How true are the claims that stem-cell research could one day lead to cures for a range of debilitating diseases and life-threatening conditions? asks DICK AHLSTROM
SUPERMAN ACTOR Christopher Reeve was tragically paralysed on May 27th, 1995, the day he tumbled from a horse and broke his neck. The riding accident left him paralysed and bound to a wheelchair, but it also gave the world a champion who campaigned tirelessly in support of stem-cell research.
Medical therapies based on the use of stem cells hold great promise for the treatment of currently intractable conditions such as Alzheimer’s disease and multiple sclerosis. Researchers also believe they may one day be used to cure the spinal-cord damage that so changed Reeve’s life before his eventual death in October 2004.
Reeve left behind a foundation that has put €60 million into spinal-injury research, including work using stem cells.
Similar support for Parkinson’s disease research has seen €110 million invested by the Michael J Fox Foundation. The actor launched the foundation after he was diagnosed with Parkinson’s almost 20 years ago, and it too is emphasising the potential of stem-cell research to deliver a cure for the disease.
Irish researchers are more cautious, however, about treatments based on stem cells. While their use offers great promise, we are unlikely to see treatments for serious conditions in less than five to 10 years, they say. Many are also concerned about fraudulent claims being made for stem-cell treatments that might actually cause more harm than good.
The subject arose at a conference on stem-cell research in Dublin last week. It discussed the decision by the parents of eight-month-old Gretta Kieran Cullen to travel to China so that their daughter can receive controversial stem-cell treatments. The infant suffers from septo-optic dysplasia, a genetic condition that has left her blind and suffering from other symptoms. Her treatments began this week and will continue for about a month.
Trinity College Dublin-based research fellow Dr Stephen Sullivan organised the conference and he fears a “backlash” against this important technology when patients who undergo unproven stem-cell treatments fail to get a positive result.
“There is a huge amount of money in offering therapies to people with terrible diseases,” he says. “But it is important not to be offering them false hope.”
Many such treatments are being advertised on the internet, but they have not undergone proper assessment, he says. “People often talk about embryonic stem cells being transplanted into the patient. This is five to 10 years away. If people come to you offering a cure and they haven’t done clinical trials then they have no evidence it will work.”
There are a number of tell-tale signs that a stem-cell treatment is unproven and possibly unsafe, he adds. “The first and most important thing is if they are asking for money up front.”
This is not to say, however, that stem-cell technology won’t find its way into useful treatments. We already have treatments based on the use of adult stem cells, a form of stem cell recovered from mature tissues, Sullivan adds. “At the moment, when it comes to stem cells, the only real treatments are from adult stem cells like bone marrow transplants.”
Researchers at NUI Galway’s regenerative medicine institute, Remedi, hope to begin testing adult stem-cell treatments in humans as early as next year.
“Our focus is on the development of therapies using [adult] stem cells,” says Prof Frank Barry, Remedi’s professor of cellular therapy. “We are very much translational and our objective has always been that we want to develop something which can be given to a patient.”
His group, which ranges in size from 50 to 70 researchers, has already set up a “stem-cell manufacturing facility” that will allow large numbers of adult stem cells to be grown up in the lab.
The group’s plan is to target two areas, osteo-arthritis of the knee and the reduced blood flow in the feet and hands seen in those with diabetes. The hope is that, once injected, the stem cells will help to reverse the symptoms associated with these two conditions, according to Barry.
THERE HAS BEEN a huge amount of public disquiet about the conduct of a particular type of stem-cell research, the type based on the use of stem cells taken from human embryos, a process which always causes the destruction of the embryo.
Researchers shied away from their use here because of the ethical problems associated with embryonic stem cells until October 2008, when the governors of University College Cork voted by just 16 to 15 to introduce a code of practice that would allow this research.
No such research has started so far, states UCC’s Dr Tom Moore, a principal investigator in the Biosciences Institute, who would like to use these cells for research. The vote, he says, “was to produce a mechanism for getting approval for the research. It has been a lengthy process and it is still ongoing”.
He believes there is nothing to compare with embryonic stem cells because these are the cells in the embryo that transform to become all the tissues of the body.
“They are pluripotent, almost totipotent. You can differentiate them into all the different cell types,” he says.
He is less concerned about using them for quick cures than for the remarkable power they offer for medical research. They allow scientists to study the changes that take place when disease occurs and compare this with healthy cells.
“Therapies are a long way down the line, but being able to use them is good for basic science. Even if stem cells were never used in human therapies, it would still be hugely valuable to facilitate the study of disease mechanisms,” he says.
He mentions his own studies of a cell type found in the base of the brain, called the purkinje cell. Although rare, it is very important because of its potential link to autism.Moore has identified a gene of interest in these cells, but it is a very difficult thing to acquire certain rare cell lines for study, including the purkinje cell.
“It would really be valuable for us to be able to make that cell line to study the gene,” he says. The manipulation of embryonic stem cells would permit that closer study.
SO TOO MIGHTan astounding research discovery made in Japan. An announcement came in November 2007 that scientists had successfully "re-programmed" an ordinary skin cell to become something akin to an embryonic stem cell.
These “induced pluripotent stem cells” seem to be identical to true embryonic cells, and while comparative studies continue, researchers believe they will allow stem-cell technology to advance quickly in the absence of the ethical burden.
If they perform like the real thing, then research groups around the world, including Ireland, will be able to exploit the technology to study disease.
“This is really a platform knowledge,” says Sullivan. “If you can make every cell type in the body, you can study every disease that affects humans.”