SOX2 has dual functions as a regulator in the progression of neuroendocrine prostate cancer

The mechanisms underlying the lineage switching from prostate adenocarcinoma (AdPC) to lethal neuroendocrine prostate cancer (NEPC) have yet to be completely elucidated. In this study, RNA sequencing data from a unique patient-derived xenograft NEPC model and a clinical NEPC cohort were used to identify the potential genes driving NEPC progression. Enrichr analysis resulted in the identification of SRY-related HMG-box gene 2 (SOX2) as a potential repressor that causes decrease in the expression of AdPC specific genes in NEPC. Assays involving the stable overexpression of SOX2 in LNCaP and CWR22RV1 cells validated this role of SOX2 in vitro. Mechanistic studies showed that the repressor role of SOX2 was attributed to the marked global hypomethylation of histone H3, which was driven by the activation of lysine-specific demethylase 1 (LSD1). Furthermore, Enrichr also predicted SOX2 as a driver gene involved in the upregulation of NEPC specific genes. However, SOX2 alone could only marginally induce the expression of some neuroendocrine markers in vitro, which was consistent with previous reports. Moreover, we also elucidated the molecular features of LNCaP-SOX2 cells that may confer resistance to androgen-deprivation therapy (ADT) and the inclination toward neuroendocrine transdifferentiation. The results of this study reveal a novel mechanism for SOX2 in the progression of NEPC via LSD1-mediated global epigenetic modulation. This discovery suggests that LSD1 may be a selective target for the prevention of NEPC progression.