Rare whale could help fight cancer

Image: Vivek Kumar / Unsplash

The genome of a rarely sighted whale could provide critical insights for cancer research, say a team of scientists.

The pygmy right whale (Caperea marginata) is the smallest of all baleen whales, although it can still grow up to six meters in length - about the size of a shipping container, and weigh up to three tons. It is the last surviving member of an otherwise extinct branch of baleen whales, and has previously received no attention from the scientific community.

However, a team of scientists from Germany and Sweden has now discovered genetic material from the whales could provide interesting information for cancer research.

Image: World Register of Marine Species, Robert Pitman, NOAA Fisheries

Due to their huge bodies, whales should be predestined for tumour diseases. This is because, the more cells you have, the greater the chance that one of your cells will mutate -which leads to the development of tumours. Yet contrary to their size and cell numbers, these giant whales seem to have an unusually low risk of cancer.

How this resistance works at the genetic level is still unknown, but deciphering it holds great potential for cancer research.

"This means that each larger whale may have its own adaptations against tumours that we could one day use."

Magnus Wolf, Goethe University

To unravel this mystery, researchers from the Senckenberg Biodiversity and Climate Research Centre (SBiK-F), the Hessian LOEWE Centre for Translational Biodiversity Genomics (TBG) and the universities of Frankfurt am Main and Lund, Sweden, analysed the genome of the pygmy right whale.

They discovered numerous genes that have significantly more mutations in large whales, such as the blue whale, fin whale or bowhead whale, than in the small pygmy right whale. While genetic mutations are generally considered harmful, a high number of mutations within a gene is usually associated with a positive effect for the species.

According to the researchers, the results suggest these positively selected genes may play a special role in whale cancer resistance.

"Our new findings demonstrate that almost every large cetacean species seems to have other positively selected genes in their genome," explains Magnus Wolf, researcher at the SBiK-F and Goethe University in Frankfurt. "This means that each larger whale may have its own adaptations against tumour that we could one day use."

In fact, most of the genes identified by the team are already known in tumour research but have not yet been extensively studied. Whale genomes could therefore provide useful information for medical research in the future.

"Genomic data is the basis for understanding biodiversity and contributes to precise conservation efforts."

Professor Axel Janke, Frankfurt University

The scientists behind this study have warned that research and medical potential of biodiversity genomics is at risk of being lost due to biodiversity loss.

"Even though baleen whales are now strictly protected, and their populations seem to be recovering, there are still traces of their former hunting within their genomes, such as a certain loss of genetic diversity – with possible long-term consequences for these whales. Therefore, a precise genomic monitoring is important," said study leader Professor Axel Janke, also a scientist at SBiK-F and Frankfurt University.

The study on the evolution and tumour resistance of baleen whales was recently published in the journal BMC Biology.