It was only six months ago that the stem cell field was aflutter over the report by the Rossi group that they could reprogram iPS cells with an astonishingly high efficiency using just RNAs. This completely non-genetic, high efficiency approach seemed like a revolution for the iPS cell field. It also seemed like what we had all been looking for- a non-genetic method that nonetheless retained good efficiency. The study was published in Cell Stem Cell– you can read it here.
Many of us hoped this was real, but worried that it was too good to be true.
It is difficult to overstate how excited people were about the idea of making iPS cells just using RNAs based on Rossi’s paper. Entire institutes said they were going to switch to the method.
But could the RNA iPS cell method be simply a flash in the pan, as the expression goes, meaning something that has a flashy beginning but fails to deliver? I hinted at this question in my top 10 list of questions for the stem cell field in October of 2010: Is the RNA only method really that good?
I’m hearing from many independent labs now that the method isn’t working for them. There are even some rumblings in the grapevine that the method stopped working for the Rossi lab itself at some point.
What does this mean?
First, despite this apparent setback, I believe this is not the end for RNA iPS.
It is very possible that RNA-only methods to produce iPS cells will in the end be developed and optimized so that they consistently work. I suspect and hope that Rossi’s method may just need some tweaking to be more reproducible. It remains incredibly exciting.
In addition, Rossi’s lab was not and is not the only one interested in this area. In fact the Givol lab published a paper making iPS like cells using only RNAs well before Rossi did, but it did not get the same attention. There has also been a kerfuffle because Rossi didn’t cite Givol’s paper (see comment here from Givol).
Second, the iPS cell field and stem cell field more generally is moving so fast and people are so excited that perhaps sometimes papers get published too fast. There is enormous pressure for scientists not to get scooped and also for journals to be the first ones to publish something that may be very high impact.
Sometimes the process gets ahead of itself.