Project description:Prostate cancer (PCa) is one of the most commonly diagnosed cancers in males worldwide. lncRNAs (long non-coding RNAs) play a significant role in the occurrence and development of PCa. eRNAs (enhancer RNA) and SE-lncRNAs (super-enhancer lncRNA) are important elements of lncRNAs, but the role of eRNAs and SE-lncRNAs in PCa remains largely unclear. In this work, we identified 681 eRNAs and 292 SE-lncRNAs that were expressed differentially in PCa using a microarray. We constructed a transcriptional regulation network that eRNA related enhancer and the target genes shared the same TF binding motifs. Further, we investigated whether CTCF played a role in mediating the transcriptional regulation network. eRNAs, especially those that regulate androgen response genes, may be candidates for prognostic biomarkers and therapy targets. Our work provide a new perspective for developing medical treatments and therapies for prostate cancer.
Project description:Enhancers are transcription factor platforms that also bind RNA polymerase II and generate enhancer RNAs (eRNA). Although eRNAs have been suggested as predictors of enhancer activities and possibly key components facilitating transcription, there is little genetic evidence to support this. We address the biology of eRNAs in vivo and investigate eRNA patterns, expression levels and possible functions within a mammary-specific super-enhancer that is composed of three units with distinct transcriptional capacities. We show that eRNA levels do not correspond with the activities of their respective enhancer units. However, changes in eRNA expression upon deletion of individual enhancer units reflect the change in overall super-enhancer activity. These data provide genetic evidence that eRNA levels are not a reliable readout of individual enhancers, but they predict superenhancer activity in the absence of constituent elements.
Project description:The genome is pervasively transcribed to produce a vast array of non-coding RNAs (ncRNAs). Long noncoding RNAs (lncRNAs) are transcripts of > 200 nucleotides and are best known for their ability to regulate gene expression. Enhancer RNAs (eRNAs) are subclass of lncRNAs that are synthesized from enhancer regions and have also been shown to coordinate gene expression. The biological function and significance of most lncRNAs and eRNAs remain to be determined. Epithelial to mesenchymal transition (EMT) is a ubiquitous cellular process that occurs during cellular migration, homeostasis, fibrosis, and cancer-cell metastasis. EMT-transcription factors, such as SNAI1 induce a complex transcriptional program that coordinates the morphological and molecular changes associated with EMT. Such complex transcriptional programs are often subject to coordination by networks of ncRNAs and thus can be leveraged to identify novel functional ncRNA loci. Here, using a genome-wide CRISPR activation (CRISPRa) screen targeting ~10,000 lncRNA loci we identified ncRNA loci that could either promote or attenuate EMT. We discovered a novel locus that we named SCREEM (SNAI1 cis-regulatory eRNAs expressed in monocytes). The SCREEM locus contained a cluster of eRNAs that when activated using CRISPRa induced expression of the neighboring gene SNAI1, driving concomitant EMT. However, the SCREEM eRNA transcripts themselves appeared dispensable for the induction of SNAI1 expression. Interestingly, the SCREEM eRNAs and SNAI1 were co-expressed in activated monocytes, where the SCREEM locus demarcated a monocyte-specific super-enhancer. These findings suggest an unexpected role for SNAI1 in monocytes. Exploration of the SCREEM-SNAI axis could reveal novel aspects of monocyte biology.
Project description:The genome is pervasively transcribed to produce a vast array of non-coding RNAs (ncRNAs). Long noncoding RNAs (lncRNAs) are transcripts of > 200 nucleotides and are best known for their ability to regulate gene expression. Enhancer RNAs (eRNAs) are subclass of lncRNAs that are synthesized from enhancer regions and have also been shown to coordinate gene expression. The biological function and significance of most lncRNAs and eRNAs remain to be determined. Epithelial to mesenchymal transition (EMT) is a ubiquitous cellular process that occurs during cellular migration, homeostasis, fibrosis, and cancer-cell metastasis. EMT-transcription factors, such as SNAI1 induce a complex transcriptional program that coordinates the morphological and molecular changes associated with EMT. Such complex transcriptional programs are often subject to coordination by networks of ncRNAs and thus can be leveraged to identify novel functional ncRNA loci. Here, using a genome-wide CRISPR activation (CRISPRa) screen targeting ~10,000 lncRNA loci we identified ncRNA loci that could either promote or attenuate EMT. We discovered a novel locus that we named SCREEM (SNAI1 cis-regulatory eRNAs expressed in monocytes). The SCREEM locus contained a cluster of eRNAs that when activated using CRISPRa induced expression of the neighboring gene SNAI1, driving concomitant EMT. However, the SCREEM eRNA transcripts themselves appeared dispensable for the induction of SNAI1 expression. Interestingly, the SCREEM eRNAs and SNAI1 were co-expressed in activated monocytes, where the SCREEM locus demarcated a monocyte-specific super-enhancer. These findings suggest an unexpected role for SNAI1 in monocytes. Exploration of the SCREEM-SNAI axis could reveal novel aspects of monocyte biology.
Project description:The genome is pervasively transcribed to produce a vast array of non-coding RNAs (ncRNAs). Long noncoding RNAs (lncRNAs) are transcripts of > 200 nucleotides and are best known for their ability to regulate gene expression. Enhancer RNAs (eRNAs) are subclass of lncRNAs that are synthesized from enhancer regions and have also been shown to coordinate gene expression. The biological function and significance of most lncRNAs and eRNAs remain to be determined. Epithelial to mesenchymal transition (EMT) is a ubiquitous cellular process that occurs during cellular migration, homeostasis, fibrosis, and cancer-cell metastasis. EMT-transcription factors, such as SNAI1 induce a complex transcriptional program that coordinates the morphological and molecular changes associated with EMT. Such complex transcriptional programs are often subject to coordination by networks of ncRNAs and thus can be leveraged to identify novel functional ncRNA loci. Here, using a genome-wide CRISPR activation (CRISPRa) screen targeting ~10,000 lncRNA loci we identified ncRNA loci that could either promote or attenuate EMT. We discovered a novel locus that we named SCREEM (SNAI1 cis-regulatory eRNAs expressed in monocytes). The SCREEM locus contained a cluster of eRNAs that when activated using CRISPRa induced expression of the neighboring gene SNAI1, driving concomitant EMT. However, the SCREEM eRNA transcripts themselves appeared dispensable for the induction of SNAI1 expression. Interestingly, the SCREEM eRNAs and SNAI1 were co-expressed in activated monocytes, where the SCREEM locus demarcated a monocyte-specific super-enhancer. These findings suggest an unexpected role for SNAI1 in monocytes. Exploration of the SCREEM-SNAI axis could reveal novel aspects of monocyte biology.
Project description:Here we apply integrated epigenomic and transcriptomic profiling to uncover super-enhancer heterogeneity between breast cancer subtypes, and provide clinically relevant biological insights towards TNBC. Using CRISPR/Cas9-mediated gene editing, we identify genes that are specifically regulated by TNBC-specific super-enhancers, including FOXC1 and MET, thereby unveiling a mechanism for specific overexpression of the key oncogenes in TNBC. We also identify ANLN as a novel TNBC-specific gene regulated by super-enhancer. Our studies reveal a TNBC-specific epigenomic landscape, contributing to the dysregulated oncogene expression in breast tumorigenesis.
Project description:Super-enhancers comprise of dense transcription factor platforms highly enriched for active chromatin marks. A paucity of functional data led us to investigate their role in the mammary gland, an organ characterized by exceptional gene regulatory dynamics during pregnancy. ChIP-Seq for the master regulator STAT5, the glucocorticoid receptor, H3K27ac and MED1, identified 440 mammary-specific super-enhancers, half of which were associated with genes activated during pregnancy. We interrogated the Wap super-enhancer, generating mice carrying mutations in STAT5 binding sites within its three constituent enhancers. Individually, only the most distal site displayed significant enhancer activity. However, combinatorial mutations showed that the 1,000-fold gene induction relied on all enhancers. Disabling the binding sites of STAT5, NFIB and ELF5 in the proximal enhancer incapacitated the entire super-enhancer, suggesting an enhancer hierarchy. The identification of mammary-specific super-enhancers and the mechanistic exploration of the Wap locus provide insight into the complexity of cell-specific and hormone-regulated genes. ChIP-Seq for STAT5A, GR, H3K27ac, MED1, NFIB, ELF5, RNA Pol II, and H3K4me3 in wild type (WT) mammary tissues at day one of lactation (L1), and ChIP-Seq for STAT5A, GR, H3K27ac, MED1, NFIB, ELF5, and H3K4me3 in WT mammary tissues at day 13 of pregnancy (p13). ChIP-Seq for STAT5A, GR, H3K27a in Wap-delE1a, -delE1b, -delE1c, -delE2 and -delE3 mutant mammary tissues at L1, and ChIP-Seq for NFIB and ELF5 in Wap-delE1b and -delE1c mutant mammary tissues at L1. ChIP-Seq for H3K4me3 in mammary-epthelial cells at p13 and L1. DNase-seq in WT mammary tissues at L1 and DNase-seq in Wap-delE1a, -delE1c, and -delE3 mutant mammary tissues at L1.