Australian wins Nobel for work on ageing

STOCKHOLM: Australian researcher Elizabeth Blackburn and U.S. colleagues Carol Greider and Jack Szostak have won the Nobel Prize for Physiology or Medicine for identifying a key molecular switch in cellular ageing.

The trio were honoured for the discovery of how chromosomes are protected by telomeres and the role of an enzyme called telomerase in maintaining or stripping away this vital shield.

"The award of the Nobel Prize recognises the discovery of a fundamental mechanism in the cell, a discovery that has stimulated the development of new therapeutic strategies," the Nobel jury said.

The three scientists told Swedish Radio they were overjoyed by the news. Greider said she was "just thrilled, I just think that the recognition for curiosity-driven basic science is very, very nice," adding that she was up doing laundry in the U.S. when the early morning call came from Sweden.

First Australian woman

Blackburn, 60, a Hobart-born graduate of Melbourne University, becomes the first Australian woman to win a Nobel Prize. She said she knew when they made their discovery that they were on to something big. "I felt very excited ... and I thought this is very interesting, this is a very important result, and you don't often feel that about a result," she said.

Blackburn, who has worked in the U.S. for many years, was one of the favourites for the Nobel for physiology or medicine.

Szostak said meanwhile he expected "to have a big party at some point" to celebrate the prestigious award.
Telomeres are a minute yet vital factor in ageing. They are like a nubby, protective cap, fitting on the ends of the strands of DNA - the chemical recipe for life - that are packed into chromosomes.

Blackburn and Szostak discovered in 1982 that a unique DNA sequence in the telomeres protects the chromosomes from degradation when the cells divide. With Greider, Blackburn also identified telomerase, the enzyme that makes the telomere DNA.

If telomeres become worn, cells age. But if telomerase levels are high, the telomere length is maintained, and cellular ageing is braked.

A small number of rare but very destructive diseases, including a form of severe anaemia, are linked to defective telomerase, resulting in damaged cells.

Insights into cancer

Yet there is also a darker and more complex side to this picture. Many experts initially speculated that ageing could be pinned to telomere shortening, but the process has emerged as something that encompasses different factors, as well as telomeres.

In addition, high telomerase also helps cancer, enabling its cells to replicate endlessly and achieve what scientists call 'cellular immortality'. Finding ways of blocking this machinery through 'telomerase inhibitors' is one of the most eagerly explored areas of cancer research.

The trio's work has "added a new dimension to our understanding of the cell, shed light on disease mechanisms, and stimulated the development of potential new therapies," the Nobel citation said.