They are the building blocks of life, serving as essential components in nearly all cellular processes. They facilitate communication between cells and ensure that biological systems function properly.

Put simply, life wouldn’t exist without proteins. That’s why researchers around the world are dedicated to understanding them.

Now, a new study from the University of Copenhagen highlights how protein research could revolutionize multiple areas within biology and medicine. The study, published in the journal Cell, was led by scientists at the University of Copenhagen’s Novo Nordisk Foundation Center for Protein Research.

“We hope our findings will help explore how drugs influence protein turnover and contribute to the development of better medicines. Our research could also reveal how protein stability changes with age and how we might promote healthy aging,” says Professor Jesper Velgaard Olsen.

“In short, we have developed a cutting-edge technology that allows us to analyse and quantify proteins in individual cells with unprecedented depth. We can now identify exactly which proteins are present and in what quantities.”

With this new approach, researchers can measure how individual cells produce and break down proteins — a process known as ‘protein turnover’. The technique, called SC-pSILAC, enables scientists to track both the abundance of proteins and the rate at which they are turned over in single cells. These insights could have significant implications for cancer research, drug development, and personalized medicine.

Mapping the impact of cancer treatments

Despite their fundamental importance, there is still much we don’t know about proteins — including how many exist in a human cell.

SC-pSILAC is a breakthrough since it can distinguish between dividing and non-dividing cells. A prime example is cancer cells, which divide rapidly and are typically targeted by chemotherapy.

However, some cancer cells do not divide, allowing them to evade chemotherapy. The new method helps identify these treatment-resistant cells, leading to better therapies.

“We can now observe that non-dividing cells remain metabolically active and continue to affect their surroundings — something previous methods couldn’t detect,” explains Olsen.

The researchers have also used this technique to examine how specific drugs impact protein turnover in individual cells, including the cancer medication bortezomib. Their findings uncovered specific proteins and previously unknown biological processes influenced by the treatment.

“This method represents a significant leap in protein research,” Olsen states.

“In my field, we have worked for years to analyze proteins within cells. Only recently has technological progress enabled us to do so at the single-cell level.”

Thanks to this innovation, scientists now have a far more detailed understanding of how proteins operate at the molecular level. The hope is that this knowledge will drive advancements in disease diagnostics and treatment strategies.