Thursday, October 6, 2011

Cloning Methods Create Stem Cells From Patients

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By Robert Langreth - Oct 6, 2011 6:01 AM GMT+0700

Researchers have created embryonic stem cells using human eggs for the first time, a feat that may bring scientists one step closer to treatments that can be devised from a patient’s own cells.

Researchers from the New York Stem Cell Foundation Laboratory and Columbia University Medical Center took DNA from skin cells of patients with Type 1 diabetes, and placed it into unfertilized human eggs from donors. The research is the first to show that the cells could thrive long enough to create embryonic stem cells with the DNA from patients, according to the results published today in the journal Nature.

The findings may reignite excitement about the potential for creating stem cells from a patient’s own genetic material that could be used to treat diseases. That goal, though, has been difficult to achieve as stem cells produced from the latest research had three sets of chromosomes, an abnormality making them useless for therapeutic purposes, researchers said.

“I would call it a major advance,” George Daley, director of the stem cell transplantation program at Children’s Hospital Boston, said in a telephone interview. “It is a big deal.” Daley, who wasn’t involved in the research, wrote an editorial accompanying the study.

Altered Technique

The method used by the New York scientists is similar to the one used to create Dolly the cloned sheep in 1996, though the goal wasn’t to clone a human. The approach, known as somatic-cell nuclear transfer, involves replacing the genetic material inside an egg cell, whose nucleus has been removed, with that of an adult cell. The method, however, hasn’t worked in human eggs. The New York scientists altered the technique by adding the adult cell to an egg that still had its nucleus.

The new research was only partly successful because the stem cells contained DNA from two sources. To advance to personalized medicine, stem cells need to be specific to the patient.

“This research brings us an important step closer to creating new healthy cells for patients to replace their cells that are damaged or lost through injury,” said Susan L. Solomon, chief executive officer of the New York Stem Cell Foundation, in a statement.

Reprogrammed cells could be used directly to treat disease, and also may be helpful for testing for drugs, and studying the cause of ailments such as Alzheimer’s disease and amyotrophic lateral sclerosis, or ALS, commonly known as Lou Gehrig’s disease.

No Immediate Implications

While today’s finding didn’t have immediate medical implications, it may provide insights that help improve another method for creating-patient specific stem cells that doesn’t involve donor eggs, Daley said. This technique, called induced pluripotent cells, may be more practical for large-scale use in the long run, he said.

“What we really want to do now is directly compare the molecular state and behavior of the IPS cells to the nuclear transfer cells,” Daley said in a telephone interview. “What I hope is that the nuclear transfer study will teach lessons that will allow us to make IPS cells more efficiently.”

While the nuclear transfer method has worked in various laboratory animals, it has been difficult to perform in human cells, until now.

In 2004, South Korean researcher Hwang Woo Suk published a study claiming to have created stem cells from DNA placed into a donor egg. The study and a follow-up turned out to be faked, a 2006 Seoul National University investigation found.

In a statement, the New York Stem Cell Foundation researchers said they were confident they would be able to develop reprogrammed cells containing only the patient’s DNA in the “not-too-distant future.”

To contact the reporter on this story: Robert Langreth in New York

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