The needs of the many outweigh the needs of the few

Original post:  Oct 13, 2015

I want to live like an elephant. No, not the memory part. That's actually a myth.

With about 100 times as many cells as humans, it would seem that their odds of contracting cancer are also 100 times higher. That is not the case according to an article in Slate:

In reality, given their size and prodigious lifespans, elephants have one of the lowest cancer mortality rates in the animal kingdom: 4.8 percent, compared to a range of 11 to 25 percent for humans. How can this be?

Scientists at the Huntsman Cancer Institute, University of Utah School of Medicine, and Primary Children’s Hospital helped figure out the answer, published Thursday in the Journal of the American Medical Association. Another team, made up of University of Chicago researchers and their colleagues, posted a related paper this week. As it turns out, elephants have developed some ingenious safeguards against developing cancer. Understanding their cellular protections might help us learn more about how to suppress cancer in humans.

There are countless ways that cell division can go wrong. That’s why—as we learned from the winners of this week’s Chemistry Nobel Prize—your cells come equipped with a host of repair enzymes whose sole purpose is to prevent or repair genetic mistakes. These cellular copy editors proofread each strand of newly divided DNA, identifying errors and repairing the faulty bits to ensure that your DNA stays fresh and clean and functional. In humans, just one of those enzymes can fix a thousand different kinds of errors. Not too shabby! 

But elephants have one-upped us. For the JAMA study, researchers first compared cancer rates across the animal kingdom to find out that elephants were remarkably cancer-free given their size. (Other animals fared well, too. For comparison, rock hyraxes have a 1 percent cancer mortality rate, African wild dogs have an 8 percent rate, and lions have a 2 percent rate.) Then, they scoured the elephant genome to find out why.

The article goes on to single out one of their genes (known as p53) for its protective properties. They analyzed real elephant cells to discover:

....When they compared elephant cells to human cells, they found something amazing: The damaged cells in elephants were far more likely to resort to cell suicide—known as apoptosis—to avoid propagating errors in their descendants. It was a brutally efficient, even ruthless, system for protecting the organism at all costs.

It's that old Star Trek adage come to life:  The needs of the many outweigh the needs of the few (or the one)!

Here is the link to the full article:  Why elephants don’t get cancer: extra tumor-suppressors.