Washington D.C., Jul 24, 2009 / 21:17 pm
Two teams of Chinese researchers reported a medical breakthrough this morning, creating living mice from connective tissue that had been reverted to its embryonic state, a development that may eliminate the "need" to destroy human embryos for research.
Researchers accomplished this by first inducing the cells from the connective tissue to revert back to their embryonic state. This feat was first achieved two years ago, however researchers had never been successful in creating new living animals from these "induced pluripotent stem" (iPS) cells, raising questions about their developmental potential.
Results published today by the online journals "Nature" and "Cell Stem Cell" answer those questions, as scientists have shown that the iPS cells truly do function identically to embryonic stem cells. This proves that like embryonic stem cells, iPS cells are pluripotent, or able to develop into any type of cell, rather than simply multipotent, as adult stem cells are, only able to develop into a limited number of cells.
Fr. Tadeusz Pacholczyk, neuroscientist, staff ethicist, and director of education at the National Catholic Bioethics Center, explained to CNA that the breakthrough offers hope that iPS cells may be effective in providing an ethically acceptable alternative to human embryonic stem cell research.
"This procedure does not require the destruction of human embryos," Fr. Pacholczyk
said. "Therefore, it is certainly preferable to embryonic stem cell research."
"Nature" reports how researchers from the Chinese Academy of Sciences and Shanghai Jiao Tong University successfully produced 27 live offspring, while the National Institute of Biological Sciences produced four. Some of the mice have successfully mated to produce hundreds of second and third generation mice, however some of the first-generation mice had abnormalities.
Due to these abnormalities and the large number of failures necessary to produce a few successes, scientists argued that the experiments were too dangerous to attempt on humans.
Pacholczyk stressed that such procedures would also be ethically unacceptable. "You would run into exactly the same set of concerns that human closing raises," he told CNA, explaining that such procedures were acceptable when applied to animals, but "absolutely unethical" for humans.
While the process used to create the mice is technically different from cloning, both yield an organism that is genetically identical to its cell donor. The Catholic Church opposes this artificial creation of life when applied to human beings.
However, while it cannot be ethically used to create new humans, iPS cells offer hopes for the ethical treatment of human diseases and other ailments.
In the realm of medicine, where the goal is not to create a new human being but to development treatment for an illness, iPS cells would provide an ethical alternative to processes that use embryonic stem cells, destroying human embryos in the process.
With today’s report showing that iPS cells have identities and behaviors identical to those of embryonic stem cells, therapeutic experiments and research can be carried out without destroying innocent human life.
"We have the perfect alternative here," Fr. Pacholczyk said, referring to iPS cells, because they "don’t require the dismemberment of any human embryos."
With the iPS cells, Pacholczyk explained that "there are still all the difficulties that you encounter with embryonic stem cells," but that research can now be done and possible progress can be made in an ethical manner by using the iPS cells instead of embryonic stem cells.
In time, he explained, perhaps the problems will be solved and such cells will be able to be controlled for use in such medicinal procedures. At that point, iPS cells would be extremely useful as an ethically acceptable alternative to human embryonic stem cells.
(Story continues below)
For now, Pacholczyk believes that the greatest hope in therapeutic procedures comes not from iPS cells but from adult stem cells. These cells are already being used to effectively treat various diseases and conditions, he explained.
Pacholczyk hopes that scientists who do want to continue researching with embryonic stem cells will be open to the use of iPS cells over fetal cells. At the same time, however, he noted the disproportionate amount of funding given to research with human embryos.
"Our President has completely liberalized the posture of the federal government towards funding this kind of research," he told CNA, noting that this is true despite the science showing such research to be largely ineffective compared to other means.
Fr. Pacholczyk expressed his hopes that today’s development may help shift the focus of stem cell research to cells created by ethical means, working for the good of humanity while respecting the dignity of each human life.