On Sep 3, 7:51Â am, "bigflet...@
gmail.com"
gmail.com>
wrote:> On Sep 3, 3:28Â pm, Immortalist
yahoo.com> wrote:
>
>
>
>
>>> On Sep 2, 8:42 pm, Sir Frederick
fuzzysys.com> wrote:>
>>> How would you like to live 1,000,000 years?
>>> Quantum processes are ageless.
>>> ---------------------------------------------------------------------------ÂÂ-
>
>
>>> An enzyme linked to most human cancers has finally yielded its secrets – it may
>>> also help defeat ageing
>>> Â 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.
>
>> A telomere is a region of highly repetitive DNA at the end of a linear
>> chromosome that functions as a disposable buffer. Every time linear
>> eukaryotic chromosomes are replicated during late S-phase the DNA
>> polymerase complex is incapable of replicating all the way to the end
>> of the chromosome; if it were not for telomeres, this would quickly
>> result in the loss of useful genetic information, which is needed to
>> sustain a cell's activities. Every time a cell with linear genes
>> divides, it will lose a small piece of one of its strands of DNA. This
>> process has been referred to by James Watson and Alexei Olovnikov as
>> the "end replication problem" (1971).
>
>> ...because of DNA replication mechanisms and because TERT expression
>> is repressed in many types of human cells, the telomeres of these
>> cells shrink a little bit every time a cell divides although in other
>> cellular compartments which require extensive cell division, such as
>> stem cells and certain white blood cells, TERT is expressed and
>> telomere length is maintained.
>
>> ...In most multicellular eukaryotes, telomerase is only active in germ
>> cells. There are theories that the steady shortening of telomeres with
>> each replication in somatic (body) cells may have a role in senescence
>> and in the prevention of cancer. This is because the telomeres act as
>> a sort of time-delay "fuse", eventually running out after a certain
>> number of cell divisions and resulting in the eventual loss of vital
>> genetic information from the cell's chromosome with future divisions.
>
>> If telomeres become too short, they will potentially unfold from their
>> presumed closed structure. It is thought that the cell detects this
>> uncapping as DNA damage and will enter cellular senescence, growth
>> arrest or apoptosis depending on the cell's genetic background (p53
>> status). Uncapped telomeres also result in chromosomal fusions. Since
>> this damage cannot be repaired in normal somatic cells, the cell may
>> even go into apoptosis. Many aging-related diseases are linked to
>> shortened telomeres. Organs deteriorate as more and more of their
>> cells die off or enter cellular senescence.
>
>
>
>>> 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
>>> ******************************************- Hide quoted text -
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> I suspect the next step is to identify the psychsomatic influence over
> telomerase.Particularly in 'spontanipous remission' patients.
>
> I love living for ever, but I am also happy to inhabit new bodies. I
> even get bored with my car body after a few years.
>
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The mystic's version of "out with the old, in with the new ".
Reincarnation as a 'leases on life' philosophy ?
Arising from a business practice of leasing new cars every three
years? :-)
