Two of the winners of the 2001 Nobel prize in physiology or medicine, announced on Monday, will have come as no surprise to students of this coveted award. Sir Paul Nurse, director of the Imperial Cancer Research Fund in London, and Dr Leland Hartwell, director of the Fred Hutchinson Cancer Research Center in Seattle, have both been hotly tipped for the past few years.
The third of the trio, Dr Tim Hunt, also of the Imperial Cancer Research Fund, is a less predictable but no less appropriate choice. All three will share the £650000 ($975000) prize, and all three have made big contributions to our understanding of the control of the life cycle of cells.
Having completed its initial growth phase, a cell will first copy its chromosomes by duplicating its complement of DNA. It then prepares itself for division. Each of its two daughter cells will go on to repeat this same process.
Good coordination and control is essential if cells are to divide as and when required. Errors lead to the formation of chromosomal aberrations of the type seen in some cancer cells.
Leland Hartwell, born in 1939 and the elder statesman of cell cycle research, began by working on yeast—which rapidly became the model organism for these studies. In the 1970s he identified a series of genes responsible for controlling the cycle.
Paul Nurse, working for the Imperial Cancer Research Fund in Oxford and London, not only found similar genes in another species of yeast, but went on to show that one of them was identical with a gene in human cells. This was compelling evidence of a common control system among all living organisms.
In the early 1980s Tim Hunt discovered the first of a family of molecules called cyclins. It is through changes in the production of cyclins during the cell cycle that the activity of the genes controlling it are themselves regulated.
Moves are already under way to apply this understanding to cancer diagnosis. The discoveries also have potential as a source of new treatments for reasserting control over cancer cells.
Figure.
JOHNY GREEN/PA
Britons Sir Paul Nurse, left, and Dr Tim Hunt, right, will share the £650000 prize with American Dr Leland Hartwell