BACKGROUND: The RET proto-oncogene is expressed as part of the estrogen receptor (ER) cluster in breast cancer. We sought to determine if TFAP2C regulates Ret expression directly or indirectly through ER. METHODS: Chromatin immunoprecipitation sequencing (ChIP-Seq) and gel-shift assay were used to identify TFAP2C binding sites in the RET promoter in four breast cancer cell lines. Ret mRNA and protein levels were evaluated in ER-positive and ER-negative breast cancer cell lines after knockdown of TFAP2C. Luciferase expression assay was performed to assess expression from two of the identified sites. RESULTS: ChIP-Seq identified five main binding peaks for TFAP2C in the RET promoter at -101.5 kb, -50.7 kb, -32.5 kb, +5.0 kb, and +33.6 from the RET transcriptional start site. Binding at three of the AP-2 sites was conserved across all four cell lines, whereas the RET -101.5 and RET +33.6 sites were each found to be unbound by TFAP2C in one cell line. A TFAP2C consensus element was confirmed for all five sites. Knockdown of TFAP2C by siRNA in ER-positive MCF-7 cells resulted in significant down regulation of Ret mRNA compared to nontargeting (NT) siRNA (0.09 vs. 1.0, P < 0.001). Knockdown of TFAP2C in ER-negative MDA-MB-453 cells also led to a significant reduction in Ret mRNA compared to NT siRNA (0.16 vs. 1.0, P < 0.001). In MCF-7 cells, knockdown of TFAP2C abrogated Ret protein expression (0.02 vs. 1.0, P < 0.001) before reduction in ER. CONCLUSIONS: TFAP2C regulates expression of the RET proto-oncogene through five AP-2 regulatory sites in the RET promoter. Regulation of Ret by TFAP2C occurs independently of ER expression in breast carcinoma.
BACKGROUND: The RET proto-oncogene is expressed as part of the estrogen receptor (ER) cluster in breast cancer. We sought to determine if TFAP2C regulates Ret expression directly or indirectly through ER. METHODS: Chromatin immunoprecipitation sequencing (ChIP-Seq) and gel-shift assay were used to identify TFAP2C binding sites in the RET promoter in four breast cancer cell lines. Ret mRNA and protein levels were evaluated in ER-positive and ER-negative breast cancer cell lines after knockdown of TFAP2C. Luciferase expression assay was performed to assess expression from two of the identified sites. RESULTS: ChIP-Seq identified five main binding peaks for TFAP2C in the RET promoter at -101.5 kb, -50.7 kb, -32.5 kb, +5.0 kb, and +33.6 from the RET transcriptional start site. Binding at three of the AP-2 sites was conserved across all four cell lines, whereas the RET -101.5 and RET +33.6 sites were each found to be unbound by TFAP2C in one cell line. A TFAP2C consensus element was confirmed for all five sites. Knockdown of TFAP2C by siRNA in ER-positive MCF-7 cells resulted in significant down regulation of Ret mRNA compared to nontargeting (NT) siRNA (0.09 vs. 1.0, P < 0.001). Knockdown of TFAP2C in ER-negative MDA-MB-453 cells also led to a significant reduction in Ret mRNA compared to NT siRNA (0.16 vs. 1.0, P < 0.001). In MCF-7 cells, knockdown of TFAP2C abrogated Ret protein expression (0.02 vs. 1.0, P < 0.001) before reduction in ER. CONCLUSIONS:TFAP2C regulates expression of the RET proto-oncogene through five AP-2 regulatory sites in the RET promoter. Regulation of Ret by TFAP2C occurs independently of ER expression in breast carcinoma.
Authors: George W Woodfield; Yizhen Chen; Thomas B Bair; Frederick E Domann; Ronald J Weigel Journal: Genes Chromosomes Cancer Date: 2010-10 Impact factor: 5.006
Authors: Zachary E Stine; David M McGaughey; Seneca L Bessling; Shengchao Li; Andrew S McCallion Journal: Hum Mol Genet Date: 2011-07-07 Impact factor: 6.150
Authors: S Tozlu; I Girault; S Vacher; J Vendrell; C Andrieu; F Spyratos; P Cohen; R Lidereau; I Bieche Journal: Endocr Relat Cancer Date: 2006-12 Impact factor: 5.678
Authors: George W Woodfield; Michael J Hitchler; Yizhen Chen; Frederick E Domann; Ronald J Weigel Journal: Clin Cancer Res Date: 2009-05-19 Impact factor: 12.531
Authors: I Plaza-Menacho; A Morandi; D Robertson; S Pancholi; S Drury; M Dowsett; L-A Martin; C M Isacke Journal: Oncogene Date: 2010-06-07 Impact factor: 9.867
Authors: Jessica Kao; Keyan Salari; Melanie Bocanegra; Yoon-La Choi; Luc Girard; Jeet Gandhi; Kevin A Kwei; Tina Hernandez-Boussard; Pei Wang; Adi F Gazdar; John D Minna; Jonathan R Pollack Journal: PLoS One Date: 2009-07-03 Impact factor: 3.240
Authors: Selma Esseghir; S Katrina Todd; Toby Hunt; Richard Poulsom; Ivan Plaza-Menacho; Jorge S Reis-Filho; Clare M Isacke Journal: Cancer Res Date: 2007-12-15 Impact factor: 12.701
Authors: Philip M Spanheimer; Allison W Lorenzen; James P De Andrade; Mikhail V Kulak; Jennifer C Carr; George W Woodfield; Sonia L Sugg; Ronald J Weigel Journal: Ann Surg Oncol Date: 2015-05-14 Impact factor: 5.344
Authors: Christopher M Franke; Vivian W Gu; Benjamin G Grimm; Victoria C Cassady; Jeffrey R White; Ronald J Weigel; Mikhail V Kulak Journal: Oncogene Date: 2019-10-21 Impact factor: 9.867
Authors: James P De Andrade; Jung M Park; Vivian W Gu; George W Woodfield; Mikhail V Kulak; Allison W Lorenzen; Vincent T Wu; Sarah E Van Dorin; Philip M Spanheimer; Ronald J Weigel Journal: Mol Cancer Ther Date: 2016-02-01 Impact factor: 6.261
Authors: Philip M Spanheimer; Jung-Min Park; Ryan W Askeland; Mikhail V Kulak; George W Woodfield; James P De Andrade; Anthony R Cyr; Sonia L Sugg; Alexandra Thomas; Ronald J Weigel Journal: Clin Cancer Res Date: 2014-02-13 Impact factor: 12.531
Authors: Philip M Spanheimer; Anthony R Cyr; Matthew P Gillum; George W Woodfield; Ryan W Askeland; Ronald J Weigel Journal: Ann Surg Date: 2014-04 Impact factor: 12.969
Authors: Philip M Spanheimer; Amani Bashir; Allison W Lorenzen; Anna C Beck; Junlin Liao; Ingrid M Lizarraga; Lillian M Erdahl; Sonia L Sugg; Mark W Karwal; Ronald J Weigel Journal: Am J Clin Oncol Date: 2021-09-01 Impact factor: 2.787