Since the November announcement that scientists derived stem cells that appear to have the power of those from embryos (but without embryo destruction), much hay has been made about the stem cell debates’ future. As I describe in a new short essay published at the Hasting Center's Bioethics Forum, many advocates of embryonic stem cell research have been remarkably skeptical, if not outright dismissive, of the new technique’s potential, called induced pluripotent stem (iPS) cells. Two articles – one in Nature and one in an offshoot journal - indicate the spectrum of response.
On the balanced end of the spectrum, journalist David Cyranoski assesses the prospects for iPS by examining “five things to know before jumping on the iPS bandwagon.” His conclusions?
- Anyone can do it: Fact (mostly)
- Everyone can have their own custom-tailored cells: Fiction (unless you're rich)
- The cures are on their way: Too soon to tell
- Embryonic stem cells are the same as iPS cells: Fact (so far, anyway)
- iPS cells have no ethical issues: Fiction (depends on what you want to do)
Notwithstanding the article’s snide title, Cyranoksi’s approach is critical yet balanced. In fact, I don't think anything this tough-but-fair, has ever been published in an outlet such as Nature or Science on cloning-based stem cell research, which is the primary rival to iPS.
Perhaps his most interesting point concerns iPS's potential to derive patient-specific custom stem cell lines - the "personal biological repair kit" that's also the long-standing goal of cloning-based stem cell research. Cyranoski cites a neuroscientist who assert that patient-tailored iPS cell lines "would take a ridiculous amount of money" - at least several hundred thousand dollars. If that's that case, wouldn't such lines derived via cloning be at least as expensive?
At the other end of the spectrum, Nature Reports: Stem Cells published a commentary by researcher Thomas P. Zwaka which goes so far as to imply that human stem cells have already been derived via cloning (here called somatic cell nuclear transfer). Discussing cell reprogramming (that is, iPS), he says that:
[I]n contrast to reprogramming by SCNT, the acquisition of pluripotency [by iPS] requires multiple days, and it is still unclear which sorts of cells can be reprogrammed. Not only does SCNT currently yield higher-quality pluripotent cells, it also possesses a significant advantage because it does not use genomic alteration to introduce reprogramming factors....
Suppose, though, that iPS cells can be generated without genetic manipulation. Many labs are pursuing this goal, and it could be achieved soon. Does this mean that SCNT can be discarded, that it should become a relic like mouth pipetting? Absolutely not! [emphasis mine]
Not only does the author fail to mention that human stem cells have yet to be derived from cloning, but he also skips over the two major risks posed by the technique: the need for numerous fresh human eggs, and the technical groundwork it would lay for human reproductive cloning.
Previously on Biopolitical Times: