Downregulated Regucalcin Expression Induces a Cancer-like Phenotype in Non-Neoplastic Prostate Cells and Augments the Aggressiveness of Prostate Cancer Cells: Interplay with the G Protein-Coupled Oestrogen Receptor?

Bioinformatic analysis showed that the loss of RGN correlates with the development of metastatic PCa and poor survival outcomes. RGN knockdown induced a cancer-like phenotype in PNT1A cells, indicated by increased cell viability and proliferation and reduced apoptosis. In DU145 PCa cells, RGN knockdown augmented migration and enhanced the glycolytic profile, which indicates increased aggressiveness, in line with patients' data. GPER activation modulated RGN expression in PCa cells and RGN knockdown in DU145 cells influenced GPER actions, which highlighted an interplay between these molecular players with relevance for their potential use as biomarkers or therapeutic targets.

Bioinformatic analysis assessed the relationship between RGN expression levels and patients' outcomes. RGN knockdown (siRNA) was performed in non-neoplastic prostate and castration-resistant PCa. Wild-type and RGN knockdown PCa cells were treated with the GPER agonist G1. Viability (MTT), proliferation (Ki-67 immunocytochemistry), apoptosis (caspase-3-like activity) and migration (Transwell assays) were evaluated. Spectrophotometric analysis was used to determine glucose consumption, lactate production and lactate dehydrogenase activity. Lipid content was assessed using the Oil Red assay.