Project description:NF1 loss-of-function mutations are enriched in hormone receptor positive (HR+) metastatic breast cancer (MBC) and mediate endocrine therapy resistance. To identify therapeutic vulnerabilities in this context, we performed CRISPR/Cas9 screens in wildtype and NF1 knockout isogenic HR+ models and identified NR2F2, an orphan nuclear receptor, to be essential specifically in NF1 loss cells. The NR2F2 dependence was induced as a consequence of NR2F2 upregulation via the activation of the MAPK pathway in these cells. Enforced overexpression of NR2F2 was sufficient to confer endocrine therapy resistance in the absence of NF1 loss, while of NR2F2 knockout or knockdown could enhance the efficacy of endocrine therapies in NF1 WT and NF1 loss models. Mechanistically, our comprehensive multi-omics approaches revealed that NR2F2 modulates chromatin accessibility and regulates ER-dependent transcription through its interaction with ER, transcriptional coregulators and chromatin remodelers at chromatin. Specifically, increased NR2F2 in NF1 loss cells dramatically enhanced the association with transcriptional corepressors, which resulted in attenuation of chromatin accessibility and ER occupancy, and impaired ER transcriptional program. Our findings identify the nuclear receptor NR2F2 as a downstream effector of NF1 loss, and it is essential and potentially druggable mediator of endocrine therapy resistance. We performed ER chromatin binding profiling analysis using data obtained from ChIP-seq of MCF7 sgNT, sgNF1, sgNR2F2 and double knockout (DKO) cells under the conditions of full media, estrogen starvation and estrogen stimulation. We also performed NR2F chromatin binding profiling analysis using data obtained from ChIP-seq of MCF7 sgNT and sgNF1 cells under full media culture condition
Project description:Estrogen-related receptor (ERR) alpha is an orphan nuclear receptor highly expressed in the kidneys. ERRalpha is implicated in renal sodium and potassium homeostasis and blood pressure regulation. We used microarray analysis to identify differentially expressed genes in ERR alpha knockout mice kidneys versus wild-type. The results provide insight on the roles of ERRalpha in the kidney.
Project description:Estrogen-related receptor (ERR) alpha is an orphan nuclear receptor highly expressed in the kidneys. ERRalpha is implicated in renal sodium and potassium homeostasis and blood pressure regulation. We used microarray analysis to identify differentially expressed genes in ERR alpha knockout mice kidneys versus wild-type. The results provide insight on the roles of ERRalpha in the kidney. Three biological replicates of WT and ERRaKO were performed, for a total of 6 samples. 2-3 month old males of each genotype were used.
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:NF1 loss-of-function mutations are enriched in hormone receptor positive (HR+) metastatic breast cancer (MBC) and mediate endocrine therapy resistance. To identify therapeutic vulnerabilities in this context, we performed CRISPR/Cas9 screens in wildtype and NF1 knockout isogenic HR+ models and identified NR2F2, an orphan nuclear receptor, to be essential specifically in NF1 loss cells. The NR2F2 dependence was induced as a consequence of NR2F2 upregulation via the activation of the MAPK pathway in these cells. Enforced overexpression of NR2F2 was sufficient to confer endocrine therapy resistance in the absence of NF1 loss, while of NR2F2 knockout or knockdown could enhance the efficacy of endocrine therapies in NF1 WT and NF1 loss models. Mechanistically, our comprehensive multi-omics approaches revealed that NR2F2 modulates chromatin accessibility and regulates ER-dependent transcription through its interaction with ER, transcriptional coregulators and chromatin remodelers at chromatin. Specifically, increased NR2F2 in NF1 loss cells dramatically enhanced the association with transcriptional corepressors, which resulted in attenuation of chromatin accessibility and ER occupancy, and impaired ER transcriptional program. Our findings identify the nuclear receptor NR2F2 as a downstream effector of NF1 loss, and it is essential and potentially druggable mediator of endocrine therapy resistance. We performed chromatin accessibility profiling analysis using data obtained from ATAC-seq of MCF7 sgNT, sgNF1, sgNR2F2 and double knockout (DKO) cells.
Project description:NF1 loss-of-function mutations are enriched in hormone receptor positive (HR+) metastatic breast cancer (MBC) and mediate endocrine therapy resistance. To identify therapeutic vulnerabilities in this context, we performed CRISPR/Cas9 screens in wildtype and NF1 knockout isogenic HR+ models and identified NR2F2, an orphan nuclear receptor, to be essential specifically in NF1 loss cells. The NR2F2 dependence was induced as a consequence of NR2F2 upregulation via the activation of the MAPK pathway in these cells. Enforced overexpression of NR2F2 was sufficient to confer endocrine therapy resistance in the absence of NF1 loss, while of NR2F2 knockout or knockdown could enhance the efficacy of endocrine therapies in NF1 WT and NF1 loss models. Mechanistically, our comprehensive multi-omics approaches revealed that NR2F2 modulates chromatin accessibility and regulates ER-dependent transcription through its interaction with ER, transcriptional coregulators and chromatin remodelers at chromatin. Specifically, increased NR2F2 in NF1 loss cells dramatically enhanced the association with transcriptional corepressors, which resulted in attenuation of chromatin accessibility and ER occupancy, and impaired ER transcriptional program. Our findings identify the nuclear receptor NR2F2 as a downstream effector of NF1 loss, and it is essential and potentially druggable mediator of endocrine therapy resistance. We performed gene expression profiling analysis using data obtained from RNA-seq of MCF7 sgNT, sgNF1, sgNR2F2 and double knockout (DKO) cells under different conditions.
Project description:This study is to identify estrogen receptor alpha targeting in liver cancer and breast cancer using RNA-Seq and ChIP-Seq and reveal the mechanisms underlying estrogen receptor alpha in the regulation of liver cancer and breast cancer.