Cancer Findings from Under the Sea

Bowhead Whales, CIRBP, and Cancer Prevention

Have you ever heard of Peto’s paradox? Cancer occurs from mutations in the cell that disrupt the cell cycle and trigger unregulated cell replication. Mutations have a low likelihood of happening, so it would make sense that the more cells an organism has, the higher rates of cancer would be, right? Between individuals of the same species, this holds true. Taller people have higher cancer rates than shorter people. Across species, however, it is a different story. Mice, for example, have higher rates of cancer than people despite being much smaller. Whales and elephants have many more cells than we do but are less likely to develop cancer than a human.

This observation has led scientists to conclude that larger animals likely have better cell cycle regulation than smaller ones. Thus, by studying the cells of a whale, for example, scientists could gain insight in how to prevent cancer in humans. That is exactly what Firsanov et al. did in their recent study Evidence for improved DNA repair in the long-lived bowhead whale. Despite being the second largest animal on Earth, the bowhead whale does not see high incidence of cancer. When comparing human and bowhead whale cells, they found that the whale cells exhibited a higher ability to faithfully repair double strand breaks in DNA, indicating lower mutation rate overall.

The researchers identified this to likely be due to the cold-inducible RNA binding protein (CIRBP) which is associated with cell repair in humans. CIRBP is highly expressed in the bowhead whales’ fibroblasts and tissues. When the bowhead CIRPB was introduced to human cells, the cells exhibited increased homologous recombination and DNA end protection. In Drosophila, introduction of CIRPB increased both the insects’ lifespans and their resistance to ionizing radiation.

These results show promise in the development of cancer prevention drugs via DNA repair. This could help the elderly and people who are genetically predisposed for cancer and possibly result in lower cancer rates in populations as a whole. Of course, more research needs to be done on the safety and viability of these treatments, but this development is very exciting news in the long fight against cancer.