Ethical Bio-Replacements on the Way Thanks to Adult Stem Cell Breakthroughs
By John Wolper, eFluxMedia, December 23, 2007
Following in the footsteps of their Japanese and U.S. colleagues, another team of U.S. scientists has come up with a way to produce “safe patient-specific” cells that don’t pose the risk of developing cancer. This new finding delivers another significant blow to embryonic stem cell research.
Two teams of U.S. and Japanese biologists made the most significant medical discovery of 2007 back in November. The journals Science and Cell reported that the scientists had by-passed the un-ethical procedure of destroying human embryos, and created embryonic stem cells from a non-embryonic source. Dr. Shinya Yamanaka, from the University of Kyoto- who led the research in this domain- successfully reprogrammed human adult cells to function like pluripotent embryonic stem (ES) cells.
For the “re-construction” of body-parts affected by accidents (burns, spinal cord-injuries, head-traumas, etc.), or the most promising cure for most of the degenerative diseases affecting elderly people (Alzheimer, Parkinson), stem cells are the most promising cure. Stem cells an be “programmed” to give rise to highly specialized cells of each tissue type (using the appropriate “input” signal). This characteristic makes these cells, which are undifferentiated somatic cells with the capability of indefinitely replicating (they divide giving birth to exact replicas of themselves), valuable to medical science.
Compatibility is one of the hurdles that make organ transplant procedures dangerous; stem cells eliminate this dilemma. Since the body doesn’t recognize the donor's genetic code, the patient is at risk of developing an immune reaction to the new organ. The problem if immune reaction will be remedied once organs “crafted” from the patient’s own cells become a reality.
Yamanaka's breakthrough research has been evolved further as the journal Nature reported with a story about Dr. George Daley’s team from the Children's Hospital, in Boston, Massachusetts. Skin samples taken from a healthy human volunteer, foetal lung and skin cells, and neo-natal skin cells were induced to form pluripotent stem cells (or iPS, the kind of cells obtained previously by Yamanaka). By implanting four genes into the cells, the procedure is similar to the experimental version done by the Japanese team. The researchers proved that experimental cells lose their highly-specialized profile and become iPS with the help of a retrovirus.
But what is really outstanding is that Daley’s team obtained iPS without a cancer gene called c-Myc, which induced many cancers in lab mice during testing.
There is still a long road ahead for stem cell researchers who are utilizing this new technology.
Clinical success with human iPS cells must await the development of methods that avoid potentially harmful genetic modification," the Nature article said.
Regardless, further enhancements to the technology will continue at the currently feverish pace. It may not be long as some think, before this technology is treating patients around the world.