Headlines last week reported that researchers successfully produced stem cells from cloned monkey embryos. Using a process that has become almost routine with mice, scientists can now make make primate embryonic stem cells that are genetically identical to a given DNA donor. Once we learn to do this in humans, the possibility of stem cell based treatments for heart disease, neurodegeneration, and more will be closer to reality. But in the US and elsewhere, can we develop the political will to let this research move forward?
In case you missed the headlines, the story is this: a group of researchers at the Oregon Health and Science University led by Dr. Shoukhrat Mitalipov used the process of somatic cell nuclear transfer (SCNT) to create cloned Rhesus macaque embryonic stem cells. SCNT involves taking the DNA from an adult skin cell and implanting this DNA into an egg cell from which the DNA has been removed. This DNA transplant procedure can produce an embryo without the need for a fertilized egg - and most importantly, it produces an embryo genetically identical the DNA donor, which means that potential therapies using SCNT-derived stem cells wouldn't be rejected by a patient's immune system.
SCNT itself is old news; what is impressive in this research is the new ability to do SCNT with primate cells. This breakthrough was enabled by better imaging technology. SCNT is like a heart transplant where you just rip out the old heart with a giant tug, leaving a lot of damage behind. With the new technology, Dr. Mitalipov's team was able to better see what they were doing as they carried out the procedure.
If it can be done in monkeys, it's just a matter of time before it can be done in humans. Back in 2004 the world thought that human stem cells had been created from such cloned embryos, but that research turned out to be faked. The researcher behind those studies, Woo Suk Hwang from Seoul National University, was exposed as a crook and the already controversial image of human stem cell research was tarnished. Because of this history, Nature and Dr. Mitalipov went to great lengths to prove that the macaque embryonic stem cells reported in this paper are real, including requesting genetic confirmation from an independent group.
Where does this research go from here? Scientifically, we're still some way off from using these cells to replace ailing nerve or heart tissue in patients with terminal diseases. The many political and legal hurdles are even more formidable in the immediate future. To take just one example, at SCNT's current success rates you need hundreds of eggs from donors before you get just one successful embryo. Egg donation is not a pleasant process, and laws in some states prevent researchers from financially compensating donors, unlike other types of research volunteers who are paid for their time and trouble. Success rates will no doubt improve as researchers learn important tweaks in the procedure, but that can't be done without lots of trying. If the US doesn't develop the political will to make it possible for stem cell researchers to do their work, future treatments will be developed elsewhere and the US will lack the expertise in both research and patient treatment. The macaque stem cell paper indicates that the day when we will know how to use embryonic stem cells for medical treatments looms ahead, and unless we make changes in this country, we won't benefit from them.
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