Mammalian Eps15 homology domain 1 potentiates angiogenesis of non-small cell lung cancer by regulating 2AR signaling

BackgroundNon-small cell lung cancer (NSCLC) is a devastating disease with a heterogeneous prognosis, and the molecular mechanisms underlying tumor progression remain elusive. Mammalian Eps15 homology domain 1 (EHD1) plays a promotive role in tumor progression, but its role in cancer angiogenesis remains unknown. This study thus explored the role of EHD1 in angiogenesis in NSCLC.MethodsThe changes in angiogenesis were evaluated through human umbilical vein endothelial cell (HUVEC) proliferation, migration and tube formation assays. The impact of EHD1 on 2-adrenoceptor (2AR) signaling was evaluated by Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, and enzyme-linked immunosorbent assay (ELISA). The interaction between EHD1 and 2AR was confirmed by immunofluorescence (IF) and coimmunoprecipitation (Co-IP) experiments, and confocal microscopy immunofluorescence studies revealed that 2AR colocalized with the recycling endosome marker Rab11, which indicated 2AR endocytosis. Xenograft tumor models were used to investigate the role of EHD1 in NSCLC tumor growth.ResultsThe microarray analysis revealed that EHD1 was significantly correlated with tumor angiogenesis, and loss- and gain-of-function experiments demonstrated that EHD1 potentiates HUVEC proliferation, migration and tube formation. EHD1 knockdown inhibited 2AR signaling activity, and EHD1 upregulation promoted vascular endothelial growth factor A (VEGFA) and 2AR expression. Interestingly, EHD1 interacted with 2AR and played a novel and critical role in 2AR endocytic recycling to prevent receptor degradation. Aberrant VEGFA or 2AR expression significantly affected EHD1-mediated tumor angiogenesis. The proangiogenic role of EHD1 was confirmed in xenograft tumor models, and immunohistochemistry (IHC) analysis confirmed that EHD1 expression was positively correlated with VEGFA expression, microvessel density (MVD) and 2AR expression in patient specimens.ConclusionCollectively, the data obtained in this study suggest that EHD1 plays a critical role in NSCLC angiogenesis via 2AR signaling and highlight a potential target for antiangiogenic therapy.