July 2, 2014 at 1:00 am

Scientists retract claim about making stem cells

Researcher Haruko Obokata, the lead author of a widely heralded stem-cell research paper, and other scientists have acknowledged 'extensive' errors that meant 'we are unable to say without a doubt' that their method works. (AP)

New York — U.S. and Japanese scientists who reported that they’d found a startlingly simple way to make stem cells withdrew that claim Wednesday, admitting to “extensive” errors in the research.

In two papers published in January in the journal Nature, the researchers said that they’d been able to transform ordinary mouse cells into versatile stem cells by exposing them to a mildly acidic environment. Someday, scientists hope to harness stem cells to grow replacement tissue for treating a variety of diseases.

While researchers have long been able to perform such transformations with a different method, the newly reported technique was far simpler, and the papers caused a sensation — and some skepticism — in the research community. They were also widely reported in the media, including by the Associated Press.

But before long, the government-funded Riken Center for Developmental Biology in Japan accused one of its scientists, Haruko Obokata, of falsifying data in the research. Obokata, the key author of the papers, defended the results during a televised news conference in April while apologizing for using wrong and altered images in the published reports. She also said she opposed withdrawing the papers, a process called retraction, and the 30-year-old attributed her mistakes to inexperience.

On Wednesday, Nature released a statement from Obokata and the other authors of the papers that retracted the papers, a rare occurrence for the prestigious journal.