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.

Graphical Abstract

中文翻译：

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GALNT2 是一种 O-糖基化酶，是非小细胞肺癌放射抗性的关键调节因子：来自综合多组学分析的证据

放射抵抗是非小细胞肺癌（NSCLC）患者放疗失败的主要原因。糖基化相关的改变与肿瘤放射抗性密切相关。然而，糖基化与NSCLC放射抗性之间的关系尚不清楚。在这里，我们通过分次照射生成了抗放射非小细胞肺癌细胞模型。通过转录组学、蛋白质组学和糖组学分析阐明了与 NSCLC 相关的放射抗性有关的异常糖基化。我们进行了体外和体内研究以确定糖基化的生物学功能。此外，还推断并验证了其下游途径和上游调节因子。我们证明粘蛋白型 O-糖基化和 O-糖基化酶 GALNT2 在放射抗性 NSCLC 细胞中高度表达。发现 GALNT2 在 NSCLC 组织中升高；这种升高的水平显示出与放射治疗的反应以及总体生存率显着相关。功能实验表明，GALNT2 敲低通过诱导细胞凋亡改善 NSCLC 放射敏感性。通过使用凝集素下拉系统，我们发现IGF1R上的粘蛋白型O-聚糖被GALNT2修饰，并且IGF1R可以影响凋亡相关基因的表达。此外，IGF1R 抑制增强了 GALNT2 敲低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测定，miR-30a-5p 负调节 GALNT2。总之，我们的研究结果表明 GALNT2 是 NSCLC 放射抗性的关键贡献者。因此，靶向GALNT2可能是NSCLC的一种有前景的治疗策略。

图形概要