Possible solution found for cancer obstacle in stem cell applications

November 21, 2012

By KAYOKO GEJI/ Staff Writer

Japanese scientists said they have developed a possible remedy for a major obstacle in developing regenerative therapies that use artificial body cells derived from pluripotent stem cells.

The researchers from Keio University and other institutions in Japan said they used experiments on mice to sift out superfluous, and potentially cancerous, cells from a colony of heart muscle cells derived from human induced pluripotent stem (iPS) cells and embryonic stem (ES) cells.

In other words, they “purified” the cells to prevent them from becoming cancerous.

"The method will be crucial to enhancing safety for clinical applications," said Yoshiki Sawa, a professor of cardiovascular surgery at Osaka University. "Further tests will be necessary before eventual clinical application, such as safety checks using larger animals and the creation of safety standards."

Graduate student Shugo Tohyama, cardiology professor Keiichi Fukuda and other members of the team depleted glucose from their culture medium and added lactate.

Noncardiac cells, which multiply fast, feed on glucose, while cardiac cells, which do not multiply, feed on lactate.

The process created colonies comprising up to 99 percent cardiac cells in about a week.

The scientists used this method to purify cardiac cells derived from human ES cells and transplanted them in the testes of 20 mice. They said no tumors were formed.

iPS cells and ES cells can only be transplanted after they are changed, or differentiated, into target body cells. The mixture of undifferentiated cells can induce cancer, making purification of cells a major challenge toward the clinical application of stem cell technologies.

The latest method could also help to significantly lower the expenses related to culture media, the scientists said.

The results of the study were published online on Nov. 15 in Cell Stem Cell, a U.S. scientific journal.


To read The Asahi Shimbun story on iPS cells in a Q&A format, visit:


By KAYOKO GEJI/ Staff Writer
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iPS cells (Provided by University of Kyoto)

iPS cells (Provided by University of Kyoto)

  • iPS cells (Provided by University of Kyoto)

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