Tardigrade superpowers: Shielding healthy cells from radiotherapy
Tardigrades, microscopic organisms renowned for their extraordinary resistance to radiation, may offer a means to protect healthy cells in patients undergoing cancer treatment. Scientists have recently discovered a way to harness these "superpowers" for medical use and have published their findings in the scientific journal "Nature Biomedical Engineering".
A research team led by Ameya Kirtane from Harvard Medical School and Jianling Bi from the University of Iowa has isolated the tardigrades' ability to survive radiation through messenger RNA (mRNA). When introduced into human cells, this mRNA protects them from the damage usually caused by radiotherapy, according to a report by Science Alert.
Tardigrades to aid the ill
Radiation therapy for cancer not only targets tumors but also impacts healthy cells, leading to widespread cell death and inflammation. According to James Byrne, a radiation oncologist at the University of Iowa, this can cause a range of issues, from mild symptoms like painful mouth ulcers that make eating difficult to more serious complications requiring hospitalization due to severe pain, weight loss, or bleeding.
Tardigrades, also called "water bears," are tiny, eight-legged creatures known for surviving extreme conditions. Scientists have demonstrated that these invertebrates can endure temperatures of up to 302°F, pressures exceeding 88,000 psi, decades without water, and high concentrations of chemical toxins that would be lethal to most life forms. Tardigrades can also withstand radiation doses a thousand times greater than those fatal to humans, thanks to the Dsup ("damage suppressor") protein, which protects their DNA from harm.
For Dsup to work, it needs to reach the cell's nucleus. However, delivering the protein directly is challenging, and introducing genes carries potential risks. Kirtane explains that their approach uses mRNA, which allows temporary protein expression and is considered safer than DNA, which could integrate into the cell’s genome.
The scientists used polymer-lipid nanoparticles to introduce Dsup mRNA into cells. These nanoparticles transport mRNA into the cell's interior, where it produces the Dsup protein before degrading. Kirtane explains that by integrating polymers and lipids, they aimed to enhance RNA delivery, and their observations confirmed the effectiveness of this approach.
In experiments on mice, introducing Dsup mRNA reduced radiation-induced DNA damage by half in colon cells and by two-thirds in mouth cells. Crucially, the treatment did not affect cancer cells. According to Science Alert, these findings might lead to new ways of protecting healthy tissues during cancer therapies. The study authors propose that Dsup mRNA could have broader clinical applications, including protecting healthy tissues from DNA-damaging chemotherapy and addressing conditions like cancer predisposition, chromosomal instability, and heightened sensitivity to DNA-damaging agents.
