放射抵抗是非小细胞肺癌（NSCLC）患者放射治疗失败的主要原因。糖基化相关的变化在肿瘤放射抵抗中起着关键作用。然而，糖基化与NSCLC放射抵抗之间的关系还不清楚。在这里，我们通过分数照射生成了放射抵抗的NSCLC细胞模型。通过转录组学、蛋白质组学和糖组学分析，阐明了与NSCLC相关的放射抵抗中参与的异常糖基化。我们进行了体外和体内研究以确定糖基化的生物功能。此外，我们推断和验证了其下游途径和上游调节因子。我们证明了粘液型O-糖基化和O-糖基化酶GALNT2在放射抵抗的NSCLC细胞中高度表达。发现GALNT2在NSCLC组织中升高；这种升高水平与对放射治疗的反应以及总体生存率有明显关联。功能实验显示GALNT2敲除通过诱导凋亡改善了NSCLC的放射敏感性。通过使用植物凝集素拉下法，我们发现GALNT2修饰了IGF1R上的粘液型O-糖基，IGF1R能够影响与凋亡相关的基因的表达。此外，IGF1R抑制增加了GALNT2敲除介导的体外放射增敏作用。根据miRNA阵列分析和荧光素酶报告基因试验，miR-30a-5p负调控了GALNT2。总之，我们的研究结果确定了GALNT2是NSCLC放射抗性的重要贡献者。因此，针对GALNT2可能是NSCLC的一种有前景的治疗策略。© 2023. 本文作者授予Springer Nature B.V.专有许可。

Radioresistance is the primary reason for radiotherapy failure in non-small cell lung cancer (NSCLC) patients. Glycosylation-related alterations are critically involved in tumor radioresistance. However, the relationship between glycosylation and NSCLC radioresistance is unclear. Here, we generated radioresistant NSCLC cell models by using fractionated irradiation. The aberrant glycosylation involved in NSCLC-related radioresistance was elucidated by transcriptomic, proteomic, and glycomic analyses. We conducted in vitro and in vivo investigations for determining the biological functions of glycosylation. Additionally, its downstream pathways and upstream regulators were inferred and verified. We demonstrated that mucin-type O-glycosylation and the O-glycosylating enzyme GALNT2 were highly expressed in radioresistant NSCLC cells. GALNT2 was found to be elevated in NSCLC tissues; this elevated level showed a remarkable association with response to radiotherapy treatment as well as overall survival. Functional experiments showed that GALNT2 knockdown improved NSCLC radiosensitivity via inducing apoptosis. By using a lectin pull-down system, we revealed that mucin-type O-glycans on IGF1R were modified by GALNT2 and that IGF1R could affect the expression of apoptosis-related genes. Moreover, GALNT2 knockdown-mediated in vitro radiosensitization was enhanced by IGF1R inhibition. According to a miRNA array analysis and a luciferase reporter assay, miR-30a-5p negatively modulated GALNT2. In summary, our findings established GALNT2 as a key contributor to the radioresistance of NSCLC. Therefore, targeting GALNT2 may be a promising therapeutic strategy for NSCLC.© 2023. The Author(s), under exclusive licence to Springer Nature B.V.