Gemcitabine activates the Hippo signaling pathway and suppresses tumor growth by stabilizing large tumor suppressor kinase 2 through the hypoxia-inducible factor 1-alpha/ubiquitin protein ligase E3 component N-recognin 5 axis

To investigate the molecular mechanism by which gemcitabine (GEM) inhibits ovarian Cancer (OC) progression, focusing on the hypoxia-inducible factor 1-alpha (HIF1A)/UBR5/LATS2 axis and Hippo pathway. Bioinformatics analysis of gene expression omnibus datasets identified HIF1A-associated modules. Transcriptional regulation of UBR5 by HIF1A was validated via ChIP-PCR and dual-luciferase assays. Anti-tumor effects of GEM were assessed in OC cell lines and an orthotopic mouse model using functional assays (CCK-8, transwell), Western blot, Co-IP, and ubiquitination analysis. HIF1A transcriptionally upregulates UBR5 in OC. GEM downregulated the HIF1A/UBR5 axis, suppressing OC cell proliferation, migration, and invasion. Mechanistically, UBR5 promoted LATS2 ubiquitination and degradation. GEM inhibited this interaction, stabilizing LATS2, activating the Hippo pathway, and suppressing downstream YAP1/FGFR1 signaling. In vivo, GEM inhibited tumor growth and downregulated HIF1A, UBR5, and FGFR1. GEM suppresses OC progression by targeting the HIF1A/UBR5 axis, which subsequently stabilizes LATS2, activates the Hippo pathway, and inhibits YAP1/FGFR1 signaling, revealing a novel therapeutic mechanism.