There are many scam artists around nowadays proclaiming the benefits of their particular unproven stem cell therapy, for anything from curing cancer to making paralysed people walk again. It’s not surprising really; stem cells are a pool of cells in every organ that are almost eternally youthful and can regenerate themselves and all other cells in the organ. They sound almost magical. However, last year the FDA (the US Food and Drug Administration) had to move to crack down on these clinics, citing the of lack of evidence that any of them work and a number of serious complications reported following treatment. Complications including patients in Florida dying, a woman developing bone fragments in eyelids following a stem cell facelift, and another developing nasal tissue in her spine after a doctor promised to cure her paralysis with stem cells.
It is a field ripe for abuse partly because it is one with so much potential. Stem cells do have fascinating possible applications, and there is a lot of research going in to them at the moment. Unfortunately, most exposure people have with them is in science fiction or alternative medicine. Which is why it was very interesting to see a study published last week that underlined how much real potential this field of research has. The study used mice instead of humans, so is still at an early stage, but is very promising nonetheless.
Scientists from North Carolina were studying a deadly form of brain cancer called glioblastoma (GBM), which has extremely poor prognosis for patients diagnosed with it. The work builds on the bizarre finding that these tumours somehow attract stem cells to them. So if you look at a GBM in humans, there are stem cells inside them that shouldn’t be there. Scientists had previously used this fact to load some stem cells with chemotherapy and could show that in mice, the stem cells were attracted by the tumour as expected, but they could also release their therapy while they were there. The problem with this is that we have very few stem cells in the brain so finding them and loading them with drugs is very difficult.
In this case the scientists overcame that problem by turning skin cells into brain stem cells. They took skin cells from mice into the lab and, because skin cells originally comes from the spinal cord which is technically part of the brain, were able to trick them into reverting back into that state. They could then give these cells their chemo payload and inject them back into the mice. When they did this the stem cells made their way to the brain and reduced tumour size to almost nothing, which is obviously a very impressive response.
There are two key advantages of this approach: 1) we have lots of skin stem cells, so they are easy to get; and 2) you can do it with a patient’s own cells, meaning that you wouldn’t have to worry about rejection, which can cause severe complications. This work still has to undergo significant testing to ensure it is safe for humans, but studies so far have been positive. A group in California have carried out a clinical trial which showed that apart from tissue rejection (which isn’t an issue in this case), stem cells can be a remarkably safe form of therapy.
This work is still at an early stage, but it is very encouraging. Considering that the average survival time for a patient with GBM is only a year, any new therapeutic avenues are welcome. The stem cell field is one that is on the cusp of large-scale application, and this could be one of the first in an array of new therapies for cancer and many other diseases. At present however, 95% of clinics offering these therapies are charlatans looking to make money off vulnerable people.