Unbalanced YAP-autophagy Circuit Promotes the Malignant Progression of Pancreatic Cancer
Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is the most lethal malignancy in humans, and new therapeutic targets are urgently needed. Yes-associated protein (YAP) plays a significant role in tissue homeostasis and cancer progression. Autophagy is also closely associated with various human cancers. However, the interplay between YAP and autophagy in pancreatic cancer remains poorly understood. Methods: The expression of YAP in PDAC was evaluated by immunohistochemistry (IHC). The effects of YAP on pancreatic cancer cells ware evaluated by CCK-8, EdU, wound healing and Transwell invasion assays. Subsequent mechanistic studies were performed in PDAC cell lines by western blotting, qRT-PCR, chromatin immunoprecipitation (ChIP) assay, luciferase reporter assay and immunofluorescence assay. The consequence of the dual inhibition of YAP and autophagy on tumor growth was evaluated in AsPC-1 xenograft mice.Results: YAP was upregulated and activated in PDAC tissues. Functional assays showed that YAP promoted PDAC cell proliferation, migration and invasion. Further analysis revealed a YAP-autophagy feedback loop in pancreatic cancer. Mechanistically, YAP activated autophagy by promoting Atg5 transcription via TEAD1-mediated binding, while autophagy negatively regulated YAP by controlling its degradation. The hyperactivation of YAP in PDAC unbalanced the YAP-autophagy circuit and promoted cancer progression. The dual inhibition of YAP and autophagy suppressed the malignant progression of pancreatic cancer. Conclusions: Our study elucidates a novel mechanism involving a YAP-autophagy feedback loop and suggests that the YAP-autophagy circuit may represent a potential therapeutic target for PDAC.