The history of technology tells us that the first strategy is rarely the one that sticks. One of my favorite examples involves the English clock maker John Harris, whose many iterations of marine chronometers revolutionized sea travel. (His story is recounted in Dava Sobel’s excellent book Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time.) My English grandfather also worked on clocks and marine guidance systems so I have a soft spot for the guild.
In 1730, Harris sought to produce a clock, called the H1, which could maintain accurate time on a lengthy, rough sea voyage with widely varying conditions of temperature, pressure and humidity – a great challenge in his day. This initial prototype performed well but there was a desire for a more rugged and compact design. After several iterations and another 23 years, he produced the H4, which kept time within 39 seconds during a trans Atlantic sea trial. A subsequent design, H5, was accurate within one-third of a second – revolutionary for its time.
Fast forward to 2011, in the world of human embryonic stem cell research, the cell line H9 has been revolutionary for its time – used in thousand of published studies. In a recent article, Rohun Patel and I illustrate how it is also the most widely utilized human embryonic stem cell (hESC) line by CIRM researchers. However, we also found that CIRM grantees were carrying out research with 137 other lines including 17 that had been recently derived with CIRM funding.
A recent study in Human Molecular Genetics authored by Amander Clark at University of California, Los Angeles suggests the newly derived CIRM lines may have several improvements over the earlier models. The study compared the X chromosomes of older lines, including H9, to recently derived lines. The UCLA team found that the X chromosomes in the newer lines were more active than those in the older lines, which tended to have more of the X chromosome shut down. Furthermore, the way in which those older lines shut down portions of the X chromosome deviated from how cells normally de-activate portions of the X chromosome – called “X inactivation”. In a press release from UCLA Clark said:
“The classic signature is gone, so something else is regulating X chromosome inactivation in the established cell lines,” Clark said. “It will be important not only to find out what that is, but also to discover what else is changing in the nucleus that we cannot see.”Clark’s paper shows that in stem cell research—as in other areas of innovation—it takes time and tinkering to develop the best model. The ability of CIRM-funded researchers to develop and then investigate 17 new human embryonic stem cell lines and access hundreds of others would not be possible under federal guidelines alone. Federal agencies like the NIH can’t fund research to create new stem cell lines. Clark’s paper shows the clear need for these efforts to continue under CIRM and other agencies that fund cell line derivation. In the press release she said:
“Our data highlights the importance of maintaining hESC derivation efforts. Gold standard hESC lines should be the benchmark for human pluripotent stem cell research.”Unlike Harris, stem cell researchers don’t have 23 years to tinker with their design. Patients need therapies soon, and therapy development will be bolstered by having optimal tools available to all researchers. Clark’s work shows the value to patients in those 17 lines derived by CIRM grantees, and by all those other new lines that have been and will continue to be created through sources other than federal funding.
Human Molecular Genetics, November 30, 2011
CIRM Funding: Amander Clark (RL1-00636-1)
G.L.
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