Project description: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.
Project description:Characterization of the protein composition of exosomes and subpopulations of cells from four human PDAC cell lines (BxPC-3, PANC-1, T3M4, and MIA PaCa-2), via liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI–MS/MS).
Project description:We report that m6A reader IGF2BP2 participates in the regulation of glutamine metabolism in AML. To further clarify whether IGF2BP2 knockdown (KD) leads to translational inhibition, we perform Ribo-seq in control and IGF2BP2 KD cells.
Project description:This study investigated the role of IGF2BP2 in esophageal squamous cell carcinoma. Bulk RNA-seq was performed in ECA109 cells stably transfected with negative-control shRNA or IGF2BP2 shRNA to identify transcriptomic changes associated with IGF2BP2 knockdown.
Project description:C-Myc overexpression is an important molecular hallmark of pancreatic ductal adenocarcinoma (PDAC), but directly targeting c-Myc is extremely challenging. Identifying key upstream factors involved in c-Myc overexpression provides promising indirect targets for c-Myc. Herein, the long noncoding RNAs (lncRNAs) highly expressed in PDAC and significantly correlated with c-Myc expression were identified using RNA sequencing datasets. Among them, LINC01963 was found to interact with c-Myc, as confirmed by RNA pull-down and RIP-qPCR assays. Furthermore, high LINC01963 expression was correlated with poor PDAC prognosis, and functional studies demonstrated that its knockdown inhibited PDAC cell proliferation and xenograft tumor growth. Mechanistic studies identified LINC01963 as a key regulator of c-Myc stability, consequently affecting cell cycle through the c-Myc/p21-related signaling pathways. Further investigation revealed that LINC01963 enhanced N6-methyladenosine (m6A) modification of c-Myc mRNA by protecting methyltransferase-like 3 (METTL3) protein from KDM1B-mediated ubiquitin-proteasome degradation. Intriguingly, LINC01963 also stabilized c-Myc mRNA by facilitating the formation of a ternary complex with insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) and m6A-modified c-Myc. Our study reveals that LINC01963 promotes PDAC tumorigenesis through METTL3/IGF2BP2 axis-coordinated regulation of c-Myc, suggesting a new strategy for indirectly targeting c-Myc.
