Abstract
Background: After long-term androgen deprivation therapy, 25-30% prostate cancer (PCa) acquires an aggressive neuroendocrine (NE) phenotype. Dysregulation of YAP1, a key transcription coactivator of the Hippo pathway, has been related to cancer progression. However, its role in neuroendocrine prostate cancer (NEPC) has not been assessed. Methods: Immunohistochemistry and bioinformatics analysis were conducted to evaluate YAP1 expression levels during PCa initiation and progression. Results: YAP1 expression was present in the basal epithelial cells in benign prostatic tissues, lost in low-grade PCa, but elevated in high-grade prostate adenocarcinomas. Interestingly, the expression of YAP1 was reduced/lost in both human and mouse NEPC. Conclusions: The expression of YAP1 is elevated in high-grade prostate adenocarcinomas but lost in NEPC.