July 6, 2022

Researchers enthusiastic about induced pluripotent cells, says Nature

Pace of iPS cell development much faster

The superiority of induced pluripotent cells over embryonic stem cells is leaving scientists agog, according to a survey in the authoritative journal Nature Reports Stem Cells. Because the new cells do not pose the ethical and technical challenges of working with eggs and embryos, large numbers of researchers have leapt into the field. "The enthusiasm with which the highest-tier ES cell scientists have turned to reprogramming speaks volumes," says journalist Bruce Goldman.

Much like a new computer operating system which displaces a clunkier rival, the pace of development for iPS cells is far quicker. Human embryonic stem cells had a decade-long head start over the newer cells, but overnight this has shrunk to zero, according to the scientist who first isolated ES cells, James Thomson, of the University of Wisconsin-Madison. All of the old technology — reagents, culture media, expertise and experimental history, is transferable to the new cells. Skin cells are cheaper and better than human eggs as the raw material.

Of course, iPS cells have problems. Japanese researcher Shinya Yamanaka developed them by using retroviruses which could cause cancers. But scientists are very confident that this stumbling block will soon disappear. "It´s going to happen sooner than people think," says Richard Young, of the Whitehead Institute, one of America´s leading stem cell research centres. "A cadre of talented young investigators trained on ES cells and ready to surpass their mentors is chafing at the bit. As a result of this ferment, the convergent view of numerous leaders in the field is that the retroviral delivery problem will be solved within a year or so," writes Goldman.

Despite the bubbling interest in iPS cells, most stem cell scientists still insist that research on embryos must not be stopped. As an editorial in New Scientist puts it, "ESCs remain the gold standard for pluripotent class, and cloning remains the gold standard for developmental reprogramming." So the debate will continue, even if the purpose of destroying cloned embryos has shrunk from cures to blue sky research and drug testing . ~ Nature Reports Stem Cells, May 1; New Scientist, May 3