Elephants Rarely Get Cancer, Now We Know Why (2015) • Hacker News Board

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

#51

Post by anovikov » Sat, Nov 09, 2019, 10:12 AM UTC

luc4sdreyer wrote: post #37

londons_explore wrote: post #28

Earlier quoted context omitted.

Prehistoric human lifetime is very hard to estimate, but I have heard reports that while infant mortality was high, actual lifetimes could still reach 70+ years

It's true that life expectancy used to be very low due to very high infant mortality, but even after that it wasn't easy going: > Based on Neolithic and Bronze Age data, the total life expectancy at 15 would not exceed 34 years. Based on the data from modern hunter-gatherer populations, it is estimated that at 15, life expectancy was an additional 39 years (total 54), with a 0.60 probability of reaching 15. https://e…

That's in the times when agriculture became a thing. It meant that people lived in a very crowded way where the limited tracts of very fertile land was, settled and with very poor sanitation. Infections were rampant, and famines in poor crop years, common. Hunter-gatherers had it much better - except there were a lot fewer of them.

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

#52

Post by beerandt » Sat, Nov 09, 2019, 10:22 AM UTC

DoreenMichele wrote: post #46

beerandt wrote: post #45

Earlier quoted context omitted.

>I mean, I guess it would depend on how you are introducing the gene. How many cells it is getting into. It's cancer. You're trivializing the ultimate source of the problem. If we could ensure universal targeting of cancer cells, we wouldn't need a technically elaborate method of cellular death, like gene modification. You might as well suggest solving world hunger by just feeding everyone.

You're trivializing the ultimate source of the problem. No, I'm not. But it's occurred to me that I'm imagining this as treatment for Tasmanian devils that already have tumors. Maybe other people are envisioning it as a preventative measure. And maybe that's part of the problem in trying to discuss it.

It is by definition a preventative measure. Otherwise, it's no different then any other cancer treatment in that it has the same fundamental weakness working against it: natural selection.

If the cells knew when they were supposed to die, then it wouldn't be cancer.

If the cure is telling the cells when they're supposed to die, then the cells that don't listen survive, ergo the cancer survives.

Which, in the sense of (non-preventitive) treatment, makes it a problem of universal targeting.

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

#53

Post by amphitoky » Sat, Nov 09, 2019, 10:28 AM UTC

DoreenMichele wrote: post #16

duskwuff wrote: post #11

Earlier quoted context omitted.

The cancers you're thinking of in Tasmanian Devils are the result of a transmissible (!) tumor. The cancerous cells aren't the result of mutations within the animal's body, but instead are introduced into it from another infected animal. As such, genetic therapies are unlikely to have an effect.

As such, genetic therapies are unlikely to have an effect. Can you back that up somehow? That doesn't sound at all right to me. Edit: For the upvote, downvote brigade -- with zero reply so far, but this comment has gone to zero and back to one umpteen times already -- I'm genuinely curious. This isn't some kind of gotcha question. I have a genetic disorder. I have umpteen relatives who have had cancer. I actually hav…

as others have said, genetic therapies for these kinds of transmissible cancers are not so effective since the cells have already acquired the cancer phenotype. The usual regulatory mechanisms which prevent unchecked proliferation occur in each individual cell, and have already been circumvented by the time cells become cancerous.

I thought I would add that what makes the tasmanian case interesting is that though the body is generally pretty good about detecting and removing foreign cells (including viruses and bacteria), somehow these contagious cancers elude this detection and are allowed to proliferate [1]. It is likely that if the tasmanian devil's immune system were able to detect the intruder cancer cells as coming from another individual, it would eradicate them with ruthless efficiency. Why these cells are able to skirt the host immune system though is a different question.

[1] https://www.ncbi.nlm.nih.gov/pubmed/28695294

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

#54

Post by _Microft » Sat, Nov 09, 2019, 10:29 AM UTC

dr_dshiv wrote: post #38

kungito wrote: post #34

Earlier quoted context omitted.

I don't get this argument. Sure, some did reach old age but we are way more interested in what percentage of them it was

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.

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

#55

Post by sek » Sat, Nov 09, 2019, 10:54 AM UTC

dean177 wrote: post #36

sek wrote: post #33

Just a hypothesis I thought of: A lot of cancer cells are developed because of constant background radiation, if you get older you just were exposed to more of it. Elephants have a much higher volume to be affected by it, so just from an evolutionary perspective they had to develop a better resistance. The ones who got cancer early couldn't reproduce as well. Does that make sense? Or does the article say exactly that…

Why not have a read and find out?

Well it just says many cells should mean a lot of cancer.

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

#56

Post by sjg007 » Sat, Nov 09, 2019, 11:53 AM UTC

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…

We see cancer in the human fossil record.

https://www.cancer.org/cancer/cancer-basics/history-of-cance...

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

#57

Post by graeme » Sat, Nov 09, 2019, 11:55 AM UTC

TheSpiceIsLife wrote: post #12

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.

I live in Tasmania :) That’s a great idea. Also, I advocate to make endangered animals legal to keep as pets. Look how successful cats and dogs are.

They made a devil reserve in australia, in a similar climate. Going well I think.

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

#58

Post by davidgerard » Sat, Nov 09, 2019, 12:14 PM UTC

sl1ck731 wrote: post #26

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…

I believe I've read this verbiage around cancer in pets, such as domestic cats living far longer than "intended".

Pet rats ("fancy rats") were largely separated fron the wild gene pool about 150 years ago. They can live to three years or more, and are quite prone to benign tumours.

(source: wife used to be a fancy-rat breeder)

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

#59

Post by Smithalicious » Sat, Nov 09, 2019, 12:18 PM UTC

beerandt wrote: post #48

TheSpiceIsLife wrote: post #12

Earlier quoted context omitted.

I live in Tasmania :) That’s a great idea. Also, I advocate to make endangered animals legal to keep as pets. Look how successful cats and dogs are.

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.

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

#60

Post by dlwdlw » Sat, Nov 09, 2019, 12:32 PM UTC

Do humans happen to get more cancer than other animals? There’s this weird idea, I forget the source, that a less efficient cell garbage collection mutation allowed increased brain development, connections, etc... but at the cost of increased cancer, depression, ego, etc...