Project description:Estrogen receptor α (ERα) is a key regulator of breast growth and breast cancer development. However, the role of ERα in metabolic reprogramming, a hallmark of cancer, is not well documented. In this study, using an integrated approach combining genome-wide mapping of chromatin bound ERα with estrogen induced transcript and metabolic profiling, we demonstrate that ERα reprograms metabolism upon estrogen stimulation, including changes in aerobic glycolysis, nucleotide and amino acid synthesis, and choline metabolism. We show, for the first time, that the ERα target gene choline phosphotransferase 1 (CHPT1) plays an essential role in estrogen induced increases in phosphatidylcholine (PtdCho) levels and that CHPT1 promotes tumorigenesis and proliferation. Furthermore, we show that CHPT1 is overexpressed in tumors compared to normal breast. We also demonstrate that ERα promotes aerobic glycolysis through increased expression of glycolytic genes. In conclusion, this study highlights the importance of ERα for metabolic alterations in breast cancer cells. Furthermore, overexpression of the ERα target CHPT1 in breast cancer supports its potential as a therapeutic target.
Project description:Estrogen receptor α (ERα) is a key regulator of breast growth and breast cancer development. However, the role of ERα in metabolic reprogramming, a hallmark of cancer, is not well documented. In this study, using an integrated approach combining genome-wide mapping of chromatin bound ERα with estrogen induced transcript and metabolic profiling, we demonstrate that ERα reprograms metabolism upon estrogen stimulation, including changes in aerobic glycolysis, nucleotide and amino acid synthesis, and choline metabolism. We show, for the first time, that the ERα target gene choline phosphotransferase 1 (CHPT1) plays an essential role in estrogen induced increases in phosphatidylcholine (PtdCho) levels and that CHPT1 promotes tumorigenesis and proliferation. Furthermore, we show that CHPT1 is overexpressed in tumors compared to normal breast. We also demonstrate that ERα promotes aerobic glycolysis through increased expression of glycolytic genes. In conclusion, this study highlights the importance of ERα for metabolic alterations in breast cancer cells. Furthermore, overexpression of the ERα target CHPT1 in breast cancer supports its potential as a therapeutic target.
Project description:The Estrogen Receptor alpha (ERα) controls key cellular functions in hormone responsive breast cancer by assembling in large functional multiprotein complexes. ERα ligands are classified as agonists and antagonist, according to the response they elicit, thus the molecular characterization of the of ERα nuclear iteractome composition following estrogen and antiestrogen stimulation whose is needed to understand their effects on estrogen target tissues, in particular breast cancer. To this aim interaction proteomics coupled to mass spectrometry (MS) was applied to map the ERα nuclear interacting partners in MCF7 breast cancer cell nuclei following estrogen and antiestrogen stimuli.
Project description:Retinoic acid receptor-alpha (RAR alpha) is a known estrogen target gene in breast cancer cells. The consequence of RAR alpha induction by estrogen was previously unknown. We now show that RAR alpha is required for efficient estrogen receptor-alpha (ER)-mediated transcription and cell proliferation. RAR alpha can interact with ER-binding sites, but this occurs in an ER-dependent manner, providing a novel role for RAR alpha that is independent of its classic role. We show, on a genome-wide scale, that RAR alpha and ER can co-occupy regulatory regions together within the chromatin. This transcriptionally active co-occupancy and dependency occurs when exposed to the predominant breast cancer hormone, estrogen--an interaction that is promoted by the estrogen-ER induction of RAR alpha. These findings implicate RAR alpha as an essential component of the ER complex, potentially by maintaining ER-cofactor interactions, and suggest that different nuclear receptors can cooperate for effective transcriptional activity in breast cancer cells. RAR alpha silenced breast cancer MCF-7 cell lines or control siRNA in the presence of estrogen or a vehicle. MCF-7 cells were hormone-depleted for 3 d and treated with 100 nM estrogen for 12 h. There were three biological replicates for each of the four different groups.
Project description:Retinoic acid receptor-alpha (RAR alpha) is a known estrogen target gene in breast cancer cells. The consequence of RAR alpha induction by estrogen was previously unknown. We now show that RAR alpha is required for efficient estrogen receptor-alpha (ER)-mediated transcription and cell proliferation. RAR alpha can interact with ER-binding sites, but this occurs in an ER-dependent manner, providing a novel role for RAR alpha that is independent of its classic role. We show, on a genome-wide scale, that RAR alpha and ER can co-occupy regulatory regions together within the chromatin. This transcriptionally active co-occupancy and dependency occurs when exposed to the predominant breast cancer hormone, estrogen--an interaction that is promoted by the estrogen-ER induction of RAR alpha. These findings implicate RAR alpha as an essential component of the ER complex, potentially by maintaining ER-cofactor interactions, and suggest that different nuclear receptors can cooperate for effective transcriptional activity in breast cancer cells.
Project description:We developed Chromatin Interaction Analysis by Paired-End Tag sequencing (ChIA-PET) for de novo detection of global chromatin interactions, and comprehensively mapped the chromatin interaction network bound by estrogen receptor α (ERα) in the human genome. We performed 454 and Illumina sequencing analyses. Keywords: Epigenetics Using 454, we examined 3 libraries: IHM001 (Estrogen Receptor ChIA-PET), IHM043 (Estrogen Receptor ChIP-PET) and IHM062 (IgG ChIA-PET) Using Illumina, we examined 4 libraries: IHM001 (Estrogen Receptor ChIA-PET replicate 1, Paired End Sequencing), IHH015 (Estrogen Receptor ChIA-PET replicate 2, Paired End Sequencing), H3K4me3 ChIP-Seq and RNA polymerase II ChIP-Seq
Project description:Quantitative mass spectrometry analysis using tandem mass tags (TMT) labelling of estrogen receptor α (ERα) pull downs. Co-immunoprecipitated proteins using a anti Erα antibody were compared quantitatively with material recovered in a mock to identify ERα-interacting proteins.