months, the mice showed no signs of tumors. Tests showed the muscles were significantly stronger than in untreated mice with the condition and they performed better than other mice in tests of coordination.

"We have now looked for over four months and there has been no tumor formation," Perlingeiro said. "We're very excited to see the fibers were green and you could see dystrophin."

Perlingeiro said her team hopes eventually to develop a stem-cell therapy for humans with muscular dystrophy using a new approach for making human stem cells from reprogrammed skin cells.

This approach involves tricking human skin cells into behaving like embryonic stem cells. But the technique is far from perfected.

Perlingeiro said her research is early but holds promise. "You go brick by brick to build something," she said.

Duchenne muscular dystrophy is one of nine types of muscular dystrophy, a group of degenerative diseases. It affects 1 out of every 3,500 to 5,000 boys in the United States.