Differential gene expression by 1,25(OH)₂D₃ in an endometriosis stromal cell line

Endometriosis is a common female reproductive disease characterized by invasion of endometrial cells into other organs, frequently causing pelvic pain and infertility. Alterations of the vitamin D system have been linked to endometriosis incidence and severity. To shed light on the potential mechanism for these associations, we examined the effects of 1,25(OH)₂D₃ on gene expression in endometriosis cells. Stromal cell lines derived from endometriosis tissue were treated with 1,25(OH)₂D₃, and RNA-seq was used to identify genes differentially expressed between treated and untreated cells. Gene ontology and pathway analyses were carried out using Partek Flow and Ingenuity software suites, respectively. We identified 1627 genes that were differentially expressed (886 down-regulated and 741 up-regulated) by 1,25(OH)₂D₃. Only one gene, CYP24A1, was strongly up-regulated (369-fold). Many genes were strongly down-regulated. 1,25(OH)₂D₃ treatment down-regulated several genetic pathways related to neuroangiogenesis, cellular motility, and invasion, including pathways for axonal guidance, Rho GDP signaling, and matrix metalloprotease inhibition. These findings support a role for vitamin D in the pathophysiology of endometriosis, and provide new targets for investigation into possible causes and treatments.