Primary Cilium Forces Neuroendocrine Shift in Prostate Cancer through YAP1 Repression and Reduced Mitochondrial Activity

Primary cilia are increasingly recognized as regulators of cellular signaling and plasticity. Here, we examined their distribution and potential relevance in neuroendocrine (NE) prostate cancer. While typically absent in localized hormone-sensitive prostate tumor cells, we detected primary cilia in neuroendocrine-like cells both <i>in vitro</i> and in castration-resistant prostate cancer (CRPC) samples. <i>In vivo</i>, cilia were consistently observed in CRPC tumor cells exhibiting FDG-PET positivity and NE features, supporting an association between ciliogenesis, metabolic reprogramming, and disease progression. These aggressive tumors also displayed reduced mitochondrial activity, consistent with a shift away from oxidative metabolism. Building on our work in ccRCC, we identified a GLI1⁺/IFT20⁺ or GLI1⁺/IFT80⁺ signature enriched in ciliated, NE-prone subpopulations. <i>In vitro</i>, YAP1 inhibition alone did not induce ciliogenesis, whereas cytoskeletal remodeling with jasplakinolide restored cilium assembly and enabled partial NE transdifferentiation. Single-cell RNA-seq analyses further showed enrichment of ciliogenesis-related genes within NE clusters in CRPC. Together, these observations support a model in which primary cilia are closely associated with NE identity and metabolic adaptation, rather than serving solely as passive markers, and suggest a structural-metabolic axis that may represent a source of biomarkers and therapeutic vulnerabilities.