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"Cell Executioner" Gene
slantyyz writes: "A fascinating and possibly scary scientific discovery -- Toronto scientists have discovered a "chisel of life" gene that kills cells. Apparently this ancient gene, dubbed AIF [apoptosis (death) inducing factor] is found across all forms of life and acts as a cell executioner. While this could have uses in killing cancer cells, it could potentially open the discovery of a true fountain of youth." Nature has more, if you're a subscriber.
Indeed, but a lot of effort tends to be focused on the leading killers. So if all natural/disease based death were gone, accidents would be next on the chopping block.
New cars would make today's volvos look like deathtraps. Buckets would have little sensors that would detect drowning, and open drain holes. Ladders would automatically drill themselves into the floor or ground.
Accidents would still kill, but that 600 number would slowly drift ever higher.
Biologically there is something quite right with it. There is a theory that old age death is very good for a species. It can't really be tested at this time, of corse. The closest you can do is take a genetic programming package, find a problem it can solve, and then change it to remove old age death. Then see if it can still solve it, and if it can if that takes more generations or not. My meager experiments with the "simplified ants looking for food" problem shows a huge increase in the number of generations needed to find the solution. But don't take my word for it, it's a pretty easy experiment, go try it. (note you still kill off the bad performers, you only let the "old" ones live if they are in the top few percent)
Socially it looks like old age death is a good idea. Most mathmations (for example) make their good discoveries early, and then don't do a whole lot. Or so I have been told. Plus think of the divorce rate if we don't have the death escape hatch 50% of marriages use :-)
All kidding aside, for social effects the only place I have seen them investigated is science fiction, and the results vary quite a bit. Many of those societies I wouldn't enjoy as much as this one, except of corse, I would have far more time to enjoy them....
Economically losing old age death would be a disaster if we didn't also lose old age (forget our current social security problems, if the avg. age shot up to 150 we would be sunk!). If we lost old age as well things wouldn't be as bad, but the increasing population would make jobs a bit scarce (unless birth rates dropped dramatically).
Personally, I would love to live forever (assuming I get to do it in fairly good health, and in a more or less normal mental state). It only causes a problem when we all get to do it :-)
I read once that even if all natural and disease based causes of death were eliminated, the average human would only live about 600 years. The reason? Accidents.
One might argue that medical science's ability to clean up after our accidents will improve with time, but I doubt it is every going to figure out a way to put our brains back together if they are splattered all over the road in the course of being struck by a car.
So there is an upper bound to our life span even if we are technically 'immortal'.
-josh
This is not the fountain of youth. Your cells must die to remain healthy. The fountain of youth would be increasing the number of generations your cells can go through before they run out of steam. That's the fountain of youth problem - replacing dead cells indefinitely, not preventing the death of the cells you have now.
To begin with, there are many different types of cancer. What makes it cancer is that cells that are 'cancerous' do not kill themselves at the proper time, and always undergo mitosis no matter the circumstances. That may be inappropriate if a cell is already surrounded by other cells, for example. Anyway, somehow either the ability to not split or the ability to apoptose (kill self) if beyond repair is removed.
There is a protein called p53 that's responsible for (among other things) detecting damage in a cell, and then either trying to fix the cell, or kill it (apoptosis). The levels of this protein are elevated when cells are in distress -- for example from ultraviolet radiation, starvation, etc. Levels are also affected by mitosis phase, etc etc. In any case, if it is possible to design something that detects high levels of p53 in a cell, and then nondeterministically triggers massive expression of the apoptosis gene (this thing they discovered) then this method could be used to treat some cancers, because in some cancers, levels of p53 are elevated. While this method will likely kill a lot of cells in the middle of mitosis, in a healthy tissue only a small fraction are dividing at any one time.
In some cancers, the p53 gene is damaged and does not get expressed, so in that case some other metric would have to be used to trigger apoptosis.
Anyway, between approaches like this, chemo, surgical removal, and whatever else there is, cancer is slowly becoming a survivable disease.
-S
Apoptosis is, as the article hints, a vital part of development - at various stages of embryogenesis, tissue that has developed needs to be removed for the next step. Apoptosis is also involved in the regulation of cell growth. If a cell detects that it's becoming non-functional, apoptosis is triggered and the cell dies. This is absolutely vital in cancer prevention. Every day cells in your body pick up chance mutations that could potentially lead to cancer, but in the vast majority of cases they kill themselves before this can happen. However, if a mutation occurs in the pathway that triggers apoptosis then this can't happen, and the cell may go on to become cancerous.
AIF is important because it's likely that many cancers will have a defective copy of it. With advances in gene therapy, it should soon be possible to insert new copies of the gene into the cancerous cells thereby triggering apoptosis in them and destroyin the tumour. However, it's not much use for making you live forever. You don't die because cells decide that you've lived for too long - you die due to disease or failure of organs induced by wear and tear and picking up of mutations. It's possible that inhibiting AIF might lead to some individuals living slightly longer, but only because cells that are defective would hang around until they broke down completely rather than killing themselves cleanly. It wouldn't be terribly pleasant.
(Note: IAAB)
If it can kill cells, it could make a damn hefty genetic virus (okay, maybe that's a cartoonish thought. but still.... *shiver)
Ok, for starters: I really recommend that anyone interested in this stuff pick up a (modern) book on biology and genetics, there's a lot of stuff been discovered in the past 10 years, and we're only just scratching the surface. (Someone will make a lot of money selling computers to process all that info :).
This gene has been predicted (if not known about) for some time. It's needed, because your cells die all the time, they're supposed to. Over time, you get problems - errors - in DNA, and this is one of the problems with making cells that duplicate forever, eventually, they won't do the same things anymore (IIRC, brewing companies need to change the yeast they use periodically, because mutations that occur over time change the taste of the beer). The cells in yeast aren't all that different from the cells in your own body! (Actually, anyone who has problems with evoloution would be shocked at how much your cellular processes are (identical) to any other furry mammal).
The biggest application of this kind of technology is the real limit on human lifespan - brain cells. We can eventually replace almost everything else, somehow, but your brain is what and who you are. Once it deteriorates, you're not the same person anymore. Figuring out how to prevent brain cells from dying - brain cells are unique, in that they do not reproduce, ever - just the supporting (gidal?) cells do.
Nobody will be living forever until nanotech becomes rampant - no other mechanism to repair nerve and cellular damage is possible (and even then, it might not be enough). I wouldn't mind retaining my mental facilities until I reach the end of my lifespan, though. If you figure you'll probably live to 80, but will be signifigantly handicapped after 60 or 65, that's a 15 year productive increase.
..don't panic
The stimuli that invoke apoptosis are usually factors that will kill the cell anyway--starvation, poisoning, radiation damage. Apoptosis is the cellular equivalent of euthanasia. Without it, the cell will still die anyway, except more slowly, and it will rupture and spew its contents to surrounding cells, possibly causing those cells to die as well. The process of aging and death of a multicellular organism is ultimately mediated by entropy, not genetics, so until we can figure out a way to repair the ultrastructure of a cell with nanotechnology, immortality is still a long way away.
What this discovery does allow us to do, however, is stop apoptosis in very specific situations (assuming that we have figured out all the cascade mechanisms, which is probably not likely at this stage). For example, in the aftermath of a heart attack, a stroke, or hypotensive shock, even if blood supply is restored, cells will still commit suicide because the apoptotic pathways have been activated. Experimentally, it has been shown that if you can block the stimuli that initiate apoptosis (such as the excess glutamate released in a stroke), then in these specific situations, the cells will probably do fine once the blood supply is restored.
So there are ways to shut off genes transiently--antisense RNA, competitive inhibitors of transcription factors, etc.--preventing much of the sequelae of these vascular events.
Still, shutting off apoptosis, even transiently, has the risk of inducing cancer. In stroke, for example, the excess glutamate triggers a cascade that generates factors that damage DNA. (These DNA-damaging factors are what directly activate the apoptotic pathways.)
So it's a choice: would you rather be paralyzed, or would you rather have a tumor? The odds are probably not even, so there would be a better choice, but ultimately, entropy can't be stopped, so achieving immortality would probably entail a lot of micromanagement.
Interesting article, and I can only hope that this research pays dividends when it comes to medical research into curing such modern diseases as cancer and Alzheimer's which cause so much misery and grief.
But the idea of living forever... who would really want to live forever?
It's the sort of idea that sounds like a utopian fantasy when you first hear it. After all, nobody but Hamas suicide bombers wants to die - the fear of death is an inherent part of what makes us human. In olden days berserkers were feared for this reason - they would attack and attack without regard for their own safety, and would invariably take many down with them.
But living forever would pervert this part of what makes us human. At first it would seem like a wonderful freedom - all that time to do new things, to experiance more without worrying about not having enough time. But soon the wonder would fade and the fear would set in. Fear of death, fear of any risk which could injure yourself and fear of not being able to afford to live in a reasonable manner.
This fear would overcome any benefit eternal life could bring. People would stay in their houses, attempting to stay safe. They'd stick with their confortable jobs, never taking any risks, never letting their ambition thrive. And when you live forever, enemies are easy to make and friends easy to lose. When there's a lot more to risk, people won't want to risk it.
So I think that living forever is something that we shouldn't want, and shouldn't work towards. Humans just aren't ready to accept eternal life in this world, and we won't be unless we overcome our petty greed and our fears. And Star Trek aside, I just don't see that happening any time soon. There are too many people with too much to lose from disturbing the status quo.
Jon Erikson, IT guru
Enthusiasts of "all-natural" drugs rushed to stores these past few weeks to buy the latest pills, in hopes it would make them happy and healthy looking like the models in the commercials. Though these "Apoptosis Inducing Factor" pills are commonly associated with death, that didn't stop these proud souls, as they bought them by the pallet.
In other news, the average IQ of the world has gone up dramatically in the past few weeks, leaving researchers puzzled.
Kurdt
Kurdt
I'm not anti-social. Just pro-technology.
Now, if only venture capitalists could start throwing as much money on researching this cell as they have spent on e-pets and "get paid to surf the web"-companies, we might have something cool in a few years!
Will code a sig generator for food
Being able to kill off cancer cells and other types of viruses(maybe) this could have huge value to people.
IANAB, but I as far as I know, viruses are not cells. From this article on viruses structure, here are the components of a virus:
The bottom line is: this cell killer gene will not help fighting the flu.
--I code, therefore I am.
The rest is also quite interesting. Read it!
Ron Obvious
How ever I fail to see how this is going to help people find the fountan of life. We need to be able to regenerate other parts of the body that do not on their own. Cells die all the time, and they need to. If you think your skin is the same you were born with, your very wrong.
Fight censors!
"Not my manner of thinking but the manner of thinking of others has been the source of my unhappiness." - M
What the article is describing is the discovery of a factor that leads to apoptosis apart from the previously elucidated mechanism, which involves a protein (cytochrome c) leaking out from the mitochodria into the cytosol of the cell, where it shouldn't be. Essentially, if the cell detects that, it knows that the there is something terribly wrong, and it should suicide - which is essentially what apoptosis is.
Now, it had been arleady known that there was another mechanism, because if they knocked out the genes responsible for the known mechanism, they could still get apoptosis, though not as readily. This lead to the search of what was causing it. This article describes that discovery, which is AIF.
Interesting work. The reason that this is a more likely candidate that the previous method for fighting cancer is that cytochrome c is a very large, complex protein. Injecting it into cancer cells to initiate apoptosis would be difficult, to say the least. I didn't see enough of the article to see how large AIF is, but I bet it is smaller, and may be easier to get into cells that cystochrome c.
The thing that has me curious is if they could knock out the gene temporarily. They showed that cells were less likely to induce apoptosis under conditions of serum deprivation (starvation). Starving cells is one of the steps toward prepping the nucleus for use in cloning. If they keep more of the cells alive during that process, they might have a better success rate in cloning.
Chew on that one for a while.
If you can't beat them, embrace and extend them.
With apologies to May West, I don't want more years in my life but more life in my years.
Tomorrow is Open.
"the average human would only live about 600 years"
If the average human lives 600 years, how long does the exceptional human live?
More to the point, how do accidents represent an "upper bound"? When I get to 600 without walking in front of a car or falling on a pair of scissors, are the Probability Police going to come hunt me down so I don't "throw off the statistics"?
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