Longevity Briefs: What Can Bats Teach Us About Stopping Cancer And Ageing?

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

When it comes to lifespan, larger animals generally live longer than smaller animals. Larger animals also tend to have evolved to be more resistant to cancer – after all, they have more cells, which means more opportunities for cancer-causing mutations to occur, so they need better cancer suppression mechanisms to compensate. While these principles are mostly consistent, there is a lot of variation as well as some very significant exceptions – species that have significantly longer lifespans and less cancer risk than might be expected for their size. Humanity itself is one such exception, but studying other exceptions could give us some clues as to how we can further reduce our cancer risk and extend our lifespans.

In this preprint paper, researchers used genetic screening to study a genus of bats called Myotis, also known as mouse-eared bats. While Myotis bats live a long time, there’s still considerable variation between different species. The longest-lived species – Brandt’s bat, or Myotis brandtii – can live for over 40 years, while closely related Myotis nigricans live for ‘only’ 7 years. This diversity makes them an interesting group to study for learning what makes a species long-lived – knowledge that could one day be harnessed to extend our own lifespans.

The discovery:

By studying the genomes of 8 species, researchers were able to model the evolution of Myotis species, revealing that their lifespans rapidly increased relative to their body size during evolution. This was accompanied by a reduction in cancer risk at the cellular level thanks to the accumulation of tumour-suppressing genes. Species tend to gain tumour-suppressing genes during evolution as they evolve larger body sizes, but the body size of Myotis species has not changed significantly since their common ancestor.

The researchers found that many genes associated with systems thought to be important in ageing had been selected for during the evolution of Myotis species. These included genes related to the immune system, repairing damaged DNA, protecting against oxidative stress, the activity of senescent cells (aged cells that have lost the ability to divide), and the mTOR-IGF pathway, which controls cell growth and division based on the availability of nutrients and is the target of several mouse lifespan-extending drugs.

The implications:

Myotis bats appear to have evolved adaptations in many of the pathways we already suspect to be important in the ageing process, probably as a result of their unique biology. Bats need to maintain a high metabolic rate and also coexist with many viruses which they are able to tolerate without succumbing to disease. Their ability to do this may have involved the evolution of protective mechanisms like resistance to oxidative stress and DNA damage, which are also highly beneficial for resisting cancer and ageing. Bats fly long distances, come into contact with many species and are also social animals, so they accumulate and spread viruses quickly.

It is hoped that further study of these systems in bats and other animals could inspire treatments to reduce the risk of age-related diseases like cancer in humans. While humans have been searching in earnest for ways to slow ageing for over a century, millions of years of evolutionary trial and error have already produced organisms that are more resistant to ageing than us, and we still have a lot to learn from them.