多醇二磷酸寡糖-蛋白质糖基转移酶非催化亚基 (DDOST) 是内质网腔内催化 N 连接糖基化的寡糖基转移酶复合物的关键组成部分。 DDOST 与多种癌症和先天性糖基化障碍有关。然而，尽管其在胰腺癌中的表达丰富，但其在胰腺癌中的作用仍然难以捉摸。使用定量质谱法，我们在胰腺导管腺癌 (PDAC) 细胞系 PA-TU-8988T 中鉴定出 DDOST 敲低后的 30 种差异表达的蛋白质和磷酸肽 (DEP)。我们使用 STRING 数据库、胰腺癌 TCGA 数据中 mRNA 水平的相关性以及基因本体数据库中注释到 DEP 的生物过程评估了 DDOST / DEP 蛋白质-蛋白质相互作用网络。推断的 DDOST 调节表型在两种 PDAC 细胞系 PA-TU-8988T 和 BXPC-3 中进行了实验验证。我们发现 DDOST 敲除后增殖和细胞活力下降，而 ER 应激、ROS 形成和细胞凋亡增加。总之，我们的结果支持 DDOST 通过拦截细胞应激事件从而减少细胞凋亡而在 PDAC 中发挥致癌作用。因此，DDOST 可能是 PDAC 的潜在生物标志物和治疗靶点。© 2024。作者。

The dolichyl-diphosphooligosaccharide-protein glycosyltransferase non-catalytic subunit (DDOST) is a key component of the oligosaccharyltransferase complex catalyzing N-linked glycosylation in the endoplasmic reticulum lumen. DDOST is associated with several cancers and congenital disorders of glycosylation. However, its role in pancreatic cancer remains elusive, despite its enriched pancreatic expression. Using quantitative mass spectrometry, we identify 30 differentially expressed proteins and phosphopeptides (DEPs) after DDOST knockdown in the pancreatic ductal adenocarcinoma (PDAC) cell line PA-TU-8988T. We evaluated DDOST / DEP protein-protein interaction networks using STRING database, correlation of mRNA levels in pancreatic cancer TCGA data, and biological processes annotated to DEPs in Gene Ontology database. The inferred DDOST regulated phenotypes were experimentally verified in two PDAC cell lines, PA-TU-8988T and BXPC-3. We found decreased proliferation and cell viability after DDOST knockdown, whereas ER-stress, ROS-formation and apoptosis were increased. In conclusion, our results support an oncogenic role of DDOST in PDAC by intercepting cell stress events and thereby reducing apoptosis. As such, DDOST might be a potential biomarker and therapeutic target for PDAC.© 2024. The Author(s).