Modulation of Aromatase Expression in the Breast Tissue by ERRα-1 Orphan Receptor

摘要: Abstract We have previously identified a silencer element (S1) that is situated between promoters I.3 and II of the human aromatase gene down-regulates action these promoters. recently applied yeast one-hybrid approach to screen breast tissue hybrid cDNA expression library for genes encoding proteins binding region. Most from this belong nuclear receptor superfamily. Fifty % positive clones encode ERRα-1, other include EAR-2, EAR-3 (COUP-TF1), RARγ, p120E4F. Because ERRα-1 was found be major protein interacting with S1, we decided examine regulatory on promoter gene. Using reporter plasmid includes genomic fragment containing function in cancer SK-BR-3 cells. Gel mobility shift assays confirmed binds S1 dose-dependent manner, DNase I footprinting analysis has revealed region, 5′-AAGGTCAGAAAT-3′, which within 96 107 bp relative transcriptional start site I.3. In addition, despite fact SF1 shown bind same mediate cAMP response ovary, our screening did not find any SF-1 clones. further can an affinity copmarable ERRα-1. reverse transcription-PCR able detect mRNA or cells, it thought expressed tissue. Two RNA variants differences at 5′-end been reported. Our shorter variant 28 32 tumor specimens longer only 1 specimen. detected cells as well fibroblast line WS3TF. The results suggest one It may differently different tissues because distinct patterns transcription factors.