Induced pluripotent stem cells looked like a perfect solution to ethical debate … when they were first discovered in 2006.
Instead of destroying an embryo, iPS cells are made in a lab from ordinary skin or blood cells. Using various methods, scientists introduce 3 or 4 genes that return these cells to an embryonic-like state in which they, too, are able to turn into any type of cell.
- iPS cells can be made with tissue from people with known genetic diseases; scientists can then use them to study how diseases develop or to test the effectiveness of drugs. Already, researchers have made iPS cells from patients with Gaucher’s disease, Down Syndrome, Parkinson’s and diabetes.
But recently, scientists have started to raise concerns about iPS cells.
- Last year, a group led by Dr. Robert Lanza, chief scientific officer of ACTC.OB, compared batches of iPS cells to embryonic stem cells and noticed the iPS cells died more quickly and was much less capable of growing and expanding;
- In 7/10, Dr George Daley of the Harvard Stem Cell Institute and Medical School’s team reported more problems in the journal Nature, showing that iPS cells retain a bit of memory of their prior life as adult tissue, which could limit their use;
- An international team led by researchers at the UC, San Diego also found genetic mutations in 22 iPS cell lines taken from 7 different labs;
ACTC.OB won FDA approval last year for a clinical trial to treat a progressive form of blindness called Stargardt’s macular dystrophy, and in 1/11 won FDA approval to start using embryonic stem cells to treat macular degeneration. GERN’s 2010 success won the FDA’s nod for the first ever approved study of human embryonic stem cells to treat people whose spinal cords had been crushed. (HWM and Reuters)
The Bottom Line: Stem cell scientists are not giving up on iPS cells, but instead of a replacement for embryonic stem cells, they see them filling a unique research role. Imperfections mar hopes for reprogrammed stem cells. But while they have proven to be a powerful new way to study human disease, the reprogrammed cells known as induced pluripotent stem cells, or iPS cells are no substitute for embryonic stem cells. “It has not ever been a scientifically driven argument that iPS cells are a worthy and complete substitute for embryonic stem cells,” Daley said and those arguments were always made based on political and religious opposition to embryonic stem cells”. “There are serious problems with this iPS cell technology that still need to be solved,” Robert Lanza, CSO of ACTC.OB and abnormalities in iPS cells could raise flags among regulators that these cells could cause problems in people. But the political path for embryonic stem cells is still murky. The Obama administration overturned the strictest of the limitations imposed former President Bush on using federal funds for the research, but last summer that policy was challenged in court. A US appeals court has ruled that funding could continue while the government appeals, but grants from the NIH have been frozen, unfrozen with the court battles continuing.The gold standard cells at the present time are embryonic stem cells. But the issue has been a point of controversy for some religious conservatives, who believe the destruction of any human embryo is wrong. Will researchers be able ultimately to use iPS cells for treatments … probably in time and based on more research!