MONDAY, May 13, 2019 (HealthDay News) -- Whales, the gentle giants of the ocean, may offer clues on fighting cancer in humans, researchers say.
Age and weight are known cancer risk factors. So it would seem that whales -- which include some of the largest and longest-lived animals on Earth -- would have a high cancer risk.
Actually, though, whales are less likely than humans to develop or die from the disease, leading scientists to investigate how their cancer defenses are so effective.
For the study, they examined the genomes of humpback whales, blue whales, fin whales, bowhead whales and sperm whales.
They found that some parts of these whales' genome have evolved faster than those of other mammals. These parts contain genes that control the cell cycle, cell proliferation and DNA repair -- essentials for normal cell function.
In human cancers, many of these genes are mutated.
The whale genomes also have many duplications in tumor suppressor genes, according to the study published May 9 in the journal Molecular Biology and Evolution.
This information could help identify new targets for preventing cancer in people, said lead author Marc Tollis. He's an assistant professor in the School of Informatics, Computing and Cyber Systems at Northern Arizona University in Tempe.
For example, a protein in whales that can stop cell proliferation might be used to develop drugs that shrink tumors in humans.
Previous research found that elephants also have low rates of cancer, but they have different mechanisms than whales to suppress it. It's also known that while cancer afflicted dinosaurs, it's likely that they had efficient cancer suppression, according to the researchers.
"Our goal is not only to get nature to inform us about better cancer therapies, but to give the public a new perspective of cancer," Tollis said in a university news release.
"The fact that whales and elephants evolved to beat cancer, and that dinosaurs suffered from it as well, suggests that cancer has been a selective pressure across many millions of years of evolution, and it has always been with us," he explained.
The U.S. National Cancer Institute has more on cancer.