Researchers find new method for turning adult cells into stem cells

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Researchers find new method for turning adult cells into stem cells

Sun Mar 1, 1:33 PM

http://ca.news./s/capress/090301/health/health_programming_st

em_cells

By Sheryl Ubelacker, The Canadian Press

TORONTO - Canadian researchers have developed a new method for

generating stem cells from adult human tissue, a move they believe

will bring the dream of personalized regenerative medicine a step

closer to reality.

In a study published online Sunday in the journal Nature, scientists

at Mount Sinai Hospital in Toronto describe a new reprogramming

procedure to transform adult cells - such as those from a patch of

skin - into stem cells.

Like embryonic stem cells, they are " pluripotent, " meaning they can

give rise to almost any kind of cell in the body.

" This new method of generating stem cells does not require embryos as

starting points and could be used to generate cells from many adult

tissues, such as a patient's own skin cells, " said principal author

Andras Nagy, senior investigator at Mount Sinai's Lunenfeld

Research Institute.

One of the critical components reported in Nagy's paper was developed

in conjunction with Dr. Keisuke Kaji of the University of Edinburgh,

whose findings are also published Sunday in Nature.

The ability to transform skin cells into stem cells isn't new. But

previous approaches required the use of viruses to deliver the four

genes needed to activate the cell and accomplish that task.

Nagy said using viruses poses the risk of damaging the cell's DNA,

which could have unforeseen consequences.

" These four genes are very potent, very powerful factors, which also

if they get loose, they could create problems, " he said. " For

example, they are cancerous. "

To overcome that danger, Nagy's team used a snippet of DNA from, of

all things, a cabbage looper moth, which delivers the genes needed to

reprogram cells into stem cells. The winged creature's DNA is able to

spark the transformation into stem cells in culture dishes. It can

then be removed without leaving any trace behind.

" So it's like an organic stem cell, " said Nagy of the resulting

product. " And this is a big thing ... it opens up a big door or a

gate to a large possible human application because we eliminated a

massive risk ... from these very potent reprogramming factors after

they did their job. "

Nagy created Canada's first embryonic stem cell lines from donated

embryos no longer required for reproduction by couples undergoing

fertility treatment. Understanding how they work has played a pivotal

role in developing the new method for transforming adult cells into

stem cells, he said.

" The implication, " Nagy said of the new research, " is that these

cells could be as safe as embryonic stem cells are, because of the

removal of the factors that did the reprogramming. "

The next step for the team is to work with stem cells created from

the cells of patients with certain diseases, such as Huntington's or

Type 1 diabetes, to better understand those conditions at the

cellular level.

" But the real hope is that these cells can be used in future medicine

to repair damaged tissues or replace or regenerate areas that

underlie the disease, " Nagy said.

For instance, insulin-producing cells could be implanted in a

diabetic whose pancreas no longer supplies the vital hormone, while

dopamine-producing cells could replace damaged brain cells that lead

to Parkinson's disease.

Eventually, scientists hope to use stem cells to repair damaged

spinal cords and diseased organs like the heart, liver and kidneys -

or even to grow entire replacement organs.

And because the stem cells would be derived from a patient's own

cells, there would be no need for life-long anti-rejection drugs.

" We are very enthusiastic about this, " said Nagy. " We think it will

have an impact on the field. "

Mick Bhatia, scientific director of the Stem Cell Biology Research

Institute at McMaster University, called the method " a potentially

powerful tool. "

" It's certainly a very important method to get reprogramming of cells

because it's non-viral essentially, " Bhatia, who was not involved in

the research, said from Hamilton. " You can put it in, but then you

can take it out. "

Still, Nagy's method is not the only one recently developed to get

around the problem of possibly dangerous rogue genes getting

incorporated into a cell's DNA, as occurs when using the four virus

genes.

But what the new method offers is perhaps a better level of control

for trying to understand how the reprogramming process occurs

biologically, Bhatia said.

" I think the potential of this is great, but it remains to be seen

exactly what specific contributions it's going to make. "