Scientists investigating new ways to combat cancer report a promising lead inside the cells of the bowhead whale, a species notable for extraordinary longevity. The findings, published in Nature, contribute to comparative oncology — studying how long-lived and large animals avoid cancer despite having many cells and long lifespans, a puzzle known as Peto’s paradox.
Peto’s paradox notes that larger, longer-lived animals should face higher cancer risk because they have more cells and more time to accumulate cancer-causing mutations. Yet many such species show unusually low rates of malignant tumors, suggesting they evolved extra protections. Previous work found one strategy in elephants: they carry about 20 copies of the tumor suppressor gene that makes p53, a protein that can trigger death of damaged cells, reducing cancer risk. Humans have only one copy.
Seeking other solutions, Vera Gorbunova and colleagues focused on bowhead whales, among the longest-lived mammals, with lifespans exceeding 200 years. Indigenous Iñupiaq hunters from Barrow, Alaska, provided small tissue samples for research, enabling molecular study without large-scale collection. The team observed that bowheads show little evidence of malignant tumors and hypothesized they might prevent cells from accumulating damaging mutations in the first place rather than simply eliminating damaged cells.
Their experiments revealed bowhead cells repair broken DNA exceptionally well — roughly two to three times better than human cells in their assays. The whales appear to achieve this through high levels of a protein called CIRBP (cold-inducible RNA-binding protein). CIRBP is produced abundantly in bowhead tissues and is encoded by a gene responsive to cold, consistent with the whales’ Arctic habitat. Rather than relying primarily on cell death to remove precancerous cells, bowheads seem to invest more in maintenance: repairing DNA to keep cells healthy over centuries.
To test whether CIRBP could have broader effects, the researchers manipulated its levels in other organisms. Human cells engineered to overproduce CIRBP repaired DNA breaks more efficiently. Fruit flies made to produce extra CIRBP lived longer and were more resistant to DNA damage. These results suggest the protein can enhance genome maintenance and may point to strategies that could one day slow mutation accumulation in human cells.
Experts caution that translating findings from other species to human therapies is complex. The bowhead’s approach—ramping up repair mechanisms—likely involves trade-offs, such as energetic costs or other physiological consequences. Comparative biologists emphasize there are probably many additional mechanisms across long-lived species that contribute to cancer resistance, including those found in bats, naked mole rats, and elephants. Uncovering these mechanisms offers potential biomedical insights and strengthens arguments for conserving species that may harbor unique biological solutions.
The researchers also note the ethical and collaborative dimensions of the work: partnering with Indigenous communities was essential for obtaining samples and respectful research. There is hope the research might eventually benefit communities like the Iñupiaq, who face rising cancer rates.
Overall, the study highlights that looking beyond traditional lab models can reveal novel longevity and cancer-resistance strategies. Bowhead whales illustrate a different route than elephants: invest in superior DNA repair to maintain cell integrity across centuries, rather than increasing elimination of potentially precancerous cells. This discovery opens new avenues for exploring whether boosting similar repair pathways in humans could reduce mutation accumulation and lower cancer risk, while recognizing the challenges and trade-offs involved.
