Major

Biology, Biotechnology

Research Abstract

Nuclear hormone receptors (NHRs) control a wide range of functions during development and disease progression. 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 predominantly expressed in the testes, ovaries, breast, adrenal cortex, and lung. As an orphan NHR with a unique molecular structure, DAX-1 can interfere with gene expression by repressing transcription. Playing a key role in growth and development by modulating hormone function, DAX-1 has been implicated in Adrenal Hypoplasia Congenita (AHC) and Dosage Sensitive Sex Reversal (DSS). Previous research has also shown that DAX-1 is a suppressor of tumor growth in breast cancer. Thus, DAX-1 may serve as an indicator of aberrant growth. Here we hypothesize that DAX-1 is epigenetically regulated via methylation, specifically in cancer cells, thereby reducing its expression. In a survey of various human cancer cells we determined whether inhibiting DNA methylating enzymes released epigenetic control of the DAX-1 gene, resulting in an increase in expression. We carried out molecular assays such as methylation specific restriction enzyme analysis, to differentiate degrees of methylation between lung, breast, liver, cervical, and adrenal carcinoma cell lines. Additionally, by implementing bisulfite sequencing we determined the precise methylation sites in the DAX-1 gene. Following confirmation of these sites, we utilized chromatin immunoprecipitation (ChIP) in order to identify the modifying proteins present on the DAX-1 CpG islands. To complement our experimental data, we pursued a bioinformatics approach analyzing methylation status 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 of where this orphan NHR fits into the development and progression of cancer.

Faculty Mentor/Advisor

Christina Tzagarakis-Foster

Available for download on Sunday, January 01, 2040

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May 7th, 12:00 AM May 10th, 12:00 AM

Molecular and Bioinformatic Approach to Investigating Epigenetic Control of DAX-1 Expression in Cancer

Nuclear hormone receptors (NHRs) control a wide range of functions during development and disease progression. 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 predominantly expressed in the testes, ovaries, breast, adrenal cortex, and lung. As an orphan NHR with a unique molecular structure, DAX-1 can interfere with gene expression by repressing transcription. Playing a key role in growth and development by modulating hormone function, DAX-1 has been implicated in Adrenal Hypoplasia Congenita (AHC) and Dosage Sensitive Sex Reversal (DSS). Previous research has also shown that DAX-1 is a suppressor of tumor growth in breast cancer. Thus, DAX-1 may serve as an indicator of aberrant growth. Here we hypothesize that DAX-1 is epigenetically regulated via methylation, specifically in cancer cells, thereby reducing its expression. In a survey of various human cancer cells we determined whether inhibiting DNA methylating enzymes released epigenetic control of the DAX-1 gene, resulting in an increase in expression. We carried out molecular assays such as methylation specific restriction enzyme analysis, to differentiate degrees of methylation between lung, breast, liver, cervical, and adrenal carcinoma cell lines. Additionally, by implementing bisulfite sequencing we determined the precise methylation sites in the DAX-1 gene. Following confirmation of these sites, we utilized chromatin immunoprecipitation (ChIP) in order to identify the modifying proteins present on the DAX-1 CpG islands. To complement our experimental data, we pursued a bioinformatics approach analyzing methylation status 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 of where this orphan NHR fits into the development and progression of cancer.