After opening sessions at the World Stem Cell Summit in which speakers talked about rapid progress toward moving stem cell therapies to the clinic, Michael West, CEO of BioTime offered a reminder that there are a lot of fundamental questions about stem cells that remain unanswered.

He described the difficulty researchers often have even fully defining the identity of the cells they are working with, noting that in previous sessions here we heard people describe three different mesenchymal stem cells. Those are the second type of stem cell usually found in bone marrow, but sometimes found in fat. He also noted that getting stem cells to mature into the desired adult cell type is too often trial and error and too often yields a mixed bag of cells, which will not pass muster with regulatory bodies.

His solution: creating an international consortium to map what he calls the embryome, much like the Human Genome Mapping project. The resulting embryome would be a roster of the genes that are turned on at every stage of the growing embryo, where in the embryo they are turned on and for how long. Creating the more than 200 cell types that make up our bodies requires a very complex and creative dance of turning genes on and off in precise sequences, and in specific developing tissues. He gave the example of the developing mandible that becomes the jawbone, but also has to have certain genes turned on at certain times to produce our various teeth. A smile is not a simple thing to create.

West described a project underway at one of BioTime’s subsidiaries, Life Map Science, that is in the very early stages of mapping this genetic history of the embryo. Important for cell therapies, they are also cataloguing known protocols for maturing stem cells into certain tissues. But he noted that they have completed only a very small percent of the map. He characterized the percent as “single digits.”

Two distinguished researchers followed West discussing the proposal, Mahendra Rao of the National Institutes of Health and Chris Mason of University College London. They agreed such a map could provide a powerful tool to accelerate developing therapy. But they cautioned that with all projects involving massive amounts of data, we should start small and learn how to organize the information so that it is clear and easy to use.

It looked like a exciting tool for researchers and something I suspect we will hear more about in coming years.

Don Gibbons