2541 - Targeting ADAM17 N-glycosylation Enhances Radiosensitivity in Non-Small Cell Lung Cancer via the NOTCH-ABCC1-ROS/cGAMP axis
Presenter(s)
R. Zhang1, Z. Zhu2, J. Yu3, and D. Chen4; 1Shandong University Cancer Center;Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China, 2Department of Radiation Oncology and Shandong Provincial Key Laboratory of Precision Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China, 3Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences Department of Radiation Oncology, Jinan, Shandong, China, 4Department of Radiation Oncology and Shandong Provincial Key Laboratory of Precision Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
Purpose/Objective(s): Radioresistance is a significant barrier to effective treatment in non-small cell lung cancer (NSCLC), severely limiting therapeutic efficacy and compromising patient survival. This study investigates the mechanisms underlying radiotherapy resistance in NSCLC mediated by N-glycosylation of a disintegrin and metalloproteinase 17 (ADAM17) and explores potential strategies to enhance radiosensitivity.
Materials/Methods: Radioresistant NSCLC cell lines were established through repeated irradiation. Radiosensitivity was evaluated using clonogenic assays, western blotting, and immunofluorescence. N-glycoproteomics analysis was performed to compare N-glycosylation changes in radioresistant cell lines with their parental counterparts. Co-Immunoprecipitation Mass Spectrometry (Co-IP-MS) identified enzymes regulating the N-glycosylation of ADAM17. RNA-seq, proteomics, and secretomics were employed to delineate downstream molecular mechanisms of N-glycosylated ADAM17. Additionally, multicolor immunofluorescence staining was performed on pre-treatment biopsies from 79 NSCLC patients to validate the functional role of N-glycosylated ADAM17 in radioresistance. Finally, a short peptide designed to competitively bind the glycosylation site was used to target ADAM17 N-glycosylation.
Results: N-glycoproteomics revealed elevated N-glycosylation at asparagine 594 of ADAM17 in radioresistant NSCLC cells, mediated by STT3B. Mutation of the site N594 or pharmacological inhibition of N-glycosylation (TM treatment) increased ADAM17 membrane protein levels. Membrane-bound ADAM17 cleaved the NOTCH receptor, promoting ABCC1 ubiquitination and degradation via the released NICD. ABCC1, a membrane-bound ATP-dependent transporter, sensitizes NSCLC cells to radiotherapy when its protein level is reduced, through increased reactive oxygen species (ROS) and cyclic GMP-AMP (cGAMP) levels. Pharmacological inhibition of ADAM17 N-glycosylation using NGI-1 and the short peptide enhanced NSCLC radiosensitivity. Multicolor immunofluorescence staining of pre-treatment biopsies confirmed a positive correlation between the level of N-glycosylated ADAM17, STT3B and ABCC1 expression, and radiotherapy resistance.
Conclusion: This study emphasizes the regulatory role of ADAM17 N-glycosylation in radioresistance of NSCLC. Targeting ADAM17 N-glycosylation can increase the radiosensitivity of NSCLC by modulating the NOTCH-ABCC1-ROS/cGAMP axis, providing a potential new strategy to overcome radioresistance in NSCLC.