Tuesday, December 29, 2009

Immortality

Do you want to know what's REALLY going through my mind?  Immortality.  And how much of a crock it is.  :)  I was sitting by the pool eating a nice hot (as in chilli hot) pizza, partaking in some Jim and this thought crossed my mind, so I couldn't resist blogging it.  :)

The only things we *KNOW* are immortal are...  cancer cells.  Yes, cancer cells.  The most well known immortal cells are known as HeLa Cells which is a line of cells derived from the Cervical Cencer cells of a Henrietta Lacks who died back in 1951 aged 31.

A normal human cell will divide around 40 - 60 times before it stops dividing, becomes senescent and eventually dies.  That's regular human mortality.  HeLa Cells don't do this - they don't enter senescence.  They are immortal.

And as far as immortality goes, the reason these cells are immortal is that they don't suffer from the regular telomere shortening that occurs upon every cell division.  They achieve this by having an active Telomerase enzyme during cell division which prevents this shortening of the telomeres.

Aha, yes - telomeres are the protective ends of our chromosomes.  They act in a way similar to how melting the end of a nylon rope protects it from fraying.  When the melted section is shortened and worn away, the rope frays.  In a similar process, as our telomeres shorten to a crucial length, those cells no longer divide and eventually die.

So, as far as immortality goes, the idea of an immortal being is cancerous (on so many levels) and not something we should really aspire to, let alone worship!  :)

Regards,

The Outspoken Wookie
(who is on holidays, so this sort of thing, instead of IT, is entering his mind once again!)

2 comments:

Chris Knight said...

Stem cells also use telomerase to rebuild the telomeres and can be considered biologically immortal.

Cell transdifferentiation can potentially be another way of overcoming the Hayflick limit. There's a jellyfish that can do this, going from adult back to a polyp.

Mind you, without food and excretion pathways the cancer cell will die anyway. Also the cancer cell can still undergo mutation and become senescent again. This would have to happen quicker than the replication rate and before the host system became non-viable.

From memory hydra are considered to be biologically immortal.

And this only deals with biological immortality. Which certainly isn't as bizarre as spiritual immortality or even quantum immortality, if you believe in either of these.

Hilton Travis said...

Stem Cells rock. Undifferentiated, immortal cells. Yes, Jim helped me forget about those! :) Stem Cell research, unless blocked by right-wing nutters, will result in some amazing science down the road.

And yeah, transdifferentiation can help for a while, but it is unlikely to continue ad infinitum, and even were it to, what would the end result be and would you recognise it? Could you have a beer with it and hold a meaningful conversation?

Of course cancer cells need to eat and dump - we all do. If you don't eat you don't shit and if you don't shit you die, as the old saying goes. :)

Finally, yes, some tres interesting samples of immortality (or a similar attribute) do exist in nature. In real nature - not in "spiritual" mythology. Quantum immortality, is a different kettle of fish, totally. Some really weird shit happens down there! :)