Splice-switching ASOs targeting an Alu-derived exon in the AURKA 5'UTR collapse an SRSF1-AURKA-MYC oncogenic circuit in pancreatic cancer

Abstract

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal malignancy, driven by oncogenic KRAS mutations and dysregulated oncogenes, such as SRSF1, MYC, and AURKA. Although KRAS-targeted therapies are in development, resistance mechanisms underscore the need to identify alternative vulnerabilities. Here, we uncover an SRSF1-AURKA-MYC oncogenic circuit, wherein SRSF1 regulates AURKA 5UTR alternative splicing, enhancing AURKA protein expression; AURKA positively regulates SRSF1 and MYC post-translationally, independently of its kinase activity; and MYC in turn transcriptionally upregulates both SRSF1 and AURKA. Elevated SRSF1 in tumor cells promotes inclusion of an exonized Alu exon in the AURKA 5UTR, resulting in splicing-dependent mRNA accumulation and exon-junction- complex deposition. Modulating 5UTR splicing with splice-switching antisense oligonucleotides (ASOs) collapses the oncogenic circuit, reducing PDAC cell viability and triggering apoptosis. Our findings identify AURKA alternative splicing as a critical regulatory node and highlight ASO-mediated splice-switching as a potential therapeutic strategy that simultaneously targets SRSF1, AURKA, and MYC oncogenes.