“Political” Science on Stem Cells?

Date: 03/14/2002

Despite overheated media reports, two studies recently published in Nature DO NOT disprove the therapeutic potential of adult stem cells. Nor do they in any way bolster the case for so-called “therapeutic” cloning. In fact, the scientists involved in one of the studies admit that their theory questioning the ability of adult stem cells to transform into other tissue types (“plasticity”) is “unlikely” and “pure speculation,” and also that there is evidence against it.

Curiously, these publications come in the wake of a recent study, led by Catherine Verfaille (UMN) and published in the peer-reviewed Experimental Neurology, which demonstrates that adult stem cells can transform into numerous tissue types.  In fact, Dr. Verfaille and other researchers using adult stem cells have expressed skepticism regarding the speculations published in Nature.

The Nature studies speculate that adult stem cells do not really transform into new tissues, but rather merely fuse with already existing tissue.  This speculation is based on the researchers having mixed in cultured mouse bone marrow and brain cells with mouse embryonic stem cells.  The two types of cells fused at a low percentage, creating abnormal tetraploid cells, i.e., cells with double the normal (diploid) number of chromosomes. While admitting evidence to the contrary, the researchers speculate that this may be how adult stem cells in the body transform into other tissues.

But there is no evidence that this is what happens in the body.  Moreover, such speculation fails to explain how adult stem cells by themselves, in culture transform into many different tissues.

And no one is proposing mixing adult stem cells with embryonic stem cells to treat disease.  If anything, the study shows the potential dangers of using embryonic stem cells to treat patients, where injected embryonic stem cells may fuse with the adult cells in the patient’s body to form abnormal cells, thus risking tumor formation, a risk associated with the use of embryonic stem cells that is documented and well-known to researchers. 

In short, this study explains nothing about how adult stem cells work  and have worked, successfully, to treat human patients.  It certainly provides no argument for human embryonic cloning.  It seems another example of the fusion of “political” science with media hype.