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To cure sickle cell in mice just add skin -- no embryos necessary

DailyTech has long covered developments in stem cell research -- everything from using the stem cells in practical medical research to creation printable blood vessels to using the cells in more outlandish experiments such as the human-sheep "chimaera," which sounds like something straight out of The Island of Dr. Moreau

Most importantly new research allowed for the creation of pseudo-stem-cells from somatic (differentiated) cells, via an induction process.  The research was first pioneered by Japanese scientists and later confirmed by American researchers at Whitehead Medical Center in Massachusetts.  This new non-embryonic technique has the reluctant blessing of traditional stem cell opponents, including U.S. President George W. Bush and the Catholic Church.

The cells are dubbed induced Pluripotent Stem cells, iPS cells for short.  Last month it was shown that the cells could be created as easily from human skin tissue as mouse skin tissue.  Further, the research showed that the iPS cells behaved like true stem cells and could differentiate into the more than 200 types of cells in the human body.

Now scientists have completed groundbreaking research which gives an exciting glimpse into the tremendous potential the synthetic creation of stem cells can hold.  Researchers at Whitehead have used the artificially created stem cells, created from mouse skin tissue, to cure mice of sickle cell anemia, a potentially fatal inherited disease.   The research is published in the journal Science and is titled "Treatment of Sickle Cell Anemia Mouse Model with iPS Cells Generated from Autologous Skin."


The research
sounds so good that many might wonder why the scientists at Whitehead are not rushing to put the process to work curing human disease.  The reason for Whitehead's reluctance is that they are trying to change aspects of their creation approach in order to make it human safe.  Researchers currently utilize genetically modified viruses in the induction process.  The viruses have the potential to trigger tumor growth in healthy mammalian tissues. 

"The big issue is how to replace these viruses", commented Rudolf Jaenisch co-leader of the research at Whitehead, in an interview with the Washington Post.

The current treatment method uses multiple rounds of viruses to modify genetic behavior of the cells.  The first round of gene-modified viruses induces the cells to behave like stem cells.  Next the scientists used a gene splicing technique to snip out the undesirable sickle-cell gene and replace it with a healthy gene.  Finally the scientists used an additional round of viruses which induced the cell to develop into a bone marrow cell.

The marrow cells were injected into the mice with sickle-cell and anchored in the bone marrow and began to release healthy red blood cells. 

"All the parameters we can measure are now normal," Jaenisch enthused. "The mice are cured."

Hopefully the researchers can modify the technique to avoid tumor induction as the potential of curing sickle-cell disease would help save many human lives.  In humans sometimes sickle cell is treated by a bone marrow transplant, but only 20% of humans have a donor close enough to them to allow for a safe transplant.  And over 20% of those who do receive transplants experience failure, often resulting in death.  However, bone marrow created from a modified version of this process would be completely safe as the cells are genetically identical to the donor.

In the mice radiation was used to kill the bone marrow of the mice, but in humans chemotherapy drugs such as Idarubicin and Cytarabin can be used to kill the bone marrow in a less caustic manner.  In mice 80 percent of the marrow cells now are the genetically healthy cells and they have experienced no tumor growth.

George Q. Daley, a stem cell researcher at Children's Hospital in Boston, said the test was proof that human clinical applications of iPS cells were feasible.  He said,  "There will be lots of unanticipated setbacks before we end up in the clinic, but this work suggests that we will ultimately get there."

Jaenisch surprised some by emphasizing that despite his group's success, research on embryonic stem cells should be pushed ahead, not halted.

"All the progress in this field was only possible because we had embryonic stem cells to work with first.  We need to make more ES cells and really define which are going to be the best ones for different applications," he said.

Regardless, for stem cell proponents and opponents alike, this new research demonstrates a exciting process that may someday hold the cure for human diseases such as sickle-cell anemia, Parkinson's Disease and diabetes.


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This article is over a month old, voting and posting comments is disabled

By clovell on 12/9/2007 10:23:36 AM , Rating: 3
Stem cells aren't embryos. Who's shrooming, again?


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