Insights into inflammasome and its research advances in cancer

Inflammation has long been proven to engage in tumor initiation and progression. Inflammasome, as a member of innate immunity-induced host defense inflammation, also plays critical roles in cancer. Inflammasome is a multiprotein complex responding to pathogen-associated molecular patterns and damage-associated molecular patterns. It is composed of receptors such as NOD-like receptors and AIM2-like receptors, adaptor protein ASC, and effector caspase-1, which can process proinflammatory cytokines interleukin (IL)-1 beta and IL-18. It has been reported that upregulated inflammasome activity is correlated to various types of cancers including breast cancer, gastric cancer, brain tumor, and malignant prostate, while inflammasomes also have a protective role in colitis-associated cancer. Autophagy, an intracellular recycling process for maintaining homeostasis, is deemed to contribute to the underlying mechanism of its dual roles in cancer. It has been found that distinct tumor stages and different isotypes of caspases involved in the inflammasome pathway can affect the roles of inflammasome in cancer. In this review, we update the latest evidence of inflammasome roles in cancer and novel inflammasome pathway-targeting agents for immunotherapy and discuss future research directions of inflammasome-based target therapy.