Targeting NOX1/4 promotes macrophage phagocytosis and improves radiotherapy via YAP1/TEAD4-CD47 in non-small cell lung cancer

Abstract Radiotherapy is a mainstay treatment option for non-small cell lung cancer (NSCLC). However, radiation remodels the tumor immune microenvironment by adaptively upregulating the immunoregulatory checkpoint CD47, leading to phagocytic evasion and radioresistance. Although targeting CD47 shows promising antitumor effects, severe hemolytic toxicity caused by CD47 antibodies greatly limits their clinical application. Therefore, strategies that specifically modulate the regulatory mechanism of CD47 expression in cancer cells may offer safer and more effective therapeutic options. To find novel targets for regulating CD47 expression in NSCLC, we performed a flow cytometry-based drug screen. We found that NOX1/4 inhibition could suppress CD47 expression and reverse radiotherapy-induced CD47 upregulation in NSCLC, thereby promoting macrophage phagocytosis. Mechanistically, NOX1/4-derived reactive oxygen species (ROS) facilitate CD47 transcription via YAP1/TEAD4. In tumor-bearing mouse models, NOX1/4 inhibition enhanced the antitumor efficacy of radiotherapy through a macrophage-dependent mechanism without causing detectable hemolytic toxicity. Collectively, our findings establish the NOX1/4-ROS-YAP1/TEAD4 axis as a pivotal driver of CD47 expression in NSCLC. Targeting this axis represents a promising strategy to overcome radioresistance by enhancing macrophage phagocytosis while avoiding the hemotoxicity associated with direct CD47 blockade.