Circadian Disruption Drives Extracellular Matrix Remodeling to Facilitate Pulmonary Metastatic Colonization

SUMMARY Circadian clocks impose temporal architecture on signaling networks, and disruption of this architecture predisposes to cancer metastasis. Through direct pharmacological and genetic perturbation of core clock components, we establish that circadian desynchronization in mouse lung fibroblasts eliminates temporal migration gating, creating constitutive motility responses to TNF-α and TGF-β, and identify YAP/TEAD as the obligate, non-redundant convergence node through which clock-regulated ECM mechanical signals and cytokine-driven transcriptional programs jointly drive cellular motility. Chronic jet lag (CJL) in mice generates nocturnal TNF-α elevation (ZT12-21) that drives sustained matrix metalloprotease expression while simultaneously reorganizing Hippo and TGF-β signaling toward temporal convergence during daytime hours, enabling YAP/TEAD-dependent transcription to synergize with TGF-β signaling and drive epithelial-to-mesenchymal transition (EMT) programs that normally remain temporally restricted. Functional validation demonstrates CJL doubles metastatic colonization incidence (40% to 90%) following B16F10 melanoma inoculation. Critically, established metastases amplify these molecular changes: metastatic burden under CJL creates maximal TGF-β expression (ZT15-21), constitutive YAP activity, and sustained EMT marker expression, while eliminating M1/M2 macrophage temporal organization. Analysis of TCGA-SKCM metastatic melanoma datasets confirms that clock-disrupted human tumors exhibit selective strengthening of YAP/TAZ, EMT, and inflammatory pathway coupling, establishing that this convergence architecture is conserved in human disease. Together, these findings demonstrate that circadian disruption transforms from a facilitator of initial metastatic colonization into a driver of progressive metastatic burden by eliminating the temporal segregation that normally constrains pro-metastatic programs to discrete, non-overlapping windows, creating self-perpetuating cycles wherein pathway convergence facilitates colonization and established tumors amplify pro-metastatic signaling to maintain permissive microenvironmental conditions. Competing Interest Statement The authors have declared no competing interest.