Scientists said they had used cloning technology to make embryonic stem cells that carry a diabetic woman's genes, and turned them into insulin-producing beta cells that may one day cure her disease.
The team reported clearing an important hurdle in the quest to make "personalized stem cells" for use in disease therapy, but a bioethicist said the breakthrough also highlighted the need for better regulation of lab-grown embryos.
"We are now one step closer to being able to treat diabetic patients with their own insulin-producing cells," said Dieter Egli of the New York Stem Cell Foundation (NYSCF), who led the study published in the journal Nature.
Egli and a team had transplanted the nuclei of cells taken from the woman's skin into human eggs to create stem cells, which they could then coax into becoming beta cells -- a shortage of which causes insulin deficiency and high blood-sugar in diabetics.In doing so, the team confirmed a potentially important source for future cell-replacement therapy.
It was not the first study to create stem cells in this way, but it was the first to use cells sourced from a diseased adult person with the aim of producing therapy-specific cells. For the new study, scientists in the United States and Israel said they made "technical improvements" -- altering the chemicals used in the culture in which the cells are grown.
The stem cells could in turn be coaxed into becoming various different types of adult cells -- including beta cells, the team said.
The same team had previously made beta cells with a similar method, but using eggs with their nuclei still intact -- resulting in stem cells with three sets of chromosomes that could not be used in therapy. But using the new, improved method, the stem cells emerged with the normal two sets of chromosomes, the team wrote.
The beta cells produced in the study cannot yet be used in replacement therapy, the team said. Diabetics' immune systems attack beta cells, and ways have yet to be found to shield them.