Knockdown of SF-1 and RNF31 affects components of steroidogenesis, TGFβ, and Wnt/β-catenin signaling in adrenocortical carcinoma cells

PLoS One. 2012;7(3):e32080. doi: 10.1371/journal.pone.0032080. Epub 2012 Mar 9.

Abstract

The orphan nuclear receptor Steroidogenic Factor-1 (SF-1, NR5A1) is a critical regulator of development and homeostasis of the adrenal cortex and gonads. We recently showed that a complex containing E3 ubiquitin ligase RNF31 and the known SF-1 corepressor DAX-1 (NR0B1) interacts with SF-1 on target promoters and represses transcription of steroidogenic acute regulatory protein (StAR) and aromatase (CYP19) genes. To further evaluate the role of SF-1 in the adrenal cortex and the involvement of RNF31 in SF-1-dependent pathways, we performed genome-wide gene-expression analysis of adrenocortical NCI-H295R cells where SF-1 or RNF31 had been knocked down using RNA interference. We find RNF31 to be deeply connected to cholesterol metabolism and steroid hormone synthesis, strengthening its role as an SF-1 coregulator. We also find intriguing evidence of negative crosstalk between SF-1 and both transforming growth factor (TGF) β and Wnt/β-catenin signaling. This crosstalk could be of importance for adrenogonadal development, maintenance of adrenocortical progenitor cells and the development of adrenocortical carcinoma. Finally, the SF-1 gene profile can be used to distinguish malignant from benign adrenocortical tumors, a finding that implicates SF-1 in the development of malignant adrenocortical carcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Cortex / metabolism*
  • Adrenocortical Carcinoma / metabolism*
  • Blotting, Western
  • Bromodeoxyuridine
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line, Tumor
  • Colforsin
  • Computational Biology
  • Gene Expression Regulation / genetics
  • Gene Expression Regulation / physiology*
  • Gene Knockdown Techniques / methods
  • Gonadal Steroid Hormones / biosynthesis
  • Humans
  • Microarray Analysis
  • Polymerase Chain Reaction
  • RNA, Small Interfering / genetics
  • Steroidogenic Factor 1 / genetics
  • Steroidogenic Factor 1 / metabolism*
  • Transforming Growth Factor beta / metabolism
  • Ubiquitin-Protein Ligases
  • Wnt Signaling Pathway / physiology*
  • beta Catenin / metabolism

Substances

  • Carrier Proteins
  • Gonadal Steroid Hormones
  • NR5A1 protein, human
  • RNA, Small Interfering
  • Steroidogenic Factor 1
  • Transforming Growth Factor beta
  • beta Catenin
  • Colforsin
  • RNF31 protein, human
  • Ubiquitin-Protein Ligases
  • Bromodeoxyuridine