201. Synthetic transactivation screening reveals ETV4 as broad coactivator of hypoxia-inducible factor signaling
- Author
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Roland H. Wenger, Hubert Rehrauer, Daniel P. Stiehl, Utta Berchner-Pfannschmidt, Jun Hu, Peter Schraml, Kristin Wollenick, Glen Kristiansen, Joachim Fandrey, University of Zurich, and Wenger, R H
- Subjects
Transcriptional Activation ,Procollagen-Proline Dioxygenase ,Medizin ,Breast Neoplasms ,610 Medicine & health ,10071 Functional Genomics Center Zurich ,P300-CBP Transcription Factors ,Gene Regulation, Chromatin and Epigenetics ,Biology ,Hypoxia-Inducible Factor-Proline Dioxygenases ,03 medical and health sciences ,Transactivation ,0302 clinical medicine ,1311 Genetics ,Cell Line, Tumor ,Proto-Oncogene Proteins ,10049 Institute of Pathology and Molecular Pathology ,Coactivator ,Gene expression ,Genetics ,Humans ,p300-CBP Transcription Factors ,Promoter Regions, Genetic ,Transcription factor ,030304 developmental biology ,Regulation of gene expression ,0303 health sciences ,Binding Sites ,Proto-Oncogene Proteins c-ets ,Transferrin ,Hypoxia-Inducible Factor 1, alpha Subunit ,Molecular biology ,Protein Structure, Tertiary ,3. Good health ,Gene expression profiling ,030220 oncology & carcinogenesis ,10076 Center for Integrative Human Physiology ,570 Life sciences ,biology ,Female ,Adenovirus E1A Proteins ,Proto-Oncogene Proteins c-fos ,Chromatin immunoprecipitation ,Signal Transduction - Abstract
The human prolyl-4-hydroxylase domain (PHD) proteins 1–3 are known as cellular oxygen sensors, acting via the degradation of hypoxia-inducible factor (HIF) α-subunits. PHD2 and PHD3 genes are inducible by HIFs themselves, suggesting a negative feedback loop that involves PHD abundance. To identify novel regulators of the PHD2 gene, an expression array of 704 transcription factors was screened by a method that allows distinguishing between HIF-dependent and HIF-independent promoter regulation. Among others, the E-twenty six transcription factor ETS translocation variant 4 (ETV4) was found to contribute to PHD2 gene expression particularly under hypoxic conditions. Mechanistically, complex formation between ETV4 and HIF-1/2α was observed by mammalian two-hybrid and fluorescence resonance energy transfer analysis. HIF-1α domain mapping, CITED2 overexpression and factor inhibiting HIF depletion experiments provided evidence for cooperation between HIF-1α and p300/CBP in ETV4 binding. Chromatin immunoprecipitation confirmed ETV4 and HIF-1α corecruitment to the PHD2 promoter. Of 608 hypoxically induced transcripts found by genome-wide expression profiling, 7.7% required ETV4 for efficient hypoxic induction, suggesting a broad role of ETV4 in hypoxic gene regulation. Endogenous ETV4 highly correlated with PHD2, HIF-1/2α and several established markers of tissue hypoxia in 282 human breast cancer tissue samples, corroborating a functional interplay between the ETV4 and HIF pathways. ISSN:1362-4962 ISSN:0301-5610
- Published
- 2017