Scientists have long been stymied by human regenerative healing -- that is, wholesale regrowth of, say, a severed limb -- an ability inherent in some species but lost on humans. But new research suggests the ability to regenerate isn't based on something newts and flatworms have that we don't; rather, it's something we do have that's keeping us from regenerating tissues. Researchers think a gene called p21 may control regenerative healing, and that by switching it off, humans could perform our own regeneration.
The new research suggests that the potential to heal without scarring -- or possibly even to regrow a limb, albeit in a limited manner -- may lie dormant in human cells, kept in check by the p21 gene. A group of lab mice engineered to lack p21 were able to regenerate surgically removed tissue to the point that no evidence of the surgery remained. Holes punched in their ears -- a standard procedure for tagging lab animals -- also healed perfectly, leaving behind no traces of scar tissue or previous damage.
Essentially, switching off the p21 gene allows adult cells to behave like pluripotent stem cells, reorienting themselves into whatever kind of tissue they need to be. But naturally there is a give-and-take; p21 is closely intertwined with another gene, p53, a cell-division regulator that, if allowed to run amok, can lead to many types of cancers. The p21 gene acts as a safety valve for p53, stopping cell division in the case of DNA damage. So switching off p21 can allow cells to engage in regenerative healing, but the risks of doing so include rampant cell division (read: cancer).
However, in the p21-free lab mice there was no cancer surge as one might expect, but rather an increase in apoptosis, or cell suicide, which directs damaged cells to destroy themselves. So it would appear that by striking some kind of controlled balance between allowing regenerative cells to work, while letting apoptosis regulate out-of-control cell division, could lead to regenerative treatments for humans somewhere down the road.
That's pretty cool. I wonder when DARPA will start pushing money towards this research. God knows plenty of veterans need this.
If they can strike the perfect balance between regeneration and cancer tendencies, this could be a medical breakthrough for the ages. No more organs failing or dying. With the right medication to start and stop the sequence, you can force those dying organs to repair themselves and heal the person. How cool would that be?
That would be weird, but obviously good. Veterans would love this though. Thankfully my grandfather wasn't wounded in WWII, but he knew of plenty who were. If cancer can be prevented, I see no reason for this research to continue.
I still want them to create a new gene for cells that is a backup against the DNA damage and then give every newborn child the gene in the form of viral therapy until the world was essentially rid of cancer. Combine that with this, and well, I don't need to explain the benefits...
With this, could George W. Bush have grown a brain?
Cheney a conscience?
So Volt what happens if with the "benefits" also come in a package including new genetic diseases if every child was suddenly born with the gene gone, how could we tell that nothing would go wrong with absolutely 100% of the population? If you were in charge of making sure everyone had this gene taken away would you do it?
A bit like the problems of embedded software ( currently an issue with Toyota) you can never be 100% certain that there won't be errors that creep in because of that .
This is science, not magic. There are some limitations that mortal man will never achieve......
@QIII REgenerate, meaning grow back what you lost. so maybe, in W's case, if his brain was eroded away by the cocaine..
but a conscience is not tissue, and if it was never there in the first place, then it cannot be regenerated. :D
No. You cannot regenerate something that hasn't been there in the first place. For regenerating you need to find tissue that has the DNA that codes what you want to regenerate. In this case some early evolution dormant code has managed to wake up.
The real question is, say your kidneys failed, would you be able to regrow them in time to stop your death?
Not just veterans would benefit from it, but I wonder how expensive it would be... indenture yourself after you regrow your limb? I don't have a clue how i'd pay to have my leg back... and if i couldn't have it back simply because of money....
How scary would that be if the process could be accelerated to the point were you could heal instantaneously like wolverine from the x-men? Enemies of the U.S. would be sh**ing bricks facing an Army that can't be killed or at least very hard to kill.
A process like regrowing a limb, especially one the size of one of our arms would take a tremendous amount of energy and time, just think about how long it took you to grow from newborn to teen. Still, for our veterans to finally have their limbs back, I'd imagine they'd be willing to wait that long.
That's what dialysis machines are for, correct? Or is that liver? One or the other. Anyway, while you are getting that, a new kidney can start growing and hopefully by the time it reaches full size you aren't dead yet.
@Brian P. you might want to consider the fact that other countries that despise the US (or worse, terrorists) may come across this bio-tech and use it against us (imagine a whole bunch of terrorists blowing up a city, then regenerating and doing it all over again)(I know thats not at all plausible, but just use your imagination for once).
In the 12th episode of The X-Files season 4, Paul McCrane played a man named Leonard Betts who can regrow body parts but is riddled with cancer.
The Marvel Comics character Deadpool can also regenerate tissue and organs but is full of cancer.
it seems to be that if we have a gene that stops regeneration,
than it is there for a reason
why else would we evolve that way?
Well, this won't work for people that are already born. Since you have to switch off a gene in ALL THE CELLS OF THE BODY, you must change the first one, the egg, so that it can replicate with this gene repressed.
So there will be no treatment for already born people.
Another industry that will love to exploit this, cosmetics. The term "cell regeneration" already sells billions of dollars in anti-aging beauty products per year... www.tendances-de-mode.com/en/news
That procedure could have tremendous benefits; not only the obvious ones of limb regrowth, but the more prosaic benefits related to the ability to perform surgery without the danger of leaving potentially dangerous scar tissue.
I'm assuming that the intent would be to develop the ability to turn this gene on and off as needed, not to permanently delete it from the human genome.
"Facts do not cease to exist because they are ignored." Aldous Huxley
That's what gene therapy is for. Living people aren't excluded because our DNA can be changed on the fly. Viruses do it to us all the time, mostly against our will.
You take a modified virus, engineered to deliver this gene or mechanism that switches off p21 and enables regeneration. Pump a patient full of this stuff and once they're healed, take another modified virus that delivers the mechanism to switch everything back to normal. At least, that's how I would do it. I'm no doctor, but that sounds reasonable, doesn't it? And because the material injected into the cell does NOT replicate into new viruses, only modifying the living cell, there's no threat of viruses running amok.
Of course there's always the risk of cancer and stuff, but that's why you do it in a hospital where they can monitor it and control it precisely (at least, so goes the plan).
And The Blob is born.
"You cannot regenerate something that hasn't been there in the first place."
We may disagree on the tank, but at least on this we may have some common ground...
This technology might also help victims of forced amputations such as those circumcised as infants without their consent.
This is great as long as you can turn p21 back on again- it is part of our anti-cancer defenses. There are some great technologies out there like RNA Interference that should be able to temporarily shut off genes like p21. All you need is a good delivery mechanism that sends the small interfering RNAs (siRNAs) to the site of the injury. Your cells naturally break down and recycle RNA all the time, so the siRNAs would disappear within hours after you stop the treatment.
It seems like the same double-edge sword for telomerase. We have a gene that can be switched on, that creates telomerase, which is the enzyme that restores telomeres on the ends of chromosomes to prevent the cells from becoming seniscent. (It is responsible for the immortality witnessed in cancer cells-- the ability to divide indefinetly)
Always seems to be the choice bewteen regrowing, and risking cancer. It seems fitting, since cancer is just when a nearly-perfected system gets a bug. The question is then raised "When is the risk of cancer acceptable compared to the known and potential benefits."
@bradfordly I would tend to agree with you. Evolution has done a wonderful job of stripping away or countering the less beneficial aspects of our geneology. However, to say that a gene our reptile ancestors had was deactivated because it was too antagonistic is speculation at best.
Much as unpopular bills and pork "ride by" on popular congressional bills, so too can non-ideal genetic changes get passed on. Say for instance, our shared ancestor with the newt had a child, who had a deactivated p21 gene, but also had a few genes changed that increased his senses a measurable margin. That son then had many children, who in turn had a disporpotionate number of children, because despite their lesser ability of regeneration, they were better at avoiding injury, and avoiding death in general. Eventually one of these meta-newt decendants progressed further, and overal became one of humanity's ancestors. Thus, a favorable gene was deactivated because the same handicapped ancestors also had mutations that more than compensated.
It is also possible that an inactive p21 gene was very beneficial because another genetic change resulted in the risk of cancer this article suggests, and inacitivating p21 fixed that hiccup. Further, it is possible that due to other genetic changes since, it is now redundent (as suggested by the cell-suicide that may act as a secondary regulator of the p53 gene).
All I mean to say, is that it is not garenteed that the genetic editations from evolution are the best-possible changes to be made, or that, if they were a good change at the time, changing back now may be more benficial.
Remember that high school biology exercise where you slit a flatworm's head between the 'eyes'. Remember what happens? Now if humans had this same regenerative ability, the old saying "Two heads are better than one" might have a more literal interpretation. ;-)
You'd only need to switch off p21 at the "business" end of an amputation stump. Those are the cells that would go on to recreate the limb, etc.
As for GWB's brain, it functioned far better than whatever cancerous growth fills the space between O's ears.
I don't understand the problem here, wouldn't the best use of this change be to regrow the tissue that was cut out due to cancer? You might be more likly to develope cancer but you would be so much more likly to servive it.
If i cut off my dick will it grow back bigger??????????
@ Brian H: The current prez is showing far greater competence than Dubbya ever had... Dubbya was the best thing that ever happened to the joke writing teams for Leno, Letterman, O'Brien et al. He couldn't keep his foot out of his mouth, even when he had the luxury of time on his side: "Mission Accomplished"?!? What was he thinking?
Dubbya is the one that ignored the facts, deciding there were weapons of mass destruction with no supporting military intelligence, immersing this country in a war against Saddam Hussein that did not need to be fought-- it has done nothing more than to stir up a hornet's nest from which we will be lucky to recover, if ever... he had no exit strategy, he did nothing but cost us the lives of thousands of lives, and hundreds of billions of dollars. He sunk us into the steepest debt since The Great Depression, and you have the nerve to attack Obama?
Dubbya diverted attention from the true arch enemy, bin Laden, choosing instead to spread our resources thin and exhaust our potential. As long as bin Laden is alive, he is a major danger, yet Dubbya allowed his attention to be diverted in one of the biggest military blunders in history,and we have been paying the price dearly for seven years now.
May Obama succeed where his pathetic predecessor did not.