> How would you like to live 1,000,000 years?
> Quantum processes are ageless.
> ---------------------------------------------------------------------------­-
>
> http://www.newscientist.com/article/dn14636-key-cancer-enzyme-gives-u...
> Key cancer enzyme gives up its secret
> 14:59 01 September 2008
> NewScientist.com news service
> Gursharan Randhawa
>   HEALTH NEWS
>  Cancer milestone
>
> An enzyme linked to most human cancers has finally yielded its secrets – it may
> also help defeat ageing
>  At the heart of almost all human cancers is a rogue enzyme, telomerase. Now the
> structure of a key catalytic component of the enzyme has been discovered, paving
> the way to more effective anti-cancer and, perhaps, anti-ageing drugs.
>
> Telomerase is responsible for adding unique repetitive sequences of DNA, called
> telomeres, at one end of chromosomes. These telomere caps ensure the chromosomes
> don't fall apart, but because telomerase is dormant in most adult cells each
> time a cell divides, its telomere loses a chunk of DNA. Eventually, when cells
> can no longer divide, they die – this protects against cancer.
>
> When telomerase is more active than it should be, telomeres don't get shorter.
> Instead, cells continue dividing beyond their normal limits, and become
> cancerous.
>
> This has made telomerase a prime target for anti-cancer and anti-ageing
> therapies, but a lack of information on the structure of its catalytic subunit,
> TERT, has hindered progress.
>
> Beetle bonanza
> Emmanuel Skordalakes and his team from The Wistar Institute, Philadelphia,
> finally cracked the structure when they discovered that a gene in an insect –
> the flour beetle – could be harnessed to produce the enzyme in massive
> quantities.
>
> This enabled the team to analyse TERT using X-ray crystallography.
>
> "Structural studies of telomerase have been extremely difficult due to the size
> and complexity of the enzyme, which in turn made it difficult to isolate the
> protein component of telomerase in sufficient, stable quantities for the
> proposed studies," says Skordalakes.
>
> The structural analysis reveals that TERT (telomerase reverse transcriptase
> protein) consists of three domains, and forms a ring-like doughnut structure
> that creates a central hole. When the telomere is being built, this hole allows
> a nucleic acid template molecule about eight nucleotide bases long to fit
> inside.
>
> Anti-ageing drug?
> Previously scientists had thought that the structure of the enzyme is similar to
> HIV transcriptase and developed anti-telomerase drugs accordingly. The
> structural analysis confirms there is a similarity, but it also reveals that one
> of the domains in the TERT protein – called the carboxy-terminal extension or
> CTE – has a unique type of protein fold, never been seen before.
>
> This feature could help develop anti-telomerase drugs that specifically target
> the fold.
>
> "Now that they know what the structure of the catalytic subunit is, they can
> design drugs that can bind to the protein subunit and either inhibit its
> activity for anti-cancer treatment, or promote its activity as anti-ageing
> therapy," says Stephen Neidle, from The School of Pharmacy, University of
> London, UK.
>
> Neidle says developing drugs to target the enzyme could be used in combination
> with existing anti-telomerase anti-cancer therapies currently in clinical
> trials, such as a class of telomerase vaccines.
>
> Aubrey de Grey of the Methuselah Foundation says: "If we had a really cast-iron
> therapy against all cancers, it might well be a good idea to stimulate
> telomerase, with a drug, for example, that might have widespread anti-ageing
> effects."
>
> Journal reference: Nature (DOI:10/1038/nature07283)
>
> --
> Frederick Martin McNeill
> Poway, California, United States of America
> mmcne...@fuzzysys.com
> ******************************************
> "I never cease being dumbfounded by the unbelievable things people believe."
> - Leo Rosten
> ******************************************