Unraveling the Hippo pathway: YAP/TAZ as central players in cancer metastasis and drug resistance.

In regulating cellular plasticity, epithelial to mesenchymal transition (EMT), and tumor progression across a broad range of cancer types, the Hippo signaling pathway depends on YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ binding motif) as core effectors. This pathway can become dysregulated, disrupting tissue homeostasis and promoting oncogenic processes such as metastasis, immune evasion, and therapy resistance. This review explores the multifaceted roles of YAP/TAZ in lung, breast, ovarian, liver, and renal cancers, detailing their interactions with key signaling pathways such as TGF-β, Wnt, and PI3K/AKT and their modulation by mechanical cues like extracellular matrix stiffness and fluid shear stress. Potential YAP/TAZ mediated therapy resistance in EGFR TKI-resistant lung cancer and platinum-resistant ovarian cancer and the impact this has on tumor metabolism as a result of YAP/TAZ controlling tumor mesenchymal stem cells in the hypoxic environment of hepatocellular carcinoma is highlighted. Additionally, we discuss their role in maintaining cancer stem cell traits, creating an immunosuppressive tumor microenvironment, and driving chemoresistance in breast and renal cancers. Small molecule inhibitors, natural compounds (luteolin, apigenin, honokiol), and novel agents (nanoparticles of zinc oxide) are discussed as promising routes for disrupting YAP/TAZ. The review underscores the complexity of YAP/TAZ signaling and the need for patient stratification based on their expression levels to optimize targeted therapies. See also the graphical abstract(Fig. 1).