University of Adelaide Library

Adelaide Research and Scholarship : Schools and Disciplines : School of Molecular and Biomedical Science : Biochemistry : Biochemistry Publications

Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/57698

Type: Journal article
Title: The HIF1α-inducible pro-cell death gene BNIP3 is a novel target of SIM2s repression through cross-talk on the hypoxia response element
Other Titles: The HIF1 alpha-inducible pro-cell death gene BNIP3 is a novel target of SIM2s repression through cross-talk on the hypoxia response element
Author: Farrall, Alexandra Louise
Whitelaw, Murray Leslie
Citation: Oncogene, 2009; 28(41):3671-3680
Publisher: Nature Publishing Group
Issue Date: 2009
ISSN: 0950-9232
School/Discipline: School of Molecular and Biomedical Science : Biochemistry
Statement of
Responsibility: 
A. L. Farrall and M. L. Whitelaw
Abstract: The short isoform of single-minded 2 (SIM2s), a basic helix–loop–helix/PAS (bHLH/PAS) transcription factor, is upregulated in pancreatic and prostate tumours; however, a mechanistic role for SIM2s in these cancers is unknown. Microarray studies in prostate DU145 cells identified the pro-cell death gene, BNIP3 (Bcl-2/adenovirus E1B 19 kDa interacting protein 3), as a novel putative target of SIM2s repression. Further validation showed BNIP3 repression in several prostate and pancreatic carcinoma-derived cell lines with ectopic expression of human SIM2s. BNIP3 levels are enhanced in prostate carcinoma cells upon short interfering (si)RNA-mediated knockdown of endogenous SIM2s. Chromatin immunoprecipitation and promoter studies show that SIM2s represses BNIP3 through its activities at the proximal promoter hypoxia response element (HRE), the site through which the bHLH/PAS family member, hypoxia-inducible factor 1α (HIF1α), induces BNIP3. SIM2s attenuates BNIP3 hypoxic induction via the HRE, and increased hypoxic induction of BNIP3 occurs with siRNA knockdown of endogenous SIM2s in prostate PC3AR+ cells. BNIP3 is implicated in hypoxia-induced cell death processes. Prolonged treatment of PC3AR+ cells with hypoxia mimetics, DP and DMOG, confers hypoxia-induced autophagy, measured by enhanced LC3-II levels and SQSTM1/p62 turnover. We show that PC3AR+ cells expressing ectopic SIM2s have enhanced survival in these conditions. Induction of LC3-II and turnover of SQSTM1/p62 are attenuated in PC3AR+/SIM2s DMOG and hypoxia-treated cells, suggesting that SIM2s may attenuate autophagic cell death processes, perhaps through BNIP3 repression. These data show, for the first time, SIM2s cross-talk on an endogenous HRE. SIM2s' functional interference with HIF1α activities on BNIP3 may indicate a novel role for SIM2s in promoting tumourigenesis.
Keywords: SIM2; BNIP3; HIF1α; hypoxia; cell death; cancer
Description: © 2009 Macmillan Publishers Limited. All rights reserved
RMID: 0020093012
DOI: 10.1038/onc.2009.228
Appears in Collections:Biochemistry Publications
View citing articles in: Web of Science
Google Scholar
Scopus

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

© 2008 The University of Adelaide
library@adelaide.edu.au
CRICOS Provider Number 00123M
Service Charter | Copyright | Privacy | Disclaimer