The Exon Junction Complex component EIF4A3 plays a splicing-linked oncogenic role in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide and further research on its biology is needed to fully understand the disease. Dysregulation of alternative RNA splicing is a common hallmark in cancer, including PDAC, which provides an emerging source of knowledge and of novel biomarkers and therapeutic tools. Here, we examined the role of EIF4A3, a core component of the Exon Junction Complex intimately linked to RNA splicing, in pancreatic cancer biology. EIF4A3 is overexpressed in PDAC tissue and associated to clinical parameters of malignancy and poorer patient survival. Mechanistically, exploration of PDAC RNA-seq data unveiled the link of EIF4A3 to diverse malignancy processes, in line with its association to key molecular pathways. Accordingly, EIF4A3 targeting in vitro decreased essential functional tumor features such as proliferation, migration, colony formation and sphere formation, while its in vivo targeting reduced tumor growth. EIF4A3 silencing in PDAC cell lines severely altered its transcriptional and spliceosomic landscapes, as shown by RNA-seq analyses, suggesting a role for EIF4A3 in maintaining RNA homeostasis. Our results indicate that EIF4A3 dysregulation in PDAC has a pleiotropic regulatory role on RNA biology, influencing key cellular functions. This paves the way to explore its potential as a novel biomarker and actionable target candidate for this lethal cancer. ### Competing Interest Statement The authors have declared no competing interest.