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Precise spatio-temporal expression of genes in organogenesis is regulated by the coordinated interplay of DNA elements such as promoter and enhancers present in the regulatory region of a given locus. POU1F1 transcription factor plays a crucial role in the development of somatotrophs, lactotrophs and thyrotrophs in the anterior pituitary gland, and in maintaining high expression of growth hormone, prolactin and TSH. In mouse, expression of POU1F1 is controlled by a region fenced by two CTCF sites, containing 5 upstream enhancer elements, designated E-A (5 to 3). Elements C, B and A correspond to elements shown previously to play a role in pituitary development and hormonal expression; functional roles for elements E and D have not been reported. We performed comparative sequence analysis of this regulatory region and discovered that three elements, B, C and E, are present in all vertebrate groups except Agnatha. One very long (>2 kb) element (A) is unique to mammals suggesting a specific change in regulation of the gene in this group. Using DNA accessibility assay (ATAC-seq) we showed that conserved elements in anterior pituitary of four non-mammals are open, suggesting functionality as regulatory elements. We showed that, in many non-mammalian vertebrates, an additional upstream exon closely follows element E, leading to alternatively spliced transcripts. Here, element E functions as an alternative promoter, but in mammals this feature is lost, suggesting conversion of alternative promoter to enhancer. Our work shows that regulation of POU1F1 changed markedly during the course of vertebrate evolution, use of a low number of enhancer elements combined with alternative promoters in non-mammalian vertebrates being replaced by use of a unique combination of regulatory units in mammals. Most importantly, our work suggests that evolutionary conversion of alternate promoter to enhancer could be one of the evolutionary mechanisms of enhancer birth.

Super‐enhancers (SEs) have been recognized as key epigenetic regulators underlying cancer stemness and malignant traits by aberrant transcriptional control and promising therapeutic targets against human cancers. However, the SE landscape and their roles during head and neck squamous cell carcinoma (HNSCC) development especially in cancer stem cells (CSCs) maintenance remain underexplored yet. Here, we identify leukemia inhibitory factor (LIF)‐SE as a representative oncogenic SE to activate LIF transcription in HNSCC. LIF secreted from cancer cells and cancer‐associated fibroblasts promotes cancer stemness by driving SOX2 transcription in an autocrine/paracrine manner, respectively. Mechanistically, enhancer elements E1, 2, 4 within LIF‐SE recruit SOX2/SMAD3/BRD4/EP300 to facilitate LIF transcription; LIF activates downstream LIFR‐STAT3 signaling to drive SOX2 transcription, thus forming a previously unknown regulatory feedback loop (LIF‐SE‐LIF/LIFR‐STAT3‐SOX2) to maintain LIF overexpression and CSCs stemness. Clinically, increased LIF abundance in clinical samples correlate with malignant clinicopathological features and patient prognosis; higher LIF concentrations in presurgical plasma dramatically diminish following cancer eradication. Therapeutically, pharmacological targeting LIF‐SE‐LIF/LIFR‐STAT3 significantly impairs tumor growth and reduces CSC subpopulations in xenograft and PDX models. Our findings reveal a hitherto uncharacterized LIF‐SE‐mediated auto‐regulatory loop in regulating HNSCC stemness and highlight LIF as a novel noninvasive biomarker and potential therapeutic target for HNSCC. [ABSTRACT FROM AUTHOR]

Background: Our research endeavored to develop a robust predictive signature grounded in super-enhancer-related genes (SERGs), with the dual objectives of forecasting survival outcomes and evaluating the tumor immune microenvironment (TiME) in hepatocellular carcinoma (HCC). Methods: HCC RNA-sequencing data were retrieved from The Cancer Genome Atlas (TCGA), and 365 patients were randomly assigned to training or testing sets in 1:1 ratio. SERGs of HCC were downloaded from Super-Enhancer Database (SEdb). On the basis of training set, a SERGs signature was identified, and its prognostic value was confirmed by internal and external validation (GSE14520) sets. We subsequently examined the model for potential functional enrichment and the degree of tumor immune infiltration. Additionally, we carried out in vitro experiments to delve into the biological functions of CBX2 gene. Results: An SE-related prognostic model including CBX2, TPX2, EFNA3, DNASE1L3 and SOCS2 was established and validated. According to this risk model, patients in the high-risk group had a significantly worse prognosis, and their immune cell infiltration was significantly different from that of low-risk group. Moreover, the high-risk group exhibited a significant enrichment of tumor-associated pathological pathways. The SERGs signature can generally be utilized to screen HCC patients who are likely to respond to immunotherapy, as there is a positive correlation between the risk score and the Tumor Immune Dysfunction and Exclusion (TIDE) score. Furthermore, the downregulation of the CBX2 gene expression was found to inhibit HCC cell viability, migration, and cell cycle progression, while simultaneously promoting apoptosis. Conclusions: We developed a novel HCC prognostic model utilizing SERGs, indicating that patients with high-risk score not only face a poorer prognosis but also may exhibit a diminished therapeutic response to immune checkpoint inhibitors (ICIs). This model is designed to tailor personalized treatment strategies to the individual needs of each patient, thereby improving the overall clinical outcomes for HCC patients. Furthermore, CBX2 is a promising candidate for therapeutic intervention in HCC. [ABSTRACT FROM AUTHOR]

Background: Heat shock transcription factors (HSFs) play crucial roles in the development of malignancies. However, the specific roles of HSFs in hepatocellular carcinoma (HCC) have yet to be fully elucidated.Aims:To explore the involvement of the HSF family, particularly HSF1, in the progression and prognosis of HCC. Materials & Methods: We conducted a thorough analysis of HSF expression and copy number variations across various cancer datasets. Specifically focusing on HSF1, we examined its expression levels and prognostic implications in HCC. In vitro and in vivo experiments were carried out to evaluate the impact of HSF1 on liver cancer cell proliferation. Additionally, we utilized CUT&Tag, H3K27 acetylation enrichment, and RNA sequencing (RNA‐seq) to investigate the super‐enhancer (SE) regulatory landscapes of HSF1 in liver cancer cell lines. Results: HSF1 expression is elevated in HCC and is linked to poor prognosis in several datasets. HSF1 stimulates liver cancer cell proliferation both in vitro and in vivo, partly through modulation of H3K27ac levels, influencing enhancer distribution. Mechanistically, our findings demonstrate that HSF1 transcriptionally activates MYCN expression by binding to its promoter and SE elements, thereby promoting liver cancer cell proliferation. Moreover, increased MYCN expression was detected in HCC tumors and correlated with unfavorable patient outcomes. Discussion: Our study sheds light on previously unexplored aspects of HSF1 biology, identifying it as a transcription factor capable of shaping the epigenetic landscape in the context of HCC. Given HSF1's potential as an epigenetic regulator, targeting the HSF1‐MYCN axis could open up new therapeutic possibilities for HCC treatment. Conclusion: The HSF1‐MYCN axis constitutes a transcription‐dependent regulatory mechanism that may function as both a prognostic indicator and a promising therapeutic target in liver cancer. Further exploration of this axis could yield valuable insights into novel treatment strategies for HCC. [ABSTRACT FROM AUTHOR]

Abstract Background Our research endeavored to develop a robust predictive signature grounded in super-enhancer-related genes (SERGs), with the dual objectives of forecasting survival outcomes and evaluating the tumor immune microenvironment (TiME) in hepatocellular carcinoma (HCC). Methods HCC RNA-sequencing data were retrieved from The Cancer Genome Atlas (TCGA), and 365 patients were randomly assigned to training or testing sets in 1:1 ratio. SERGs of HCC were downloaded from Super-Enhancer Database (SEdb). On the basis of training set, a SERGs signature was identified, and its prognostic value was confirmed by internal and external validation (GSE14520) sets. We subsequently examined the model for potential functional enrichment and the degree of tumor immune infiltration. Additionally, we carried out in vitro experiments to delve into the biological functions of CBX2 gene. Results An SE-related prognostic model including CBX2, TPX2, EFNA3, DNASE1L3 and SOCS2 was established and validated. According to this risk model, patients in the high-risk group had a significantly worse prognosis, and their immune cell infiltration was significantly different from that of low-risk group. Moreover, the high-risk group exhibited a significant enrichment of tumor-associated pathological pathways. The SERGs signature can generally be utilized to screen HCC patients who are likely to respond to immunotherapy, as there is a positive correlation between the risk score and the Tumor Immune Dysfunction and Exclusion (TIDE) score. Furthermore, the downregulation of the CBX2 gene expression was found to inhibit HCC cell viability, migration, and cell cycle progression, while simultaneously promoting apoptosis. Conclusions We developed a novel HCC prognostic model utilizing SERGs, indicating that patients with high-risk score not only face a poorer prognosis but also may exhibit a diminished therapeutic response to immune checkpoint inhibitors (ICIs). This model is designed to tailor personalized treatment strategies to the individual needs of each patient, thereby improving the overall clinical outcomes for HCC patients. Furthermore, CBX2 is a promising candidate for therapeutic intervention in HCC.

Objective Rare study of the non-coding and regulatory regions of the genome limits our ability to decode the mechanisms of fatty liver hemorrhage syndrome (FLHS) in chickens. Methods Herein, we constructed the high-fat diet-induced FLHS chicken model to investigate the genome-wide active enhancers and transcriptome by H3K27ac target chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-Seq) profiles of normal and FLHS liver tissues. Concurrently, an integrative analysis combining ChIP-seq with RNA-Seq and a comparative analysis with chicken FLHS, rat non-alcoholic fatty liver disease (NAFLD) and human NAFLD at the transcriptome level revealed the enhancer and super enhancer target genes and conservative genes involved in metabolic processes. Results In total, 56 and 199 peak-genes were identified in upregulated peak-genes positively regulated by H3K27ac (Cor (peak-gene correlation) ≥0.5 and log2(FoldChange) ≥1) (PP) and downregulated peak-genes positively regulated by H3K27ac (Cor (peak-gene correlation) ≥0.5 and log2(FoldChange)≤−1) (PN), respectively; then we screened key regulatory targets mainly distributing in lipid metabolism (PCK1, APOA4, APOA1, INHBE) and apoptosis (KIT, NTRK2) together with MAPK and PPAR signaling pathway in FLHS. Intriguingly, PCK1 was also significantly covered in up-regulated super-enhancers (SEs), which further implied the vital role of PCK1 during the development of FLHS. Conclusion Together, our studies have identified potential therapeutic biomarkers of PCK1 and elucidated novel insights into the pathogenesis of FLHS, especially for the epigenetic perspective.

Abstract Background Presbycusis, also referred to as age-related hearing loss (ARHL), is a condition that results from the cumulative effects of aging on an individual's auditory capabilities. Given the limited understanding of epigenetic mechanisms in ARHL, our research focuses on alterations in chromatin-accessible regions. Methods We employed assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) in conjunction with unique identifier (UID) mRNA-seq between young and aging cochleae, and conducted integrated analysis as well as motif/TF-gene prediction. Additionally, the essential role of super-enhancers (SEs) in the development of ARHL was identified by comparative analysis to previous research. Meanwhile, an ARHL mouse model and an aging mimic hair cell (HC) model were established with a comprehensive identification of senescence phenotypes to access the role of SEs in ARHL progression. Results The control cochlear tissue exhibited greater chromatin accessibility than cochlear tissue affected by ARHL. Furthermore, the levels of histone 3 lysine 27 acetylation were significantly depressed in both aging cochlea and aging mimic HEI-OC1 cells, highlighting the essential role of SEs in the development of ARHL. The potential senescence-associated super-enhancers (SASEs) of ARHL were identified, most of which exhibited decreased chromatin accessibility. The majority of genes related to the SASEs showed obvious decreases in mRNA expression level in aging HCs and was noticeably altered following treatment with JQ1 (a commonly used SE inhibitor). Conclusion The chromatin accessibility in control cochlear tissue was higher than that in cochlear tissue affected by ARHL. Potential SEs involved in ARHL were identified, which might provide a basis for future therapeutics targeting SASEs related to ARHL.

Abstract Nasopharyngeal carcinoma (NPC), primarily found in the southern region of China, is a malignant tumor known for its highly metastatic characteristics. The high mortality rates caused by the distant metastasis and disease recurrence remain unsolved clinical problems. In clinic, the berberine (BBR) compound has widely been in NPC therapy to decrease metastasis and disease recurrence, and BBR was documented as a main component with multiple anti-NPC effects. However, the mechanism by which BBR inhibits the growth and metastasis of nasopharyngeal carcinoma remains elusive. Herein, we show that BBR effectively inhibits the growth, metastasis, and invasion of NPC via inducing a specific super enhancer (SE). From a mechanistic perspective, the RNA sequencing (RNA-seq) results suggest that the RAS–RAF1–MEK1/2–ERK1/2 signaling pathway, activated by the epidermal growth factor receptor (EGFR), plays a significant role in BBR-induced autophagy in NPC. Blockading of autophagy markedly attenuated the effect of BBR-mediated NPC cell growth and metastasis inhibition. Notably, BBR increased the expression of EGFR by transcription, and knockout of EGFR significantly inhibited BBR-induced microtubule associated protein 1 light chain 3 (LC3)-II increase and p62 inhibition, proposing that EGFR plays a pivotal role in BBR-induced autophagy in NPC. Chromatin immunoprecipitation sequencing (ChIP-seq) results found that a specific SE existed only in NPC cells treated with BBR. This SE knockdown markedly repressed the expression of EGFR and phosphorylated EGFR (EGFR-p) and reversed the inhibition of BBR on NPC proliferation, metastasis, and invasion. Furthermore, BBR-specific SE may trigger autophagy by enhancing EGFR gene transcription, thereby upregulating the RAS–RAF1–MEK1/2–ERK1/2 signaling pathway. In addition, in vivo BBR effectively inhibited NPC cells growth and metastasis, following an increase LC3 and EGFR and a decrease p62. Collectively, this study identifies a novel BBR-special SE and established a new epigenetic paradigm, by which BBR regulates autophagy, inhibits proliferation, metastasis, and invasion. It provides a rationale for BBR application as the treatment regime in NPC therapy in future.

Super‐enhancer‐associated transcription factor networks define cell identity in neuroblastoma (NB). Dysregulation of these transcription factors contributes to the initiation and maintenance of NB by enforcing early developmental identity states. We report that the class I basic helix–loop–helix (bHLH) transcription factor 4 (TCF4; also known as E2‐2) is a critical NB dependency gene that significantly contributes to these identity states through heterodimerization with cell‐identity‐specific bHLH transcription factors. Knockdown of TCF4 significantly induces apoptosis in vitro and inhibits tumorigenicity in vivo. We used genome‐wide expression profiling, TCF4 chromatin immunoprecipitation sequencing (ChIP‐seq) and TCF4 immunoprecipitation–mass spectrometry to determine the role of TCF4 in NB cells. Our results, along with recent findings in NB for the transcription factors T‐box transcription factor TBX2, heart‐ and neural crest derivatives‐expressed protein 2 (HAND2) and twist‐related protein 1 (TWIST1), propose a role for TCF4 in regulating forkhead box protein M1 (FOXM1)/transcription factor E2F‐driven gene regulatory networks that control cell cycle progression in cooperation with N‐myc proto‐oncogene protein (MYCN), TBX2, and the TCF4 dimerization partners HAND2 and TWIST1. Collectively, we showed that TCF4 promotes cell proliferation through direct transcriptional regulation of the c‐MYC/MYCN oncogenic program that drives high‐risk NB. Mechanistically, our data suggest the novel finding that TCF4 acts to support MYC activity by recruiting multiple factors known to regulate MYC function to sites of colocalization between critical NB transcription factors, TCF4 and MYC oncoproteins. Many of the TCF4‐recruited factors are druggable, giving insight into potential therapies for high‐risk NB. This study identifies a new function for class I bHLH transcription factors (e.g., TCF3, TCF4, and TCF12) that are important in cancer and development. [ABSTRACT FROM AUTHOR]

Gene regulation is crucial for cellular function and homeostasis. It involves diverse mechanisms controlling the production of specific gene products and contributing to tissue-specific variations in gene expression. The dysregulation of genes leads to disease, emphasizing the need to understand these mechanisms. Computational methods have jointly studied transcription factors (TFs), microRNA (miRNA), and messenger RNA (mRNA) to investigate gene regulatory networks. However, there remains a knowledge gap in comprehending gene regulatory networks. On the other hand, super-enhancers (SEs) have been implicated in miRNA biogenesis and function in recent experimental studies, in addition to their pivotal roles in cell identity and disease progression. However, statistical/computational methodologies harnessing the potential of SEs in deciphering gene regulation networks remain notably absent. However, to understand the effect of miRNA on mRNA, existing statistical/computational methods could be updated, or novel methods could be developed by accounting for SEs in the model. In this review, we categorize existing computational methods that utilize TF and miRNA data to understand gene regulatory networks into three broad areas and explore the challenges of integrating enhancers/SEs. The three areas include unraveling indirect regulatory networks, identifying network motifs, and enriching pathway identification by dissecting gene regulators. We hypothesize that addressing these challenges will enhance our understanding of gene regulation, aiding in the identification of therapeutic targets and disease biomarkers. We believe that constructing statistical/computational models that dissect the role of SEs in predicting the effect of miRNA on gene regulation is crucial for tackling these challenges. [ABSTRACT FROM AUTHOR]

Background: Presbycusis, also referred to as age-related hearing loss (ARHL), is a condition that results from the cumulative effects of aging on an individual's auditory capabilities. Given the limited understanding of epigenetic mechanisms in ARHL, our research focuses on alterations in chromatin-accessible regions. Methods: We employed assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) in conjunction with unique identifier (UID) mRNA-seq between young and aging cochleae, and conducted integrated analysis as well as motif/TF-gene prediction. Additionally, the essential role of super-enhancers (SEs) in the development of ARHL was identified by comparative analysis to previous research. Meanwhile, an ARHL mouse model and an aging mimic hair cell (HC) model were established with a comprehensive identification of senescence phenotypes to access the role of SEs in ARHL progression. Results: The control cochlear tissue exhibited greater chromatin accessibility than cochlear tissue affected by ARHL. Furthermore, the levels of histone 3 lysine 27 acetylation were significantly depressed in both aging cochlea and aging mimic HEI-OC1 cells, highlighting the essential role of SEs in the development of ARHL. The potential senescence-associated super-enhancers (SASEs) of ARHL were identified, most of which exhibited decreased chromatin accessibility. The majority of genes related to the SASEs showed obvious decreases in mRNA expression level in aging HCs and was noticeably altered following treatment with JQ1 (a commonly used SE inhibitor). Conclusion: The chromatin accessibility in control cochlear tissue was higher than that in cochlear tissue affected by ARHL. Potential SEs involved in ARHL were identified, which might provide a basis for future therapeutics targeting SASEs related to ARHL. [ABSTRACT FROM AUTHOR]

Liquid-liquid phase separation, a novel biochemical phenomenon, has been increasingly studied for its medical applications. It underlies the formation of membrane-less organelles and is involved in many cellular and biological processes. During transcriptional regulation, dynamic condensates are formed through interactions between transcriptional elements, such as transcription factors, coactivators, and mediators. Cancer is a disease characterized by uncontrolled cell proliferation, but the precise mechanisms underlying tumorigenesis often remain to be elucidated. Emerging evidence has linked abnormal transcriptional condensates to several diseases, especially cancer, implying that phase separation plays an important role in tumorigenesis. Condensates formed by phase separation may have an effect on gene transcription in tumors. In the present review, we focus on the correlation between phase separation and transcriptional regulation, as well as how this phenomenon contributes to cancer development. [ABSTRACT FROM AUTHOR]

Recently, biomolecular condensates formed through liquid–liquid phase separation have been widely reported to regulate key intracellular processes involved in cell biology and pathogenesis. BRD4 is a nuclear protein instrumental to the establishment of phase-separated super-enhancers (SEs) to direct the transcription of important genes. We previously observed that protein droplets of BRD4 became hydrophobic as their size increase, implying an ability of SEs to limit the ionization of water molecules by irradiation. Here, we aim to establish if SEs confer radiation resistance in cancer cells. We established an in vitro DNA damage assay that measures the effect of radicals provoked by the Fenton reaction on DNA integrity. This revealed that DNA damage was markedly reduced when BRD4 underwent phase separation with DNA. Accordingly, co-focal imaging analyses revealed that SE foci and DNA damage foci are mutually exclusive in irradiated cells. Lastly, we observed that the radioresistance of cancer cells was significantly reduced when irradiation was combined with ARV-771, a BRD4 de-stabilizer. Our data revealed the existence of innately radioresistant genomic regions driven by phase separation in cancer cells. The disruption of these phase-separated components enfolding genomic DNA may represent a novel strategy to augment the effects of radiotherapy. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC), primarily found in the southern region of China, is a malignant tumor known for its highly metastatic characteristics. The high mortality rates caused by the distant metastasis and disease recurrence remain unsolved clinical problems. In clinic, the berberine (BBR) compound has widely been in NPC therapy to decrease metastasis and disease recurrence, and BBR was documented as a main component with multiple anti-NPC effects. However, the mechanism by which BBR inhibits the growth and metastasis of nasopharyngeal carcinoma remains elusive. Herein, we show that BBR effectively inhibits the growth, metastasis, and invasion of NPC via inducing a specific super enhancer (SE). From a mechanistic perspective, the RNA sequencing (RNA-seq) results suggest that the RAS–RAF1–MEK1/2–ERK1/2 signaling pathway, activated by the epidermal growth factor receptor (EGFR), plays a significant role in BBR-induced autophagy in NPC. Blockading of autophagy markedly attenuated the effect of BBR-mediated NPC cell growth and metastasis inhibition. Notably, BBR increased the expression of EGFR by transcription, and knockout of EGFR significantly inhibited BBR-induced microtubule associated protein 1 light chain 3 (LC3)-II increase and p62 inhibition, proposing that EGFR plays a pivotal role in BBR-induced autophagy in NPC. Chromatin immunoprecipitation sequencing (ChIP-seq) results found that a specific SE existed only in NPC cells treated with BBR. This SE knockdown markedly repressed the expression of EGFR and phosphorylated EGFR (EGFR-p) and reversed the inhibition of BBR on NPC proliferation, metastasis, and invasion. Furthermore, BBR-specific SE may trigger autophagy by enhancing EGFR gene transcription, thereby upregulating the RAS–RAF1–MEK1/2–ERK1/2 signaling pathway. In addition, in vivo BBR effectively inhibited NPC cells growth and metastasis, following an increase LC3 and EGFR and a decrease p62. Collectively, this study identifies a novel BBR-special SE and established a new epigenetic paradigm, by which BBR regulates autophagy, inhibits proliferation, metastasis, and invasion. It provides a rationale for BBR application as the treatment regime in NPC therapy in future. [ABSTRACT FROM AUTHOR]

Abstract Super‐enhancers (SEs) have been recognized as key epigenetic regulators underlying cancer stemness and malignant traits by aberrant transcriptional control and promising therapeutic targets against human cancers. However, the SE landscape and their roles during head and neck squamous cell carcinoma (HNSCC) development especially in cancer stem cells (CSCs) maintenance remain underexplored yet. Here, we identify leukemia inhibitory factor (LIF)‐SE as a representative oncogenic SE to activate LIF transcription in HNSCC. LIF secreted from cancer cells and cancer‐associated fibroblasts promotes cancer stemness by driving SOX2 transcription in an autocrine/paracrine manner, respectively. Mechanistically, enhancer elements E1, 2, 4 within LIF‐SE recruit SOX2/SMAD3/BRD4/EP300 to facilitate LIF transcription; LIF activates downstream LIFR‐STAT3 signaling to drive SOX2 transcription, thus forming a previously unknown regulatory feedback loop (LIF‐SE‐LIF/LIFR‐STAT3‐SOX2) to maintain LIF overexpression and CSCs stemness. Clinically, increased LIF abundance in clinical samples correlate with malignant clinicopathological features and patient prognosis; higher LIF concentrations in presurgical plasma dramatically diminish following cancer eradication. Therapeutically, pharmacological targeting LIF‐SE‐LIF/LIFR‐STAT3 significantly impairs tumor growth and reduces CSC subpopulations in xenograft and PDX models. Our findings reveal a hitherto uncharacterized LIF‐SE‐mediated auto‐regulatory loop in regulating HNSCC stemness and highlight LIF as a novel noninvasive biomarker and potential therapeutic target for HNSCC.

Gastric cancer (GC) is a major cause of cancer-related mortality worldwide. Despite the widespread recognition of tumor immunotherapy in treating unresectable GC, challenges, including ineffective immunotherapy and drug resistance, persist. Therefore, understanding the regulatory mechanisms of PD-L1, particularly in the context of super-enhancers (SEs) and zinc finger protein 36 ring finger protein-like 1 (ZFP36L1) RNA-binding protein, is crucial. In this study, we performed H3K27ac Cleavage Under Targets and Tagmentation (CUT&Tag) sequencing, investigated the heterogeneity of SEs between two GC subtypes with differential growth patterns, and revealed the immune escape signatures driven by ZFP36L1-SE in infiltrative GC through SEs inhibitors treatment. The regulation of ZFP36L1 to PD-L1 was evaluated by quantitative PCR, western blot, flow cytometry, and immunohistochemistry. Furthermore, we explored its regulatory mechanisms using a combination of molecular biology techniques, including luciferase reporter assay, GST/RNA pull-down, chromatin immunoprecipitation (ChIP)/RIP experiments, and in vivo functional assays. We demonstrated that ZFP36L1, driven by an SE, enhances IFN-γ-induced PD-L1 expression, with SPI1 identified as the specific transcription factor binding to ZFP36L1-SE. Mechanistically, ZFP36L1 binds to the adenylate uridylate-rich element in the 3ʹ untranslated region (3ʹUTR) of HDAC3 mRNA, exacerbating its mRNA decay, and thereby facilitating PD-L1 abnormal transcriptional activation. Collectively, our findings provide mechanistic insights into the role of the SPI1-ZFP36L1-HDAC3-PD-L1 signaling axis in orchestrating immune escape mechanisms in GC, thereby offering valuable insights into the potential targets for immune checkpoint therapy in GC management.

Tumor immune microenvironment is crucial for diffuse large B-cell lymphoma (DLBCL) development. However, the mechanisms by which super-enhancers (SEs) regulate the interactions between DLBCL cells and tumor-infiltrating immune cells remains largely unknown. This study aimed to investigate the role of SE-controlled genes in regulating the interactions between DLBCL cells and tumor-infiltrating immune cells. Single-cell RNA-seq, bulk RNA-seq and H3K27ac ChIP-seq data were downloaded from the Heidelberg Open Research Data database and Gene Expression Omnibus database. HOMER algorithm and Seurat package in R were used for bioinformatics analysis. Cell proliferation and lactate dehydrogenase (LDH) release was detected by MTS and LDH release assays, respectively. Interaction between B cell cluster and CD8+ T cell and NK cell cluster was most obviously enhanced in DLBCL, with CD70-CD27, MIF-CD74/CXCR2 complex, MIF-CD74/CD44 complex and CCL3-CCR5 interactions were significantly increased. NK cell sub-cluster showed the strongest interaction with B cell cluster. ZZZ3 upregulated the transcription of CD70 by binding to its SE. Silencing CD70 in DOHH2 cells significantly promoted the proliferation of co-cultured NK92 cells and LDH release from DOHH2 cells, which was counteracted by ZZZ3 overexpression in DOHH2 cells. CD70 silencing combined with PD-L1 blockade promoted LDH release from DOHH2 cells co-cultured with NK92 cells. In conclusion, DLBCL cells inhibited the proliferation and killing of infiltrating NK cells by regulating ZZZ3/CD70 axis. Targeting ZZZ3/CD70 axis combined with PD-L1 blockade is expected to be a promising strategy for DLBCL treatment.

Abstract Background Heat shock transcription factors (HSFs) play crucial roles in the development of malignancies. However, the specific roles of HSFs in hepatocellular carcinoma (HCC) have yet to be fully elucidated.Aims:To explore the involvement of the HSF family, particularly HSF1, in the progression and prognosis of HCC. Materials & Methods We conducted a thorough analysis of HSF expression and copy number variations across various cancer datasets. Specifically focusing on HSF1, we examined its expression levels and prognostic implications in HCC. In vitro and in vivo experiments were carried out to evaluate the impact of HSF1 on liver cancer cell proliferation. Additionally, we utilized CUT&Tag, H3K27 acetylation enrichment, and RNA sequencing (RNA‐seq) to investigate the super‐enhancer (SE) regulatory landscapes of HSF1 in liver cancer cell lines. Results HSF1 expression is elevated in HCC and is linked to poor prognosis in several datasets. HSF1 stimulates liver cancer cell proliferation both in vitro and in vivo, partly through modulation of H3K27ac levels, influencing enhancer distribution. Mechanistically, our findings demonstrate that HSF1 transcriptionally activates MYCN expression by binding to its promoter and SE elements, thereby promoting liver cancer cell proliferation. Moreover, increased MYCN expression was detected in HCC tumors and correlated with unfavorable patient outcomes. Discussion Our study sheds light on previously unexplored aspects of HSF1 biology, identifying it as a transcription factor capable of shaping the epigenetic landscape in the context of HCC. Given HSF1's potential as an epigenetic regulator, targeting the HSF1‐MYCN axis could open up new therapeutic possibilities for HCC treatment. Conclusion The HSF1‐MYCN axis constitutes a transcription‐dependent regulatory mechanism that may function as both a prognostic indicator and a promising therapeutic target in liver cancer. Further exploration of this axis could yield valuable insights into novel treatment strategies for HCC.

Abstract Liquid-liquid phase separation (LLPS) is a complex and subtle phenomenon whose formation and regulation take essential roles in cancer initiation, growth, progression, invasion, and metastasis. This domain holds a wealth of underutilized unstructured data that needs further excavation for potentially valuable information. Therefore, we retrospectively analyzed the global scientific knowledge in the field over the last decade by using informatics methods (such as hierarchical clustering, regression statistics, hotspot burst, and Walktrap algorithm analysis). Over the past decade, this area enjoyed a favorable development trend (Annual Growth Rate: 34.98%) and global collaboration (International Co-authorship: 27.31%). Through unsupervised hierarchical clustering based on machine learning, the global research hotspots were divided into five dominant research clusters: Cluster 1 (Effects and Mechanisms of Phase Separation in Drug Delivery), Cluster 2 (Phase Separation in Gene Expression Regulation), Cluster 3 (Phase Separation in RNA-Protein Interaction), Cluster 4 (Reference Value of Phase Separation in Neurodegenerative Diseases for Cancer Research), and Cluster 5 (Roles and Mechanisms of Phase Separation). And further time-series analysis revealed that Cluster 5 is the emerging research cluster. In addition, results from the regression curve and hotspot burst analysis point in unison to super-enhancer (a=0.5515, R2=0.6586, p=0.0044) and stress granule (a=0.8000, R2=0.6000, p=0.0085) as the most potential star molecule in this field. More interestingly, the Random-Walk-Strategy-based Walktrap algorithm further revealed that “phase separation, cancer, transcription, super-enhancer, epigenetics”(Relevance Percentage[RP]=100%, Development Percentage[DP]=29.2%), “stress granule, immunotherapy, tumor microenvironment, RNA binding protein”(RP=79.2%, DP=33.3%) and “nanoparticle, apoptosis”(RP=70.8%, DP=25.0%) are closely associated with this field, but are still under-developed and worthy of further exploration. In conclusion, this study profiled the global scientific landscape, discovered a crucial emerging research cluster, identified several pivotal research molecules, and predicted several crucial but still under-developed directions that deserve further research, providing an important reference value for subsequent basic and clinical research of phase separation in cancer.

Abstract Class switch recombination (CSR) plays an important role in adaptive immune response by enabling mature B cells to replace the initial IgM by another antibody class (IgG, IgE or IgA). CSR is preceded by transcription of the IgH constant genes and is controlled by the super-enhancer 3′ regulatory region (3′RR) in an activation-specific manner. The 3’RR is composed of four enhancers (hs3a, hs1-2, hs3b and hs4). In mature B cells, 3’RR activity correlates with transcription of its enhancers. CSR can also occur in primary developing B cells though at low frequency, but in contrast to mature B cells, the transcriptional elements that regulate the process in developing B cells are ill-known. In particular, the role of the 3’RR in the control of constant genes’ transcription and CSR has not been addressed. Here, by using a mouse line devoid of the 3’RR and a culture system that highly enriches in pro-B cells, we show that the 3’RR activity is indeed required for switch transcription and CSR, though its effect varies in an isotype-specific manner and correlates with transcription of hs4 enhancer only.

Hypoxia and Ferroptosis are associated with the malignant behaviour of cervical cancer. Endothelial PAS domain‐containing protein 1 (EPAS1) contributes to the progression of cervical cancer. EPAS1 plays important roles in hypoxia and ferroptosis. Using the GEO dataset, machine‐learning algorithms were used to screen for hypoxia‐ and ferroptosis‐related genes (HFRGs) in cervical cancer. EPAS1 was identified as the hub gene. qPCR and WB were used to investigate the expression of EPAS1 in normal and cervical cancer tissues. The proliferation, invasion and migration of EPAS1 cells in HeLa and SiHa cell lines were detected using CCK8, transwell and wound healing assays, respectively. Apoptosis was detected by flow cytometry. A dual‐luciferase assay was used to analyse the MALAT1‐miR‐182‐5P‐EPAS1 mRNA axis and core promoter elements of the super‐enhancer. EPAS1 was significantly overexpressed in cervical cancer tissues. EPAS1 could increase the proliferation, invasion, migration of HeLa and SiHa cells and reduce the apoptosis of HeLa and SiHa cell. According to the double‐luciferase assay, EPAS1 expression was regulated by the MALAT1‐Mir‐182‐5p‐EPAS1 mRNA axis. EPAS1 is associated with super‐enhancers. Double‐luciferase assay showed that the core elements of the super‐enhancer were E1 and E3. EPAS1, an HFRG, is significantly overexpressed in cervical cancer. EPAS1 promotes malignant behaviour of cervical cancer cells. EPAS1 expression is regulated by super‐enhancers and the MALAT1‐miR‐182‐5P‐ EPAS1 mRNA axis. EPAS1 may be a target for the diagnosis and treatment of cervical cancer. [ABSTRACT FROM AUTHOR]

One major obstacle in the drug treatment of pancreatic ductal adenocarcinoma (PDAC) is its highly fibrotic tumor microenvironment, which is replete with activated pancreatic stellate cells (a‐PSCs). These a‐PSCs generate abundant extracellular matrix and secrete various cytokines to form biophysical and biochemical barriers, impeding drug access to tumor tissues. Therefore, it is imperative to develop a strategy for reversing PSC activation and thereby removing the barriers to facilitate PDAC drug treatment. Herein, by integrating chromatin immunoprecipitation (ChIP)‐seq, Assays for Transposase‐Accessible Chromatin (ATAC)‐seq, and RNA‐seq techniques, this work reveals that super‐enhancers (SEs) promote the expression of various genes involved in PSC activation. Disruption of SE‐associated transcription with JQ1 reverses the activated phenotype of a‐PSCs and decreases stromal fibrosis in both orthotopic and patient‐derived xenograft (PDX) models. More importantly, disruption of SEs by JQ1 treatments promotes vascularization, facilitates drug delivery, and alters the immune landscape in PDAC, thereby improving the efficacies of both chemotherapy (with gemcitabine) and immunotherapy (with IL‐12). In summary, this study not only elucidates the contribution of SEs of a‐PSCs in shaping the PDAC tumor microenvironment but also highlights that targeting SEs in a‐PSCs may become a gate‐opening strategy that benefits PDAC drug therapy by removing stromal barriers. [ABSTRACT FROM AUTHOR]

Liquid-liquid phase separation (LLPS) is a complex and subtle phenomenon whose formation and regulation take essential roles in cancer initiation, growth, progression, invasion, and metastasis. This domain holds a wealth of underutilized unstructured data that needs further excavation for potentially valuable information. Therefore, we retrospectively analyzed the global scientific knowledge in the field over the last decade by using informatics methods (such as hierarchical clustering, regression statistics, hotspot burst, and Walktrap algorithm analysis). Over the past decade, this area enjoyed a favorable development trend (Annual Growth Rate: 34.98%) and global collaboration (International Co-authorship: 27.31%). Through unsupervised hierarchical clustering based on machine learning, the global research hotspots were divided into five dominant research clusters: Cluster 1 (Effects and Mechanisms of Phase Separation in Drug Delivery), Cluster 2 (Phase Separation in Gene Expression Regulation), Cluster 3 (Phase Separation in RNA-Protein Interaction), Cluster 4 (Reference Value of Phase Separation in Neurodegenerative Diseases for Cancer Research), and Cluster 5 (Roles and Mechanisms of Phase Separation). And further time-series analysis revealed that Cluster 5 is the emerging research cluster. In addition, results from the regression curve and hotspot burst analysis point in unison to super-enhancer (a=0.5515, R2=0.6586, p=0.0044) and stress granule (a=0.8000, R2=0.6000, p=0.0085) as the most potential star molecule in this field. More interestingly, the Random-Walk-Strategy-based Walktrap algorithm further revealed that "phase separation, cancer, transcription, super-enhancer, epigenetics"(Relevance Percentage[RP]=100%, Development Percentage[DP]=29.2%), "stress granule, immunotherapy, tumor microenvironment, RNA binding protein"(RP=79.2%, DP=33.3%) and "nanoparticle, apoptosis"(RP=70.8%, DP=25.0%) are closely associated with this field, but are still under-developed and worthy of further exploration. In conclusion, this study profiled the global scientific landscape, discovered a crucial emerging research cluster, identified several pivotal research molecules, and predicted several crucial but still under-developed directions that deserve further research, providing an important reference value for subsequent basic and clinical research of phase separation in cancer. [ABSTRACT FROM AUTHOR]

Class switch recombination (CSR) plays an important role in adaptive immune response by enabling mature B cells to replace the initial IgM by another antibody class (IgG, IgE or IgA). CSR is preceded by transcription of the IgH constant genes and is controlled by the super-enhancer 3′ regulatory region (3′RR) in an activation-specific manner. The 3'RR is composed of four enhancers (hs3a, hs1-2, hs3b and hs4). In mature B cells, 3'RR activity correlates with transcription of its enhancers. CSR can also occur in primary developing B cells though at low frequency, but in contrast to mature B cells, the transcriptional elements that regulate the process in developing B cells are ill-known. In particular, the role of the 3'RR in the control of constant genes' transcription and CSR has not been addressed. Here, by using a mouse line devoid of the 3'RR and a culture system that highly enriches in pro-B cells, we show that the 3'RR activity is indeed required for switch transcription and CSR, though its effect varies in an isotype-specific manner and correlates with transcription of hs4 enhancer only. [ABSTRACT FROM AUTHOR]

Simple Summary: Rhabdoid tumors are a group of rare and aggressive pediatric cancers that are associated with dismal survival rates. These tumors are classified within the ~20% of all cancers showing mutations in the subunits of the SWI/SNF chromatin remodeling complex. Chromatin remodelers are large protein complexes that control gene expression at least in part through regulating DNA accessibility. In rhabdoid tumor cell lines, which harbor inactivating mutations in the SMARCB1 gene, the SWI/SNF subunit BRG1—a synthetic lethal target in these cells—retains functionality in chromatin remodeling and regulation of the rhabdoid genome. The aim of this study was to assess the contribution of BRG1 to rhabdoid gene regulation across multiple rhabdoid cell lines. These data provide valuable insights in understanding how gene regulation following SMARCB1 loss is achieved, which may be broadly applicable to other cancers marked by SWI/SNF subunit mutation. Mutations in the SWI/SNF chromatin remodeling complex occur in ~20% of cancers. In rhabdoid tumors defined by loss of the SWI/SNF subunit SMARCB1, dysregulation of enhancer-mediated gene expression is pivotal in driving oncogenesis. Enhancer dysregulation in this setting is tied to retention of the SWI/SNF ATPase BRG1—which becomes essential in the absence of SMARCB1—but precisely how BRG1 contributes to this process remains unknown. To characterize how BRG1 participates in chromatin remodeling and gene expression in SMARCB1-deficient cells, we performed a genome-wide characterization of the impact of BRG1 depletion in multiple rhabdoid tumor cell lines. We find that although BRG1-regulated open chromatin sites are distinct at the locus level, the biological characteristics of the loci are very similar, converging on a set of thematically related genes and pointing to the involvement of the AP-1 transcription factor. The open chromatin sites regulated by BRG1 colocalize with histone-marked enhancers and intriguingly include almost all super-enhancers, revealing that BRG1 plays a critical role in maintaining super-enhancer function in this setting. These studies can explain the essentiality of BRG1 to rhabdoid tumor cell identity and survival and implicate the involvement of AP-1 as a critical downstream effector of rhabdoid tumor cell transcriptional programs. [ABSTRACT FROM AUTHOR]

Genetic variants in super-enhancers (SEs) are increasingly implicated as a disease risk-driving mechanism. Previous studies have reported an associations between benzo[a]pyrene (BaP) exposure and some malignant tumor risk. Currently, it is unclear whether BaP is involved in the effect of genetic variants in SEs on prostate cancer risk, nor the associated intrinsic molecular mechanisms. In the current study, by using logistic regression analysis, we found that rs5750581T>C in 22q-SE was significantly associated with prostate cancer risk (odds ratio = 1.26, P = 7.61 × 10-5). We also have found that the rs6001092T>G, in a high linkage disequilibrium with rs5750581T>C (r² = 0.98), is located in a regulatory aryl hydrocarbon receptor (AhR) motif and may interact with the FAM227A promoter in further bioinformatics analysis. We then performed a series of functional and BaP acute exposure experiments to assess biological function of the genetic variant and the target gene. Biologically, the rs6001092-G allele strengthened the transcription factor binding affinity to AhR, thereby upregulating FAM227A, especially upon exposure to BaP, which induced the malignant phenotypes of prostate cancer. The current study highlights that AhR acts as an environmental sensor of BaP and is involved in the SE-mediated prostate cancer risk, which may provide new insights into the etiology of prostate cancer associated with the inherited SE variants under environmental carcinogen stressors. [ABSTRACT FROM AUTHOR]

Background: Early detection of cancer remains an unmet need in clinical practice, and high diagnostic sensitivity and specificity biomarkers are urgently required. Here, we attempted to identify secreted proteins encoded by super-enhancer (SE)-driven genes as diagnostic biomarkers for esophageal squamous cell carcinoma (ESCC). Methods: We conducted an integrative analysis of multiple data sets including ChIP-seq data, secretome data, CCLE data and GEO data to screen secreted proteins encoded by SE-driven genes. Using ELISA, we further identified up-regulated secreted proteins through a small size of clinical samples and verified in a multi-centre validation stage (345 in test cohort and 231 in validation cohort). Receiver operating characteristic curves were used to calculate diagnostic accuracy. Artificial intelligence (AI) method named gradient boosting machine (GBM) were applied for model construction to enhance diagnostic accuracy. Results: Serum EFNA1 and MMP13 were identified, and showed significantly higher levels in ESCC patients compared to normal controls. An integrated Five-Biomarker Panel (iFBPanel) established by combining EFNA1, MMP13, carcino-embryonic antigen, Cyfra21-1 and squmaous cell carcinoma antigen had AUCs of 0.881 and 0.880 for ESCC in test and validation cohorts, respectively. Importantly, the iFBPanel also exhibited good performance in detecting early-stage ESCC patients (0.872 and 0.864). Furthermore, the iFBPanel was further empowered by AI technology which showed excellent diagnostic performance in early-stage ESCC (0.927 and 0.907). Conclusions: Our study suggested that serum EFNA1 and MMP13 could potentially assist ESCC detection, and provided an easy-to-use detection model that might help the diagnosis of early-stage ESCC.

Immune checkpoints inhibitors are effective but it needs more precise biomarkers for patient selection. We explored the biological significance of LINC00862 in pan-cancer by bioinformatics. And we studied its regulatory mechanisms using chromatin immunoprecipitation and RNA immunoprecipitation assays etc. TCGA and single-cell sequencing data analysis indicated that LINC00862 was overexpressed in the majority of tumor and stromal cells, which was related with poor prognosis. LINC00862 expression was related with immune cell infiltration and immune checkpoints expression, and had a high predictive value for immunotherapy efficacy. Mechanistically, LINC00862 competitively bound to miR-29c-3p to unleash SIRT1’s tumor-promoting function. SIRT1 inhibitor-EX527 were screened by virtual screening and verified by in vitro and vivo assays. Notably, acetyltransferase P300-mediated super-enhancer activity stimulated LINC00862 transcription. Collectively, LINC00862 could be a diagnostic and prognostic biomarker. LINC00862 could also be a predictive biomarker for immunotherapy efficacy. Super-enhancer activity is the driver for LINC00862 overexpression in cervical cancer and gastric cancer.

Abstract The primary aim of this study is to critically evaluate and comment on the research presented in the article titled “A Novel Super-Enhancer-Related Gene Signature Predicts Prognosis and Immune Microenvironment for Breast Cancer” by Wu et al. Our specific objectives include assessing the methodology employed by the authors, particularly in regard to the utilization of a super-enhancer-related gene signature for breast cancer prognosis prediction. We propose the necessity of subgroup analysis to effectively address the heterogeneity in breast cancer subtypes, which is crucial for the applicability of the SERGs across diverse breast cancer cases. Additionally, we suggest conducting a more comprehensive immune panel study to deepen the understanding of how the immune microenvironment impacts breast cancer prognosis. Our commentary seeks to provide valuable insights into the strengths and weaknesses of the study, contributing to a more comprehensive understanding of its findings and potential clinical implications.

Abstract Background Risk stratification and personalized care are crucial in managing osteosarcoma due to its complexity and heterogeneity. However, current prognostic prediction using clinical variables has limited accuracy. Thus, this study aimed to explore potential molecular biomarkers to improve prognostic assessment. Methods High-throughput inhibitor screening of 150 compounds with broad targeting properties was performed and indicated a direction towards super-enhancers (SEs). Bulk RNA-seq, scRNA-seq, and immunohistochemistry (IHC) were used to investigate SE-associated gene expression profiles in osteosarcoma cells and patient tissue specimens. Data of 212 osteosarcoma patients who received standard treatment were collected and randomized into training and validation groups for retrospective analysis. Prognostic signatures and nomograms for overall survival (OS) and lung metastasis-free survival (LMFS) were developed using Cox regression analyses. The discriminatory power, calibration, and clinical value of nomograms were evaluated. Results High-throughput inhibitor screening showed that SEs significantly contribute to the oncogenic transcriptional output in osteosarcoma. Based on this finding, focus was given to 10 SE-associated genes with distinct characteristics and potential oncogenic function. With multi-omics approaches, the hyperexpression of these genes was observed in tumor cell subclusters of patient specimens, which were consistently correlated with poor outcomes and rapid metastasis, and the majority of these identified SE-associated genes were confirmed as independent risk factors for poor outcomes. Two molecular signatures were then developed to predict survival and occurrence of lung metastasis: the SE-derived OS-signature (comprising LACTB, CEP55, SRSF3, TCF7L2, and FOXP1) and the SE-derived LMFS-signature (comprising SRSF3, TCF7L2, FOXP1, and APOLD1). Both signatures significantly improved prognostic accuracy beyond conventional clinical factors. Conclusions Oncogenic transcription driven by SEs exhibit strong associations with osteosarcoma outcomes. The SE-derived signatures developed in this study hold promise as prognostic biomarkers for predicting OS and LMFS in patients undergoing standard treatments. Integrative prognostic models that combine conventional clinical factors with these SE-derived signatures demonstrate substantially improved accuracy, and have the potential to facilitate patient counseling and individualized management.

This article discusses the potential of the targeted agent THZ1 in the treatment of pancreatic ductal adenocarcinoma (PDAC), a challenging and often fatal form of cancer. The study highlights the importance of KRAS mutations in driving the development of PDAC and explores how THZ1 selectively inhibits PDAC cells with specific KRAS mutant subtypes. The research suggests that genetic profiling, particularly identifying specific KRAS mutation subtypes, should be integrated into the diagnostic and therapeutic decision-making processes for PDAC. The study also emphasizes the need for further research to explore the efficacy of THZ1 in PDACs with different genetic alterations and to investigate its long-term safety and impact on patient quality of life. Overall, the study represents a significant step towards precision medicine in PDAC and offers hope for improved treatment options in the future. [Extracted from the article]

Tumor budding (TB) is a small tumor cell cluster with highly aggressive behavior located ahead of the invasive tumor front. However, the molecular and biological characteristics of TB and the regulatory mechanisms governing TB phenotypes remain unclear. This study reveals that TB exhibits a particular dynamic gene signature with stemness and partial epithelial‐mesenchymal transition (p‐EMT). Importantly, nuclear expression of CYTOR is identified to be the key regulator governing stemness and the p‐EMT phenotype of TB cells, and targeting CYTOR significantly inhibits TB formation, tumor growth and lymph node metastasis in head and neck squamous cell carcinoma (HNSCC). Mechanistically, CYTOR promotes tumorigenicity and metastasis of TB cells by facilitating the formation of FOSL1 phase‐separated condensates to establish FOSL1‐dependent super enhancers (SEs). Depletion of CYTOR leads to the disruption of FOSL1‐dependent SEs, which results in the inactivation of cancer stemness and pro‐metastatic genes. In turn, activation of FOSL1 promotes the transcription of CYTOR. These findings indicate that CYTOR is a super‐lncRNA that controls the stemness and metastasis of TB cells through facilitating the formation of FOSL1 phase separation and SEs, which may be an attractive target for therapeutic interventions in HNSCC. [ABSTRACT FROM AUTHOR]

Background: Risk stratification and personalized care are crucial in managing osteosarcoma due to its complexity and heterogeneity. However, current prognostic prediction using clinical variables has limited accuracy. Thus, this study aimed to explore potential molecular biomarkers to improve prognostic assessment. Methods: High-throughput inhibitor screening of 150 compounds with broad targeting properties was performed and indicated a direction towards super-enhancers (SEs). Bulk RNA-seq, scRNA-seq, and immunohistochemistry (IHC) were used to investigate SE-associated gene expression profiles in osteosarcoma cells and patient tissue specimens. Data of 212 osteosarcoma patients who received standard treatment were collected and randomized into training and validation groups for retrospective analysis. Prognostic signatures and nomograms for overall survival (OS) and lung metastasis-free survival (LMFS) were developed using Cox regression analyses. The discriminatory power, calibration, and clinical value of nomograms were evaluated. Results: High-throughput inhibitor screening showed that SEs significantly contribute to the oncogenic transcriptional output in osteosarcoma. Based on this finding, focus was given to 10 SE-associated genes with distinct characteristics and potential oncogenic function. With multi-omics approaches, the hyperexpression of these genes was observed in tumor cell subclusters of patient specimens, which were consistently correlated with poor outcomes and rapid metastasis, and the majority of these identified SE-associated genes were confirmed as independent risk factors for poor outcomes. Two molecular signatures were then developed to predict survival and occurrence of lung metastasis: the SE-derived OS-signature (comprising LACTB, CEP55, SRSF3, TCF7L2, and FOXP1) and the SE-derived LMFS-signature (comprising SRSF3, TCF7L2, FOXP1, and APOLD1). Both signatures significantly improved prognostic accuracy beyond conventional clinical factors. Conclusions: Oncogenic transcription driven by SEs exhibit strong associations with osteosarcoma outcomes. The SE-derived signatures developed in this study hold promise as prognostic biomarkers for predicting OS and LMFS in patients undergoing standard treatments. Integrative prognostic models that combine conventional clinical factors with these SE-derived signatures demonstrate substantially improved accuracy, and have the potential to facilitate patient counseling and individualized management. [ABSTRACT FROM AUTHOR]

Background: Inhibition of CDK7, a potent transcription regulator, may bring new hope for treating pancreatic ductal adenocarcinoma (PDAC), which is featured by large genetic heterogeneity and abundant KRAS mutations. This investigation aimed at exploring the discrepant efficacies of THZ1, a small‐molecule covalent CDK7 inhibitor, on PDACs with different KRAS mutations and the underlying mechanisms. Methods: Associations of CDK7 expression with survival by KRAS mutations were first assessed. Effects of THZ1 on PDAC by different KRAS mutations were then investigated in vitro and in vivo. Moreover, the effects of THZ1 on gene transcription and phosphorylation of RNA polymerase II (RNAPOLII) in different KRAS mutant PDACs were assessed, and the effect of THZ1 on super‐enhancer activity was evaluated using chromatin immunoprecipitation sequencing. Lastly, the effects of THZ1 on the binding of H3K27ac to PIK3CA and on the PI3K/AKT/mTOR signalling were analysed. Results: High CDK7 expression was significantly linked to worse survival within PDAC patients carrying KRAS‐G12V mutation but not in those with KRAS‐G12D mutation. The apoptosis‐inducing effect of THZ1 was markedly stronger in KRAS‐G12V PDAC than KRAS‐G12D cancer. THZ1 significantly inhibited the growth of xenograft tumour with KRAS‐G12V mutation, and the inhibition was markedly stronger than for KRAS‐G12D tumour. In mini‐cell‐derived xenograft (CDX) models, THZ1 significantly suppressed KRAS‐G12V PDAC but not KRAS‐G12D cancer. THZ1 significantly suppressed the phosphorylation of RNAPOLII, and this effect was stronger in KRAS‐G12V PDAC (especially at ser5). KRAS‐G12V PDAC had more H3K27ac‐binding super‐enhancers, and the inhibition of THZ1 on super‐enhancer activity was also stronger in KRAS‐G12V PDAC. Furthermore, THZ1 significantly weakened the binding of H3K27ac to PIK3CA in KRAS‐G12V PDAC. THZ1 significantly suppressed the PI3K/AKT/mTOR pathway and its downstream markers, and this effect was stronger in KRAS‐G12V cells. Conclusions: In this hypothesis‐generating study, THZ1 might selectively inhibit certain PDACs with KRAS‐G12V mutation more potently compared with some other PDACs with KRAS‐G12D mutation, which might be associated with its effect on super‐enhancer activity and the PI3K/AKT/mTOR signalling. Our findings might offer novel key clues for the precise management of PDAC and important evidence for future targeted trial design. Highlights: THZ1 had a stronger effect on PDAC‐bearing KRAS‐G12V mutation than G12D mutation.Suppressive effect of THZ1 on phosphorylation of RNAPOLII was stronger in KRAS‐G12V than KRAS‐G12D PDAC.Inhibition of THZ1 on super‐enhancer activity and H3K27ac binding to PIK3CA was stronger in KRAS‐G12V PDAC.Suppressive effect of THZ1 on PI3K/AKT/mTOR pathway was stronger in KRAS‐G12V PDAC. [ABSTRACT FROM AUTHOR]

Abstract One major obstacle in the drug treatment of pancreatic ductal adenocarcinoma (PDAC) is its highly fibrotic tumor microenvironment, which is replete with activated pancreatic stellate cells (a‐PSCs). These a‐PSCs generate abundant extracellular matrix and secrete various cytokines to form biophysical and biochemical barriers, impeding drug access to tumor tissues. Therefore, it is imperative to develop a strategy for reversing PSC activation and thereby removing the barriers to facilitate PDAC drug treatment. Herein, by integrating chromatin immunoprecipitation (ChIP)‐seq, Assays for Transposase‐Accessible Chromatin (ATAC)‐seq, and RNA‐seq techniques, this work reveals that super‐enhancers (SEs) promote the expression of various genes involved in PSC activation. Disruption of SE‐associated transcription with JQ1 reverses the activated phenotype of a‐PSCs and decreases stromal fibrosis in both orthotopic and patient‐derived xenograft (PDX) models. More importantly, disruption of SEs by JQ1 treatments promotes vascularization, facilitates drug delivery, and alters the immune landscape in PDAC, thereby improving the efficacies of both chemotherapy (with gemcitabine) and immunotherapy (with IL‐12). In summary, this study not only elucidates the contribution of SEs of a‐PSCs in shaping the PDAC tumor microenvironment but also highlights that targeting SEs in a‐PSCs may become a gate‐opening strategy that benefits PDAC drug therapy by removing stromal barriers.

Precise spatio-temporal expression of genes in organogenesis is regulated by the coordinated interplay of DNA elements such as promoter and enhancers present in the regulatory region of a given locus. POU1F1 transcription factor plays a crucial role in the development of somatotrophs, lactotrophs and thyrotrophs in the anterior pituitary gland, and in maintaining high expression of growth hormone, prolactin and TSH. In mouse, expression of POU1F1 is controlled by a region fenced by two CTCF sites, containing 5 upstream enhancer elements, designated E-A (5′ to 3′). Elements C, B and A correspond to elements shown previously to play a role in pituitary development and hormonal expression; functional roles for elements E and D have not been reported. We performed comparative sequence analysis of this regulatory region and discovered that three elements, B, C and E, are present in all vertebrate groups except Agnatha. One very long (>2 kb) element (A) is unique to mammals suggesting a specific change in regulation of the gene in this group. Using DNA accessibility assay (ATAC-seq) we showed that conserved elements in anterior pituitary of four non-mammals are open, suggesting functionality as regulatory elements. We showed that, in many non-mammalian vertebrates, an additional upstream exon closely follows element E, leading to alternatively spliced transcripts. Here, element E functions as an alternative promoter, but in mammals this feature is lost, suggesting conversion of alternative promoter to enhancer. Our work shows that regulation of POU1F1 changed markedly during the course of vertebrate evolution, use of a low number of enhancer elements combined with alternative promoters in non-mammalian vertebrates being replaced by use of a unique combination of regulatory units in mammals. Most importantly, our work suggests that evolutionary conversion of alternate promoter to enhancer could be one of the evolutionary mechanisms of enhancer birth.

The primary aim of this study is to critically evaluate and comment on the research presented in the article titled "A Novel Super-Enhancer-Related Gene Signature Predicts Prognosis and Immune Microenvironment for Breast Cancer" by Wu et al. Our specific objectives include assessing the methodology employed by the authors, particularly in regard to the utilization of a super-enhancer-related gene signature for breast cancer prognosis prediction. We propose the necessity of subgroup analysis to effectively address the heterogeneity in breast cancer subtypes, which is crucial for the applicability of the SERGs across diverse breast cancer cases. Additionally, we suggest conducting a more comprehensive immune panel study to deepen the understanding of how the immune microenvironment impacts breast cancer prognosis. Our commentary seeks to provide valuable insights into the strengths and weaknesses of the study, contributing to a more comprehensive understanding of its findings and potential clinical implications. [ABSTRACT FROM AUTHOR]

Gene regulation is crucial for cellular function and homeostasis. It involves diverse mechanisms controlling the production of specific gene products and contributing to tissue-specific variations in gene expression. The dysregulation of genes leads to disease, emphasizing the need to understand these mechanisms. Computational methods have jointly studied transcription factors (TFs), microRNA (miRNA), and messenger RNA (mRNA) to investigate gene regulatory networks. However, there remains a knowledge gap in comprehending gene regulatory networks. On the other hand, super-enhancers (SEs) have been implicated in miRNA biogenesis and function in recent experimental studies, in addition to their pivotal roles in cell identity and disease progression. However, statistical/computational methodologies harnessing the potential of SEs in deciphering gene regulation networks remain notably absent. However, to understand the effect of miRNA on mRNA, existing statistical/computational methods could be updated, or novel methods could be developed by accounting for SEs in the model. In this review, we categorize existing computational methods that utilize TF and miRNA data to understand gene regulatory networks into three broad areas and explore the challenges of integrating enhancers/SEs. The three areas include unraveling indirect regulatory networks, identifying network motifs, and enriching pathway identification by dissecting gene regulators. We hypothesize that addressing these challenges will enhance our understanding of gene regulation, aiding in the identification of therapeutic targets and disease biomarkers. We believe that constructing statistical/computational models that dissect the role of SEs in predicting the effect of miRNA on gene regulation is crucial for tackling these challenges.

Abstract Background This study targeted at developing a robust, prognostic signature based on super-enhancer-related genes (SERGs) to reveal survival prognosis and immune microenvironment of breast cancer. Methods RNA-sequencing data of breast cancer were retrieved from The Cancer Genome Atlas (TCGA), 1069 patients of which were randomly assigned into training or testing set in 1:1 ratio. SERGs were downloaded from Super-Enhancer Database (SEdb). After which, a SERGs signature was established based on the training set, with its prognostic value further validated in the testing set. Subsequently, we identified the potential function enrichment and tumor immune infiltration of the model. Moreover, in vitro experiments were completed to further explore the biological functions of ZIC2 gene (one of the risk genes in the prognostic model) in breast cancer. Results A risk score system of prognostic value was constructed with 6 SERGs (ZIC2, NFE2, FOXJ1, KLF15, POU3F2 and SPIB) to find patients in high-risk group with significantly worse prognosis in both training and testing sets. In addition, a multivariate regression was established via integrating the 6 genes with age and N stage, indicating well performance by calibration, time-dependent receiver operating characteristic (ROC) analysis and decision curve analysis (DCA). Further analysis demonstrated that tumor-associated pathological processes and pathways were significantly enriched in the high-risk group. In general, the novel SERGs signature could be applied to screen breast cancer with immunosuppressive microenvironment for the risk score was negatively correlated with ESTIMATE score, tumor-infiltration lymphocytes (such as CD4 + and CD8 + T cell), immune checkpoints and chemotactic factors. Furthermore, down-regulation of ZIC2 gene expression inhibited the cell viability, cellular migration and cell cycle of breast cancer cells. Conclusions The novel SERGs signature could predict the prognosis of breast cancer; and SERGs might serve as potential therapeutic targets for breast cancer.

Abstract Super-enhancers (SEs) consist of multiple typical enhancers enriched at high density with transcription factors, histone-modifying enzymes and cofactors. Oncogenic SEs promote tumorigenesis and malignancy by altering protein-coding gene expression and noncoding regulatory element function. Therefore, they play central roles in the treatment of cancer. Here, we review the structural characteristics, organization, identification, and functions of SEs and the underlying molecular mechanism by which SEs drive oncogenic transcription in tumor cells. We then summarize abnormal SE complexes, SE-driven coding genes, and noncoding RNAs involved in tumor development. In summary, we believe that SEs show great potential as biomarkers and therapeutic targets.

Background: A super-enhancer (SE) is a huge cluster of multiple enhancers that control the key genes for cell identity and function. The rise of advanced chromatin immunoprecipitation sequencing (ChIP-seq) technology such as Cleavage Under Targets and Tagmentation (CUT&Tag) allows more SEs to be discovered. However, SE studies in Luchuan and Duroc pigs are very rare in animal husbandry. Results: We used the CUT&Tag technique to identify 145 and 378 SEs from the adipose tissues of Luchuan and Duroc pigs, respectively. There were significant differences in the peak coverage ratio of SE peaks in the gene promoter region between the two breeds. Not only that, peak signals at the start and end point of the SE peak profile showed obvious spikes. The proximal target genes of SE were highly expressed compared with the background genes and the typical enhancer target genes. Subsequently, in conjoint analysis with high-throughput chromosome conformation capture sequencing (Hi-C seq) data, we predicted the remote regulatory genes of SE and found that their expression level was related to the distance of SE extended to the loop's anchor, but not the length of loops. According to our prediction model, SEs can maintain promoter accessibility of partial remote target genes through loop domains. Finally, a batch of SEs closely related to fat metabolism traits were obtained by performing a coalition analysis of quantitative trait loci and SE data. Conclusions: This work enabled us to obtain hundreds of SEs from Luchuan and Duroc pigs. Our model provides a new method for predicting the SE remote target genes based on loop domains, and to further explore the potential role of super-enhancer in the regulation of fat metabolism.

Abstract Tumor budding (TB) is a small tumor cell cluster with highly aggressive behavior located ahead of the invasive tumor front. However, the molecular and biological characteristics of TB and the regulatory mechanisms governing TB phenotypes remain unclear. This study reveals that TB exhibits a particular dynamic gene signature with stemness and partial epithelial‐mesenchymal transition (p‐EMT). Importantly, nuclear expression of CYTOR is identified to be the key regulator governing stemness and the p‐EMT phenotype of TB cells, and targeting CYTOR significantly inhibits TB formation, tumor growth and lymph node metastasis in head and neck squamous cell carcinoma (HNSCC). Mechanistically, CYTOR promotes tumorigenicity and metastasis of TB cells by facilitating the formation of FOSL1 phase‐separated condensates to establish FOSL1‐dependent super enhancers (SEs). Depletion of CYTOR leads to the disruption of FOSL1‐dependent SEs, which results in the inactivation of cancer stemness and pro‐metastatic genes. In turn, activation of FOSL1 promotes the transcription of CYTOR. These findings indicate that CYTOR is a super‐lncRNA that controls the stemness and metastasis of TB cells through facilitating the formation of FOSL1 phase separation and SEs, which may be an attractive target for therapeutic interventions in HNSCC.

One major characteristic of tumor cells is the aberrant activation of epigenetic regulatory elements, which remodel the tumor transcriptome and ultimately promote cancer progression and drug resistance. However, the oncogenic functions and mechanisms of ovarian cancer (OC) remain elusive. Here, super‐enhancer (SE) regulatory elements that are aberrantly activated in OC are identified and it is found that SEs drive the relative specific expression of the transcription factor KLF5 in OC patients and poly(ADP‐ribose) polymerase inhibitor (PARPi)‐resistant patients. KLF5 expression is associated with poor outcomes in OC patients and can drive tumor progression in vitro and in vivo. Mechanistically, KLF5 forms a transcriptional complex with EHF and ELF3 and binds to the promoter region of RAD51 to enhance its transcription, strengthening the homologous recombination repair (HRR) pathway. Notably, the combination of suberoylanilide hydroxamic acid (SAHA) and olaparib significantly inhibits tumor growth and metastasis of PARPi‐resistant OC cells with high KLF5. In conclusion, it is discovered that SEs‐driven KLF5 is a key regulatory factor in OC progression and PARPi resistance; and potential therapeutic strategies for OC patients with PARPi resistance and high KLF5 are identified. [ABSTRACT FROM AUTHOR]

Introduction: In the past decade, super-enhancer (SE) has become a research hotspot with increasing attention on cancer occurrence, development, and prognosis. To illustrate the hotspots of SE in cancer research and its evolutionary tendency, bibliometric analysis was carried out for this topic. Methods: Literature published before Dec 31, 2022, in WOSCC, was systematically classified, and Citespace, bibliometric.com/app, and GraphPad Prism analyzed the data. Results: After screening out inappropriate documents and duplicate data, 911 publications were selected for further bibliometric analysis. The top five research areas were Oncology (257, 28.211%), Cell Biology (210, 23.052%), Biochemistry Molecular Biology (209, 22.942%), Science Technology Other Topics (138, 15.148%), and Genetics Heredity (132, 14.490%). The United States of America (United States) has the highest number of documents (462, 50.71%), followed by China (303, 33.26%). Among the most productive institutions, four of which are from the United States and one from Singapore, the National University of Singapore. Harvard Medical School (7.68%) has the highest percentage of articles. Young, Richard A, with 32 publications, ranks first in the number of articles. The top three authors came from Whitehead Institute for Biomedical Research as a research team. More than two-thirds of the research are supported by the National Institutes of Health of the United States (337, 37.654%) and the United States Department of Health Human Services (337, 37.654%). And "super enhancer" (525), "cell identity" (258), "expression" (223), "cancer" (205), and "transcription factor" (193) account for the top 5 occurrence keywords. Discussion: Since 2013, SE and cancer related publications have shown a rapid growth trend. The United States continues to play a leading role in this field, as the top literature numbers, affiliations, funding agencies, and authors were all from the United States, followed by China and European countries. A high degree of active cooperation is evident among a multitude of countries. The role of SEs in cell identity, gene transcription, expression, and inhibition, as well as the relationship between SEs and TFs, and the selective inhibition of SEs, have received much attention, suggesting that they are hot issues for research. [ABSTRACT FROM AUTHOR]

Background: Super enhancers (SE) play pivotal roles in cell identity and diseases occur including tumorigenesis. The depletion of SE‐associated lncRNA transcripts, also known as super‐lncRNA, causes the activity of SE to be dysregulated. Methods: We screened and identified an elevated metastasis‐associated SE‐lncRNA SUCLG2‐AS1 in nasopharyngeal carcinoma (NPC) using RNA‐sequencing, real‐time quantitative polymerase chain reaction (RT‐qPCR) and bioinformatics. Western blotting, RT‐qPCR, methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation, chromatin immunoprecipitation, RNA pull‐down and 3C (chromosome conformation capture assays) were used for mechanistic studies. Results: SUCLG2‐AS1 was correlated with a poor prognosis. SUCLG2‐AS1 promotes NPC cell invasion and metastasis while repressing apoptosis and radiosensitivity in vitro and in vivo. Mechanistically, high SUCLG2‐AS1 expression occurred in an m6A‐dependent manner. SUCLG2‐AS1 was found to be located in the SE region of SOX2, and it regulated the expression of SOX2 via long‐range chromatin loop formation, which via mediating CTCF (transcription factor) occupied the SE and promoter region of SOX2, thus regulating the metastasis and radiosensitivity of NPC. Conclusions: Taken together, our data suggest that SUCLG2‐AS1 may serve as a novel intervention target for the clinical treatment of NPC. [ABSTRACT FROM AUTHOR]

Abstract Background Extranodal natural killer/T-cell lymphoma (NKTL) is an aggressive type of non-Hodgkin lymphoma with dismal outcome. A better understanding of disease biology and key oncogenic process is necessary for the development of targeted therapy. Super-enhancers (SEs) have been shown to drive pivotal oncogenes in various malignancies. However, the landscape of SEs and SE-associated oncogenes remain elusive in NKTL. Methods We used Nano-ChIP-seq of the active enhancer marker histone H3 lysine 27 acetylation (H3K27ac) to profile unique SEs NKTL primary tumor samples. Integrative analysis of RNA-seq and survival data further pinned down high value, novel SE oncogenes. We utilized shRNA knockdown, CRISPR-dCas9, luciferase reporter assay, ChIP-PCR to investigate the regulation of transcription factor (TF) on SE oncogenes. Multi-color immunofluorescence (mIF) staining was performed on an independent cohort of clinical samples. Various function experiments were performed to evaluate the effects of TOX2 on the malignancy of NKTL in vitro and in vivo. Results SE landscape was substantially different in NKTL samples in comparison with normal tonsils. Several SEs at key transcriptional factor (TF) genes, including TOX2, TBX21(T-bet), EOMES, RUNX2, and ID2, were identified. We confirmed that TOX2 was aberrantly overexpressed in NKTL relative to normal NK cells and high expression of TOX2 was associated with worse survival. Modulation of TOX2 expression by shRNA, CRISPR-dCas9 interference of SE function impacted on cell proliferation, survival and colony formation ability of NKTL cells. Mechanistically, we found that RUNX3 regulates TOX2 transcription by binding to the active elements of its SE. Silencing TOX2 also impaired tumor formation of NKTL cells in vivo. Metastasis-associated phosphatase PRL-3 has been identified and validated as a key downstream effector of TOX2-mediated oncogenesis. Conclusions Our integrative SE profiling strategy revealed the landscape of SEs, novel targets and insights into molecular pathogenesis of NKTL. The RUNX3-TOX2-SE-TOX2-PRL-3 regulatory pathway may represent a hallmark of NKTL biology. Targeting TOX2 could be a valuable therapeutic intervene for NKTL patients and warrants further study in clinic.

Abstract Diffuse large B-cell lymphoma (DLBCL) exhibits significant genetic heterogeneity which contributes to drug resistance, necessitating development of novel therapeutic approaches. Pharmacological inhibitors of cyclin-dependent kinases (CDK) demonstrated pre-clinical activity in DLBCL, however many stalled in clinical development. Here we show that AZD4573, a selective inhibitor of CDK9, restricted growth of DLBCL cells. CDK9 inhibition (CDK9i) resulted in rapid changes in the transcriptome and proteome, with downmodulation of multiple oncoproteins (eg, MYC, Mcl-1, JunB, PIM3) and deregulation of phosphoinotiside-3 kinase (PI3K) and senescence pathways. Following initial transcriptional repression due to RNAPII pausing, we observed transcriptional recovery of several oncogenes, including MYC and PIM3. ATAC-Seq and ChIP-Seq experiments revealed that CDK9i induced epigenetic remodeling with bi-directional changes in chromatin accessibility, suppressed promoter activation and led to sustained reprograming of the super-enhancer landscape. A CRISPR library screen suggested that SE-associated genes in the Mediator complex, as well as AKT1, confer resistance to CDK9i. Consistent with this, sgRNA-mediated knockout of MED12 sensitized cells to CDK9i. Informed by our mechanistic findings, we combined AZD4573 with either PIM kinase or PI3K inhibitors. Both combinations decreased proliferation and induced apoptosis in DLBCL and primary lymphoma cells in vitro as well as resulted in delayed tumor progression and extended survival of mice xenografted with DLBCL in vivo. Thus, CDK9i induces reprogramming of the epigenetic landscape, and super-enhancer driven recovery of select oncogenes may contribute to resistance to CDK9i. PIM and PI3K represent potential targets to circumvent resistance to CDK9i in the heterogeneous landscape of DLBCL.

Abstract Background Super-enhancers (SEs), driving high-level expression of genes with tumor-promoting functions, have been investigated recently. However, the roles of super-enhancer-associated lncRNAs (SE-lncRNAs) in tumors remain undetermined, especially in gliomas. We here established a SE-lncRNAs expression-based prognostic signature to choose the effective treatment of glioma and identify a novel therapeutic target. Methods Combined analysis of RNA sequencing (RNA-seq) data and ChIP sequencing (ChIP-seq) data of glioma patient-derived glioma stem cells (GSCs) screened SE-lncRNAs. Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA) datasets served to construct and validate SE-lncRNA prognostic signature. The immune profiles and potential immuno- and chemotherapies response prediction value of the signature were also explored. Moreover, we verified the epigenetic activation mechanism of LINC00945 via the ChIP assay, and its effect on glioma was determined by performing the functional assay and a mouse xenograft model. Results 6 SE-lncRNAs were obtained and identified three subgroups of glioma patients with different prognostic and clinical features. A risk signature was further constructed and demonstrated to be an independent prognostic factor. The high-risk group exhibited an immunosuppressive microenvironment and was higher enrichment of M2 macrophage, regulatory T cells (Tregs), and Cancer-associated fibroblasts (CAFs). Patients in the high-risk group were better candidates for immunotherapy and chemotherapeutics. The SE of LINC00945 was further verified via ChIP assay. Mechanistically, BRD4 may mediate epigenetic activation of LINC00945. Additionally, overexpression of LINC00945 promoted glioma cell proliferation, EMT, migration, and invasion in vitro and xenograft tumor formation in vivo. Conclusion Our study constructed the first prognostic SE-lncRNA signature with the ability to optimize the choice of patients receiving immuno- and chemotherapies and provided a potential therapeutic target for glioma.

Abstract One major characteristic of tumor cells is the aberrant activation of epigenetic regulatory elements, which remodel the tumor transcriptome and ultimately promote cancer progression and drug resistance. However, the oncogenic functions and mechanisms of ovarian cancer (OC) remain elusive. Here, super‐enhancer (SE) regulatory elements that are aberrantly activated in OC are identified and it is found that SEs drive the relative specific expression of the transcription factor KLF5 in OC patients and poly(ADP‐ribose) polymerase inhibitor (PARPi)‐resistant patients. KLF5 expression is associated with poor outcomes in OC patients and can drive tumor progression in vitro and in vivo. Mechanistically, KLF5 forms a transcriptional complex with EHF and ELF3 and binds to the promoter region of RAD51 to enhance its transcription, strengthening the homologous recombination repair (HRR) pathway. Notably, the combination of suberoylanilide hydroxamic acid (SAHA) and olaparib significantly inhibits tumor growth and metastasis of PARPi‐resistant OC cells with high KLF5. In conclusion, it is discovered that SEs‐driven KLF5 is a key regulatory factor in OC progression and PARPi resistance; and potential therapeutic strategies for OC patients with PARPi resistance and high KLF5 are identified.