Yamanaka's stem cell lead thrown in doubt

Osaka-based Bayer Yakuhin Ltd., an arm of the German chemicals giant, likely beat world-renowned Kyoto University researcher Shinya Yamanaka in the race to produce stem cells from human skin, sources said Friday.

The finding could force the government to review its strategy of using iPS (induced pluripotent stem) cells in regenerative medicine treatments of diseases.

Kazuhiro Sakurada, who led the drugmaker's Research Center Kobe, told The Asahi Shimbun that his team created an iPS cell from human skin around April 2007, some seven months before Yamanaka announced his breakthrough to world acclaim.

The Bayer Yakuhin team announced its findings in the online edition of the science magazine Stem Cell Research, based in The Netherlands, in January this year.

Yamanaka has suggested his team generated its iPS cell around July 2007.

"I had the impression that we created it earlier (than Yamanaka) because he told science magazines around that time that he had not yet succeeded," Sakurada said.

Yamanaka made headlines in November when he announced the iPS cell's creation from human skin, instead of from human eggs.

Researchers from the University of Wisconsin separately reported a similar breakthrough the same day.

At question is which of the three groups--or possibly others--will be granted patents.

The iPS cell, like the embryonic stem (ES) cell, may eventually be used to grow tissues and organs, such as nerve cells and heart muscle.

Regenerative medicine based on iPS cells is expected to aid in spinal cord injuries and maladies such as Alzheimer's and Parkinson's disease.

No group has said if it has applied for patents. Sakurada, who has since left Bayer Yakuhin, declined to comment if an application has been filed, citing a confidentiality agreement.

Bayer Yakuhin shut its Research Center Kobe in December. Sakurada has moved to a U.S. start-up.

Bayer Yakuhin said it has not filed a patent application and is asking the German parent if it filed one.

Industry experts say that researchers at drugmakers usually apply for patents before announcing discoveries in science magazines.

In Japan, Europe and other countries, a patent is granted to the party that files first. In the United States, patents go to the party that first invented the technology.

The content of a patent application is not made public until 11/2 years after an application is filed.

"We cannot rule out the chance that other companies have applied for patents," a researcher said. "We may find related technologies have been patented by overseas rivals."

The government has earmarked about 3 billion yen in the fiscal 2008 budget for iPS cell research.

Fumio Kishida, state minister in charge of science and technology affairs, said, "Many details remain unclear, such as whether a patent application was filed and when the iPS cell was produced."

Kishida added the government's strategy to apply the iPS cell technologies to regenerative medicine may be affected if a private-sector company gains related patents.

Experts said Yamanaka's achievements will not be undermined even if the Bayer Yakuhin team developed iPS cells earlier.

Yamanaka reported in August 2006 that his team created the world's first iPS cell using mouse skin--setting off fierce competition.

The iPS cell allows scientists to bypass the ethical controversy over use of human eggs to produce embryonic stem cells.(IHT/Asahi: April 12,2008)