Scientists Create DNA Tool to Hunt Down Zombie Cells That Cause Disease

A Chance Conversation Sparks Scientific Revolution

Two graduate students chatting at a Mayo Clinic scientific event have triggered what could become a game-changing breakthrough in aging research. The project began with the quirky idea of a Mayo Clinic graduate student who had a chance conversation with a classmate. At a scientific event, the two happened to chat about their graduate thesis projects. What emerged from that casual conversation was a revolutionary method to track down the cellular culprits behind aging and age-related diseases.

Keenan Pearson, Ph.D. — who recently received his degree from Mayo Clinic Graduate School of Biomedical Sciences — was working under the mentorship of Dr. Maher, studying how aptamers might address neurodegenerative diseases or brain cancer. A few floors away, Sarah Jachim, Ph.D., — who was also then conducting her graduate research — was working in the lab of researcher Nathan LeBrasseur, Ph.D., Director, Mayo Clinic Robert and Arlene Kogod Center on Aging, who studies senescent cells and aging. When Pearson suggested using his aptamer technology to identify senescent cells, the collaboration that followed would reshape how scientists approach cellular aging.

The Zombie Cell Problem

These cells -- also known as "zombie cells" -- stop multiplying but fail to clear themselves from the body as healthy cells normally do. Their presence has been linked to aging and several major illnesses, including cancer and Alzheimer's disease. Unlike healthy cells that die when they should, senescent cells linger in tissues, secreting inflammatory substances that damage their neighbors.

While scientists have been exploring ways to remove or repair these malfunctioning cells, one major obstacle has been finding a reliable way to spot them among healthy cells in living tissues. Traditional methods have proven inadequate for detecting these cellular troublemakers in real-world conditions. The challenge has frustrated researchers for decades, limiting their ability to develop targeted treatments.

DNA Molecules as Cellular Detectives

Their approach uses "aptamers" -- short pieces of synthetic DNA that fold into three-dimensional structures. These structures can attach to proteins found on the outer surfaces of cells. Think of aptamers as molecular bloodhounds that can sniff out specific cellular signatures with remarkable precision.

In experiments with mouse cells, the team identified several rare aptamers, selected from more than 100 trillion random DNA sequences, that were able to recognize specific surface proteins and mark senescent cells. The researchers discovered that several aptamers consistently latched onto a variant of fibronectin, a protein on senescent cell surfaces. Dr. Pearson notes that aptamers are less costly and more flexible than traditional antibodies, which are commonly used to distinguish one cell type from another.

Future Implications for Human Health

"This approach established the principle that aptamers are a technology that can be used to distinguish senescent cells from healthy ones," says biochemist and molecular biologist Jim Maher, III, Ph.D., a principal investigator of the study. "Though this study is a first step, the results suggest the approach could eventually apply to human cells." The implications extend far beyond simple detection.

If aptamers can be adapted for this purpose, they could eventually be used to deliver treatments directly to these cells. This targeted approach could revolutionize how doctors treat age-related diseases, potentially slowing aging processes or preventing conditions like arthritis and neurodegeneration. While more research is needed to adapt the technology for human use, this student-inspired breakthrough represents a crucial step toward understanding and combating cellular aging at its source.