Tumors in a (quack) human stem cell therapy

It’s almost like a bad Yakov Smirnoff joke, “In America you test therapies in animals before giving them to humans, in Russia…” All I can do is wonder, what were they thinking? Injecting stem cells into a kid’s spinal fluid to correct a genetic disorder? Are they insane?

Stem cells, in particular embryonic and fetal stem cells, are useful because they represent cells that are less differentiated than the cells that are working at specific functions throughout your body. Another result of being stem cells is that they are able to divide and proliferate without differentiating or undergoing apoptosis and as cells differentiate towards their final fate they tend to divide less and ultimately commit cellular suicide if they are signaled to begin dividing again – a protection against cancerous growth. The downside of this is that stem cells act, in their normal state, a bit like cancerous cells. In fact one of the assays to demonstrate the pluripotency of a cell (the ability of a stem cell to make many kinds of other tissues) is to inject them into an animal where they will make tumors called teratomas which are (usually) benign growths of cells that represent endoderm, mesoderm, and ectoderm – the three germ layers than give rise to all tissues in the body during development.

As a scientist who works with stem cells, both in culture and in vivo I could have told you this therapy was a bad idea. A year ago Jake explained why this was a bad idea. If you had described this therapy to us, we would have told you exactly what would happen based on scientific knowledge of how these cells act in vivo. The therapies offered to stem cell tourists are frank quackery. They are unproven, untested, unstudied, and unmonitored. And to you anti-FDA libertarians out there, this is what you get when you don’t have regulatory oversight of human therapies. You get stupid quackery. The fact that this kid’s cancer was detected is probably just luck – there are likely many more people who have tried these therapies of desperation who suffered side effects, and possibly even death, but we just haven’t heard about it yet.

Ethical human trials require many things. At the very least, the therapy should have been tested extensively for safety in animals and ideally for efficacy in animal models of the disease. The patients should be selected carefully, should have a reasonable expectation of therapeutic benefit, and after the treatment follow-up should be extensive. Further, in the case of such a novel therapy, the bar should have been set higher before attempts in humans were made. In this case we have a child with a rare genetic neurodegenerative disorder that was experimented on without proper oversight, or a reasonable expectation that this therapy should do anything. Ataxia Telangiectasia is an autosomal recessive disorder in which every cell in the child’s body lacks the appropriate gene which is involved in cell cycle regulation and DNA repair. By what mechanism did they think neural stem cells would have an effect on such a disorder? Would the cells replace the child’s entire central nervous system? Would they miraculously repair the genetic defect? Or manage to insert themselves in just the right places to fix symptoms caused by a universal defect in the the hosts genome? This is magical thinking, not scientific thinking, and further I believe it is grossly unethical and stupid.

It is of no surprise that the careless injection of fetal stem cells into a child would result in tumors. This was a mind-bogglingly stupid act. What’s worse, as we hear more about the damaging quackery being offered in countries without proper regulation and oversight of human therapy we will likely hear more stories like this one.

In the rush to find some dramatic cure for a disease using stem cells it is likely efforts like these will damage the success of legitimate and careful studies in regenerative medicine and stem cell therapies. Injury and deaths from careless stupid quacks using these cells will create and association in people’s minds between stem cell therapies and cancer. We know the obstacles to using these cells in humans. The major one – immune compatibility – may have been solved already. The major remaining obstacles towards implementation of some fairly crude stem cell therapies are going to be (1) differentiating the cells into the appropriate tissues, (2) purifying the cells so that undifferentiated cells aren’t accidentally transplanted into humans, (3) preventing tumorous growth in the transplanted cells (possibly including a lethal gene to reverse the therapy if necessary), and (4) proper anatomic delivery of the cells so they perform a useful function and survive in the host. We know what the problems are. Careful study must include addressing each of these issues and ensuring they are resolved before shoving them into someone’s spinal fluid.

This quackery is not only going to prove harmful to individual human patients, but will likely harm the burgeoning field of regenerative medicine as a whole. For the sake of the patients, and for all future patients that might benefit from well-studied therapies, this quackery must be stopped.