Breakthrough May Revolutionize Stem Cell Research
I have always wanted to have my cake and eat it too, but alas, that have-it-all scenario is not possible. Or is it? Breakthroughs by scientists from Kyoto University in Japan and MIT and Harvard University in the US now make it possible to generate embryonic-like stem cells (ELSCs) without destroying human embryos. These research teams produced ELSCs from mice adult skin cells. Neither eggs nor embryos were necessary.
The biomedical community hopes that embryonic stem cell research (ESCR) will lead to techniques that can generate replacement tissues from embryonic stem cells (ESCs). They claim that implanting replacement tissue derived from ESCs into damaged and diseased organs provides the means to treat and possibly cure many horrendous diseases and debilitating injuries. Unfortunately, in order to harvest stem cells from human embryos, the embryo must be destroyed.
In addition to ethical concerns, use of ESCs is riddled with several serious technical problems. Perhaps the largest hurdle facing this biotechnology is rejection due to genetic mismatch between the ESCs and the patient. This problem is identical to rejection that can occur after organ transplant procedures. If the donor and recipient are not compatible, the recipient’s body rejects the organ. It’s almost certain that the recipient’s body will treat genetically incompatible ESCs as foreign material and reject the cells before they can deliver any promised benefit.
Both research teams were able to transform skin cells called fibroblasts into ELSCs by transferring four genes into these easily isolated cells using a retrovirus as a carrier. The ELSCs can develop into all the different cell types in the human body, just like ESCs. ELSCs don't raise any ethical concerns, however, since they derive from adult cells, not embryos. Biomedical applications of ELSCs won't be frustrated by rejection because the fibroblasts used to produce them can be taken from the patient.
At this point, it is not clear if human fibroblasts can be coaxed to form ELSCs. Safety concerns are also a factor. Researchers are troubled by the use of a retrovirus to introduce genes into the fibroblast. They are also cautious because one of the transforming genes is involved in tumor formation. Still, the initial results are exciting and future work should address these potential pitfalls.
The discovery of methods to generate ELSCs from adult fibroblasts augments exciting advances already taking place with adult stem cells. These cells can be readily isolated from adult tissues like scalp, dental pulp, bone marrow, the olfactory bulb, the umbilical cord, and the placenta. No embryos are destroyed and no human life is lost in the process of isolating adult stem cells.
Numerous new discoveries indicate that several types of adult stem cells behave like embryonic stem cells. Under laboratory conditions these adult stem cells can be coaxed to develop into a wide range of cell types that are suitable for use in tissue replacement therapies. An increasing number of biomedical researchers are focusing their efforts on adult stem cells. The number of papers published in scientific journals on adult stem cells and their potential as therapeutic agents is growing week by week. Use of adult stem cells in tissue replacement therapies has an added advantage. Adult stem cells do not suffer from the problems associated with use of embryonic stem cells, like rejection and tumor formation.
As biomedical applications for adult stem cells (and hopefully ELSCs) matriculate to clinical applications, treatments for diseases and injuries that cause dreadful human suffering will be available without requiring the destruction of human embryos. That prospect leaves a good taste in my mouth.
Now if only someone could come up with cake that can be eaten without causing weight gain!
For more information on stem cell research see A collection of interview questions posed to, and answered by, Dr. Fazale “Fuz” Rana.