SWEDEN: Studies of a tiny worm have allowed three scientists to share the 2002 Nobel Prize for medicine. Their discoveries showed how individual genes could control growth and also programmed cell death, findings that have immediate use in understanding human diseases such as cancer.
Dr Sydney Brenner and Sir John Sulston of Britain and Dr Robert Horvitz of the United States share the $1 million prize, awarded yesterday by Sweden's Karolinska Institute. Their collective work was based on the humblest of creatures, however, a millimetre-long worm, Caenorhabditis elegans.
Detailed genetic analysis of the worm helped the three to make seminal discoveries of how genes could control the development and growth of organs. Other genes were discovered that played a central role in apoptosis, the tightly regulated process of programmed cell death.
Controlled cell death is a natural process in which billions of cells die every day to make way for a similar number of new ones. "Knowledge of programmed cell death has helped us to understand the mechanisms by which some viruses and bacteria invade our cells," the institute said. "We also know that in AIDS, neurodegenerative diseases, stroke and myocardial infarction [heart attack\] cells are lost as a result of excessive cell death."
Dr Brenner (75), born in South Africa and founder of the Molecular Sciences Institute in Berkeley, California, where he continues to work, started his research on C elegans in the 1960s. He realised that the transparent worm's simple structure made it ideal for research. He showed that different mutations in its body could be linked to specific genes and demonstrated how they could affect development.
Sir John (60) extended Dr Brenner's work. He described the detailed, visible steps as a cell triggered its internal programmed death system. He also showed how mutated genes altered the process. His work involved the detailing of the worm's entire genetic blueprint, making the C elegans genome the first to be described in full for a living organism.
Dr Horvitz (55) is at the Massachusetts Institute of Technology in Boston. He used the worm to study whether there was a genetic programme controlling cell death. He identified certain "death genes" which always came into play when the cell suicide programme was triggered. He showed that these genes were a prerequisite for cell mortality.
"I would find nothing more gratifying [than if] one or more of my discoveries led to cures for human diseases. That is the dream," Dr Horvitz said yesterday.
Sir John described what it was like when the early discoveries were being made. "It was just looking down a microscope and discovering how it all worked in ways that people had not been able to see before," he said.
Although their work was based on a tiny worm, the knowledge gained is immediately applicable to humans. Despite the obvious physical differences, the two species share many common genes, which behave in a similar way and produce similar proteins needed to support life.
"A number of these genes have similar functions in humans and when disrupted, when the genes are turned on or off inappropriately, can cause various sorts of problems," Sir John said. "The worm really has contributed a lot to biology."
Dr Brenner founded the institute where he continues his work, which combines genome studies with computer modelling.
Sir John also played a major role in the sequencing of the human genome. From 1992 to 2000 he headed the Sanger Centre in Cambridge, the British unit of a global team mapping the human genome.
(Additional reporting Reuters)