The immune system has various means to detect infectious invaders, like bacteria and viruses. and non-infectious ones, like cancer. Some cancers, however, can evade immune surveillance and even switch off our immune system. To assist the immune system, several cancer immunotherapies have been developed and have shown beneficial for many cancer patients, including those in advanced stages and with metastatic cancers. These therapies work by either stimulating the immune system’s normal defenses or using lab-made materials that mimic immune system functions.
For patients with tumors that lack immune cells and other cancer fighting molecules in and around the tumor, also known as cold tumors, the effectiveness of cancer immunotherapies can be low. To help these patients, Honggang Cui, Feihu Wang, Hao Su, and other colleagues, investigated a possible combination chemo-immunotherapy approach using a known chemotherapy drug called camptothecin (CPT) and activating a cell signaling pathway called stimulator of interferon genes (STING), which stimulates the immune system.