
Two Naked Mole Rats, Seemingly Immune to Cancer, Got Cancer - dkarapetyan
https://www.nytimes.com/2016/02/20/science/two-naked-mole-rats-seemingly-immune-to-cancer-got-cancer.html
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reasonattlm
Bear in mind that researchers have colonies of thousands of these animals, and
in all the time people have been looking, only a tiny number of cases of
cancer have been cataloged in this species. [1] Compare that with the cancer
incidence and mortality rates in other mammals.

The present thinking on various mole rat breeds and their cancer resistance is
that they have more active and more useful cancer suppression gene activities
for p16, p21, p27, ARF, etc, and that their tissues have a lot more high
molecular weight hyaluronan than peer species [2]. Disabling the gene
producing the hyaluronan makes them vulnerable to cancer, and that appears
connected to p16 activity.

The important outcome of the particular setup for naked mole rat biochemistry
may be that their cells are a lot more sensitive to crowding, and will more
readily self-destruct when that happens. Without that, cancer is more easily
induced.

[1]:
[http://dx.doi.org/10.1177/0300985816630796](http://dx.doi.org/10.1177/0300985816630796)

[2]:
[http://www.rochester.edu/news/show.php?id=6572](http://www.rochester.edu/news/show.php?id=6572)

~~~
derefr
Is "crowding" a common state for tissue to get into? Polyploid plant tissue
comes to mind.

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maxander
> Dr. Delaney and her colleagues have studied lesions on naked mole rats for
> more than a decade [...]

One of the wonders of science is the important discoveries that come from a
focused investigation into some of the most obscure things.

~~~
Waterluvian
When we find people who are both talented and dedicated enough to focus on
such a specific realm of science, we really ought to have plenty of money and
resources for them.

I suspect we can be doing a lot better, but I doubt this is the worst of all
the parallel universes when it comes to supporting science.

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vecter
> Three months later they found no remnants of the cancer, making him the
> first known naked mole rat cancer survivor.

Did it magically cure itself? Does that ever happen in humans when there is no
medical intervention? That seems amazing.

~~~
throw_away_777
The body is fairly good at fighting off illnesses and disease. Not a doctor,
but from what I have read often by the time someone is diagnosed with cancer
it has progressed to a stage where the body's immune system has failed to
fight it off, so it is probably rare for cancer to go away on its own. Here is
one article suggesting that cancer can go away on its own:
[http://articles.mercola.com/sites/articles/archive/2008/12/1...](http://articles.mercola.com/sites/articles/archive/2008/12/18/some-
cancers-may-just-go-away.aspx)

~~~
sandworm101
>> so it is probably rare for cancer to go away on its own.

It is actually very common. It has happened to you many times without you
knowing it. Cancerous cells can appear and be taken care of immediately by
various natural mechanisms. There are mechanisms to correct errors in DNA
before a cell divides, or a damaged cells can self-destruct. This happens all
the time as skin cells deal with DNA damaged by UV light. And there are
diseases that cause cancer not directly but because of breakdowns in these
repair mechanisms (see DNA repair-deficiency disorder). If you looked at every
cell in your body no doubt a great many are technically cancerous at any one
time. A clinical case starts when the natural mechanisms fail and damaged
cells divide enough to cause the disease we call cancer.

The distinction is medically important because if you go looking for every
tiny little bit of cancer you will find a great many that would never give
rise to a clinical case, that would never impact the patient.

~~~
nonbel
Have you looked into what combination of mutation rates and number of required
mutations would be necessary for your model to work? Usually people say it is
something like 10^-8 per bp per division and you need to collect 3-6 mutations
to get cancer.

~~~
sandworm101
Isn't cancer predicated on mutations that result in uncontrolled cell growth?
I imagine there are a great many mutations that result in cell death or an
inability to properly divide. Those mutations wouldn't contribute to cancer
risk. So maybe you need 3-6 but only amongst those bits of DNA that actually
matter.

~~~
nonbel
Yes, that is correct. It would only be some "special" combinations of
mutations, not just any set.

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lngnmn
What is the immunity to a cancer supposed to mean? Immunity to a random
mutation in a cell's DNA?

~~~
mannykannot
I don't think so - I think it means the ability to destroy, or otherwise
render harmless, those mutations that behave in a cancer-forming way.

~~~
lngnmn
The cell looks like normal one, perfectly legitimate, it just divide and
divide..

