Project description:Estrogen receptor α (ERα) is key player in the progression of breast cancer. ERα binds to DNA and mediates long-range chromatin interactions throughout the genome, but the underlying mechanism in this process is unclear. Here, we show that AP-2 motifs are highly enriched in the ERα binding sites (ERBS) identified from the recent ChIA-PET of ERα. More importantly, we demonstrate that AP-2γ (also known as TFAP2C), a member of the AP-2 family which has been implicated in breast cancer oncogenesis, is recruited to chromatin in a ligand-independent manner and co-localized with ERα binding events. Furthermore, pertubation of AP-2γ expression disrupts ERα DNA binding, long-range chromatin interactions, and gene transcription. Using ChIP-seq, we show that AP-2γ and ERα binding occurs in close proximity on a genome-wide scale. The majority of these shared genomic regions are also occupied by the pioneer factor, FoxA1. AP-2γ is required for efficient FoxA1 binding and vice versa. Finally, we show that most ERBS associated with long-range chromatin interactions are co-localized with both AP-2γ and FoxA1. Together, our results suggest AP-2γ is an essential factor in ERα-mediated transcription, primarily working together with FoxA1 to facilitate ERα binding and long-range chromatin interactions.
Project description:Estrogen receptor α (ERα) is key player in the progression of breast cancer. ERα binds to DNA and mediates long-range chromatin interactions throughout the genome, but the underlying mechanism in this process is unclear. Here, we show that AP-2 motifs are highly enriched in the ERα binding sites (ERBS) identified from the recent ChIA-PET of ERα. More importantly, we demonstrate that AP-2γ (also known as TFAP2C), a member of the AP-2 family which has been implicated in breast cancer oncogenesis, is recruited to chromatin in a ligand-independent manner and co-localized with ERα binding events. Furthermore, pertubation of AP-2γ expression disrupts ERα DNA binding, long-range chromatin interactions, and gene transcription. Using ChIP-seq, we show that AP-2γ and ERα binding occurs in close proximity on a genome-wide scale. The majority of these shared genomic regions are also occupied by the pioneer factor, FoxA1. AP-2γ is required for efficient FoxA1 binding and vice versa. Finally, we show that most ERBS associated with long-range chromatin interactions are co-localized with both AP-2γ and FoxA1. Together, our results suggest AP-2γ is an essential factor in ERα-mediated transcription, primarily working together with FoxA1 to facilitate ERα binding and long-range chromatin interactions.
Project description:Estrogen receptor α (ERα) is key player in the progression of breast cancer. ERα binds to DNA and mediates long-range chromatin interactions throughout the genome, but the underlying mechanism in this process is unclear. Here, we show that AP-2 motifs are highly enriched in the ERα binding sites (ERBS) identified from the recent ChIA-PET of ERα. More importantly, we demonstrate that AP-2γ (also known as TFAP2C), a member of the AP-2 family which has been implicated in breast cancer oncogenesis, is recruited to chromatin in a ligand-independent manner and co-localized with ERα binding events. Furthermore, pertubation of AP-2γ expression disrupts ERα DNA binding, long-range chromatin interactions, and gene transcription. Using ChIP-seq, we show that AP-2γ and ERα binding occurs in close proximity on a genome-wide scale. The majority of these shared genomic regions are also occupied by the pioneer factor, FoxA1. AP-2γ is required for efficient FoxA1 binding and vice versa. Finally, we show that most ERBS associated with long-range chromatin interactions are co-localized with both AP-2γ and FoxA1. Together, our results suggest AP-2γ is an essential factor in ERα-mediated transcription, primarily working together with FoxA1 to facilitate ERα binding and long-range chromatin interactions. Gene expression profiling of negative control (NC) and AP-2γ siRNA transfected MCF-7, with and without E2 (estradiol) stimulation using microarray.
Project description:Estrogen receptor α (ERα) is key player in the progression of breast cancer. ERα binds to DNA and mediates long-range chromatin interactions throughout the genome, but the underlying mechanism in this process is unclear. Here, we show that AP-2 motifs are highly enriched in the ERα binding sites (ERBS) identified from the recent ChIA-PET of ERα. More importantly, we demonstrate that AP-2γ (also known as TFAP2C), a member of the AP-2 family which has been implicated in breast cancer oncogenesis, is recruited to chromatin in a ligand-independent manner and co-localized with ERα binding events. Furthermore, pertubation of AP-2γ expression disrupts ERα DNA binding, long-range chromatin interactions, and gene transcription. Using ChIP-seq, we show that AP-2γ and ERα binding occurs in close proximity on a genome-wide scale. The majority of these shared genomic regions are also occupied by the pioneer factor, FoxA1. AP-2γ is required for efficient FoxA1 binding and vice versa. Finally, we show that most ERBS associated with long-range chromatin interactions are co-localized with both AP-2γ and FoxA1. Together, our results suggest AP-2γ is an essential factor in ERα-mediated transcription, primarily working together with FoxA1 to facilitate ERα binding and long-range chromatin interactions. Gene expression profiling of negative control (NC) and AP-2γ siRNA transfected MCF-7, with and without E2 (estradiol) stimulation using microarray.
Project description:Estrogen receptor M-NM-1 (ERM-NM-1) is key player in the progression of breast cancer. ERM-NM-1 binds to DNA and mediates long-range chromatin interactions throughout the genome, but the underlying mechanism in this process is unclear. Here, we show that AP-2 motifs are highly enriched in the ERM-NM-1 binding sites (ERBS) identified from the recent ChIA-PET of ERM-NM-1. More importantly, we demonstrate that AP-2M-NM-3 (also known as TFAP2C), a member of the AP-2 family which has been implicated in breast cancer oncogenesis, is recruited to chromatin in a ligand-independent manner and co-localized with ERM-NM-1 binding events. Furthermore, pertubation of AP-2M-NM-3 expression disrupts ERM-NM-1 DNA binding, long-range chromatin interactions, and gene transcription. Using ChIP-seq, we show that AP-2M-NM-3 and ERM-NM-1 binding occurs in close proximity on a genome-wide scale. The majority of these shared genomic regions are also occupied by the pioneer factor, FoxA1. AP-2M-NM-3 is required for efficient FoxA1 binding and vice versa. Finally, we show that most ERBS associated with long-range chromatin interactions are co-localized with both AP-2M-NM-3 and FoxA1. Together, our results suggest AP-2M-NM-3 is an essential factor in ERM-NM-1-mediated transcription, primarily working together with FoxA1 to facilitate ERM-NM-1 binding and long-range chromatin interactions. Genome-wide binding analysis of AP-2M-NM-3 and FoxA1 in MCF-7 with and without E2 (estradiol) stimulation using ChIP-Seq.
Project description:Alterations of glycosyltransferase expression are often associated with tumor occurrence and progression. Among the many glycosyltransferases, increased expression of fucosyltransferase 8 (FUT8) has been frequently observed to be involved in progression and metastasis of various types of cancer. The regulatory mechanisms of FUT8 expression remain unclear. FUT8 expression was shown, in this study, to be elevated in breast cancer. Systematic analysis revealed that transcription factor activator protein 2γ (AP-2γ) is the target gene of microRNA-10b (miR-10b), which we previously identified as a positive regulator of FUT8. Overexpression of AP-2γ inhibited FUT8 expression, with associated reduction of cell invasiveness and migration ability. AP-2γ was capable of binding to transcription factor STAT3, and phosphorylation of STAT3 induced transcription of the FUT8 gene. On the basis of our findings, we propose that binding of AP-2γ to STAT3 results in formation of the AP-2γ/STAT3 complex and consequent inhibition of STAT3 phosphorylation, thereby preventing entry of p-STAT3 into the nucleus to initiate FUT8 transcription. This study clarifies the molecular mechanisms whereby transcription factor AP-2γ regulates FUT8 expression in breast cancer.
Project description:This SuperSeries is composed of the following subset Series: GSE25314: FoxA1 is a critical determinant of Estrogen Receptor function and endocrine response (part I) GSE25315: FoxA1 is a critical determinant of Estrogen Receptor function and endocrine response (part II) Refer to individual Series
Project description:Expression of estrogen-related receptor alpha (ERRalpha) has recently been shown to carry negative prognostic significance in breast and ovarian cancers. The specific role of this orphan nuclear receptor in tumor growth and progression, however, is yet to be fully understood. The significant homology between estrogen receptor alpha (ERalpha) and ERRalpha initially suggested that these receptors may have similar transcriptional targets. Using the well-characterized ERalpha-positive MCF-7 breast cancer cell line, we sought to gain a genome-wide picture of ERalpha-ERRalpha cross-talk using an unbiased microarray approach. In addition to generating a host of novel ERRalpha target genes, this study yielded the surprising result that most ERRalpha-regulated genes are unrelated to estrogen signaling. The relatively small number of genes regulated by both ERalpha and ERRalpha led us to expand our study to the more aggressive and less clinically treatable ERalpha-negative class of breast cancers. In this setting, we found that ERRalpha expression is required for the basal level of expression of many known and novel ERRalpha target genes. Introduction of a small interfering RNA directed to ERRalpha into the highly aggressive breast carcinoma MDA-MB-231 cell line dramatically reduced the migratory potential of these cells. Although stable knockdown of ERRalpha expression in MDA-MB-231 cells had no effect on in vitro cell proliferation, a significant reduction of tumor growth rate was observed when these cells were implanted as xenografts. Our results confirm a role for ERRalpha in breast cancer growth and highlight it as a potential therapeutic target for estrogen receptor-negative breast cancer.
Project description:Estrogen Receptor alpha (ER?) is a ligand-inducible transcription factor that mediates estrogen signaling in hormone-responsive cells, where it controls key cellular functions by assembling in gene-regulatory multiprotein complexes. For this reason, interaction proteomics has been shown to represent a useful tool to investigate the molecular mechanisms underlying ER? action in target cells. RNAs have emerged as bridging molecules, involved in both assembly and activity of transcription regulatory protein complexes. By applying Tandem Affinity Purification (TAP) coupled to mass spectrometry (MS) before and after RNase digestion in vitro, we generated a dataset of nuclear ER? molecular partners whose association with the receptor involves RNAs. These data provide a useful resource to elucidate the combined role of nuclear RNAs and the proteins identified here in ER? signaling to the genome in breast cancer and other cell types.