Monday, December 21, 2009

Stories Untold Behind Cancer (4)

The reason why cancer is considered a prematured aging condition,
is because it's a manifestation of "exhausted" cell renewal (or cell division).

In the life science arena, very often,
one sees conferences and symposia
that loop both Cancer and Senesence (i.e. aging) under one big theme.
They share too many similarities!

This second hallmark of cancer
is due to one core principle:
All somatic cells (normal, non-sex, non-stem cells)
has their particular finite number of cell division in their lifetime.

Beyond this finite number of cell division
which is also known as Hayflick Threshold/Limit,
the exhausted cells will go haywired, dysfunctional and
eventually into death.

Hayflick limit is a deliberate act of nature.
One may call it a ticking time bomb,
but it is there to serve a purpose
(to reduce the chance of replication error).

This pre-programed cell division limit is
so important that there are several mechanisms
to make sure that it happens!

One of the interesting mechanisms is that:
During cell division,
when the chromosomes replicate and split into daugther cells,
the telomeres (a non-genetic structure at the ends of each chromosome)
are shortened.

During our early age, the shortening of telemore
has no effect on the cells and our body whatsoever,
as telemore doesn't bear any genetic code.

But as we age, when the whole stretch of telemore is depleted,
and the chromosomes continue to shorten (due to continuous cell division),
it will etch into genetic region of the chromosome.
Gene codes hence become haywired
and the cell will begin to trigger a self-suicidal program
to demolish itself.
-- This is aging in cellular and molecular level.
in over-simplified description :P

Why cancer is deemed as a fast forwarded aging,
is because:
When the overall body condition is begining to deteriorate,
bad cells are naturally destroyed.
In order to sustain a normal body function,
the neighbouring normal cells has to divide quickly
and many times more than usual, to replace the loss of bad cells.

This in turn pushes the normal cells towards Hayflick limit
at a faster pace.

Usually, beyond Hayflick limit,
when a cell's genetic code gets haywired,
a self-suicidal program will be activated,
so that the haywired bad cell will not propagate.

But once in a while, due to many external factors interfering,
the programmed cell death doesn't get activated
and the bad cells will propagate indefinitely and become a tumour.

If we allow our body to deteriorate,
hoping that good cells will divide and replace the bad cells,
we are first pushing ourselves towards pre-matured senescence,
and kick off an endless viscous cycle:
bad cell --> push good cells beyond Hayflick Limit -->
more bad cells --> push more good cells beyond Hayflick Limit -->...

When one gets into pre-matured senescence
(i.e. too many cells approaching or going beyond Hayflick Limit)
the chance of haywired genetic event swell up exponentially.
Cancer occurence hence increases drastically.

And what's worse is that,
because the cancer is caused by haywired genetic code,
there is no traceable link or clue to offer any specific treatment.
(Hence, again, cancer cells can not be treated by any specific target drug,
they all are genetically different.)

With metta,
Kee Yew

p/s:  Please ask questions as I guess it's not easy to understand :P :P
I know it's difficult to explain on a blog, but this basic concept is too important to skip!

{Learning Holistic Wellness for Wisdom and Compassion}

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...