Vitamin D derivatives inhibit mesenchymal transition of mesothelial cells and mitigate peritoneal dissemination of ovarian cancer.

Ovarian cancer (OvCa) is a leading cause of gynecological cancer-related mortality, primarily due to peritoneal dissemination, which facilitates metastasis in the abdominal cavity. This study explored the potential of vitamin D and its synthetic derivatives in mitigating peritoneal dissemination by modulating the behavior of mesothelial cells (MCs). Vitamin D, through its receptor (VDR), is known to influence cancer progression, and our findings demonstrate that vitamin D derivatives can inhibit mesenchymal transition of MCs induced by TGF-β1, a key driver of peritoneal dissemination. This study used patient-derived primary MCs and in vivo mouse model to assess the effects of vitamin D derivatives on cell morphology, gene expression, and OvCa cell adhesion. Two vitamin D derivatives, VDR agonist, showed significant efficacy in maintaining epithelial-like MC morphology, reducing TGF-β1-induced changes, and inhibiting OvCa cell adhesion to the peritoneum, similar to calcitriol. Conversely, the VDR antagonist derivative induced MC apoptosis, highlighting the essential role of vitamin D in MC survival. These findings suggest that vitamin D derivatives could serve as promising therapeutic agents for OvCa by preserving peritoneal homeostasis and preventing metastasis. Further research is required to explore a broader range of derivatives and their underlying molecular mechanisms.