Friday, November 30, 2007
stamcellen
Summary and Comment
Landmark Human Stem Cell Breakthrough
A feat once deemed impossible has been accomplished — the deprogramming of a fully differentiated human cell into an embryonic stem cell.
Two laboratories report a breakthrough that may one day allow full exploration of the potential benefits of human embryonic stem cell (ESC) therapy and that will eliminate the ethical objections.
In June 2007, Japanese and American teams reported that they had tricked fully differentiated mouse cells into becoming undifferentiated pluripotent cells with all the characteristics of mouse ESCs (Journal Watch Jun 21 2007). Now, just 5 months later, the Japanese team and another American team report the same feat with human cells. Both teams introduced four genes into differentiated cells using retroviral vectors. A small number of cells emerged that had all the biochemical markers of ESCs and that could differentiate into all three germ layers in vitro.
Comment: It now is possible to make embryonic stem cells containing the genome of a patient who might need them, without creating (and then destroying) a human embryo — the primary ethical concern about ESC therapy. There is a risk of turning cells cancerous when retroviral vectors are used and when (as was true with the Japanese group) an oncogene is part of the "cocktail" for creating ESCs. Therefore, more work is needed to optimize this technique before it can be used for regenerative therapy. Nevertheless, a feat once deemed impossible has been accomplished — the deprogramming of a fully differentiated human cell into an ESC. Almost surely, this work will be regarded as a turning point in the history of human stem cell therapy.
— Anthony L. Komaroff, MD
Published in Journal Watch General Medicine November 29, 2007
Citation(s):
Takahashi K et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell 2007 Nov 20; [e-pub ahead of print]. (http://images.cell.com/images/edimages/cell/ieps/3661.pdf)
Yu J et al. Induced pluripotent stem cell lines derived from human somatic cells. Science 2007 Nov 20; [e-pub ahead of print]. (http://dx.doi.org/10.1126/science.1151526)
Landmark Human Stem Cell Breakthrough
A feat once deemed impossible has been accomplished — the deprogramming of a fully differentiated human cell into an embryonic stem cell.
Two laboratories report a breakthrough that may one day allow full exploration of the potential benefits of human embryonic stem cell (ESC) therapy and that will eliminate the ethical objections.
In June 2007, Japanese and American teams reported that they had tricked fully differentiated mouse cells into becoming undifferentiated pluripotent cells with all the characteristics of mouse ESCs (Journal Watch Jun 21 2007). Now, just 5 months later, the Japanese team and another American team report the same feat with human cells. Both teams introduced four genes into differentiated cells using retroviral vectors. A small number of cells emerged that had all the biochemical markers of ESCs and that could differentiate into all three germ layers in vitro.
Comment: It now is possible to make embryonic stem cells containing the genome of a patient who might need them, without creating (and then destroying) a human embryo — the primary ethical concern about ESC therapy. There is a risk of turning cells cancerous when retroviral vectors are used and when (as was true with the Japanese group) an oncogene is part of the "cocktail" for creating ESCs. Therefore, more work is needed to optimize this technique before it can be used for regenerative therapy. Nevertheless, a feat once deemed impossible has been accomplished — the deprogramming of a fully differentiated human cell into an ESC. Almost surely, this work will be regarded as a turning point in the history of human stem cell therapy.
— Anthony L. Komaroff, MD
Published in Journal Watch General Medicine November 29, 2007
Citation(s):
Takahashi K et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell 2007 Nov 20; [e-pub ahead of print]. (http://images.cell.com/images/edimages/cell/ieps/3661.pdf)
Yu J et al. Induced pluripotent stem cell lines derived from human somatic cells. Science 2007 Nov 20; [e-pub ahead of print]. (http://dx.doi.org/10.1126/science.1151526)
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