On the Attack

Salmonella enterica is a nasty bacteria that tends to make people very sick. But Washington University in St. Louis researcher Kelly Flentie is trying to use it to make cancer patients better, says Paige Brown at the From the Lab Bench blog. Flentie uses bioluminescent imaging to study the interactions between bacteria and cancer cells, by inserting a derivative of firefly luciferin — the chemical which makes the insects glow — into the microscopic bacteria. Making the bacteria bioluminescent allows researchers to image the bacteria through the skin and analyze the interactions between cancer and bacteria without invasive measures, Brown says. "Such interactions include bacteria localization to malignant tumors when the bacteria are injected into tumor-bearing animals, and smaller-scale interactions between the bacteria and individual cancer cells. These interactions may change how the bacteria behave and which genes they express, enabling them to better colonize tumors, which have a different microenvironment than healthy tissues," she adds. Flentie's research suggests that Salmonella, or other bacteria like Shigella or E. coli, could be used to diagnose cancer, and possibly be adapted to treat tumors. For example, bioluminescent Salmonella could be engineered to seek out tumors, and could serve as a beacon for drugs or anti-cancer compounds, Brown says.