Stem Cells may not be the Ultimate Cure-all
It has become a political battleground—stem-cell research. Lines have been drawn as the two different sides try to argue their opinions in the matter. At Apologetics Press, our belief is that stem-cell research is perfectly acceptable—as long as it does not involve the destruction of human life. We recognize that adult stem cells and stem cells collected from umbilical cords do not involve the destruction of human life. Yet, far too often, scientists want to cross the line and argue for the use of embryonic stem cells. We always have maintained (and will continue to do so) that faithful Christians cannot ignore the sanctity of human life in the hope that embryonic stem cells will cure some dreaded disease.
But a new report out of Oregon may vaporize the entire stem-cell argument. Research at the Oregon Health and Science University has defied the long-held assumption that stem cells are responsible for repairing diseased tissue. Holger Willenbring and colleagues found that macrophages (white blood cells that act as phagocytes to ingest foreign particles) “derived from bone marrow stem cells, and not bone marrow stem cells themselves, are what fused with diseased liver cells, ultimately curing a genetic liver disease” (see Science Daily, 2004, p. 1). In fact, they are not sure the stem cells did anything in the cells he and his coworkers evaluated. This landmark discovery was reported in the July issue of Nature Medicine (see Willenbring, et al., 2004).
Markus Grompe, one of the co-authors in the study, observed: “The most important discovery is you don’t need to transplant stem cells at all. If you transplant only macrophages, you’ll get liver cells that correct liver disease in mice” (Science Daily, 2004, p. 1). These findings are the latest in a series of discoveries from Grompe’s laboratory. This group already has demonstrated that blood-forming stem cells derived from bone marrow (known as hematopoietic stem cells) can cure liver disease in mice. They also have reported that liver cells were corrected by cell fusion rather than differentiation of the transplanted stem cells. As Grompe noted:
Various labs have reported that bone marrow or blood stem cells are like super cells. They can turn into anything—liver, lung, brain, muscle. Our thought was that blood stem cells are really there to repair all tissues, and we showed that you can cure liver disease with blood stem cell transplantation. Then we found out that bone marrow cells were not turning into liver cells directly, but that they were fusing with preexisting liver cells instead. In cell fusion, two distinct cells meld to form a single new cell. The liver cells were turning the blood cells into their own kind (Science Daily, p. 2).
In fact, Willenbring and his colleagues reported a “robust production” (10:744) of bone marrow-derived hepatocytes that cured the genetic liver disease. The importance of this discovery should not be overlooked. In the case of many stem cell transplants, patients are subjected to lethal doses of preparative irradiation in an effect to help combat the diseased tissue. As Grompe declared: “Here we show this harsh treatment is not necessary for macrophages to turn into useful liver cells” (Science Daily, p. 2).
Additionally, it should be noted that macrophages can easily be grown in tissue culture, and they do not involve the destruction of human life. Thus, scientists could grow large quantities in a laboratory setting, and never even take into consideration the “stem-cell debate.” Research could continue, and the sanctity of human life would be preserved. Keep in mind that this experiment evaluated only the repair of liver cells, so we will have to wait some time to see if this research proves useful in other areas. But the initial results are extremely promising, given the macrophage’s ability to repair damaged cells.
Science Daily (2004), “Macrophages, not Stem Cells, Correct Liver Disease by Fusion,” [On-line], URL: http://www.sciencedaily.com/releases/2004/07/040708014035.htm.
Willenbring, Holger, Alexis S. Bailey, Mark Foster, Yassmine Akkari, Craig Dorrell, Susan Olson, Milton Finegold, William H. Fleming, and Markus Grompe (2004), “Myelomonocytic Cells are Sufficient for Therapeutic Cell Fusion in Liver,” Nature Medicine, 10:744-748, July.