Exciting (Ignored) Adult Stem Cell Stories

There's better things to do than to arguing about whether Advanced Cell Technology really made embryonic stem cells and whether it's worth millions of dollars if they did: how about learning about knee regeneration and finding a key to making adult stem cells work they way we want them to work, where they're needed? And the University of Minnesota wants us to know that they're recruiting patients for phase II and III in their stem cell transplant treatment for children with inborn errors of metabolism.


The Houston Chronicle reports that doctors in Houston, Texas are doing actual research on growing knee cartilege from a patient's own bone marrow stem cells, the mesenchymal stem cells.

And the University of Pennsylvania announced two days ago that they have discovered additional information about how stem cells differentiate appropriately: they sense their physical as well as their chemical environment.

The the first clinical trials using mesenchymal stem cells from the patient's own bone marrow to heal knee cartilege are underway, and the preliminary results are due in October. 800,000 people per year have part of their meniscus removed due to injury. In this study, 55 patients who have under-gone surgery to remove part of the meniscus - that half-moon-shaped cartilege in the knee - have been assigned to one of two legs of a controlled, double-blinded study. Half are injected with their own mesenchymal cells (harvested from their bone marrow) and half are subjected to "dummy" operations. All of the patients are being followed by MRI.

("Dummy" means that the doc is sticking a needle into the knee joint, but neither they nor the doc know until later whether the needle had any stem cells in it.

The double blind is the golden standard of research, so that the expectations or wants and wishes of the patient or the doc will not affect the outcome. Ethically, the ability to do "dummy" procedures is acceptable if the risk of harm is slight or if the potential gains are substantial. The justification leans more on the autonomy of a patient who gives his consent and the expectation of a greater good for many with a slight risk for some, than on the "First, do no harm," school of thought. It depends heavily on informed consent and following the patients closely and closing the "blinded" part of the experiment if significant good or bad effects are observed. Normally, at the end, the researchers open the envelopes, or virtual envelopes, to know how to interpret what has already happened and been measured.)

The second story reinforces the importance of the environment for stem cell differentiation, which, Wesley Smith notes was a twist in the ACT experiment. It also may explain some of the low yields, such as in spinal cord trauma and heart attacks.

The physical, as well as the chemical environment of the stem cells is vital. Mesenchymal cells react to the force needed The key will be in finding ways to "prime" (or train?) stem cells to work in diseased or injured tissue.

The big fuss earlier this year about phase I fetal neural stem cell treatment for Batten's disease overshadowed any attention given to the trial for several similar diseases, started in 1995. That series is evidently now entering further testing and recruiting more patients.