Devices Made Of DNA Detect Cancer

A new cancer-detecting tool uses tiny circuits made of DNA to identify cancer cells by the molecular signatures on their surfaceDuke University researchers fashioned the simple circuits from interacting strands of synthetic DNA that are tens of thousands of times finer than a human hair. Unlike the circuits in a computer, these circuits work by attaching to the outside of a cell and analyzing it for proteins found in greater numbers on some cell types than others. If a circuit finds its targets, it labels the cell with a tiny light-up tag. Because the devices distinguish cell types with higher specificity than previous methods, the researchers hope their work might improve diagnosis, and give cancer therapies better aim.

A team led by Duke computer scientist John Reif and his former Ph.D. student Tianqi Song described their approach in a recent issue of the Journal of the American Chemical Society.

The cell membrane is studded with proteins that researchers can use to discriminate between tumor cells and normal cells, or among cancer cells of different types or disease stages.

Similar techniques have been used previously to detect cancer, but they’re more prone to false alarmsmisidentifications that occur when mixtures of cells sport one or more of the proteins a DNA circuit is designed to screen for, but no single cell type has them all. For every cancer cell that is correctly detected using current methods, some fraction of healthy cells also get mislabeled as possibly cancerous when they’re not. Each type of cancer cell has a characteristic set of cell membrane proteins on its cell surface. To cut down on cases of mistaken identity, the Duke team designed a DNA circuit that must latch onto that specific combination of proteins on the same cell to work. As a result they’re much less likely to flag the wrong cells, Reif said.

The technology could be used as a screening tool to help rule out cancer, which could mean fewer unnecessary follow-ups, or to develop more targeted cancer treatments with fewer side effects.

Source: https://today.duke.edu/