1. Systems level-based RNAi screening by high content analysis identifies UBR5 as a regulator of estrogen receptor-α protein levels and activity.
- Author
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Bolt, M J, Stossi, F, Callison, A M, Mancini, M G, Dandekar, R, and Mancini, M A
- Subjects
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GENETICS of breast cancer , *RNA interference , *ESTROGEN receptors , *GENETIC testing , *TRANSCRIPTION factors , *GENE libraries , *DNA damage , *IMMUNE response - Abstract
Estrogen receptor-α (ERα) is a central transcription factor that regulates mammary gland physiology and a key driver in breast cancer. In the present study, we aimed to identify novel modulators of ERα-mediated transcriptional regulation via a custom-built siRNA library screen. This screen was directed against a variety of coregulators, transcription modifiers, signaling molecules and DNA damage response proteins. By utilizing a microscopy-based, multi-end point, estrogen responsive biosensor cell line platform, the primary screen identified a wide range of factors that altered ERα protein levels, chromatin remodeling and mRNA output. We then focused on UBR5, a ubiquitin ligase and known oncogene that modulates ERα protein levels and transcriptional output. Finally, we demonstrated that UBR5 also affects endogenous ERα target genes and E2-mediated cell proliferation in breast cancer cells. In conclusion, our multi-end point RNAi screen identified novel modulators of ERα levels and activity, and provided a robust systems level view of factors involved in mechanisms of nuclear receptor action and pathophysiology. Utilizing a high throughput RNAi screening approach we identified UBR5, a protein commonly amplified in breast cancer, as a novel regulator of ERα protein levels and transcriptional activity. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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