Elephants are one of the most majestic animals on the planet. Some can weigh upwards of 14,000 pounds and, surprisingly, many live well past the age of 70. Why is that? These gigantic creatures rarely get cancer. 

In a study published in the Journal of the American Medical Association, scientists discovered that African elephants have 20 times more TP53 (a cancer-fighting gene responsible for suppressing the formation of tumors) than do humans. Elephants have 20 pairs of TP53, while humans have only one pair.

“[Elephants] are 100 times our size, and have so many cells, and live for such a long time, it stands to reason that just by chance alone all elephants should be dying from cancer. But they don't," said pediatric oncologist Joshua Schiffman of the Huntsman Cancer Institute in Salt Lake City.

After analyzing zoo death records of 644 elephants, the scientists discovered that just 4.8 percent died of cancer. By contrast, the cancer death rate in humans is 11 to 25 percent according to the study. Also, more than 1.6 million Americans will be diagnosed with cancer this year alone and nearly 600,000 will die according to the American Cancer Society.

The team of scientists performed a variety of experiments to show how the extra copies of TP53 help elephants fend off cancer. One such experiment involved drawing blood from eight African and Asian elephants and comparing them to blood drawn from 21 people—10 healthy individuals and 11 who had Li-Fraumeni Syndrome (a rare genetic condition in which patients have just a single copy of TP53, giving them up to a 90 percent lifetime risk for developing cancer). Both human and elephant blood samples were exposed to radiation. The scientists observed that during the process, the elephants’ TP53 genes began killing off damaged cells, destroying five times as many than those in Li-Fraumeni Syndrome patients, while human TP53 genes focused more on simply repairing cells.

Based on this experiment, Schiffman noted a drug that simulates the elephant’s TP53 genes (killing instead of mending the cancer-causing cells) may be the key to a solution for humans. Although there’s still a long way to go, cancer is the second-leading cause of death in the U.S., so any new discoveries such as this can only be considered a step toward the cure.

 

Source:

  1. JAMA: Potential Mechanisms for Cancer Resistance in Elephants and Comparative Cellular Response to DNA Damage in Humans
  2. HealthDay: Elephants' Cancer-Crushing Secrets May Someday Help People
  3. American Cancer Society