No Need to Tinker With Human Embryos
Programmed adult stem cells can do everything, but some researchers are determined to keep tinkering with human beings.
Leave it to the Russians to rebuke the Americans on ethics. Would anyone have expected that in 1970? A press release from the Moscow Institute of Physics and Technology has determined that induced pluripotent stem cells (iPS) are, for all practical purposes of measurement, identical to embryonic stem cells (ES). ES cells have long been considered the “gold standard” of totipotency (ability to transform into any cell). Though stem cell researchers were glad when induced pluripotent stem cells came out, many expressed doubts they were as good as the highly popular ES cells that had been promoted as miracle cures in the mid 2000s.
There are two ways to get pluripotent stem cells. The first is to extract them from the excess embryos produced during the in vitro fertilization procedure. But this practice is still controversial technically and ethically because it does destroy an embryo which could have been implanted. This is why researchers came up with the second way to get pluripotent stem cells – reprogramming adult cells.
The process of “turning on” genes that are active in a stem cell and “turning off” genes that are responsible for cell specialization is called reprogramming. This technology was pioneered by Shinya Yamanaka, who showed that the introduction of four specific proteins that are essential during early embryonic development could be used to convert adult cells into pluripotent cells. He was awarded the 2012 Nobel Prize along with Sir John Gurdon “for the discovery that mature cells can be reprogrammed to become pluripotent.” (Fig.2).
So are the iPS cells just as good? Science Daily said so with its headline: “Scientists approve the similarity between reprogrammed and embryonic stem cells: Researchers have concluded that reprogramming does not create differences between reprogrammed and embryonic stem cells.”
The type of adult cells which were reprogrammed and the process of reprogramming itself did not leave any marks, concluded scientists. Differences between cells that did occur were thought to be the impact of random factors. “We defined the best induced pluripotent stem cells line concept. The minimum number of iPSC clones that would be enough for at least one to be similar to “gold standard” with 95% confidence is five.” – says Dmitry Ischenko, MIPT PhD and Institute of Physical Chemical Medicine researcher.
If adult stem cells are just as good as embryonic stem cells, it seems gratuitously unethical to use the latter. Yet PNAS published some positive results with the use of “fetal grafts” to alleviate symptoms of Parkinson’s disease, while New Scientist celebrated “remarkable results” using mesenchymal stem cells from donor bone marrow that are allowing stroke victims to walk again.
Other News on Medical Ethics
Netherlands wants to grow human embryos for ‘limited’ research (PhysOrg): The Dutch Health Minister “wants to allow the creation of embryos for scientific research—and under very strict conditions to give people the possibility of (healthy) children.” She wants to extend the “14-day rule” for maintaining a human embryo in a petri dish; it’s too limiting. “Until now the ban on the cultivation of embryos have hampered research which could help with the treatment of diseases on the short to medium-long term.” It always starts with good intentions.
Synthetic human genome: We’ve read the human genome. Now, should we write it? “Plan to synthesize human genome triggers mixed response,” Ewen Callaway writes in Nature. “Some admire project’s ambition; others say that it hasn’t justified its aims.” So what are its aims? “We’re not trying to make an army of clones or start a new era of eugenics,” says Jef Boeke, a synthetic geneticist from New York University. “That is not the plan” — at least for now, so they always say. But could it become an ancillary spin-off? Many became suspicious over a private meeting to discuss a “Human Genome Project – Write” concept. “Did Harvard Scientists Secretly Discuss Making a Human from Scratch?” Jeff Bessen wrote for Live Science. Even though he concludes the press coverage was misleading, he agrees that “When ethically fraught science is discussed behind closed doors, people get suspicious.”
CRISPR views of embryos and cells (Science Magazine): Work is proceeding on embryos—zebrafish embryos. As reported last year (6/05/15), the CRISPR gene editing technique brings a host of ethical issues in its train as researchers consider ways to apply it to humans.
Three-person embryos may fail to vanquish mutant mitochondria (Nature): Last month, Ewen Callaway reported that a proposed method to use a donor’s genes to fix mitochondrial mutations in a human embryo has backfired. Ethicists had been concerned about the method leading to “designer babies” and a new round of eugenics.
Brain scans reveal hidden consciousness in patients (Medical Xpress). More progress has been made identifying whether patients classified as vegetative actually are conscious and aware. Though unable to respond outwardly, some have hidden signs of awareness that new brain scans are able to detect.
Everything that needs doing in medicine can be done without taking another life. It’s immoral to kill someone for the sake of letting another live. Cross that line, and terrible trends can begin. It becomes OK to kill an unborn baby “for the life of the mother” initially. Then, “for the health of the mother.” Health is redefined to include mental health, then depression, or just inconvenience. Result: death of the baby for any reason whatsoever, all the way to the moment of birth. If a human being doesn’t begin at conception, when all the genes for progress to adulthood are together, when does it begin? Well, it begins when the cell divides. Then it begins at the fourth cell division. Then it begins in 14 days. Then that cut-off date becomes inconvenient. On and on it goes. We must not tolerate that first deadly decision.
Exercise: Discuss the ethics of the “human-on-a-chip” project announced by Medical Xpress going on at Lawrence Livermore.