Oct 09 2012

2012 Nobel Prize in Physiology or Medicine

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5 Responses to “2012 Nobel Prize in Physiology or Medicine”

  1. Amy R.on 09 Oct 2012 at 12:09 pm

    Dr. Novella, I disagree with you that induced pluripotent cells (iPSCs) can entirely replace embryonic stem cells (ESCs) at this time.

    1. The reprogramming of iPSCs is a notoriously ineffcient process, with less than 1% of cells used effectively reprogrammed. While this may be acceptable in the laboratory setting, such inefficiency may present difficulties in a clinical application if enough iPSCs cannot be produced to create an adequate amount of cells for differentiation and tissue regeneration.

    2. The use of cMyc in iPSC reprogramming has led to concerns that tumors may arise since cMyc is a proto-oncogene. cMyc can be eliminated from the reprogramming process, but the efficiency is reduced even further.

    3. ESCs and iPSCs, while sharing the ability to differentiate and form embryoid bodies, are not identical at a genetic level. In Takahashi and Yamanaka’s original paper, they noted a great deal of DNA methylation in iPSCs where there was none in ESCs. We do not know the effects of these genetic differences.

    4. At least one research group has found iPSCs did not perform as well in differentiation and tissue formation as ESCs. Mauritz et. al. differentiated mouse iPSCs and ESCs into cardiomyocytes and found iPSCs were less successfully differentiated and produced lower levels of troponin T. Other researchers comparing iPSCs to ESCs have found similar differentiation ability in both, but the Mauritz example shows this is not universal.

    I’m not trying to put down iPSCs. I think they’re neat, and if the problems above are worked out, great. Using iPSCs donated from the patient would eliminate the problem of immune rejection. I just don’t think we’re there yet.

    References:

    Mauritz et. al. “Generation of functional murine cardiac myocytes from induced pluripotent stem cells.”Circulation 2008
    Miura et. al. “Variation in the safety of induced pluripotent stem cell lines“ Nature Biotechnology 2009
    Takahashi K, Yamanaka S. “Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors.” Cell. 2006
    Warren et. Al. “Highly efficient reprogramming to pluripotency and directed differentiation of human cells with synthetic modified mRNA.”Cell Stem Cell 2010

  2. Enzoon 09 Oct 2012 at 2:16 pm

    I had the good fortune to attend a lecture by Dr. Yamanaka recounting the tales of his poor graduate student toiling over transcription factor combination after transcription factor combination until something hit. I have no idea how much Shinya was playing to the crowd, but that’s a hell of a path to something that won a Nobel Prize. I found Gurdon’s contribution much more scientifically elegant but LOVE the combination of these two scientists’ work! Congrats to the winners!

  3. Thadiuson 09 Oct 2012 at 3:18 pm

    Cool, but I have read that the “Skin Gun” was a pablicity stunt and not real medicine.

  4. HHCon 10 Oct 2012 at 12:31 am

    Can the skin gun work on third degree burns?

  5. KMorrison 10 Oct 2012 at 2:46 pm

    Researchers at Stanford are currently using iPS cells in hearing loss research. You can read more about the research and Dr. Heller’s vision for iPS cells in hearing loss cures and prevention here: bitly.com/SKmO3I

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