Two regenerative medicine pioneers share this year’s Nobel Prize in Physiology or Medicine for their discovery of the science behind the reprogramming of adult cells into induced pluripotent stem cells.
The Nobel committee at Karolinska Institute awarded the prize to Sir John B. Gurdon, Ph.D., 79, of the University of Cambridge and Shinya Yamanaka, Ph.D., 50, of Kyoto University. Dr. Gurdon discovered in 1962 that living tadpoles could be created from fully-grown frog cells by extracting the cell nucleus from an adult intestinal cell, then injecting it into a frog egg from which the original nucleus was removed. The egg reprogrammed the introduced nucleus by directing its genes to switch the intestinal cell’s functions to those of a developing egg.
“It was almost 50 years before the value—the potential value—of that basic scientific research came to light,” Dr. Gurdon said Monday, speaking to reporters from London.
Forty-four years later, Dr. Yamanaka discovered while working with mice that the reprogramming can be accomplished in the egg by just four transcription factors, proteins made by master genes to regulate other genes.
He successfully revered the cell back to its primitive, or stem-cell, form by injecting the transcription factors into an adult cell. The discovery demonstrated that mature cells can be successfully reprogrammed to an early state of development with the potential for developing into specialized cells much like human embryonic stem cells, but without the moral issues and attendant ethical debate associated with harvesting them.
“Without [Dr. Gurdon’s] work, which he published 50 years ago, the same year I was born, without his work I would never done this and we would have never studied this project,” Dr. Yamanaka told reporters from Japan.
The research by both winners “revolutionized our understanding of how cells and organisms develop,” the committee said—and is expected someday to lead to treatment for various diseases involving the growth and transplant of customized tissue generated from patients’ own cells.
In an interview with Reuters this morning, Dr. Yamanaka warned against the growing popularity of unproven stem cell therapies often performed overseas in industry-friendly havens, through clinics affiliated with U.S. doctors relying on the Internet to draw patients. “This type of practice is an enormous problem. It is a threat. Many so-called stem cell therapies are being conducted without any data using animals, preclinical safety checks,” Dr. Yamanaka said, echoing a warning sounded by researchers in recent years, including in a recent GEN article.
Articles by these two distinguished scientists are available free online on the Stem Cells and Development website, a Mary Ann Liebert, Inc. publication. Sir John Gurdon is the corresponding author of an original research report on "Widespread Transcription in an Amphibian Oocyte Relates to Its Reprogramming Activity on Transplanted Somatic Nuclei." Dr. Yamanaka was a coauthor of the article "Generation of Naive-Like Porcine-Induced Pluripotent Stem Cells Capable of Contributing to Embryonic and Fetal Development."