Super-paramagnetic iron oxide nanoparticles reprogram the tumor microenvironment and reduce lung cancer growth

Tumor associated macrophages (TAMs) are known to play a role in a multitude of processes that facilitate lung cancer growth, including the suppression of tumoricidal immune activation and the absorption of chemotherapeutics. Therefore, deciphering new therapies to reprogram TAMs towards an anti-tumor phenotype is at the cutting-edge of therapy development. The presence of iron-loaded macrophages has been associated with a better prognosis in lung cancer patients. Iron accumulation in macrophages stimulates pro-tumoricidal macrophage activity that triggers cytotoxic T-cell responses in the tumor microenvironment. In this study, we propose super-paramagnetic iron oxide nanoparticles (SPIONs) as a promising anti-lung cancer adjuvant therapy to reduce tumor cell growth. We used SPIONs to target iron to macrophages and observed that SPION-loaded macrophages reduced tumor cell growth due to the oxidative stress. Additionally, we found that SPIONs completely rewire the tumor microenvironment in mice towards an anti-tumor state and that in combination with crizotinib, a lung cancer targeted therapy, SPIONs show an additive effect in decelerating tumor growth