Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, 100730, China.
Department of Pathology, Institute of Basic Medical Sciences, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, 100730, China.
Cell Death Differ. 2023 Aug;30(8):1988-2004. doi: 10.1038/s41418-023-01188-z. Epub 2023 Jul 21.
Pancreatic ductal adenocarcinoma (PDAC) remains a highly fatal malignancy partially due to the acquired alterations related to aberrant protein glycosylation that pathologically remodel molecular biological processes and protect PDAC cells from death. Ferroptosis driven by lethal lipid peroxidation provides a targetable vulnerability for PDAC. However, the crosstalk between glycosylation and ferroptosis remains unclear. Here, we identified 4F2hc, a subunit of the glutamate-cystine antiporter system X, and its asparagine (N)-glycosylation is involved in PDAC ferroptosis by N- and O-linked glycoproteomics. Knockdown of SLC3A2 (gene name of 4F2hc) or blocking the N-glycosylation of 4F2hc potentiates ferroptosis sensitization of PDAC cells by impairing the activity of system X manifested by a marked decrease in intracellular glutathione. Mechanistically, we found that the glycosyltransferase B3GNT3 catalyzes the glycosylation of 4F2hc, stabilizes the 4F2hc protein, and enhances the interaction between 4F2hc and xCT. Knockout of B3GNT3 or deletion of enzymatically active B3GNT3 sensitizes PDAC cells to ferroptosis. Reconstitution of 4F2hc-deficient cells with wildtype 4F2hc restores ferroptosis resistance while glycosylation-mutated 4F2hc does not. Additionally, upon combination with a ferroptosis inducer, treatment with the classical N-glycosylation inhibitor tunicamycin (TM) markedly triggers the overactivation of lipid peroxidation and enhances the sensitivity of PDAC cells to ferroptosis. Notably, we confirmed that genetic perturbation of SLC3A2 or combination treatment with TM significantly augments ferroptosis-induced inhibition of orthotopic PDAC. Clinically, high expression of 4F2hc and B3GNT3 contributes to the progression and poor survival of PDAC patients. Collectively, our findings reveal a previously unappreciated function of N-glycosylation of 4F2hc in ferroptosis and suggest that dual targeting the vulnerabilities of N-glycosylation and ferroptosis may be an innovative therapeutic strategy for PDAC.
胰腺导管腺癌(PDAC)仍然是一种高度致命的恶性肿瘤,部分原因是与异常蛋白糖基化相关的获得性改变,这些改变病理性地重塑了分子生物学过程,并使 PDAC 细胞免受死亡。由致命脂质过氧化引起的铁死亡为 PDAC 提供了一个可靶向的弱点。然而,糖基化和铁死亡之间的串扰仍然不清楚。在这里,我们鉴定了谷氨酸-胱氨酸逆向转运系统 X 的亚基 4F2hc,其天冬酰胺(N)-糖基化通过 N 和 O 连接糖蛋白组学参与 PDAC 铁死亡。SLC3A2(4F2hc 的基因名称)的敲低或阻断 4F2hc 的 N-糖基化通过损害系统 X 的活性来增强 PDAC 细胞的铁死亡敏感性,表现为细胞内谷胱甘肽的明显减少。在机制上,我们发现糖基转移酶 B3GNT3 催化 4F2hc 的糖基化,稳定 4F2hc 蛋白,并增强 4F2hc 和 xCT 之间的相互作用。B3GNT3 的敲除或酶活性缺失的 B3GNT3 使 PDAC 细胞对铁死亡敏感。用野生型 4F2hc 重建缺乏 4F2hc 的细胞恢复铁死亡抗性,而糖基化突变的 4F2hc 则不能。此外,与铁死亡诱导剂联合使用时,用经典的 N-糖基化抑制剂衣霉素(TM)处理会显著引发脂质过氧化的过度激活,并增强 PDAC 细胞对铁死亡的敏感性。值得注意的是,我们证实 SLC3A2 的遗传扰动或与 TM 联合治疗显著增强了铁死亡诱导的对原位 PDAC 的抑制作用。临床上,4F2hc 和 B3GNT3 的高表达促进了 PDAC 患者的进展和生存不良。总之,我们的研究结果揭示了 4F2hc 的 N-糖基化在铁死亡中的一个以前未被认识到的功能,并表明双重靶向 N-糖基化和铁死亡的脆弱性可能是 PDAC 的一种创新治疗策略。