As evidenced by this boy's experience, one of the biggest potential problems with stem cell therapy is the development of tumors.
But there are other problems as well.
Stem cells directed to become beating heart cells might mistakenly end up in the brain. Or insulin-producing beta cells which can't stop means the body can no longer regulate insulin levels.
"You've totally lost control," Dr. Crystal says. "What do you do?"
The best chance of circumventing these issues is genetic modification of the stem cells prior to actually transplanting them, Dr. Crystal says. Theoretically, this is similar to how gene therapy is used to treat cancer, but with important improvements.
"Instead of gene therapy being done in the patient, as is the case in cancer, it's being done in the cells in a laboratory before doctors use them for therapy so that they still have control of these cells," Dr. Crystal explains.
Therapists would rig certain genes to respond to a "remote control" signal. For instance, giving a certain drug could prompt a "suicide" gene to kill a budding tumor.
But gene therapy also needs to be carefully done and, ideally, two independent gene-manipulation systems would be used to ensure that stem cells remain firmly in control of clinicians.
|Contact: John Rodgers|
New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College