In recent years, scientists have discovered that targeted drugs known as CDK4/6 inhibitors and certain chemotherapy agents not only hamper the internal workings of cancer cells but can also make them the prey of an immune system attack. A new study in Cancer Discovery by Dana-Farber scientists adds another class of drugs to the list: PARP inhibitors.
In the paper, Dana-Farber researchers and colleagues found that in triple-negative breast cancer, treatment with olaparib lures legions of immune system CD8+ T cells inside the tumor, where they wage battle against it. The investigators traced the chain of events, within the cancer cells and the surrounding tissue, that sets the attack in motion.
“Our results indicate that the anti-cancer effect of PARP inhibitors is two-pronged,” says Geoffrey Shapiro, MD, PhD, a co-senior author of the study. “The loss of a DNA-repair pathway weakens tumor cells internally and exposes them to a powerful immune response at the same time.”