Association among Vitamin D, Retinoic Acid-Related Orphan Receptors, and Vitamin D Hydroxyderivatives in Ovarian Cancer

Abstract

Vitamin D and its derivatives, acting via the vitamin D receptor (VDR) and retinoic acid-related orphan receptors γ and α (RORγ and RORα), show anticancer properties. Since pathological conditions are characterized by disturbances in the expression of these receptors, in this study, we investigated their expression in ovarian cancers (OCs), as well as explored the phenotypic effects of vitamin D hydroxyderivatives and RORγ/α agonists on OC cells. The VDR and RORγ showed both a nuclear and a cytoplasmic location, and their expression levels were found to be reduced in the primary and metastatic OCs in comparison to normal ovarian epithelium, as well as correlated to the tumor grade. This reduction in VDR and RORγ expression correlated with a shorter overall disease-free survival. VDR, RORγ, and RORα were also detected in SKOV-3 and OVCAR-3 cell lines with increased expression in the latter line. 20-Hydroxy-lumisterol3 (20(OH)L3) and synthetic RORα/RORγ agonist SR1078 inhibited proliferation only in the OVCAR-3 line, while 20-hydroxyvitamin-D3 (20(OH)D3) only inhibited SKOV-3 cell proliferation. 1,25(OH)2D3, 20(OH)L3, and SR1078, but not 20(OH)D3, inhibited spheroid formation in SKOV-3 cells. In summary, decreases in VDR, RORγ, and RORα expression correlated with an unfavorable outcome for OC, and compounds targeting these receptors had a context-dependent anti-tumor activity in vitro. We conclude that VDR and RORγ expression can be used in the diagnosis and prognosis of OC and suggest their ligands as potential candidates for OC therapy.

The Role of the Vitamin D Receptor in the Pathogenesis, Prognosis, and Treatment of Cutaneous Melanoma

“…Importantly, recent experimental studies have shown that knocking out of the VDR in melanoma cells increase their malignant behavior and decreases responsiveness to active form of vitamin D indicating that the VDR can serve as the melanoma tumor suppressor gene (69), which is consistent with the role of the VDR as the tumor suppressor gene in the skin as originally proposed by Bikle (44). Of note, defects in VDR lead to increased malignant behavior in other tumors including bladder, ovarian, lung and breast cancers, lymphomas (70)(71)(72)(73)(74)(75).…”

Knocking out the Vitamin D Receptor Enhances Malignancy and Decreases Responsiveness to Vitamin D3 Hydroxyderivatives in Human Melanoma Cells

“…The VDR is implicated in the regulation of an array of biological activities, including development and progression of cancer, for example breast, prostate and ovarian cancers and melanoma [53][54][55]. Brozyna et al [31,46] showed that less advanced tumors exhibited significantly higher VDR expression than those in the advanced stage.…”

Deciphering the Functional Role of RIPK4 in Melanoma

“…In negative controls, the primary antibodies were omitted and replaced with antibody diluent. The sections were evaluated semi-quantitatively, as previously described [ 43 , 44 ]. Since we observed heterogenous: agranular and granular staining, the assessment was performed separately for each staining pattern.…”