London, Sep 2 (UNI) Researchers have started to unmask an enzyme that could open the door to "one-fits-all" cancer drugs that can tackle many different forms of the disease.
Experts have been trying for more than a decade to devise anti-cancer therapies that target the enzyme, telomerase. But they have been thwarted by lack of knowledge about the molecule's construction.
The new findings, published in the online edition of the journal Nature, reveal atomic-level details of telomerase showing how it works to replicate the ends of chromosomes - a process critical both to tumour development and ageing.
The results are expected to boost development of telomerase inhibitors.
Dr Emmanuel Skordalakes, from The Wistar Institute in Philadelphia, US, said: "Telomerase is an ideal target for chemotherapy because it is active in almost all human tumours, but inactive in most normal cells. That means a drug that deactivates telomerase would likely work against all cancers, with few side effects." Telomerase helps prevent the chromosomes - bundles of DNA which contain the genes - suffering damage and the loss of genetic information during cell division.
The enzyme adds protective "caps" known as "telomeres" to the ends of chromosomes which act like the plastic tips on shoe laces that prevent fraying.
When telomerase is dormant, the telomeres shorten each time a cell divides, eventually leading to genetic instability and cell death.
This is a key element of the ageing process.
The enzyme is active in cells that multiple frequently, such as immature cells in embryos, but switched off almost completely in normal adult cells.
However cancer cells often regain the ability to activate telomerase, allowing them to replicate indefinitely, and the enzyme has been implicated in 90 per cent of human tumours.
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