Slashdot Mirror
Researchers Claim To Produce Stem Cells From Adult Cells
coljac writes: "An article in The Times on Monday details the claims of British researcher Ilham Abuljadayel who says she can produce stem cells from adult cells (in this case, white blood cells). Stem cells, the main source of which is currently human embryos, are undifferentiated cells which under the right biochemical conditions can grow into any kind of tissue cell. Stem cell research promises breakthroughs in many areas of disease (and even aging) research, but until now has been dogged by controversy because of the use of human embryos. If verified, this is a pretty exciting development."
What's really interesting about this story is how sure the scientific community is that this is impossible.
Could this be another cold-fusion, or are we looking at a revolution in bio-sciences that the current scientists fear?
And what of the ethics? Could this be used to reverse ageing? (unlikely, but if it could, what are the ethics of keeping entire generations around just so they can oppress their descendants).
Thoughts as I teach a class....
Beware the Whyte Wolf.
With a gun barrel between your teeth, you speak only in vowels...
Just keep generating a supply of stem cells, and build over any failed component. The existing material could easily be reprocessed as a source of building material.
Regeneration, rather than age prevention, may be the real secret of longetivity.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Maybe it's because I'm just finishing up reading Bill Joy's remarkable article over at Wired (go find it for yourself!), but producing stem cells definitely leans towards eventual immortality, and the only way to survive that on earth is to completely stop reproducing.
Do people ever stop and think about whether a given development is a good thing or not, before pushing forward on it?
"People who do stupid things with hazardous materials often die." -- Jim Davidson on alt.folklore.urban
The non-obvious importance is that we can start "growing" meat and other kinds of animal tissue (perhaps vegetable as well?) on an industrial scale...
It won't be a hundred years before we stop raising cattle, pigs, chickens, etc. and start eating artificial food that can be engineered to spec. I'm sure it would be more efficient from a thermodynamic viewpoint.
The bad news is that the rich will live forever. The good news is that you won't have to eat tofu.
Nothing can give us immortality. What is possible is that we won't age. We would still die from non age related diseases, accidents, wars etc.
And the planet can easily take 20 billion people.
So relax and try to get some sleep, OK?
1. Longevity can be achieved, eventually, through this, but not immortality. Severe truama to the brain or other vital organ will likely still be fatal [though all organs beside the brain will depend on proximity to a proper treatment center]
2. There may be some unforeseen limit on this that we will only discover after implementing it [maybe these stem cells have some maximum ability to regenerate tissues, at which point nothing an bring it back, sort of like a rechargable battery]
3. Repairing brain damage will enable full function, but not recovery of memories, personality, etc. So a tumor/shot to the head will still be very life altering.
-={(Astynax)}=-
-={(Astynax)}=-
"Darkness beyond Twilight"
I've done a "decent" amount of reading in hematology (being a 3rd med) and I can't seem to reconcile some things. Some things just don't stand up.
In blood, there are (as the article points out) a number of stem cells which, while they retain their ability to differentiate, also give off progeny as needed. These progeny are then directed, by various growth factors in turn directed by the biological needs, to differentiate into the various cells. Theoretically, all blood cells (with the exception of red blood cells or erythrocytes) retain the complete genetic code.
But I can't see how it can really be reversed. White blood cells aquire a bunch of different organelles within them depending on their decided function. Do they loose these organelles too? Or do they just regain the ability to differentiate?
What might happen is that certain regulators which prevent certain things from happening in cells may be removed.
But does anyone really think that "just" the needed things are removed? If the cells in your heart or skin suddenly regained the ability to differentiate into anything, they would still first be respective cells of those parts. My (limited) guess is that they've just removed regulating factors and that probably brings the cells closer to neoplastic (a.k.a. uncontrolled cell growth) and that's about it.
Also, some of the top hematologists would be reviewing this paper before it was "not accepted" in a number of journals. Don't you think that these journals would be aching to be the ones to publish something so legendary? In the end, I can't see how "forgetting" to add something to the media suddenly would do this. I wish they'd let out more information.
Perhaps it was bad science. The researchers thought they isolated only white blood cells and managed to trap some astrocyes. It wouldn't be the first scientific trap that caught something other than intended. Perhaps it was bad journalism. What kind of person wrote the article, from what resources, with what background with what purpose? I remember when the MIR space station lost pressure and the CNN science correspondant had to look up how much pressure a Torr was (maybe CNN can't afford interns).
Then the last possability (I'll bother with). It was good science and good enuff reporting. In my experience pure researchers have this insane laser like focus on their specialty. They literally don't see anything else of the world. Their time table estimates are wildly inaccurate with an optimistic bias. Perhaps that's a necessary character trait, to maintain the relentless intensity and make the breakthough. Without a good perspective on how well and how poorly researchers tend to see the world can a writer really present an accurate depiction? Given a researchers appearent success should a journalist hold a that scientists predictions as highly suspect? If they did, what would the reader think?
I think I've done enough preaching, but I'll make one final remark ala Jerry Springer. At the end of the day, we all make our own judgements as to what the objective truth really is, factoring out other peoples prejudices and factoring our own. And don't pay prostitutes with a personal check if you're the mayor of a major city.
--Jimmy has fancy plans; and pants to match.
There's a little problem nobody here seems to have mentioned yet.
* Split Infinity Music
Experiments with Dolly (baaaaaaa) indicate that while she is a genetic copy of her "parent" donor sheep, so is the "genetic age" of her DNA.
As it turns out, DNA ages just like the rest of the body. Over time, it deteriorates and genetic errors build up. At some point (known to be around 120 years in humans) the decay begins to trigger the cell self-destruction mechanisms, even if those cells are otherwise healthy. The body begins to die one way or the other.
So the "fear" is that even perfectly cloned bodies (or body parts) are not immortal.
Who knows what dying in that fashion would be like - perfectly healthy organs, and then things begin to fail rapidly and suddenly - with little chance of repair.
Don't count on playing God - He's a lot sneakier than we suspected just a couple years ago.
* ~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
--Brandon / Split Infinity Music
With the execption of our teeth and eyes. We are only about 30 days old. All your old cells die, and new ones take their place. The real question on aging is, why do we even age at all? Dispite the fact that we competely replace our cells about one a month, we still age.
This could go a long way to heal things like heart disease, cancer, etc. Where the problems are they cells can't regenerate like they should. But this won't save you from aging.
NOTE: this is just what I remember from what biology I've had in the past. Anyone wants to prove me wrong, feel free.
The problem then would most likely shift from not wanting to cause undue suffering to animals over to being scared of Frankenstein foods. (not commenting on the legitimacy of that fear, just mentioning it)
-----
While regenerating stem cells from differentiated cells is a big deal--since it takes forever to isolate stem cells and grow them--it's nowhere near being able to generate a completely cloned human from a single random cell. There's an enormous difference between pluripotent stem cells and the totipotent cells found in a very early embryo. While a pluripotent CFU can generate each and every single blood cell type, it can't generate neurons or striated muscle. While a pluripotent cell from the neural plate could theoretically generate any type of neuron and even cells that color your skin, the cells that help generate your teeth, and the cells in your adrenal glands, you wouldn't be able to make a liver or a pancreas from them. Only cells from before morulation have this kind of totipotency, and there's really no indication that they're actually causing cells to revert back to this level.
It's not an enormous leap to imagine being able to revert some differentiated cells to their stem cell derivatives. Obviously, erthryocytes can't since they've dumped all their DNA, and neither can lymphocytes, since they've spliced out a lot of theirs, but if other leukocytes keep their DNA intact, all it takes is removing certain regulatory proteins. Not a mean feat by far, but it's not magic either. And nowhere in the article do they claim they've retrodifferentiated completely differentiated NK cells, macrophages, or anything like that. For all we know, they could have just retrodifferentiated stem cells that are less pluripotent (like CFU-GM cells, which can only make granulocytes and macrophages) or even just the non-differentiated forms of RBCs or WBCs (For example, polychromatic erythroblasts, while normally committed to erythrocyte production, still have all their DNA and can still divide, so it wouldn't be too hard to get them to revert)
More obviously, they really haven't claimed that they've done anything about the telomere problem, which really puts a damper on the whole immortality idea. Sure, you could just add telomerase to the mix, but that's more likely to generate uncontrollably dividing cells than anything useful.
In other words, this is over-hyped. Sure, it's good news to people suffering from leukemia and other disorders of hematopoiesis, but if you need a new liver, don't get too excited.
Experiments with Dolly (baaaaaaa) indicate that while she is a genetic copy of her "parent" donor sheep, so is the "genetic age" of her DNA.
As it turns out, DNA ages just like the rest of the body. Over time, it deteriorates and genetic errors build up. At some point (known to be around 120 years in humans) the decay begins to trigger the cell self-destruction mechanisms, even if those cells are otherwise healthy. The body begins to die one way or the other.
You're confusing two mechanisms:
- Error building up.
- The protective (hayflick limit) cell-reproduction counter running out and shutting down the cells.
The site of the counter has been discovered: It's the repeating sequences on the end of the chromosomes (telomeres), which don't copy completely and get shorter with each reproduction. In the absense of an enzyme (telomerase) which adds more repeats to them, the cell reproduction stops after a certain number of copies.
There are several places in the body where the cells contain telomerase and "reset the counter". One of them is a step in producing germ cells (eggs and sperm). So the baby starts out with the counter reset. They procedure they used to make Dolly did NOT reset the counter. But it would be trivial fix that, i.e. by dosing the DNA-sample cell with the enzyme.
(While the degradation of the telomeres is apparently a consequence of the way open-ended chromosomes are copied, the lack of telomerase in most tissues appears to be a protective mechanism to reduce the cancer rate from the geneic errors you mention. To become cancer a cell must acquire errors that BOTH stick its reproduction switch "on" AND switch on the production of telomerase before it has run out the clock. If it misses the second step the tumor stops growing, typically at about the size of a pea, and may then self-destruct.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Alright. There is a reason that embryo stem cells are preferred: they are different.
And there are a number of possibilities for what happens as the cells differentiate. (Production of DNA-regulation enzymes, phosphorilation of DNA bases, DNA edits, folding, etc.)
If the cells were anything BUT white cells (by which I assume they mean fully-mature antibody-producing white cells), I'd be less sceptical.
One step in the maturation of white cells is the differentiation of the antibodies. This involves the deletion of two small segments of DNA in the sites corresponding to the hypervariable regions of the antibodies. This is a noisy deletion, happening differently in each of the many cells in which it occurs, leading to the variety of antibodies with which we are blessed (and sometimes cursed).
Deletions like that are NOT reversable. (They correspond to editing out a chunk of a tape recording, and reversing them would consist of figuring out the missing waveform and editing it back IN. The information is LOST, so you don't have it to put back.)
Assuming all the OTHER steps in cell differentiation from totipotent to adult are members of a limited set of easily reversable changes, applying such fixes to an adult white cell would give you something that looked very much like a stem cell, and could fix most tissues of the body. But try to replace the immune system and you find that the splices were already done. Maybe the markers that control the edits are gone, and you get all one type of antibody. Less likely: the edits still happen but the variety is greatly reduced.
Make a clone and the clone has a defective immune system. If it survives to reproduce its offspring inherit the deficit as a nasty recessive.
Nevertheless, this IS very encouraging news. It sounds like the researcher may have found a way to reverse all the non-DNA-edit differentiation steps, producing a cell that "thinks" it's a stem cell. If true, even with an antibody coding problem such a cell could be used to repair many tissue types and grow replacement organs. And once the process is understood it might be adapted to a cell type that DIDN'T have DNA edits in its differentiation history.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way