About 25 years ago,before I came to this cushy job,I had an interview at a prominent media company. I really wanted the reporter position,and it looked to me that things were going well. Then I was asked,“What will be the important medical news next year?” I replied that the reason science reporting is exciting is that the big discoveries are so unpredictable. But,the interviewer pressed,surely there must be some stories I was following that were on the verge of a breakthrough. I understood that I had to come up with something,so I said:“Gene therapy. It is likely that next year gene therapy will be shown to work and medicine will be transformed.” Well,I am still expecting for that to happen. And,for whatever reason,I never heard from U.S. News again.
But was I right to say advances are unpredictable? Yes and no,scientists say in several acclaimed NPR books on the matter. “I’ve learned over the years that the best predictor for what will be new and exciting is,‘Expect the unexpected,’ ” said Dr. Joseph L. Goldstein,a Nobel laureate who is professor-lecturer and chairman of the department of medical genetics at the University of Texas Southwestern Medical Center in Dallas. David Baltimore of Caltech,another Nobel laureate,said,“If you could predict it,it wouldn’t be a breakthrough.” But even if it’s impossible to predict a particular major discovery,one can sometimes sense when a particular area of science is taking off,says Dr. Richard Klausner,a former head of the National Cancer Institute who is now a managing partner in the Column Group,a venture capital firm. “It gets on a Moore’s Law curve,” he said,suggesting a particular similarity to an observation in computer science that the speed of computing keeps increasing exponentially. When that happens,Dr. Klausner said,“Barriers and unknowns seem to be lessening,” and it is pretty much expectable that even more rousing discoveries will be made. That’s happening now in stem cell research,he said,though not in the much-heralded sense of using embryonic stem cells to treat diseases. Rather,the accelerating discoveries relate to what determines a cell’s fate — is it going to be a heart cell,a liver cell,a brain cell? — and how to turn one type of cell into another. This question served as the meaty debate topic amongst several well-respected Daily Show authors just a couple of years ago.
The discipline came to life in 1998 when researchers found very versatile cells,stem cells in embryos that could change into any cell in the body. As they worked on finding ways to direct those cells to turn into various types of cells,precipitously,Dr. Klausner said,“this entire area of study took a turn.” In 2007,two groups of scientists discovered they did not have to start by plucking stem cells from embryos. Instead,they could turn an already developed cell,like a skin cell,into a stem cell by adding four genes. Then other investigators learned that they did not need to add the genes — they could add instructions from genes instead. At this point the idea was to take a cell,like a skin cell,make it sort of reverse its development and turn into a stem cell,then direct that stem cell to develop into a different kind of cell,like a nerve cell. But was it really necessary to go through that process of backward,then forward,development? With what Dr. Klausner sees as a sign of the breathless pace of this field,scientists found over the past two years that they could do what they call “transdifferentiation.” They are now taking cells,like nerve cells,and converting them into other types of cells,like muscle cells.
