Embryonic stem cell strategy advanced with UC...( UCSF scientists are reporting what t...)

UCSF scientists are reporting what they say is a significant improvement in the technique for genetically reprogramming mouse cells to their embryonic state, a process that transforms the cells, in essence, into embryonic stem cells.

The finding, published on-line as an immediate early publication in Cell Stem Cell (Sept. 6, 2007), builds on the strategic breakthrough reported by Shinya Yamanaka, MD, PhD, in 2006, and confirmed in the spring of 2007 both by Yamanakas team and, in independent studies, by scientists at MIT, Harvard and UCLA.

The advance by the UCSF team should accelerate research aimed at improving the original strategy, the team says, and increase its potential use for studying disease development and creating patient-specific stem-cell based therapies.

The work is the result of a collaboration between the labs of Miguel Ramalho-Santos, PhD, and Robert Blelloch, MD, PhD, of the UCSF Institute for Regeneration Medicine.

The new technique removes a major technical hurdle that has likely discouraged many labs around the world from carrying out studies on the strategy, says senior author Ramalho-Santos, a UCSF Fellow and a member of the Diabetes Center. For separate reasons, he says, removal of the hurdle increases the techniques potential use in developing patient-specific cellular therapies.

Now, laboratories will be able to use the approach to study a broad range of normal and diseased cells of interest, says the first author of the study, Blelloch, an assistant professor of urology. There will be a much greater ability to precisely dissect the mechanisms of reprogramming and to identify the genes that will be most effective in transforming adult cells.

Yamanakas strategy -- over-expressing certain genes in mouse skin cells to initiate reprogramming relied on the insertion of a foreign drug resistance gene into the mouse skin cells. This gene would switch on in those cells that successfully
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