Identification of genes regulated by overexpressed SF-1 in human adrenocortical cells

SF-1, a transcription factor belonging to the nuclear receptor superfamily, has a pivotal role for adrenogonadal development in humans and mice. A constant feature of childhood adrenocortical tumors (ACT) is SF-1 amplification and overexpression. Using an inducible cellular system, here we show that SF-1 overexpression increases human adrenocortical cell proliferation through opposing effects on cell cycle and apoptosis. SF-1 overexpression also selectively modulates steroidogenesis, reducing cortisol and aldosterone secretion. We identified a novel pro-apoptotic factor for adrenocortical cells, NOV/CCN3, whose levels are significantly reduced by SF-1 overexpression in human adrenocortical cells and are also reduced in primary adrenal tumors. Moreover, Sf-1 overexpression triggers adrenocortical hyperplasia and tumor formation in mice. These tumors express gonadal markers and activated Stat3. Our studies reveal the critical role of SF-1 gene dosage for adrenocortical tumorigenesis and constitute a rationale for the development of drugs targeting SF-1 transcriptional activity for ACT therapy. Keywords: differential expression, transcription factor Gene expression profiles were analyzed in two different H295R TR/SF-1 WT clones overexpressing SF-1 in a tetracycline-regulated fashion cultured in basal conditions or after three days of doxycycline treatment. For each condition, two biological replicates were examined. Array #22354 Clone #1 replicate 1 basal Cy3/Dox Cy5 Array #22416 Clone #1 replicate 2 basal Cy5/Dox Cy3 Array #22446 Clone #2 replicate 1 basal Cy3/Dox Cy5 Array #22447 Clone #2 replicate 2 basal Cy5/Dox Cy3