DNA METHYLATION IS NOT INVOLVED IN DOWN-REGULATION OF TR3( (NGFIB) AND HSD3B2 GENES IN HUMAN ADRENAL CORTEX ANDROGENS SECRETING CELLS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 389-413-Signaling and Transcriptional Control in Endocrine Systems
Basic/Translational
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-392
Maria Sonia Baquedano*, Sabrina Madjinca, Natalia Perez Garrido, Marco A Rivarola and Alicia Belgorosky
Hospital de Pediatria Garrahan, Buenos Aires, Argentina
The nuclear hormone receptor TR3( is critical for the regulation of HSD3B2 transcription playing an important role in adult adrenal cortex zonation. TR3 expression parallels the minimal expression of HSD3B2 in androgen-producing adrenal cortex tissue such as pediatric virilizing adrenocortical tumors (ACT), fetal zone and  zona reticularis cells . However, the mechanisms of adult adrenal cortex zonation is poorly understood Epigenetic regulation is critical for mammalian embryonic and postnatal development and cellular differentiation, while dysregulation causes human cancer and potentially a wide range of adult-onset chronic diseases. This study aimed to evaluate developmental changes in DNA methylation of TR3 and HSD3B2 genes in virilizing ACT and normal human adrenal tissues (HAT). Virilizing ACT tissues (n=4, age range 0.75-4.5 yr) and normal HAT from 3 postnatal age groups were collected as previously reported (1): Gr1: 3 to 26 days, n=3, fetal zone involution; Gr2: 1.83 to 4 yr, n=3, pre-adrenarche; and Gr3: 14 to 20 yr, n=3, post-adrenarche period. Total DNA from each whole tissue and from laser capture microdissected zona fasciculata and zona reticularis in Gr3 was isolated. HSD3B2 and TR3 genes were in silico screened for the presence of CpG islands. Unlike HSD3B2 promoter, TR3 promoter was found to be embedded within a CpG island, suggesting that TR3 gene expression might be related to the mathylation status of CpG island. Promoter methylation pattern of the TR3 gene was examined by bisulfite sequencing. TR3 promoter remained completely unmethylated in normal HAT from the 3 age groups and in ACT tissues. Furthermore, no differences in adrenal zone-specific TR3promoter methylation were observed. 

Taken together our results suggested that DNA methylation was not involved in the zone-specific or pathophysiological regulation of adrenal TR3 expression. Furthermore, the known downregulation of HSD3B2 gene expression in human zona reticularis cells might not be directly mediated by DNA methylation

1) Baquedano MS, Saraco N, Berensztein E, Pepe C, Bianchini M, Levy E, Goñi J, Rivarola MA, Belgorosky A Identification and developmental changes of aromatase and estrogen receptor expression in prepubertal and pubertal human adrenal tissues. J Clin Endocrinol Metab. 2007 Jun;92(6):2215-22. Epub 2007 Apr 3.

Nothing to Disclose: MSB, SM, NP, MAR, AB

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: supported by FONCY PICT-2010 0555,Argentina