Unique Protein That Helps Tardigrades Endure Deadly Radiation Could Help Us Fight Cancer

Tardigrades, the microscopic animals popularly known as “water bears,” have rightfully earned their reputation as the most sturdy organisms in the world. They’re undeterred by the harshest conditions that nature has to offer, living at temperatures plummeting to absolute zero (around minus 459 degrees Fahrenheit) and surpassing 300 degrees Fahrenheit.

Believe it or not, tardigrades can achieve an even more impressive feat of survival; the tiny creatures are capable of enduring 1,000 times more intense radiation than mammals can handle.

What allows them to do this, according to a new study published in the Journal of Molecular Biology, is a special protein called “Dsup,” which guards DNA from radiation-induced damage, and could one day help researchers in the fight against cancer.

Tardigrades: The Best Survivors in Nature

For years, scientists weren’t sure how tardigrades could live when exposed to extreme radiation. Initially, they surmised that it had something to do with anhydrobiosis, an ability that allows the micro-animals to live in a limbo-like state after they shed almost all of their intracellular water.

When anhydrobiosis occurs, tardigrades enter a “tun” state during which they dry out and curl into a seemingly lifeless ball, slowing their metabolism to a near halt. Some tardigrade species (of which there are over 1,300) can rehydrate and come back to life after years of essentially shutting down in their tun state.

It may sound like this superpower is the reason why tardigrades are protected against radiation, but studies have shown that some species can still endure radiation even in a hydrated state.

Read More: Tardigrade Tattoos Could Pave the Way for Microscopic Medical Devices

A Radiation-Proof Protein

The true answer to tardigrades’ radiation resistance appears to be the Dsup (damage suppressor) protein. While this protein is unique to tardigrades, several studies have tampered with other animals’ genomes to see if the protein would maintain the same benefits.

One study that gave mice the genetic instructions to produce Dsup found that they sustained less DNA damage than untreated mice when subjected to high doses of radiation. Another study expressed the Dsup gene in the nematode Caenorhabditis elegans, enabling it to tolerate x-ray exposure and to exhibit an extended life span.

Based on the outcomes of these studies, researchers began to realize the exciting potential of Dsup. However, they didn't quite understand how it worked in tardigrades to prevent DNA damage. Some thought of it as more of a shield that blocked radiation, while others believed it was mostly helping cells to repair DNA before damage could accumulate.

The new study has found a path forward when it comes to understanding Dsup in tardigrades. In the study, researchers examined the biochemical and structural properties of Dsup that lead to DNA protection. In doing so, they realized that after the protein binds to single- or double-stranded DNA, it partially unwinds the DNA. This change in shape makes the DNA less susceptible to radiation damage.

The protein also isn’t the only protective measure that tardigrades have. Some species use additional methods to survive extreme radiation, like one discovered in 2020 that can transform lethal levels of UV light into harmless blue light thanks to fluorescent pigments under its skin.

Preventing DNA Damage From Cancer

As researchers continue to work with Dsup, new opportunities for human health may start to open up. The protein could someday help prevent cells from turning cancerous, as DNA damage is a significant feature of most cancers. Dsup could even benefit astronauts, who are exposed to ionizing radiation when spending long periods of time in space.

Although Dsup sounds promising, there are still obstacles that could hinder its applications in humans. One 2023 study, for example, found that the protein promotes neurotoxicity in cortical neurons, meaning it may not be viable to use in treatments involving the brain.

Dsup’s properties could still revolutionize healthcare, yet more research is needed to understand its true potential.

Read More: Tardigrades May Still Be Living on the Moon After Lunar Lander Crash

Article Sources:

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• This article references information from the recent study published in Nature Biomedical Engineering: Radioprotection of healthy tissue via nanoparticle-delivered mRNA encoding for a damage-suppressor protein found in tardigrades
• This article references information from the recent study published in the Journal of Molecular Biology. Biochemical and Structural Analyses of the Tardigrade DNA-Damage Suppressor Protein, Dsup
• This article references information from the recent study published in Science Advances. Tardigrade Dsup extends C. elegans life span by impeding mitochondrial respiration and promoting oxidative stress resistance
• This article references information from the recent study published in Biology Letters: Naturally occurring fluorescence protects the eutardigrade Paramacrobiotus sp. from ultraviolet radiation
• This article references information from the recent study published in Molecular and Cellular Neuroscience: The Tardigrade damage suppressor protein Dsup promotes DNA damage in neurons