Greenland bowhead whales are among the largest and longest-lived mammals known, able to live for more than 200 years and reach over 80 tons. For decades scientists have been trying to understand how such a large animal can live so long without developing serious illnesses such as cancer, since the enormous number of cells that compose its body would theoretically raise that risk.
A new international study, published in the journal Nature and released by Springer Nature, may now help explain this enigma.
Resilient Cells and DNA That Repair Rapidly
The researchers compared Greenland bowhead whale cells and human cells in the laboratory, exposing both to stimuli that typically trigger cancer-causing mutations, such as ultraviolet radiation. The results showed that, although whale cells could undergo mutations, they exhibited far fewer genetic damages than human cells and, above all, were able to repair damaged DNA with great speed and efficiency.
“These whales seem to have developed exceptional cellular mechanisms of genetic repair, which may be one of the keys to their extraordinary longevity,” explain the authors, among them Jan Vijg and Vera Gorbunova, experts in cellular aging.
A Protein That Extends Lifespan
The team also identified a protein associated with DNA repair in Greenland bowhead whales. When this protein was produced in greater quantities in human cells, these showed an improvement in the capacity to repair DNA. In a subsequent step, the same compound was tested in fruit flies, where it increased the insects’ lifespan — an indication that this protein may lie at the origin of the whales’ notable resistance and longevity.
A Paradox Resolved
The study helps to explain the so-called “Peto’s paradox,” the observation that larger animals with more cells, such as whales, do not exhibit a higher incidence of cancer than smaller species. According to the authors, enhanced DNA repair could be the answer.
Still, the researchers emphasize that there are limitations: the experiments were performed with human fibroblasts — connective tissue cells — and not with epithelial cells, where most cancers originate.
Even with this caveat, the conclusions open new clues about the biological mechanisms of aging and point to potential avenues in research on longevity and cancer prevention in humans.
“Greenland bowhead whales can teach us a lot about how cells resist the ravages of time and disease,” the authors conclude.
