title: WT1 and DAX-1 inhibit aromatase P450 expression in human endometrial and endometriotic stromal cells.
abstract: The orphan nuclear receptor steroidogenic factor-1 (SF-1) induces the expression of Müllerian inhibiting substance (MIS) and many steroidogenic genes, including aromatase P450 (P450arom). Dosage-sensitive sex reversal adrenal hypoplasia congenita critical region on the X chromosome gene 1 (DAX-1) inhibits SF-1-mediated induction of MIS and other steroidogenic genes, whereas Wilms' tumor suppressor gene (WT1) augments SF-1-mediated MIS expression. The effects of WT1 on steroidogenesis or P450arom expression have not been explored to date. In human endometriotic stromal cells, extremely high levels of P450arom mRNA and enzyme activity are present. Prostaglandin E(2) stimulates cAMP formation, SF-1 binding activity, P450arom mRNA levels, and estrogen synthesis in endometriotic stromal cells. Stromal cells of eutopic endometrium from disease-free women, on other hand, do not contain readily detectable levels of P450arom mRNA. Thus, we evaluated herein the possible roles of WT1 and DAX-1 in cAMP/SF-1-mediated regulation of P450arom expression in endometriotic and endometrial stromal cells. We also determined the cellular distribution and levels of these transcription factors in pathological endometriotic vs. normal eutopic endometrial tissues by immunohistochemistry to understand their in vivo roles. In vitro transcriptional regulation studies showed that both WT1 and DAX-1 inhibited cAMP and/or SF-1-induced P450arom promoter activity in a dose-dependent fashion in cultured human endometriotic and endometrial stromal cells. Site-directed disruption of the SF-1 binding site (-136/-124 bp) in the P450arom promoter abolished basal or cAMP/SF-1-induced promoter activity in the presence or absence of WT1 or DAX-1. Immunohistochemistry and H-scoring showed that DAX-1 was ubiquitously present in epithelial and stromal cells of both tissues. WT1, on the other hand, was preferentially expressed in stromal (vs. epithelial) cells. Moreover, WT1 levels in endometriotic stromal cells are significantly down-regulated compared with normal endometrial stromal cells. In summary, WT1 or DAX-1 inhibits cAMP-SF-1 pathway-dependent P450arom expression in cultured human endometriotic and endometrial stromal cells. In vivo down-regulation of WT1 in endometriotic stromal cells (vs. normal endometrial stromal cells) may in part be responsible for aberrantly increased P450arom expression and estrogen formation in this pathological tissue.
authors.affiliation: Department of Obstetrics and Gynecology, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
authors.forename: Bilgin
authors.initials: B
authors.lastname: Gurates
authors.forename: Siby
authors.initials: S
authors.lastname: Sebastian
authors.forename: Sijun
authors.initials: S
authors.lastname: Yang
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Zhou
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Tamura
authors.forename: Zongjuan
authors.initials: Z
authors.lastname: Fang
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sasano
authors.forename: Serdar E
authors.initials: SE
authors.lastname: Bulun
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D001141:Aromatase / Q000235:genetics*; D001483:Base Sequence; D001706:Biopsy; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000235:genetics*; D004715:Endometriosis / Q000201:enzymology* / Q000473:pathology; D004717:Endometrium / Q000201:enzymology*; D004847:Epithelial Cells / Q000201:enzymology / Q000473:pathology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; D017154:Stromal Cells / Q000201:enzymology*; D014157:Transcription Factors / Q000235:genetics*; D025721:WT1 Proteins / Q000235:genetics*
chemical_list: D020121:5' Untranslated Regions; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; C539965:NR0B1 protein, human; C515057:NR5A1 protein, human; D018168:Receptors, Retinoic Acid; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D025721:WT1 Proteins; D008156:Luciferases; D001141:Aromatase