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Elephants Rarely Get Cancer, Now We Know Why (2015)

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Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#61

Post by Merrill »

gigatexal wrote: post #10

Could we use CRISPR to copy this gene more times in humans then?

p53: Regular or super?

Increased p53 expression under the endogenous promoter protects “super p53” mice from tumorigenesis without the undesirable effects of premature aging.

https://www.sciencedirect.com/science/article/pii/S153561080...

>Garcia-Cao and collaborators report the generation of novel transgenic mice, called “super p53.” The super p53 mice express wild-type endogenous p53, and also carry one or two extra copies of a normal p53 gene, inserted as transgenes in the form of large genomic fragments of 130 to 175 kilobases. Because the additional p53 gene is expressed from its own promoter, the transgenically expressed p53 seems to be regulated in the same fashion as endogenous p53.

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#62

Post by bnegreve »

chubot wrote: post #22

Didn't early humans also rarely get cancer? My understanding is that cancer is one of those things you die from if you don't die at child birth, get eaten by predators, or get the flu, polio, malaria, the plague, etc. That is, the reason cancer is such a big deal in modern times is because other causes of death have been controlled. I don't know much about elephants but I imagine cancer is still low on their list of…

From what I understand, there's only a limited number of times you can perform cellular division without getting erroneous DNA copies (cancerous cells).

Like humans, elephants start their life with one cell, which is then replicated over and over again until the end of their lives. But somehow, elephants manage to reach body sizes 100 times bigger than humans (meaning many more cellular divisions) without having cancerous cells.

I think that's the basic observation that triggers this kind of research.

Disclaimer: I am no expert at all.

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#63

Post by usrusr »

joebaf wrote: post #24
chubot wrote: post #22

Didn't early humans also rarely get cancer? My understanding is that cancer is one of those things you die from if you don't die at child birth, get eaten by predators, or get the flu, polio, malaria, the plague, etc. That is, the reason cancer is such a big deal in modern times is because other causes of death have been controlled. I don't know much about elephants but I imagine cancer is still low on their list of…

Still, we have pediatric cancers that are not caused by lifestyle. I wonder what's the ratio for small elephants. Are the also more protected ?

But how often would those be encountered in an average city? Because that's about the size of the total elephant population and if a handful of individuals got a rare cancer, chances that biologists would learn of it are still slim.

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#64

Post by herf »

Pulled from the comments (which are remarkably smart):

"Upregulated p53 activity in humans is implicated in Huntington's disease. Which makes sense, since the symptoms involve early death of brain cells. So this isn't a panacea in itself. But as we learn more of the gene regulatory networks involved, we may be able to develop something much more fine-tuned that has the benefits without the costs." - Suzanne Sadedin

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#65

Post by ninkendo »

bnegreve wrote: post #62
chubot wrote: post #22

Didn't early humans also rarely get cancer? My understanding is that cancer is one of those things you die from if you don't die at child birth, get eaten by predators, or get the flu, polio, malaria, the plague, etc. That is, the reason cancer is such a big deal in modern times is because other causes of death have been controlled. I don't know much about elephants but I imagine cancer is still low on their list of…

From what I understand, there's only a limited number of times you can perform cellular division without getting erroneous DNA copies (cancerous cells). Like humans, elephants start their life with one cell, which is then replicated over and over again until the end of their lives. But somehow, elephants manage to reach body sizes 100 times bigger than humans (meaning many more cellular divisions) without having canc…

Our gamete cells have been undergoing an unlimited number of cellular divisions since... well, since life started. What's so special about somatic cells that makes them cancerous after so many divisions?

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#66

Post by beerandt »

Smithalicious wrote: post #59
beerandt wrote: post #48

Earlier quoted context omitted.

You'd have to domesticate them. And then it's a philosophical question of if they're even Tasmanian Devils anymore. After all, the success of dogs didn't do anything to prevent the near extinction of the wolf.

There are many pets that aren't domesticated like fish, snakes, tarantulas. That's not to say that Tasmanian devils are docile enough to be that kind of pet, though.

True, but...

Part of what makes the cancer so transmissible with Tasmanian devils is their predisposition for biting each other, especially on the face, well past the point of drawing blood.

I mean, they're not called devils because they're red with horns.

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#67

Post by 1_over_n »

pmoriarty wrote: post #5

"Mouse cells given extra copies of the p53 gene seemed to develop some cancer resistance, he said." I wonder if they could try putting it in to tasmanian devils, which have suffered enormous cancer rates recently.

just looked then to see if naked mole rats have upregulated p53 too as they are resistant to cancer and it seems to be regulated by same mechanism

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3511137/

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#68

Post by lone-commenter »

ninkendo wrote: post #65
bnegreve wrote: post #62

Earlier quoted context omitted.

From what I understand, there's only a limited number of times you can perform cellular division without getting erroneous DNA copies (cancerous cells). Like humans, elephants start their life with one cell, which is then replicated over and over again until the end of their lives. But somehow, elephants manage to reach body sizes 100 times bigger than humans (meaning many more cellular divisions) without having canc…

Our gamete cells have been undergoing an unlimited number of cellular divisions since... well, since life started. What's so special about somatic cells that makes them cancerous after so many divisions?

> What's so special about somatic cells that makes them cancerous after so many divisions?

Nothing, actually. I'd rephrase the parent comment.

There is in fact a fixed (somewhat small) probability that replication ends up in a mutation. But looking at the continuous replication going on in our cells as a Bernoulli process, you can find a number N such that there is a probability of Q (say 99%) that a mutation happened before the Nth replication.

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#69

Post by vikramkr »

ninkendo wrote: post #65
bnegreve wrote: post #62

Earlier quoted context omitted.

From what I understand, there's only a limited number of times you can perform cellular division without getting erroneous DNA copies (cancerous cells). Like humans, elephants start their life with one cell, which is then replicated over and over again until the end of their lives. But somehow, elephants manage to reach body sizes 100 times bigger than humans (meaning many more cellular divisions) without having canc…

Our gamete cells have been undergoing an unlimited number of cellular divisions since... well, since life started. What's so special about somatic cells that makes them cancerous after so many divisions?

It's actually that they aren't special. With gametes the body cares about making sure things work out well, and you only need the one embryonic stem cell to be issue free (discarding any with mutations) to create a new healthy human. With the somatic cells though you just need one (oversimplifying massively here of course) cell to become cancerous to kill the person, and the DNA repair mechanisms become more likely to fail throughout life

Re: Elephants Rarely Get Cancer, Now We Know Why (2015)

#70

Post by earthboundkid »

_Microft wrote: post #54
dr_dshiv wrote: post #38

Earlier quoted context omitted.

Assume half of babies die in childbirth or by age 3. Assume another half die before they reach 25. Even assume that another half die before age 60. That means there are still tribal elders that can pass on information and educate the small children they take care of while parents are out getting food. It's a huge deal for a species based on cultural learning.

> That means there are still tribal elders that can pass on information [...] It's a huge deal for a species based on cultural learning. True, it might be easy to claim that there is no way to select for longevity because longevity happens after the birth of the offspring. Having elder generations around to improve the odds of survival for the descendants should make longevity a possible factor in selection.

FWIW, the human birth process is not viable without cultural accumulation. Baby heads are too damn big and kill women if they don't have a midwife to help them through. But it's a cycle and the midwife is only helpful herself because she has an oversized brain to pass along cultural knowledge.
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