Amphiregulin reflects brain metastasis progression and leads to PD-L1 expression in non-small cell lung cancer cells - 09/05/26

The Hippo kinase Nuclear Dbf2-related kinase 2 (NDR2) promotes brain metastasis (BM) in non-small cell lung cancer (NSCLC) by disrupting Yes-associated protein 1 (YAP-1), suggesting a role in circulating tumor cells and/or brain colonization. However, the underlying mechanism remains to be clarified.

Human bronchial epithelial tumor cells (HBECs)–A549, H ₁₉₇₅ , H ₂₀₃₀ , and the brain-tropic H ₂₀₃₀ -BrM3 line–depleted or not of NDR2 (via siRNA or shRNA), were exposed to shear stress (up to 40 dyn/cm ² for 3 hours) using an Ibidi® pump system, in the presence or absence of exogenous Amphiregulin (AREG), and subsequently reseeded or not. Viability, apoptosis, proliferation, and YAP-dependent gene expression were analyzed. H ₂₀₃₀ -BrM3 cells (shControl or shNDR2) were injected intracardially into nude athymic mice ( n = 10/group) to evaluate plasma AREG levels correlation with BM. AREG expression was assessed in human NSCLC tumor samples from primary and/or brain metastatic sites.

HBECs tolerated shear stress and showed reduced apoptosis after reseeding when expressing NDR2. Shear stress induced a stem-like phenotype (via Sox2/9 variation) and increased AREG expression in most HBECs. AREG enhanced HBEC survival and proliferation under shear stress. In mice, plasma AREG levels correlated with BM volume. In human NSCLC samples, AREG positive tumors displayed elevated Programmed Death-Ligand 1 (PD-L1), suggesting immune escape. Exogenous AREG treatment in H ₂₀₃₀ -BrM3 cells induced PD-L1 expression in vitro.

AREG supports tumor adaptation to mechanical stress and may drive immune tolerance via PD-L1. Its correlation with BM burden highlights its potential as a biomarker and therapeutic target in NSCLC.