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BLOG: November 2007
Stem cells cure promiseCan you imagine having diseased body or organ tissue simply dissolved, and replaced by a brand new, healthy tissue grown by your own body? This is the stem cells cure promise. Just a little while back, something like that would sound as a science fiction story; not anymore. The main obstacle for further progress in this field of medicine - obtaining stem cells - may be possible to resolve without the controversy of having to use embryos for that purpose.
Media articles (CNN, BBC News) report that researchers in Japan (Yamanaka et al., Kyoto University) and the US (Thomson at al., University of Wisconsin-Madison), have found simple way to transform ordinary human cell into pluripotent state, that is, into stem cell. Such cell has the capacity to grow into any of 220 different cell types forming the human body.
While these cells are not quite identical to embryonic stem cells, the experiments have shown that they "do all the things embryonic stem cells do" (Thomson). The researchers used these "made-up" stem cells to create heart and brain tissue. In 12 days, those used in the Japanese study have grown into a beating heart muscle tissue.
The only concern, at present, is the presence of viruses used to transport the cell-transforming genetic material. It is unknown what longer-term effects - if any - it may have. Thus, further research is needed to make sure that stem cells obtained in this manner don't have a hidden glitch that could have a health effect after some time.
But securing supply of stem cells are only the first step. It is just as crucial to be able to eliminate the old, diseased tissue, so that the body can grow healthy replacement using new stem cell supply. Rather primitive, brutal method is already used in bone-marrow transplant (friend of mine, who recently went through it, calls it by far the most dehumanizing experience of his entire life). It is based on near-deadly chemo-therapy used to kill the diseased cells - but also a whole lot of healthy ones in the process. Such procedure wouldn't be an option for any other but life-threatening diseases.
The good news comes from Stanford University, US (Weissman et al.). In experiments on mice, they were able to target and destroy specifically blood cells, by attaching to them cell-specific antibodies. The rest of body remained unharmed. This significantly reduces negative effects of diseased tissue removal, making such method feasible for much wider range of diseases.
It is reasonable to expect that similar techniques can be used on other types of cells - and on human cells as well. If so, that would add the final necessary ingredient for use of stem cells to cure variety of human diseases.