Each month CIRM President Alan Trounson gives his perspective on recently published papers he thinks will be valuable in moving the field of stem cell research forward. This month’s report, along with an archive of past reports, is available on the CIRM website.

My report this month opens with a journal article that earns that rarely deserved descriptor of “a breakthrough.” After more than a decade of teams around the world coming up short when trying to create embryonic stem cells from cloned human embryos, a Team from Oregon reported success. My colleague wrote about the science behind this breakthrough here.

So, I want to devote this blog to a policy issue drawn to the fore by these new stem cell lines. This research was loudly opposed by many of the same groups that oppose embryonic stem cell (ES cells) research. They often discuss “proof” this work is not needed by pointing to our ability to reprogram adult cells such as skin into cells that appear to be much like embryonic stem cells, so called iPS cells.

What these groups don’t seem to understand is just how much we don’t know about iPS cells and their similarities to, and difference from ES cells (we’ve written about this work here). Up until now our best tool for defining the true nature of iPS cells was embryonic stem cells. But it has been difficult to pin down whether certain differences between two cell lines was attributable to iPS cells versus embryonic stem cells or just variations in the genetics of the donor tissue for each.

Now we have new opportunities to compare embryonic stem cells and iPS cells. This gives us the opportunity to compare the genetic stability of the two types of stem cells. It will allow us to see if one is better than the other at being coaxed into becoming various adult tissues needed for repairing damage. Also, new reprogramming factors discovered in the eggs used for cloned cells could help improve the efficiency of creating iPS cells.

Those who hope iPS cells will eliminate the need for the use of embryonic stem cells should be applauding this opportunity to do the work that could help determine the true value of iPS cells.

After the paper came out some concerns were raised about errors involving duplication of figures (Science wrote a summary of those concerns). This was unacceptable for science and needs explanation by the team. The resulting cell lines should be independently analyzed by geneticists who should be able to detect DNA from the donor egg as well as from the adult cell that was cloned. Importantly, we need independent confirmation from other labs of the findings. However, I do think the results will stand and will open the door to some critical comparative analysis.

A.T.