A Japanese laboratory at the center of a research controversy says it is scaling back its stem-cell unit after having to retract papers reporting potential breakthroughs in the field.
Researchers at the Riken Center for Developmental Biology, investigating the original experiments, say they have been unable to replicate results first reported in two scientific papers published in the journal Nature in January which were then retracted in July.
The papers had raised expectations of a simple method of creating stem cells for growing replacement tissue to treat a number of diseases, but were later retracted by Nature amid allegations of slack data management, inadequate peer-review processes within the institution and poor research ethics.
"As the one responsible for Riken's operations, I deeply regret our failure in risk management and preventing misconduct," said Ryoji Noyori, a Nobel Prize winner who heads the government-affiliated Riken research institution.
Riken officials have announced plans to cut the stem-cell center's center staff by half, rename it and bring in a director who would take input from non-Japanese scientists.
The restructuring would "promote honest research," Noyori said.
The scandal erupted after a scientist at the center, Haruko Obokata, was found to have manipulated data presented in the Nature papers.
The published studies claimed to demonstrate a ground-breaking method of easily creating stem cells by immersing normal cells in a mildly acidic solution.
In announcing its retraction, which Nature said had been agreed to by Obokata, the journal said it made its decision after finding data mistakes and misleading photo captions and because the work could not be repeated by other researchers.
Riken officials say Obokata has been allowed to continue working at the center and has been given until November to attempt to reproduce her original claimed results.
Obokata has admitted to errors in her research but maintains the central thesis of her work is valid.
Scientists at other research facilities have been unable to replicate a creation of stem cells Obokata has claimed to discover.
Independent attempts at Riken have also failed.
"Researchers have conducted 22 experiments thus far, but we could not confirm the emergence of cells in the conditions described in (Obokata's) papers," Riken said in an interim report issued Wednesday.
Although the institute has only named Obokata in its investigation of alleged misconduct, Yoshiki Sasai, the stem-cell center's deputy director who supervised the controversial research and was a co-author on the Nature papers, committed suicide earlier this month.
The controversy has ignited debate about the research ethics of Japanese scientists exposed to intense "results first" pressures.
