They discover why bats rarely get cancer

They discover why bats rarely get cancer

When we think of bats, we usually associate them with myths, superstitions and, especially since the Corona pandemic, with their direct or indirect ability to transmit viruses that can cause serious illnesses in humans.

Sometimes the image of his human relative Batman comes to mind, a superhero with his own ideal of justice in the fight against crime. But even if this is a different (and fictional) story, it is true that bats have extraordinary characteristics worthy of a Marvel character: they are extremely long-lived for their size, immune to many viruses and, on top of that, they display a enviable resistance to cancer.

Bats as role models in science

Although they are not as common in laboratories as mice or rats, bats have unique characteristics, the study of which allows us to gain knowledge in various scientific fields and their possible applications. Thus, unlike other mammals, bats are capable of flight (there are species of mammals that can glide or glide, but cannot actively fly). Its physiology and biomechanics of flight are areas of interest for students of flight evolution in animals of the vertebrate group.

Additionally, bats have the ability to see through sound, which is called echolocation. This interesting phenomenon is the subject of the study of sensory perception from a neurobiological point of view. And of course, bats are essential pollinators for our ecosystems and play a very important role in pest control. Since they are among endangered species, research into their biology and habitats is crucial for the conservation and preservation of ecosystems.

Longevity and disease resistance

Surprisingly, some species of bats live longer than other mammals of similar size. Most small mammals such as mice, rats and hamsters typically do not live past three years (excluding deaths from predators). However, many bats can live in the wild for decades, with records for some species extending over 40 years. Longevity is associated, among other things, with their ability to hibernate or the fact that they live in caves.

In addition, bats show remarkable resistance to certain diseases, including some viruses that are deadly to other mammals. Thus, these flying mammals have been involved in, but not affected by, emerging zoonotic (transmitted to humans) outbreaks, including Marburg virus, Nipah virus, and severe acute respiratory syndrome coronavirus 1 (SARS-CoV). -1) and 2 (SARS). -CoV-2), either through direct human contact or through animals acting as intermediaries.

Molecular and cellular adaptations

Various studies suggest that bats may have adaptations at the genetic and cellular levels that protect them from aging, viruses and diseases, including cancer.

Although it is known that bats are not completely immune to cancer, no tumors have been reported in the longest-lived species. In this sense, two of the longest-living species, Myotis brandtii and Myotis myotis, have been described as having genetic adaptations related to tumor suppression that could contribute to their extreme longevity.

In addition, an improvement in DNA repair and immune competence, stabilization of the microbiota, as well as a reduction in inflammation and resistance to viruses through a more flexible thermoregulation (the one mentioned above related to hibernation) were also noted. It has also been suggested that their tolerance to many viral infections is due to unusual features of their innate immune response.

Taking all these adaptations into account, it is more than obvious that bats are a very interesting model to study the diverse genotype-phenotype relationships and their clinical implications. For example, if we can understand the mechanisms of the immune system of bats that allow them to tolerate viral infections, we could be better prepared to prevent zoonotic outbreaks.

Genomics and evolution to study cancer

But it is also extremely interesting to carry out comparative genomic analyzes between bats and other mammals more susceptible to cancer, as the results obtained provide clues to the causes of cancer or the connections between cancer and immunity, and can thus search for solutions to combat it.

To this end, an article was published today in the prestigious journal Genome Biology and Evolution in which they report a new and complex method for genomic sequencing in two species of bats: the Jamaican flying fox Artibeus jamaicensis and the Mesoamerican mustache bat Pteronotus mesoamericanus. The results were compared with those of other mammals (humans, mice, dogs, pigs, horses and 13 other bat species).

The research group found that one type of interferon (INF-Omega) is more common in bats and that antiviral genes stimulated by type I interferons have also evolved rapidly, with strong selection favoring the IFIT2 genes ( due to the special antiviral activity). ) and PRDM9 (related to recombination and also involved in responses to infections), adaptations that most likely allow them to harbor viruses without contracting the disease.

They also found evidence of positive selection in 33 tumor suppressor genes and 6 DNA repair genes across the bat evolutionary branch, which may be linked to the low cancer rates and longevity observed in these very peculiar mammals.

One of Batman’s quotes is: “Sometimes people deserve to have their faith rewarded.” Let us believe in science and we will be rewarded.

Francisco Jose Esteban Ruiz He is a full professor of cell biology at the University of Jaén

This article was originally published on The Conversation.

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