Friday, March 27, 2009

Another path to virus-free iPS: Thomson does it again

The man who discovered human embryonic stem cells in 1998, and who co-discovered with Yamanaka in 2007 the embryonic-type iPS cells derived from adult cells, has now pushed the science of iPS direct reprogramming a step further. James Thomson was the man who said – re his dual discovery of hESC and their uncontentious successor, human iPS cells – "Isn't it great to start a field and then to end it?"

He has taken a step further towards the end of ESC research - and certainly of its degenerate descendant, cloning –with his elegant demonstration that no virus integration is required to produce successful reprogramming of an adult cell to an embryonic-type cell. His technique differs from that of an earlier post but the outcome is the same: no viral contamination of the resultant pluripotent stem cell.

After the breakthroughs in virus-free iPS this month, there is no longer any excuse for politicians or scientific lobbyists to denigrate iPS technology because of the 'virus / cancer' risk. That will not, however, stop them repeating this outdated propaganda – be sure, even next year in the Senate debate on the review of our cloning legislation in the light of the new iPS alternative, that the "Oh Dear What About The Viruses" card will be played…

Here is the Science journal article link (online publication 26th March 2009)

Here is the science news report:

Scientists excise vector, exotic genes from induced stem cells

A team of University of Wisconsin-Madison researchers reports that it has created induced human pluripotent stem (iPS) cells completely free of viral vectors and exotic genes.

By reprogramming skin cells to an embryonic state using a plasmid rather than a virus to ferry reprogramming genes into adult cells, the Wisconsin group's work removes a key safety concern about the potential use of iPS cells in therapeutic settings.

The new method, which is reported in today's (March 26) online issue of the journal Science, also removes the exotic reprogramming genes from the iPS equation, as the plasmid and the genes it carries do not integrate into an induced cell's genome and can be screened out of subsequent generations of cells. Thus, cells made using the new method are completely free of any genetic artifacts that could compromise therapeutic safety or skew research results, according to the Science report.