TOKYO -- Data in a widely lauded stem-cell research paper was falsified, a Japanese government-funded laboratory said Tuesday, as the lead researcher accused of the malpractice denied any wrongdoing.
The research from the Riken Center for Development Biology in Kobe, western Japan, had been hailed as a possible breakthrough for growing tissue to treat illnesses such as diabetes and Parkinson's disease using a simple lab procedure.
But significant discrepancies in the "game-changing" research published in January in scientific journal Nature led a panel of scientists at Riken to conclude they stemmed from falsified data.
They said researcher Haruko Obokata, the lead author of the paper in Nature, had manipulated or falsified images of DNA fragments used in the research.
"The investigation committee has concluded that Ms. Obokata is responsible for manipulation and therefore for research malpractice," said Shunsuke Ishii, the Riken scientist who led the committee charged with investigating allegations the work was falsified.
In mid-March, Riken officials had weighed retracting the article over "discrepancies" in how the research article was prepared.
Obokata vehemently objected to the committee's findings.
"I was outraged and shocked by the committee's report," she said in a statement. "I cannot accept the finding, and I intend to make an appeal to Riken in coming days."
Prime Minister Shinzo Abe has made greater gender equality and female advancement in the workforce a plank of his economic revival strategy for Japan. But the recognition of Obokata, a fashionable young woman, as a leading scientist still made waves in conservative, male-dominated Japan.
The dispute over the research is also a setback for government efforts to market Japan's research and development expertise as a 21st century industry needed to revitalize the country's manufacturing.
Juliette Savin, a spokeswoman for Riken, said that she could not comment on Obokata's employment status.
In a news conference, Riken's director Ryoji Noyori said that after allowing for an appeal, disciplinary action would be taken, including calling for retraction of the suspect paper.
"Research misconduct occurred due to a young researcher's lack of experience and awareness of the importance of research ethics," Noyori said.
But he also blamed a "lack of leadership" among researchers in a position to help Obokata, and a lack of mutual verification among research groups. He warned against any "personal attacks or violations of the human rights of the authors."
The institute said it would take months more to determine whether the stem cell findings are valid regardless of any questions about the data. Obokata asserts the findings are genuine.
The scientists investigating the case said three other co-authors of the papers had not falsified the data but were still "gravely responsible" for negligence in failing to fully verify the research findings. The discrepancies in the data showed up as anomalous lines in an image of DNA fragments.
In March Teruhiko Wakayama, a professor at Japan's University of Yamanashi who was part of the researcher team, said the study should be retracted.
Three authors of the paper had agreed to a retraction, Masatoshi Takeichi, head of RIKEN's Center for Developmental Biology, said at the time, but a final decision hinged on a consensus of all the authors and the journal itself.
Researchers in Boston and Japan conducted the experiments in using a simple procedure to turn ordinary cells from mice into stem cells by exposing cells from spleens of newborn mice to a more acidic environment than they are used to.
Cells from other tissue of newborn mice appeared to go through the same change if exposed to any of a variety of stressful situations, the researchers said.
Scientists hope to harness stem cells to replace defective tissue in a wide variety of diseases. Making stem cells from a patient would eliminate the risk of transplant rejection.