The Niche

Horst-Dietrich Elvers, Burkhard Jandrig, and Christof Tannert write:
The Nature News story “Simple switch turns cells embryonic” (Nature 447, 618-619; 2007) presents the results of three independent research teams showing that normal skin cells can be reprogrammed to an embryonic state in mice. If this can be successfully adapted to human cells, the creation of human germ cells out of these pluripotent cells should be possible (as was indicated already by Huebner et al. Science 300, 1251-1256, 2003). Now, the road seems to be prepared to create human tissues for therapeutic purposes without using or destructing human embryos. This is, doubtless, an important progress for the whole field of regenerative medicine and avoids many morally questionable decisions, which so far have led to an international mix of regulatory frameworks. Therefore it is not surprising that excitement is overall huge at the moment.
The published results seem to indicate that the ethical problems of human embryo research are solved now.

Continue reading "Reprogramming breakthrough does not displace ethical debate" »

Posted by Monya Baker on July 09, 2007
Categories: Correspondence, Reprogramming/Pluripotency | Permalink | Comments (2) | TrackBacks (0)

In June, widely publicized work from three labs showed that specialized cells could be reprogrammed after transfection with four genes. In this correspondence, James Trosko suggests an alternative explanation, that the reprogrammed cells identified by groups led by Shinya Yamanaka, Rudolf Jaenisch, and Konrad Hochedlinger and Kathrin Plath could in fact be skin stem cells reprogrammed to an embryonic state.

Another thread discusses how reprogramming work alters perceptions of whether dedifferentiation is active or passive, and adds insight from in silico modeling. http://blogs.nature.com/reports/theniche/2007/07/reprogramming_insights_in_sili.html

Below is the email correspondence between the scientists:

Continue reading "Do induced pluripotent stem cells arise from skin stem cells?" »

Posted by Monya Baker on July 09, 2007
Categories: Correspondence, Reprogramming/Pluripotency | Permalink | Comments (0) | TrackBacks (0)

Eric Werner writes:
The recent results of dedifferentiating adult mouse fibroblast cells into stem cells brings into focus the fundamental question of how differentiation and development are controlled. (Cyranoski, D., Nature 447, 618-9; 2007). (Okita, K., et al. Nature doi 10.1038/nature05934, 2007). The fact that just four regulatory genes inserted into cells using viral vectors, can transform normal, differentiated cells into pluripotent stem cells indicates that for some cell types, at least, the process of dedifferentiation is more a process of activation rather than deactivation (Reik, W., Nature 447, 425-32; 2007). Indeed, this falls in line with in silico studies where stem cells, and, more generally, multicellular differentiation and development are modeled on computers.

Continue reading "Reprogramming insights: in silico modeling suggests active dedifferentiation" »

Posted by Monya Baker on July 09, 2007
Categories: Correspondence, Reprogramming/Pluripotency | Permalink | Comments (0) | TrackBacks (0)