It’s not every day you learn to kill an almost infinite number of birds with a single stone, invent time-travel, and put a decade of political controversy to rest. But that’s just what Sir John Gurdon and Dr. Shinya Yamanaka accomplished with their Nobel Prize-winning discovery that mature human cells can be reprogrammed into stem cells with the potential to develop into any other type of cell in the body.
Back in the early 1960s, Gurdon did what no one thought possible: he put a cell from a mature adult frog into an egg from another frog, and then coaxed the egg to develop into a new adult that was an exact clone of the one that provided the original, mature cell. In essence, he started the frog’s life cycle over again, proving that a specialized adult cell could “de-evolve” into a blank stem cell.
Forty-four years later, Yamanaka brought Gurdon’s findings to fruition by determining which genes are activated in stem cells, but not in mature cells. He took these specific, activated genes and inserted them into mature cells, turning back the clock and inducing the mature cells to become “pluripotent” stem cells. Yamanaka was thus able to give mice a dose of their very own stem cells, potentially curing the mouse equivalents of sickle cell anemia and Parkinson’s disease. Soon after, Yamanaka was able to achieve the same feat using human cells.
"I was able to study my projects because of [Gurdon’s] experiments 50 years ago," said Yamanaka in an interview for nobelprize.org. "Actually, he published his work in 1962, and that was the year I was born, so I really feel greatly honored."
Their groundbreaking research may also bring resolution to the thorny political issue of embryonic stem cells, which critics say are unethical to use because they can only be derived from human embryos.
Speaking with Reuters in 2007 about the therapeutic potential of his discoveries, Yamanaka said, “What’s significant about this technology is not only can we avoid the ethical controversy of using embryos, but also a transplant patient can avoid organ rejection because the treatment will be done using the patient’s own cells and not somebody else’s.”
Scientists in Japan plan to use Yamanaka’s “induced pluripotent cells” (iPCs) in an upcoming human trial to repair eyesight in patients with macular degeneration. It may, however, be years before iPCs travel from the lab to your local clinic. In the future, scientists may be able to clone a person’s organs and tissues—or even the entire person—using only a few skin cells. Gurdon and Yamanaka will use the $1.2 million Nobel award to continue their research into the medical applications of iPCs.
Meanwhile, this year’s Nobel Prize winners in chemistry—American scientists Robert Lefkowitz and Brian Kobilka—are changing the way we view communication among cells, hormones, and neurotransmitters. Lefkowitz and Kobilka discovered and mapped the cell receptor proteins that allow cells to respond to chemical messages and outside stimuli. For example, the receptors relay the message that your heart rate should increase and your vision become more focused in response to a rush of adrenaline.
These receptors are "the targets for about half of all pharmaceutical drugs made today," said a representative of the Royal Swedish Academy of Sciences who helped present the Nobel Prize. "These are used in treatment of conditions like high blood pressure, neuropsychiatric disorders, Parkinson’s disease, migraines, gastric disorders, you name it."
By better understanding how these receptor proteins are shaped, manufacturers can create more targeted drugs that only attach to their intended cell targets. When drug molecules attach to receptors they shouldn’t, it can cause serious side effects.
In an interview with the New York Times, Kobilka said, “We hope by knowing the three-dimensional structure [of these receptors] we might be able to develop more selective drugs and more effective drugs.”