TY - JOUR
T1 - Twist contributes to hormone resistance in breast cancer by downregulating estrogen receptor-α
AU - Vesuna, F.
AU - Lisok, A.
AU - Kimble, B.
AU - Domek, J.
AU - Kato, Y.
AU - Van Der Groep, P.
AU - Artemov, D.
AU - Kowalski, J.
AU - Carraway, H.
AU - Van Diest, P.
AU - Raman, V.
N1 - Funding Information:
We thank the UMC Utrecht Biobank and M van Blokland for their help in obtaining the human breast cancer RNA. We also thank Flonne Wildes and Gary Cromwell for helping with mice, Yelena Mironchik for helping with cell culture, and Mary McAllister, Paul T Winnard Jr, and Balaji Krishnamachary for critically reading the manuscript. We also thank Kayleen Bailey for help with methylation experiments. ER promoter and ERE-luciferase constructs were kindly provided by Professor Nancy Davidson (Johns Hopkins University, MD). Twist mutant constructs were kindly provided by Professor Jacky Bonaventure (INSERM, France). This work was supported by the National Institutes of Health (1RO1CA140226 to VR).
PY - 2012/7/5
Y1 - 2012/7/5
N2 - The role of estrogen receptor-α (ER) in breast cancer development, and as a primary clinical marker for breast cancer prognosis, has been well documented. In this study, we identified the oncogenic protein, TWIST1 (Twist), which is overexpressed in high-grade breast cancers, as a potential negative regulator of ER expression. Functional characterization of ER regulation by Twist was performed using Twist low (MCF-7, T-47D) and Twist high (Hs 578T, MDA-MB-231, MCF-7/Twist) expressing cell lines. All Twist high expressing cell lines exhibited low ER transcript and protein levels. By chromatin immunoprecipitation and promoter assays, we demonstrated that Twist could directly bind to E-boxes in the ER promoter and significantly downregulate ER promoter activity in vitro. Functionally, Twist overexpression caused estrogen-independent proliferation of breast cells, and promoted hormone resistance to the selective estrogen receptor modulator tamoxifen and selective estrogen receptor down-regulator fulvestrant. Importantly, this effect was reversible on downregulating Twist. In addition, orthotopic tumors generated in mice using MCF-7/Twist cells were resistant to tamoxifen. These tumors had high vascular volume and permeability surface area, as determined by magnetic resonance imaging (MRI). Mechanistically, Twist recruited DNA methyltransferase 3B (DNMT3B) to the ER promoter, leading to a significantly higher degree of ER promoter methylation compared with parental cells. Furthermore, we demonstrated by co-immunoprecipitation that Twist interacted with histone deacetylase 1 (HDAC1) at the ER promoter, causing histone deacetylation and chromatin condensation, further reducing ER transcript levels. Functional re-expression of ER was achieved using the demethylating agent, 5-azacytidine, and the HDAC inhibitor, valproic acid. Finally, an inverse relationship was observed between Twist and ER expression in human breast tumors. In summary, the regulation of ER by Twist could be an underlying mechanism for the loss of ER activity observed in breast tumors, and may contribute to the generation of hormone-resistant, ER-negative breast cancer.
AB - The role of estrogen receptor-α (ER) in breast cancer development, and as a primary clinical marker for breast cancer prognosis, has been well documented. In this study, we identified the oncogenic protein, TWIST1 (Twist), which is overexpressed in high-grade breast cancers, as a potential negative regulator of ER expression. Functional characterization of ER regulation by Twist was performed using Twist low (MCF-7, T-47D) and Twist high (Hs 578T, MDA-MB-231, MCF-7/Twist) expressing cell lines. All Twist high expressing cell lines exhibited low ER transcript and protein levels. By chromatin immunoprecipitation and promoter assays, we demonstrated that Twist could directly bind to E-boxes in the ER promoter and significantly downregulate ER promoter activity in vitro. Functionally, Twist overexpression caused estrogen-independent proliferation of breast cells, and promoted hormone resistance to the selective estrogen receptor modulator tamoxifen and selective estrogen receptor down-regulator fulvestrant. Importantly, this effect was reversible on downregulating Twist. In addition, orthotopic tumors generated in mice using MCF-7/Twist cells were resistant to tamoxifen. These tumors had high vascular volume and permeability surface area, as determined by magnetic resonance imaging (MRI). Mechanistically, Twist recruited DNA methyltransferase 3B (DNMT3B) to the ER promoter, leading to a significantly higher degree of ER promoter methylation compared with parental cells. Furthermore, we demonstrated by co-immunoprecipitation that Twist interacted with histone deacetylase 1 (HDAC1) at the ER promoter, causing histone deacetylation and chromatin condensation, further reducing ER transcript levels. Functional re-expression of ER was achieved using the demethylating agent, 5-azacytidine, and the HDAC inhibitor, valproic acid. Finally, an inverse relationship was observed between Twist and ER expression in human breast tumors. In summary, the regulation of ER by Twist could be an underlying mechanism for the loss of ER activity observed in breast tumors, and may contribute to the generation of hormone-resistant, ER-negative breast cancer.
KW - ER transcriptional regulation
KW - Twist
KW - breast cancer
KW - histone deacetylation
KW - hormone resistance
KW - methylation
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U2 - 10.1038/onc.2011.483
DO - 10.1038/onc.2011.483
M3 - Article
C2 - 22056872
AN - SCOPUS:84863725383
SN - 0950-9232
VL - 31
SP - 3223
EP - 3234
JO - Oncogene
JF - Oncogene
IS - 27
ER -