METTL3-dependent m6A methylation of circCEACAM5 fuels pancreatic cancer progression through DKC1 activation.

Abstract

Background: Pancreatic cancer is highly lethal and has a poor prognosis. Research has highlighted the role of circular RNAs and m6A methylation in cancer progression. METTL3, a key m6A methyltransferase, is linked to various cancers, but its interaction with circular RNAs in pancreatic cancer is unclear. This study examined the role of circCEACAM5 in pancreatic cancer, particularly its regulation by METTL3-mediated m6A methylation and interaction with effectors such as DKC1.

Methods: circCEACAM5 expression in pancreatic cancer tissues and cell lines was evaluated via RT‒qPCR. Its characteristics were validated through Sanger sequencing, stability assays, and FISH. Functional assays (CCK-8, EdU, Transwell, and flow cytometry) were conducted in AsPC-1 cells, and in vivo tumor models were established. m6A modification was analyzed via bioinformatics tools and m6A-specific immunoprecipitation, while RNA pull-down assays were used to examine the interaction of circCEACAM5 with METTL3 and DKC1.

Results: circCEACAM5 was significantly upregulated in pancreatic cancer and correlated with poor clinical outcomes. CircCEACAM5 promoted cell proliferation, invasion, and migration while inhibiting apoptosis both in vitro and in vivo. METTL3-mediated m6A methylation of circCEACAM5 was confirmed, and METTL3 knockdown reversed the effects of circCEACAM5 silencing on the malignant behavior of pancreatic cancer cells. circCEACAM5 interacted with DKC1, and DKC1 overexpression reversed the effects of circCEACAM5 knockdown on the malignant behavior of pancreatic cancer cells.

Conclusion: METTL3-mediated m6A methylation of circCEACAM5 drives pancreatic cancer progression by increasing DKC1 expression, suggesting potential new therapeutic targets for this aggressive malignancy.