The omentum – a fatty tissue that suspends from the stomach – is a common site of metastasis for abdominal cancers, especially ovarian cancers. The omentum contains abundant clusters of immune cells, but it is unclear why they do not effectively defend against cancer cells. In a new study, researchers led by WonJae Lee, Ph.D., and Honami Naora, Ph.D., showed that neutrophils release webs of DNA called neutrophil extracellular traps (NETs) that specifically attract innate-like B cells to the omentum. Furthermore, NETs stimulate these B cells to produce an immunosuppressive cytokine called interleukin (IL)-10 that helps cancer cells settle and grow.
The study shows that NETs alter immune cells in the omentum before metastasis occurs, creating an immunocompromised environment that supports cancer cell colonization. Inhibiting NETs decreases these innate-like B cells in lab models, highlighting a potential therapeutic strategy.