Targeted H3R26 deimination specifically facilitates ER binding by modifying nucleosome structure
Ontology highlight
ABSTRACT: The precise mechanisms by which hormone receptors bind to DNA in the context of chromatin remain unclear. Here we report that the genomic distributions of estrogen receptor (ER) and H3R26 deimination (H3R26Cit) in breast cancer cells are strikingly coincident, linearly correlated, and observed as early as 2 minutes following estradiol treatment. Paired-end MNase ChIP-seq indicates that the charge-neutral H3R26Cit modification facilitates ER binding to DNA by altering the fine structure of the nucleosome. Clinically, we find that PAD2 and H3R26Cit levels correlate with ER expression in breast tumors and that high PAD2 expression is associated with increased survival in ER+ breast cancer patients. Our study suggests that PAD2-mediated histone deimination is fundamental to ER signaling in breast cancer.
Project description:The precise mechanisms by which hormone receptors bind to DNA in the context of chromatin remain unclear. Here we report that the genomic distributions of estrogen receptor (ER) and H3R26 deimination (H3R26Cit) in breast cancer cells are strikingly coincident, linearly correlated, and observed as early as 2 minutes following estradiol treatment. Paired-end MNase ChIP-seq indicates that the charge-neutral H3R26Cit modification facilitates ER binding to DNA by altering the fine structure of the nucleosome. Clinically, we find that PAD2 and H3R26Cit levels correlate with ER expression in breast tumors and that high PAD2 expression is associated with increased survival in ER+ breast cancer patients. Our study suggests that PAD2-mediated histone deimination is fundamental to ER signaling in breast cancer. We performed replicate H3R26Cit ChIP-seq experiments prior to estrogen treatment and 2min, 5min, 10min, 40min, and 160min after E2 treatment. Additionally, we performed H3R26Cit and H3K27ac ChIP on MNase digested chromatin.
Project description:PAD2, one of a family of PAD enzymes that convert positively charged arginine residues on target proteins to neutrally charged citrulline, has been shown to play a role in estrogen signaling through interactions with histone H3R26. The objectives of this project are to define the role of PAD2 in estrogen receptor alpha signaling, tumor progression, and tamoxifen resistance.
Project description:PAD2, one of a family of PAD enzymes that convert positively charged arginine residues on target proteins to neutrally charged citrulline, has been shown to play a role in estrogen signaling through interactions with histone H3R26. The objectives of this project are to define the role of PAD2 in estrogen receptor alpha signaling, tumor progression, and tamoxifen resistance.
Project description:Estrogen receptor M-NM-1 (ER), a member of the nuclear hormone receptor superfamily, regulates transcriptional activity by ligand-dependent recruitment of cofactors which, in turn, locally alter chromatin structure. It is generally believed that co-factor activity at target promoters leads to a more open, transcriptionally permissive chromatin structure, however, these mechanisms remain to be fully established. Peptidylarginine deiminases (PADIs) catalyze the conversion of positively charged arginine and methylarginine residues to neutrally charged citrulline and this activity has been linked to the gene regulation. Here, we found that PADI2 citrullinate H3 Arginine 26 (H3R26) in vitro and, using a specific H3R26 citrulline (H3Cit26) antibody, we demonstrate that H3Cit26 occurs in vivo following 17M-NM-2-estradiol (E2) stimulation and this unique and pronounced global activation of H3Cit26 is ER-dependent. Using a mammalian-based promoter chromosomal array system, we observed that citrullination at H3R26 is robust and co-localizes with ER at decondensed chromatin loci. Additionally, this histone modification is specifically enriched at ER bound regions of target promoters, forming a permissive chromatin environment for gene transactivation. Interestingly, we have shown in a reciprocal way, that either depletion of PADI2 or inhibition of ER not only dramatically abolished E2-induced activation of H3Cit26 on gene promoters but also affect ER recruitment. Collectively, our results demonstrate that citrullination of H3R26 by PADI2 following estrogen stimulation plays a role in ER target gene activation, likely via decondensation of the local chromatin architecture. Two H3Cit26 ChIP-chip biological replicates under vehicle treatment and two H3Cit26 ChIP-chip biological replicates under E2 stimulation from MCF-7 human breast cancer cells are included.
Project description:To investigate the potential role of peptidylarginine deiminase 2 (PAD2) in gene expression, we created stable shRNA scrambled control and PAD2 knockdown MCF-7 breast cancer cell lines. After validating the specific knockdown of PAD2 at the mRNA and protein level, we utilized an Agilent microarray platform to compare the gene expression profile of the two cell lines to generate a candidate list of genes regulated by PAD2.
Project description:To investigate the potential role of peptidylarginine deiminase 2 (PAD2) in gene expression, we created stable shRNA scrambled control and PAD2 knockdown MCF-7 breast cancer cell lines. After validating the specific knockdown of PAD2 at the mRNA and protein level, we utilized an Agilent microarray platform to compare the gene expression profile of the two cell lines to generate a candidate list of genes regulated by PAD2. Control and PAD2 knockdown cells were created by stably transfecting shRNA constructs into MCF-7 cells. Stable cells were selected using puromycin and knockdown validate at the mRNA and protein level. Microarray data represents 4 independent biological replicates contain control and PAD2 knockdown samples.
Project description:Estrogen receptor α (ER), a member of the nuclear hormone receptor superfamily, regulates transcriptional activity by ligand-dependent recruitment of cofactors which, in turn, locally alter chromatin structure. It is generally believed that co-factor activity at target promoters leads to a more open, transcriptionally permissive chromatin structure, however, these mechanisms remain to be fully established. Peptidylarginine deiminases (PADIs) catalyze the conversion of positively charged arginine and methylarginine residues to neutrally charged citrulline and this activity has been linked to the gene regulation. Here, we found that PADI2 citrullinate H3 Arginine 26 (H3R26) in vitro and, using a specific H3R26 citrulline (H3Cit26) antibody, we demonstrate that H3Cit26 occurs in vivo following 17β-estradiol (E2) stimulation and this unique and pronounced global activation of H3Cit26 is ER-dependent. Using a mammalian-based promoter chromosomal array system, we observed that citrullination at H3R26 is robust and co-localizes with ER at decondensed chromatin loci. Additionally, this histone modification is specifically enriched at ER bound regions of target promoters, forming a permissive chromatin environment for gene transactivation. Interestingly, we have shown in a reciprocal way, that either depletion of PADI2 or inhibition of ER not only dramatically abolished E2-induced activation of H3Cit26 on gene promoters but also affect ER recruitment. Collectively, our results demonstrate that citrullination of H3R26 by PADI2 following estrogen stimulation plays a role in ER target gene activation, likely via decondensation of the local chromatin architecture.
Project description:An effective anti-cancer therapy should exclusively target cancer cells and trigger in them a broad spectrum of cell death pathways that will prevent avoidance. Here, we present a novel paradigm in cancer therapy that specifically targets the mitochondria and ER of cancer cells. We developed a peptide derived from the flexible and transmembrane domains of the human protein NAF-1/CISD2. This peptide (NAF-1) specifically permeated through the plasma membranes of human epithelial breast cancer cells, abolished their mitochondrial-ER network, and triggered cell death with characteristics of apoptosis, ferroptosis and necroptosis. In vivo analysis revealed that the peptide significantly decreased tumor growth in mice carrying xenograft human tumors. Computational simulations of cancer vs. normal cells membranes revealed that the specificity of the peptide to cancer cells is due to its selective recognition of their membrane composition. NAF-1 represents therefore a promising anti-cancer lead compound that acts via a unique mechanism.
Project description:Limited knowledge of the changes in estrogen receptor (ER) signaling during the transformation of the normal mammary gland to breast cancer hinders the development of effective prevention and treatment strategies. Differences in estrogen signaling between normal human primary breast epithelial cells and primary breast tumors obtained immediately following surgical excision were explored. Transcriptional profiling of normal ER+ mature luminal mammary epithelial cells and ER+ breast tumors revealed significant difference in the response to estrogen stimulation. Consistent with these differences in gene expression, the normal and tumor ER cistromes were distinct and sufficient to segregate normal breast tissues from breast tumors. The selective enrichment of the DNA binding motif GRHL2 in the breast cancer-specific ER cistrome suggests that it may play a role in the differential function of ER in breast cancer. Depletion of GRHL2 resulted in altered ER binding and differential transcriptional responses to estrogen stimulation. Furthermore, GRHL2 was demonstrated to be essential for estrogen-stimulated proliferation of ER+ breast cancer cells. DLC1 was also identified as an estrogen-induced tumor suppressor in the normal mammary gland with decreased expression in breast cancer. In clinical cohorts, loss of DLC1 and gain of GRHL2 expression are associated with breast cancer and are independently predictive for worse survival. This study suggests that normal ER signaling is lost and tumor-specific ER signaling is gained during breast tumorigenesis. Unraveling these changes in ER signaling during breast cancer progression should aid the development of more effective prevention strategies and targeted therapeutics. SIGNIFICANCE STATEMENT: Abnormal estrogen receptor (ER) signaling drives the majority of breast cancers and is targeted by endocrine therapies. However, in normal breast tissue, ER signaling has been demonstrated to promote benign functions such as development and differentiation. Using genomic techniques to characterize ER function in normal breast and breast tumors, this study reveals differential patterns of ER signaling, suggesting that normal ER signaling is lost and tumorigenic ER signaling gained during breast tumor formation. Better understanding of this process can aid the development of improved breast cancer prevention strategies and therapies.