Two Americans and a Briton won the 2019 Nobel Medicine Prize on Monday for discovering a molecular switch that regulates how cells adapt to fluctuating oxygen levels, opening up new approaches to treating heart failure, anemia and cancer. William Kaelin at the US Dana-Farber Cancer Institute and Harvard Medical School was "almost speechless" when told that he and two other doctors, Gregg Semenza of Johns Hopkins University and Briton Peter Ratcliffe of Oxford University, would share the 9-million Swedish-crown ($913,000) prize, the Nobel award-giving body said. "They were extremely happy, and happy to share the prize with each other," Thomas Perlmann, a member of the Nobel Assembly, told reporters as the prize was announced. The scientists' work established the basis for understanding of how oxygen levels are sensed by cells — a discovery that is being explored by medical researchers seeking to develop treatments for various diseases that work by either activating or blocking the body's oxygen-sensing machinery. Their work centers on the hypoxic response — the way the body reacts to oxygen flux — and "revealed the elegant mechanisms by which our cells sense oxygen levels and respond" said Andrew Murray, an expert at Britain's University of Cambridge who congratulated the three. Randall Johnson, a professor at Sweden's Karolinska Institute where the annual prize is awarded, noted that since "oxygen is essential for life and is used by virtually all animal cells," the work is central to how the body functions. "It's a prize that really tells us the fundamental truth about how cells work," he said. "For example when you're exercising, you ́re using up oxygen at a much more rapid pace ... and this is a switch that helps the cell figure out how much oxygen it's getting and how it should behave." "If you have a stroke there's suddenly no oxygen going to the brain... Those cells, if they are going to survive, need to find a way to adapt to that level of oxygen," he said. Medicine is the first of the Nobel Prizes given each year. The prizes for achievements in science, peace and literature have been awarded since 1901 and were created in the will of dynamite inventor and businessman Alfred Nobel. Nobel medicine laureates have included scientific greats such as Alexander Fleming, the discoverer of penicillin, and Karl Landsteiner, who identified separate blood types and so enabled safe transfusions to be widely introduced. Perlmann said he had reached Kaelin by phone early on Monday, after first having dialed the wrong number. "He was really happy, almost speechless," Perlmann said. Ratcliffe was at his office and Semenza was asleep, he said. Last year American James Allison and Japanese Tasuku Honjo won the prize for discoveries about how to harness the immune system in cancer therapies. — Reuters
