Notch-1 induces M2 polarization of tumor-associated macrophages via the YAP/EZH2/FOXD1/CD47 signaling axis, thereby driving non-small cell lung cancer progression

Abstract

Objective To investigate the mechanism by which Notch1 induces M2 polarization of tumor-associated macrophages (TAMs) through regulation of the YAP/EZH2/JMJD3/PTEN/FOXD1/galectin-3/CD47 signaling pathway and its role in non-small cell lung cancer (NSCLC). Methods Bioinformatics analysis was utilized to identify Notch1 and M2 polarization-related genes. In vivo tumor progression was assessed using a subcutaneous xenograft tumor model in nude mice. In vitro experiments employed Western blot to detect relevant protein expression levels, real-time quantitative polymerase chain reaction (RT-qPCR) to detect IL-1β, TNF-α, arginase-1, and Cathepsin B/K, flow cytometry to detect apoptosis and proliferation, plate colony formation assay to detect clonogenic ability, scratch assay to detect cell migration, and Transwell assay to detect cell invasion. Results In NSCLC, tumor cells activate Notch1 signaling through Jagged-1, triggering NICD/RBP-J-mediated YAP synthesis and activation. Activated YAP enhances Jagged-1 expression through positive feedback, forming a Notch1/YAP signal amplification loop, and inhibits PTEN expression by activating EZH2 (in antagonism with JMJD3). PTEN deficiency relieves dual inhibition of the PI3K/Hippo pathways, leading to sustained YAP activation, which subsequently drives FOXD1 transcription and downstream expression of galectin-3 and C-MYC. C-MYC not only promotes tumor proliferation and invasion but also induces high expression of the immune checkpoint molecule CD47. CD47 binds to SIRPα on the surface of tumor-associated TAMs, blocking M1 polarization, driving M2 polarization, and activating the STAT3/PD-L1 axis. PD-L1 further induces endoplasmic reticulum stress (ERS) and promotes Cathepsin K/B expression. Conclusion Notch1 induces M2 polarization of TAMs by activating the YAP/EZH2/JMJD3/PTEN/FOXD1/galectin-3/CD47 signaling pathway, thereby promoting NSCLC progression. This study provides important clues for understanding the molecular mechanisms of NSCLC and identifying potential therapeutic targets.