Scientist induces pluripotent stem cells without genetic manipulation

May 12, 2008

A Chinese researcher based in the U.S. revealed Sunday at a Japan Science and Technology Agency conference in Kyoto that he had succeeded in creating induced pluripotent stem (iPS) cells of both mice and humans after replacing one or two of the four genes used in creating iPS cells with synthetic chemicals.

Sheng Ding, associate professor at the Scripps Research Institute in California, said at the International Symposium on Induced Pluripotent Stem Cell Research that he generated mice iPS cells using a small molecule and two genes, and by using one small molecule and three genes.

Ding told The Yomiuri Shimbun and The Daily Yomiuri that he had succeeded in creating human iPS cells using the same method. Ding found the compounds by screening 50,000 chemicals from the institute's database, he said.

The 32-year-old researcher said that among the four genes used in the establishment of iPS cells developed by Kyoto Univ. Prof. Shinya Yamanaka—Oct3/4, Sox2, c-Myc and Klf4—he had used Oct3/4 and Klf4 with a synthetic compound to induce pluripotent stem cells of mice.

He also said the use of Sox2, c-Myc and Klf4 with a small molecule allowed him to create iPS cells as well. Until now, Oct3/4 and Sox2 have been considered necessary genes for creating iPS cells, which have the potential to develop into almost any kind of cell, but Ding said they were not actually required.

One of the challenges in the clinical application of iPS cells is that since the cells are artificially created to have pluripotency by inducing genes, they are inclined to form tumors. Ding said nongenetic approaches, such as using compounds instead of genes, would result in a more efficient way of producing iPS cells that were also safer.

Ding said creating iPS cells solely from chemicals could be realized "optimistically, in a couple of years." Even before that, he says, it might be possible to generate the cells using another form of nongenetic manipulation.

However, he said there was still work to be done in understanding how the iPS cells then differentiate themselves into other types of cells.

During the conference, which was organized by the Japan Science and Technology Agency, Yamanaka also gave a presentation about his research into iPS cells, as did other renowned scientists such as Prof. Rudolf Jaenisch of Massachusetts Institute of Technology.

SOURCE: The Daily Yomiuri