Stem cells hold the promise of curing disease because they can become any type of cell, but the research has caused controversy because until recently the only way to harvest such cells was through destruction of a human embryo. The use of skin cells would avoid those ethical problems raised by US President George W Bush and other social conservatives.
The scientists at the University of California in Los Angeles used genetic alteration to "turn back the clock" on the skin cells to produce cells that were "virtually indistinguishable from human embryonic stem cells," Kathrin Plath, an assistant professor of biological chemistry, said in a statement. The findings were published online by the journal Proceedings of the National Academy of Science.
In November, separate teams of Japanese and US scientists at Kyoto University and the University of Wisconsin reported they had inserted genes into cells derived from skin to create cells that share features with those from human embryos.
New research is a milestone
The new research demonstrates that such cells can be easily created at different laboratories and venues, and could thus "mark a milestone in stem-cell-based regenerative medicine," the scientists said.
Some of the California researchers were recruited into UCLA's stem cell research programme after the state's voters in 2004 approved three billion dollars of state money to fund embryonic stem cell research to work around a ban on federal funding for such studies.
Nancy Reagan, a Republican stalwart and widow of the late president Ronald Reagan who suffered from Alzheimer's, backed the California referendum in defiance of Bush, who banned the use of federal money to create new lines of embryonic stem cells.
The research itself, however, has not been banned, and there are no limits on privately funded research.
Further research still needed
While the new findings reinforce the possibility that there's an alternative to destroying embryos, the scientists noted they believed embryo-based research must continue. "It is important to remember that our research does not eliminate the need for embryo-based human embryonic stem cell research, but rather provides another avenue of worthwhile investigation," said William Lowry, an assistant professor of molecular, cell and developmental biology and first author on the study.
Embryonic stem cells have the ability to develop into any type of cell and hold the hope of curing diseases. In the case of a leukaemia patient, for example, the scientists hope that the person's skin cells could be used to create a stem-cell line which could then produce a new blood supply.
"Our findings are an important step towards manipulating differentiated human cells to generate an unlimited supply of patient specific pluripotent stem cells," said Plath. "We are very excited about the potential implications."
Pluripotent means a cell can be prodded into turning into other body cells, such as blood, neurons and liver cells.
Bush hailed the November findings, saying through a spokeswoman that he believed medical problems could be solved without "compromising either the high aims of science or the sanctity of human life."
Among the concerns to be overcome before the technique could be used for practical purposes is the potential of developing cancer, as one of the genes used by the Japanese team is known to trigger the disease. – (Sapa) - (February 2008)