scholarly journals Investigation of Epigenetic Control of DAX-1 Expression in Human Cell Lines

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A506-A507
Author(s):  
Caroline P Riedstra ◽  
Christina Tzagarakis-Foster
Keyword(s):  
Cancer Cells ◽  
Cell Lines ◽  
X Chromosome ◽  
Sex Reversal ◽  
Nuclear Hormone Receptor ◽  
Molecular Techniques ◽  
Enzyme Analysis ◽  
Epigenetic Control ◽  
Adrenal Hypoplasia Congenita ◽  
Adrenal Hypoplasia

Abstract Dosage-Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, Critical Region on the X chromosome, gene 1 (DAX-1 or NR0B1) is an orphan nuclear hormone receptor implicated in Adrenal Hypoplasia Congenita (AHC) and Dosage Sensitive Sex Reversal (DSS). In both instances, DAX-1 plays a key role in growth and development by modulating hormone function. In DSS, mutations on the X-chromosome lead to duplication of the region containing DAX-1, resulting in sex reversal, and in AHC, mutations in the DAX-1 gene diminish development of adrenal tissue which leads to a reduction in adrenal hormone production. Expressed predominantly in tissues such as the testes, ovaries, breast, adrenal cortex, and lung, DAX-1 may serve as an indicator of aberrant growth. Here we hypothesize that DAX-1 is epigenetically regulated, specifically in cancer cells, thereby reducing its expression. We surveyed various human cancer cells in order to determine whether inhibiting DNA methylating enzymes released epigenetic control of the DAX-1 gene, resulting in an increase in expression. By implementing molecular techniques, such as bisulfite sequencing, we determined the precise methylation sites in the DAX-1 gene. Additionally, we carried out methylation specific restriction enzyme analysis to differentiate degrees of methylation between lung, breast, liver, cervical, and adrenal carcinoma cell lines. Following confirmation of the precise methylation sites, we utilized chromatin immunoprecipitation (ChIP) in order to identify the modifying proteins present on the DAX-1 CpG islands. In conjunction with these experimental techniques, we implemented a bioinformatics approach to analyze methylation in the promoter region of the DAX-1 gene across tissue sample data acquired from The Cancer Genome Atlas Program. The results of this research could lead to a translational application of understanding where this orphan NHR fits into the development and progression of cancer. As a quickly growing field, cancer epigenetics is a key player in the ongoing pursuit for identifying biomarkers that may be pertinent in future therapeutic applications.

scholarly journals Dax-1 (Dosage-Sensitive Sex Reversal-Adrenal Hypoplasia Congenita Critical Region on the X Chromosome, Gene 1) Gene Transcription Is Regulated by Wnt4 in the Female Developing Gonad

2003 ◽  
Vol 17 (4) ◽  
pp. 507-519 ◽  
Author(s):  
Hirofumi Mizusaki ◽  
Ken Kawabe ◽  
Tokuo Mukai ◽  
Etsuko Ariyoshi ◽  
Megumi Kasahara ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gene Transcription ◽  
X Chromosome ◽  
Transcriptional Activation ◽  
Critical Region ◽  
Sex Reversal ◽  
Adrenal Hypoplasia Congenita ◽  
Chromosome Gene ◽  
Adrenal Hypoplasia ◽  
Amino Acid Cluster

Abstract Dax-1 [dosage-sensitive sex reversal-adrenal hypoplasia congenita critical region on the X chromosome, gene 1 (NR0B1)] is an orphan nuclear receptor acting as a suppressor of Ad4 binding protein/steroidogenic factor 1 [Ad4BP/SF-1 (NR5A1)] and as an anti-Sry factor in the process of gonadal sex differentiation. The roles of these nuclear receptors in the differentiation of the gonads and the adrenal cortex have been established through studies of the mutant phenotype in both mice and humans. However, the mechanisms underlying transcriptional regulation of these genes remain largely unknown. Here, we examined the relationship between Dax-1 gene transcription and the Wnt4 pathway. Reporter gene analysis revealed that Dax-1 gene transcription was activated by β-catenin, a key signal-transducing protein in the Wnt pathway, acting in synergy with Ad4BP/SF-1. Interaction between β-catenin and Ad4BP/SF-1 was observed using yeast two-hybrid and in vitro pull-down assays. The region of Ad4BP/SF-1 essential for this interaction consists of an acidic amino acid cluster, which resides in the first helix of the ligand-binding domain. Mutation of the amino acid cluster impaired transcriptional activation of Dax-1 as well as interaction of Ad4BP/SF-1 with β-catenin. These results were supported by in vivo observations using Wnt4 gene-disrupted mice, in which Dax-1 gene expression was decreased significantly in sexually differentiating female gonads. We thus conclude that Wnt4 signaling mediates the increased expression of Dax-1 as the ovary becomes sexually differentiated.

scholarly journals Minireview: Role Of Orphan Nuclear Receptors in Cancer and Potential as Drug Targets

2014 ◽  
Vol 28 (2) ◽  
pp. 157-172 ◽  
Author(s):  
Stephen Safe ◽  
Un-Ho Jin ◽  
Erik Hedrick ◽  
Alexandra Reeder ◽  
Syng-Ook Lee
Keyword(s):  
Tumor Suppressor ◽  
Cancer Patients ◽  
Cell Lines ◽  
Cancer Cell ◽  
Critical Region ◽  
Chromosome X ◽  
Orphan Receptors ◽  
Adrenal Hypoplasia Congenita ◽  
Testicular Receptor ◽  
Adrenal Hypoplasia

Abstract The nuclear orphan receptors for which endogenous ligands have not been identified include nuclear receptor (NR)0B1 (adrenal hypoplasia congenita critical region on chromosome X gene), NR0B2 (small heterodimer partner), NR1D1/2 (Rev-Erbα/β), NR2C1 (testicular receptor 2), NR2C2 (testicular receptor 4), NR2E1 (tailless), NR2E3 (photoreceptor-specific NR [PNR]), NR2F1 chicken ovalbumin upstream promoter transcription factor 1 (COUP-TFI), NR2F2 (COUP-TFII), NR2F6 (v-erbA-related protein), NR4A1 (Nur77), NR4A2 (Nurr1), NR4A3 (Nor1), and NR6A1 (GCNF). These receptors play essential roles in development, cellular homeostasis, and disease including cancer where over- or underexpression of some receptors has prognostic significance for patient survival. Results of receptor knockdown or overexpression in vivo and in cancer cell lines demonstrate that orphan receptors exhibit tumor-specific pro-oncogenic or tumor suppressor-like activity. For example, COUP-TFII expression is both a positive (ovarian) and negative (prostate and breast) prognostic factor for cancer patients; in contrast, the prognostic activity of adrenal hypoplasia congenita critical region on chromosome X gene for the same tumors is the inverse of COUP-TFII. Functional studies show that Nur77 is tumor suppressor like in acute leukemia, whereas silencing Nur77 in pancreatic, colon, lung, lymphoma, melanoma, cervical, ovarian, gastric, and some breast cancer cell lines induces one or more of several responses including growth inhibition and decreased survival, migration, and invasion. Although endogenous ligands for the orphan receptors have not been identified, there is increasing evidence that different structural classes of compounds activate, inactivate, and directly bind several orphan receptors. Thus, the screening and development of selective orphan receptor modulators will have important clinical applications as novel mechanism-based agents for treating cancer patients overexpressing one or more orphan receptors and also for combined drug therapies.

Xp duplications and sex reversal

1995 ◽  
Vol 350 (1333) ◽  
pp. 291-296 ◽  
Keyword(s):  
Ovarian Development ◽  
Hypogonadotropic Hypogonadism ◽  
Sex Reversal ◽  
Nuclear Receptor Superfamily ◽  
Adrenal Hypoplasia Congenita ◽  
Male Phenotype ◽  
Adrenal Hypoplasia ◽  
Male To Female ◽  
Atypical Member ◽  
Functional Deficiency

Male to female sex reversal has been observed in individuals with duplications of the short arm of the X chromosome. The study of Xp duplicated patients demonstrated that sex reversal results from the presence of two active copies of the DSS (dosage sensitive sex reversal) locus. A double dosage of DSS disrupts testis formation whereas its absence is compatible with a male phenotype, suggesting a role for DSS in ovarian development and as a link between ovary and testis formation. DSS was localized to a 160 kb region of Xp21, overlapping the adrenal hypoplasia congenita locus. The search for expressed sequences in the DSS critical region led to the identification of two types of genes: the DAM family and DAX-1, an atypical member of the nuclear receptor superfamily. Although no function is currently known for DAM genes, functional deficiency for DAX-1 has been shown to be responsible for adrenal hypoplasia congenita and hypogonadotropic hypogonadism. The search for the DSS gene(s) is still open and both the DAM genes and DAX-1 represent DSS candidate genes.

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