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Cell Death Nets 2002 Nobel Prize in Medicine
An anonymous reader writes "The recent press release at the Nobel website details the first of the 2002 Nobel Prizes. This year the Medicine prize goes to Sydney Brenner, H. Robert Horvitz, and John E. Sulston for their discovery of programmed cell death (also called apoptosis). Their seminal work in the model organism C. elegans established the foundation of cell suicide as a normal physiologic process. The implications are wide ranging including understanding organ development and cancer."
The next step is to quantify the signals (chemicals) responsible for triggering the series of events that are called apoptosis and to elucidate just how transcription switches work. All 'switches' in the body are based off the concentration of various molecules, be they enzymes, cofactors, structural proteins, minerals (Na+, K+, Ca+), etc. The most interesting exploration would entail studying how a concentration of a signal yields a binary switch, that an event either be triggered or not.
The cell widely uses feedback loops, both positive and negative, to exponentially increase and decrease the amount of signal that is being produced at any one time. This signal may interact with other signal-producers to give a multi-signal, multi-enzyme response system that, through the non-linear dynamics of the system, yields a definitive high and low concentration of signal that determines whether an event is to be triggered or not.
To fully understand the mind-boggling complexity of a single cell, imagine a system composed of 5000 enzymes (or more) all interacting with 10,000 molecules (or more) with thousands of possible reactions. Now try to simulate this all at the same time, using non-linear kinetics, and predict the outcome of an initial state.
A lot of crazy things happen, including shifts in entire groups of genes (responsible for protein & sRNA synthesis) caused by very tiny disturbances. The non-linear dynamics of the cell are set up so perfectly that its self-regulation is simply amazing.
My Two Cents...not meant to be a full explanation of why apoptosis is so cool or where the research is going from there.
Salis
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It's a little bit of both. Cancer is the result of uncontrolled cellular replication due to genetic damage to cellular regulatory machinery. Apoptosis is supposed to kill off cells that have problems with their internal structure (for example, a genetic error causing a fault in the systems that regulate growth and proliferation) as well as cells at the end of their useful lifespan.
If we could make periodic adjustments to the way cells replicate perhaps this would work?
And you've just hit on the holy grail of oncology. Unfortunately, we can't just tell all the body's cells to commit suicide. Cures cancer--but results in unsatisfied customers. And some quickly replicating cells are supposed to be that way (bone marrow, gut lining, hair, etc.) so we can't even just mow down fast-growing cells. Actually, that's sort of what chemo and radiation therapies do in a very ham-fisted way--toast all the fast-growing cells, and hope that the cancer dies faster than the rest of the body. It's why chemo makes your hair fall out, and causes anemia and nausea.
Rest assured, however, that your tax dollars are hard at work on a solution.
I've also heard that hair/nails can still grow for some time after death? I suppose those cells keep on going. Creepy
This one is mostly an urban legend. Mostly, it's due to the slight dessication/dehydration the body underdoes after death. There's a bit of evaporation, and shrinkage. Contraction of surrounding tissue can force hair and nails to protrude further than before death, giving a perception of growth. Also, there were cases up until the last century or so that involved patients in deep coma states--still alive, but apparently dead. Yes, hair and nails grew on those 'dead' people. And they got pissed off when they got buried.
~Idarubicin