Scientists Show Stem Cells Don't Ca...( Solving this problem is an important ...),Health

Solving this problem is an important step before moving on to potential therapies

THURSDAY, Feb. 14 (HealthDay News) -- A major concern with using stem cells to treat disease has been the possibility that the retrovirus used to implant the cells might cause cancer, but now a group of scientists appears to have solved that problem.

In November, two groups of researchers -- one in Japan and one in the United States -- showed that adult human and mouse skin cells could be reprogrammed into stem cells similar to embryonic stem cells, which can be made into any type of cell. These cells, called induced pluripotent stem cells (iPS), could be the key to using stem cells to cure a variety of diseases.

In this latest study, published in the Feb. 14 issue of Science, the Japanese researchers prove these stem cells are made from normal mature adult cells, and they show that these stem cells can be implanted using a retrovirus without fear of causing cancer.

"This is a real nice follow-up and confirmation of the previous papers that looked at inducing normal cells to become stem cells," said Dr. Hugh Taylor, an associate professor at Yale University School of Medicine.

"The question that still existed from the previous paper was whether these stem cells were some sort of adult stem cells," Taylor said. "This paper shows that these stem cells are fully differentiated adult cells, that they can be reprogrammed into stem cells," he added. "You can probably take almost any adult cell and turn it into a stem cell."

In addition, there has been a fear that using a retrovirus to implant stem cells results in an increased risk of cancer. This study showed that doesn't happen, Taylor said. "It proves, without a doubt, that these cells are safe for human use," he noted.

However, Taylor thinks the cells need to be studied over a longer period to ensure they don't have an elevated cancer risk.