Nanotechnology: A New Strategy for Lung Cancer Treatment Targeting Pro-Tumor Neutrophils

Primary and metastatic lung cancers are malignant lung tumors each with of which has a different pathogenesis, although both threaten patient lives. Tumor development and progression involve communication between tumor cells and the host microenvironment. Neutrophils are the most abundant immune cells in the tumor microenvironment (TME); they participate in the generation of an inflammatory milieu and influence patient survival through their anti- and pro-tumor abilities. Neutrophils can be classified into various categories according to different criteria; frequent categories include N1 antitumor neutrophils and N2 immunosuppressive neutrophils. The antitumor effects of neutrophils are reported to be mediated through a combination of reactive oxygen species, tumor necrosis factor-related apoptosis-inducing ligand, and receptor for advanced glycation end-products–cathepsin G association, as well as the regulation of the activities of other immune cells. There have also been reports that neutrophils can function as tumor promoters that contribute to lung cancer progression and metastasis by influencing processes including carcinogenesis, angiogenesis, cancer cell proliferation, and invasion ability, as well as having similar roles in the lung metastasis of other cancers. The rapid development of nanotechnology has provided new strategies for cancer treatment targeting neutrophils.