Rejuvenation and Cancer

== Rejuvenation and Cancer == 

It is obvious that any mechanism which has the power to rejuvenate or regenerate 
a system has also the power to destroy it: if the regeneration process goes
wrong, and something different is generated instead of the original system,
then the consequences are very severe.

Cancer itself is like uncontrolled "rejuvenation" in an organism: "rejuvenation" went awry.
Like stem cells or embryonic cells, cancer cells do not age and can proliferate 
without limits. Cancer cells and small tumors influence their environment to increase 
local blood supply and they suppress the maternal immune system, just like embryos.
Cancer cells act like embryonic cells, who proliferate vigorously, are 
capable of extensive migration, and secrete factors that increase the local supply of blood.
In general one can find many similarities, tumor cells may grow and spread by exploiting
the genetic programs normally active only during embryonic and fetal development
[http://www.scientificamerican.com/article.cfm?id=cancer-clues-from-embryos]:

* Tumor originating cells ([[Cancer_Stem_Cell|cancer stem cells]]) are like stem cells
* Tumors themselves are like embryos 
* Tumor development resembles embryonic and fetal development

If there is indeed a close link between rejuvenation and cancer,
then the consequences would be severe: suppressing tumor promoting 
proteins would prevent them from doing needed repair work, i.e.
suppressing cancer may increase aging processes, while rejuvenating 
drugs which replace and repair damaged or senescent tissues would
increase the risk of cancer.

== Self-renewal and Stem Cells ==

Self-renewal is the key property of stem cells. They are fundamental for organ 
development and tissue repair. Although they belong to the
most beneficial cells and enable rejuvenation and regeneration of the body,
they also seem to be at the heart of every tumor, as new research about
[[Cancer_Stem_Cell|cancer stem cells]] has found out. Cancer cells and stem 
cells are disturbingly similar [http://www.nature.com/nature/journal/v460/n7259/full/4601085a.html].
Is it possible that the same cells which are responsible for maintaining a tissue or 
an organ are also responsible for destroying it through the worst form of disease?

A link between self-renewal, [[Self-Rejuvenation|self-rejuvenation]] and self-reproduction would
perhaps explain why cancer is most common in the organs responsible for 
self-reproduction: breast cancer or endometrial cancer in women, and prostate
cancer in men. It would also explain why “many of the body’s tissues that
are most prone to cancer, like the blood, skin and lining of the gut”
are self-regenerating tissues. These self-regenerating tissues are composed of
short-lived cells, and contain a self-renewing population of stem cells that
maintain them.

Cancer is a very complex disease. It can take years and decades until
enough mutations and damages are accumulated to enable a tumor. One
problem is that every tumor looks different. 
Future research will hopefully shed more light on this complicated topic.
Recent research has found a close relationship between stem cells and tumor
generating cancer cells. Tumors seem to be the price for high
age. The reason is not only accumulated damage in form of progressive
deterioration, gradual abraison and inevitable wear and tear damages. Old
age is only possible through rejuvenation and repair. It looks like stem
cells which are responsible for renewal, rejuvenation and regeneration have
not only the ability to regenerate a system, but also the possibility to destroy
a system.

The more specialized an organism or a cell is, the more it seems to loose
its ability to replicate and regenerate itself. Stem cells are primal undifferentiated
cells that retain the ability to produce an identical copy of themselves,
whereas ordinary cells, specialized for a certain purpose, loose the ability to
produce an identical copy of themselves. Intermediary cells are restricted by
an internal counting mechanism to a finite number of cell divisions, which
declines with increasing differentiation.

Has this something to do with the unique history of each organism or
cell (are old, highly differentiated and specialized cells usually polluted or
used up) ? Or is this hierarchy useful for avoiding chaos and confusing which
could arise if every cell would be allowed to replicate itself?
If no cells would be able to copy and replicate itself, then the body would
not be able to rejuvenate and repair itself in order to replace damaged or old
cells. If all cells would be able to do this, this would result in ”chaos” and
every cell would be a potential cancer cell. It looks like Nature has invented
a compromise in form of stem cells.
Stem cells are a blessing, because they can replace damaged or old cells,
but mutated or damaged stem cells are a curse. Stem cells have like tumor
generating cancer cells the same potential to proliferate, they have an
unlimited life span and the ability to generate a diverse range of other cell
types.

New research gives strong evidence that cancer is the price for an
evolvable system (subject to mutation) with the ability of self-replication, 
[[Self-Rejuvenation|self-rejuvenation]], [[Self-Regeneration|self-regeneration]]
and self-repair. It seems to be the price for the self-* properties
which enable our existence and keep us alive. Perhaps this helps to explain
why it is so difficult to find a cure for it. Recently, researchers have suggest
again new strategies to fight cancer, for instance viruses (modified common
cold viruses), chillies (spicy food) or sugars (a combination of sugar and
short-chain fatty acid). So far, there is no miracle cure for cancer. And
probably none of these new approaches will be a miracle cure, either. But
hopefully one approach in the future - perhaps due to the new insight that
the disease is related to self-rejuvenation - will lead to something useful in
the ongoing battle against this terrible disease.

== Cancer in CAS ==

This rises the urgent question if artificial systems can develop some form
of cancer, too, if we try to build systems with these very desirable [[Self-Star_Properties|self-* properties]]. 
Is there a form of cancer in complex adaptive systems in general, not only 
in biological organisms, but also in ecological, economical, social or
political systems ? This would perhaps be an element arising from the need
for self-rejuvenation which proliferates, spreads and replicates itself until it
has destroyed the whole system. Joseph Schumpeter introduced a similar idea of 
[[Creative Destruction|creative destruction]] in the context of capitalism. [[Creative Destruction|Creative destruction]] 
means one thing is replaced by another from within. 

* Ecologies systems allow the self-rejuvenation by “granting the right” to create new species and to explore new ways to survive. In an ecological system, this freedom can lead to mass extinctions or epedimics caused by parasites or viruses with the capacity to damage or destroy the whole ecological system.

* Economies allow the self-rejuvenation by granting the right to found new companies and to explore new market forms. In an economical system, this freedom can lead to market monopolies, which destroy the market system. Or it can lead to disruptive innovations which destroy a large number of existing companies by [[Creative Destruction|creative destruction]] 

* Democracies allow the self-rejuvenation by granting the rights to found new parties, to assemble, to demonstrate, and to educate. In a political system, this can lead to terrorism or an ideology like fascism. In a religious system, it can lead to schisms and sects.

* Science allows the self-rejuvenation by “granting the right” to create new theories and to explore new ways to explain nature. This freedom can lead to subsystems with the capacity to threaten the whole scientific system, for example in form of a paradigm shift.

In general, if a [[Complex_Adaptive_System|complex adaptive system]] has a built-in self-rejuvenation ability, and it grants it’s agents the rights to create and to found new elements, these elements can severely damage or threaten the function of the whole system. Any system which is able to remould and reinvent itself can replace itself by something else.

[[Category:Cancer]]