There are many advertisements touting the power of stem cell treatments to reverse ageing and cure diseases, but consumers should be careful because many of these claims are misleading.
Dr Roger Barker, professor of clinical neurosciences at University of Cambridge, says many of the scientifically proven stem cell treatments are only at the clinical trial stage. Barker’s own research includes the use of stem cells in developing cures for Parkinson’s and Huntington’s disease.
“There are a lot of clinics offering unproven stem cell therapies for all sorts of conditions, and the problem is that the science underpinning these is either very poor or non-existent,” he says.
Another point of contention is how much is charged for these therapies. “You should not have to pay for any new therapy that is part of a new experimental treatment. It should be part of a clinical trial. So, I always advise people if they see clinics advertising these kinds of therapies to be extremely cautious because they are unlikely to be offering anything that is going to help you,” Barker says.
Dr William James, professor of virology at University of Oxford, says consumers should also be cautious of stem cell banks.
“There is a lot of marketing of stem cell banking going on, saying, ‘Give us the cord blood when your child is born or give us the first tooth when it’s lost, then you’ll have a bank of stem cells that can cure you later in life.’ It may be good, it may work indeed, but I worry a little bit that it’s hitting people at a time when they’re most vulnerable, most worried and hopeful. I’m worried there may be a danger of exploitation, so we have to be quite cautious about that,” James says.
Barker and James were speaking at the Second Cambridge-Oxford-Sunway Biomedical Symposium on the translation of stem cell research to therapies for various diseases. Stem cells are cells that can grow and develop into many different cell types. According to the International Society for Stem Cell Research, at the moment, stem cells are only proven to treat diseases of the blood through routines such as bone marrow transplants, as well as tissue grafts to treat diseases or injuries to the bone, skin and the surface of the eye.
Stem cells from different parts of the body have their own functions and can only grow into specific types of cells. Pluripotent stem cells could form all different cell types, but they are not a good candidate for treatments currently because without careful instruction, they might overgrow and cause tumours.
“I would say that you have to look very carefully at the data people are presenting because the other big problem in this area is that stem cells are used generically as a term that covers a whole mass of different types of cells. So, when people say stem cell therapy, you might not even know what stem cell you’re getting,” Barker says.
“The International Society for Stem Cell Research has a lot of information on their website for patients. The big problem in this area, especially for a lot of diseases of the brain, is people are desperate, they can’t wait five or 10 years for the therapy to come to market because they won’t be alive or they’ll be severely disabled. So the companies, sadly, prey on people’s vulnerability.”
As for beauty centres that offer stem cell treatments, Barker says as far as he knows, there is no scientific basis, but “they’re probably very safe because they probably just smear them on your face. I think, anything that enters your body or is injected under your skin — all of those things are bad”.
Earlier in July this year, experts from 15 countries wrote a piece in a scientific journal calling for more stringent regulation of stem cell therapies. Deaths due to bogus stem cell treatments have been recorded as people travel to other countries to seek illegal treatments as a last resort. The US Food and Drug Administration began cracking down on clinics offering unproven stem cell therapies in August.
But other than being used as a cure by replacing damaged cells, stem cells are also used in the process of research to develop new drugs or treatments. They can be turned into models of diseased cells that researchers can use to develop treatments.
“I find stem cells absolutely transformational to the type of science that I can do. Questions I wasn’t able to ask before, we can meaningfully answer with stem cell technology. I think that’s where the biggest impact has been so far,” James says, although he emphasises that there are still a lot of challenges.
“We have a long way to go before we see lots of stem cell therapies, but I’m sure they will come. And I think using stem cells will speed up the process of discovering effective, low-cost drugs. That’s where the biggest impact is going to be in the next few years. People sometimes call it ‘disease in a dish’; you use the stem cells to generate a tissue in a dish that is like the tissue in the body, then you can make it behave like it does in a disease, and you can look for drugs to put it right again. Once you’ve got that, then pharmaceutical companies have all the expertise you need for screening very large compound libraries to take them on from there.”
Barker says he sees the most progress in stem cell research for diseases such as Parkinson’s, eye-related ones and diabetes.
For Parkinson’s disease, scientists can aim to use stem cells to create replacements for dopamine in the brain. Some research has shown that for degeneration of the eye due to old age, certain types of stem cells can repair the damage or prevent it. This, he adds, is already in clinical trials.
“I think the third major area people are very interested in is diabetes and the capacity to make insulin because, again, it’s very obvious what you need to make to have a direct impact. The areas where [stem cell therapy is] least successful is in heart disease because it’s very unclear what you need to make and whether the environment is right. Another area that has recently received a lot of interest is skin,” Barker says.
Some of the challenges of turning stem cell research into therapies involve the origin of the stem cells, the process of manipulating the stem cells and the impact of inserting stem cells into human bodies.
For one, Barker says, there are concerns about the transmission of viruses through stem cells, so the origin of the stem cells used for therapy must be clear.
“The second thing is you have to manufacture it, which in itself isn’t a big problem, but you need to have the processes that allow you to manufacture things in a robust, reproducible way with quality control,” he adds.
Thirdly, he continues, the big risk with any stem cell product is tumours. “Stem cells make tumours, so can we be certain that the cells we put in don’t possess any stem cells or have the capacity to revert to that form?” he asks. “We feel fairly confident that’s being solved, but that’s unknown until we go into patients, because most animal studies that we do at most will last two years, but stem cell therapies in patients will last decades.
“For brain diseases, it can also be harder to measure whether the stem cells have made any difference.”
Gene editing is another emerging technology within the medical space that will hasten new cures and treatments for diseases. For instance, CRISPR is a new gene editing technology that can edit DNA at precise locations and could be used to correct mutations and treat genetic diseases.
James says this may work for many genetic diseases that are affecting patients, such as one patient he worked with who had an inherited immunodeficiency disease. Patients with that disease tend to die young even if given antibiotics, but can live compromised lives for longer with a bone marrow transplant.
“There are a variety of diseases of this sort where you might not have to correct every cell in the body. You can probably correct half the blood cells, and that would give you enough to be able to control the disease. So, those are the types of diseases that we are going to see in gene correction therapy. They’re not even in clinical trials yet, but I think it will happen in the next few years,” he says.