Pioneer Factors and Architectural Proteins Mediating Embryonic Expression Signatures in Cancer

Nuclear microRNA 9 mediates G-quadruplex formation and 3D genome organization during TGF-β-induced transcription

The dynamics of three-dimensional (3D) genome organization are essential to transcriptional regulation. While enhancers regulate spatiotemporal gene expression, chromatin looping is a means for enhancer-promoter interactions yielding cell-type-specific gene expression. Further, non-canonical DNA secondary structures, such as G-quadruplexes (G4s), are related to increased gene expression. However, the role of G4s in promoter-distal regulatory elements, such as super-enhancers (SE), and in chromatin looping has remained elusive. Here we show that mature microRNA 9 (miR-9) is enriched at promoters and SE of genes that are inducible by transforming growth factor beta 1 (TGFB1) signaling. Moreover, we find that miR-9 is required for formation of G4s, promoter-super-enhancer looping and broad domains of the euchromatin histone mark H3K4me3 at TGFB1-responsive genes. Our study places miR-9 in the same functional context with G4s and promoter-enhancer interactions during 3D genome organization and transcriptional activation induced by TGFB1 signaling, a critical signaling pathway in cancer and fibrosis.

Implications in Cancer of Nuclear Micro RNAs, Long Non-Coding RNAs, and Circular RNAs Bound by PRC2 and FUS

The eukaryotic genome is mainly transcribed into non-coding RNAs (ncRNAs), including different RNA biotypes, such as micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), among others. Although miRNAs are assumed to act primarily in the cytosol, mature miRNAs have been reported and functionally characterized in the nuclei of different cells. Further, lncRNAs are important regulators of different biological processes in the cell nucleus as part of different ribonucleoprotein complexes. CircRNAs constitute a relatively less-characterized RNA biotype that has a circular structure as result of a back-splicing process. However, circRNAs have recently attracted attention in different scientific fields due to their involvement in various biological processes and pathologies. In this review, we will summarize recent studies that link to cancer miRNAs that have been functionally characterized in the cell nucleus, as well as lncRNAs and circRNAs that are bound by core components of the polycomb repressive complex 2 (PRC2) or the protein fused in sarcoma (FUS), highlighting mechanistic aspects and their diagnostic and therapeutic potential.

MAF functions as a pioneer transcription factor that initiates and sustains myelomagenesis

Deregulated expression of lineage-affiliated transcription factors (TFs) is a major mechanism of oncogenesis. However, how the deregulation of nonlineage affiliated TF affects chromatin to initiate oncogenic transcriptional programs is not well-known. To address this, we studied the chromatin effects imposed by oncogenic MAF as the cancer-initiating driver in the plasma cell cancer multiple myeloma. We found that the ectopically expressed MAF endows myeloma plasma cells with migratory and proliferative transcriptional potential. This potential is regulated by the activation of enhancers and superenhancers, previously inactive in healthy B cells and plasma cells, and the cooperation of MAF with the plasma cell-defining TF IRF4. Forced ectopic MAF expression confirms the de novo ability of oncogenic MAF to convert transcriptionally inert chromatin to active chromatin with the features of superenhancers, leading to the activation of the MAF-specific oncogenic transcriptome and the acquisition of cancer-related cellular phenotypes such as CCR1-dependent cell migration. These findings establish oncogenic MAF as a pioneer transcription factor that can initiate as well as sustain oncogenic transcriptomes and cancer phenotypes. However, despite its pioneer function, myeloma cells remain MAF-dependent, thus validating oncogenic MAF as a therapeutic target that would be able to circumvent the challenges of subsequent genetic diversification driving disease relapse and drug resistance.

Preliminary results from the EMoLung clinical study showing early lung cancer detection by the LC score

BACKGROUND

Lung cancer (LC) causes more deaths worldwide than any other cancer type. Despite advances in therapeutic strategies, the fatality rate of LC cases remains high (95%) since the majority of patients are diagnosed at late stages when patient prognosis is poor. Analysis of the International Association for the Study of Lung Cancer (IASLC) database indicates that early diagnosis is significantly associated with favorable outcome. However, since symptoms of LC at early stages are unspecific and resemble those of benign pathologies, current diagnostic approaches are mostly initiated at advanced LC stages.

METHODS

We developed a LC diagnosis test based on the analysis of distinct RNA isoforms expressed from the GATA6 and NKX2-1 gene loci, which are detected in exhaled breath condensates (EBCs). Levels of these transcript isoforms in EBCs were combined to calculate a diagnostic score (the LC score). In the present study, we aimed to confirm the applicability of the LC score for the diagnosis of early stage LC under clinical settings. Thus, we evaluated EBCs from patients with early stage, resectable non-small cell lung cancer (NSCLC), who were prospectively enrolled in the EMoLung study at three sites in Germany.

RESULTS

LC score-based classification of EBCs confirmed its performance under clinical conditions, achieving a sensitivity of 95.7%, 91.3% and 84.6% for LC detection at stages I, II and III, respectively.

CONCLUSIONS

The LC score is an accurate and non-invasive option for early LC diagnosis and a valuable complement to LC screening procedures based on computed tomography.

NF-κB/p52 augments ETS1 binding genome-wide to promote glioma progression

Gliomas are highly invasive and chemoresistant cancers, making them challenging to treat. Chronic inflammation is a key driver of glioma progression as it promotes aberrant activation of inflammatory pathways such as NF-κB signalling, which drives cancer cell invasion and angiogenesis. NF-κB factors typically dimerise with its own family members, but emerging evidence of their promiscuous interactions with other oncogenic factors has been reported to promote transcription of new target genes and function. Here, we show that non-canonical NF-κB activation directly regulates p52 at the ETS1 promoter, activating its expression. This impacts the genomic and transcriptional landscape of ETS1 in a glioma-specific manner. We further show that enhanced non-canonical NF-κB signalling promotes the co-localisation of p52 and ETS1, resulting in transcriptional activation of non-κB and/or non-ETS glioma-promoting genes. We conclude that p52-induced ETS1 overexpression in glioma cells remodels the genome-wide regulatory network of p52 and ETS1 to transcriptionally drive cancer progression.

Evolutionary Origins of Metabolic Reprogramming in Cancer

Metabolic changes that facilitate tumor growth are one of the hallmarks of cancer. These changes are not specific to tumors but also take place during the physiological growth of tissues. Indeed, the cellular and tissue mechanisms present in the tumor have their physiological counterpart in the repair of tissue lesions and wound healing. These molecular mechanisms have been acquired during metazoan evolution, first to eliminate the infection of the tissue injury, then to enter an effective regenerative phase. Cancer itself could be considered a phenomenon of antagonistic pleiotropy of the genes involved in effective tissue repair. Cancer and tissue repair are complex traits that share many intermediate phenotypes at the molecular, cellular, and tissue levels, and all of these are integrated within a Systems Biology structure. Complex traits are influenced by a multitude of common genes, each with a weak effect. This polygenic component of complex traits is mainly unknown and so makes up part of the missing heritability. Here, we try to integrate these different perspectives from the point of view of the metabolic changes observed in cancer.

Premature translation of the Drosophila zygotic genome activator Zelda is not sufficient to precociously activate gene expression

Following fertilization, the unified germ cells rapidly transition to a totipotent embryo. Maternally deposited mRNAs encode the proteins necessary for this reprogramming as the zygotic genome remains transcriptionally quiescent during the initial stages of development. The transcription factors required to activate the zygotic genome are among these maternally deposited mRNAs and are robustly translated following fertilization. In Drosophila, the mRNA encoding Zelda, the major activator of the zygotic genome, is not translated until 1 h after fertilization. Here we demonstrate that zelda translation is repressed in the early embryo by the TRIM-NHL protein Brain tumor (BRAT). BRAT also regulates Zelda levels in the larval neuroblast lineage. In the embryo, BRAT-mediated translational repression is regulated by the Pan Gu kinase, which is triggered by egg activation. The Pan Gu kinase phosphorylates translational regulators, suggesting that Pan Gu kinase activity alleviates translational repression of zelda by BRAT and coupling translation of zelda with that of other regulators of early embryonic development. Using the premature translation of zelda in embryos lacking BRAT activity, we showed that early translation of a zygotic genome activator is not sufficient to drive precocious gene expression. Instead, Zelda-target genes showed increased expression at the time they are normally activated. We propose that transition through early development requires the integration of multiple processes, including the slowing of the nuclear division cycle and activation of the zygotic genome. These processes are coordinately controlled by Pan Gu kinase-mediated regulation of translation.

Impact of the Exposome on the Epigenome in Inflammatory Bowel Disease Patients and Animal Models

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders of the gastrointestinal tract that encompass two main phenotypes, namely Crohn's disease and ulcerative colitis. These conditions occur in genetically predisposed individuals in response to environmental factors. Epigenetics, acting by DNA methylation, post-translational histones modifications or by non-coding RNAs, could explain how the exposome (or all environmental influences over the life course, from conception to death) could influence the gene expression to contribute to intestinal inflammation. We performed a scoping search using Medline to identify all the elements of the exposome that may play a role in intestinal inflammation through epigenetic modifications, as well as the underlying mechanisms. The environmental factors epigenetically influencing the occurrence of intestinal inflammation are the maternal lifestyle (mainly diet, the occurrence of infection during pregnancy and smoking); breastfeeding; microbiota; diet (including a low-fiber diet, high-fat diet and deficiency in micronutrients); smoking habits, vitamin D and drugs (e.g., IBD treatments, antibiotics and probiotics). Influenced by both microbiota and diet, short-chain fatty acids are gut microbiota-derived metabolites resulting from the anaerobic fermentation of non-digestible dietary fibers, playing an epigenetically mediated role in the integrity of the epithelial barrier and in the defense against invading microorganisms. Although the impact of some environmental factors has been identified, the exposome-induced epimutations in IBD remain a largely underexplored field. How these environmental exposures induce epigenetic modifications (in terms of duration, frequency and the timing at which they occur) and how other environmental factors associated with IBD modulate epigenetics deserve to be further investigated.

Single-cell chromatin profiling of the primitive gut tube reveals regulatory dynamics underlying lineage fate decisions

Development of the gastrointestinal system occurs after gut tube closure, guided by spatial and temporal control of gene expression. However, it remains unclear what forces regulate these spatiotemporal gene expression patterns. Here we perform single-cell chromatin profiling of the primitive gut tube to reveal organ-specific chromatin patterns that reflect the anatomical patterns of distinct organs. We generate a comprehensive map of epigenomic changes throughout gut development, demonstrating that dynamic chromatin accessibility patterns associate with lineage-specific transcription factor binding events to regulate organ-specific gene expression. Additionally, we show that loss of Sox2 and Cdx2, foregut and hindgut lineage-specific transcription factors, respectively, leads to fate shifts in epigenomic patterns, linking transcription factor binding, chromatin accessibility, and lineage fate decisions in gut development. Notably, abnormal expression of Sox2 in the pancreas and intestine impairs lineage fate decisions in both development and adult homeostasis. Together, our findings define the chromatin and transcriptional mechanisms of organ identity and lineage plasticity in development and adult homeostasis.

Pioneer transcription factors are associated with the modulation of DNA methylation patterns across cancers

Methylation of cytosines on DNA is a prominent modification associated with gene expression regulation. Aberrant DNA methylation patterns have recurrently been linked to dysregulation of the regulatory program in cancer cells. To shed light on the underlying molecular mechanism driving this process, we hypothesised that aberrant methylation patterns could be controlled by the binding of specific transcription factors (TFs) across cancer types. By combining DNA methylation arrays and gene expression data with TF binding sites (TFBSs), we explored the interplay between TF binding and DNA methylation in 19 cancer types. We performed emQTL (expression-methylation quantitative trait loci) analyses independently in each cancer type and identified 13 TFs whose expression levels are correlated with local DNA methylation patterns around their binding sites in at least 2 cancer types. The 13 TFs are mainly associated with local demethylation and are enriched for pioneer function, suggesting a specific role for these TFs in modulating chromatin structure and transcription in cancer patients. Furthermore, we confirmed that de novo methylation is precluded across cancers at CpGs lying in genomic regions enriched for TF binding signatures associated with SP1, CTCF, NRF1, GABPA, KLF9, and/or YY1. The modulation of DNA methylation associated with TF binding was observed at cis-regulatory regions controlling immune- and cancer-associated pathways, corroborating that the emQTL signals were derived from both cancer and tumor-infiltrating cells. As a case example, we experimentally confirmed that FOXA1 knock-down is associated with higher methylation in regions bound by FOXA1 in breast cancer MCF-7 cells. Finally, we reported physical interactions between FOXA1 with TET1 and TET2 both in an in vitro setup and in vivo at physiological levels in MCF-7 cells, adding further support for FOXA1 attracting TET1 and TET2 to induce local demethylation in cancer cells.

Lymphoid-specific helicase in epigenetics, DNA repair and cancer

Lymphoid-specific helicase (LSH) is a member of the SNF2 helicase family of chromatin-remodelling proteins. Dysfunctions or mutations in LSH causes an autosomal recessive disease known as immunodeficiency-centromeric instability-facial anomaly (ICF) syndrome. Interestingly, LSH participates in various aspects of epigenetic regulation, including nucleosome remodelling, DNA methylation, histone modifications and heterochromatin formation. Further, LSH plays a crucial role during DNA-damage repair, specifically during double-strand break (DSB) repair, since murine LSH was shown to be essential for non-homologous end joining (NHEJ) and homologous recombination (HR). Accordingly, overexpression of LSH drives tumorigenesis and malignancy. On the other hand, LSH homologs stabilise the genome. Thus, LSH might be implemented as a biomarker for various cancer types and potential target molecule to develop therapeutic strategies against them. In this review, we focus on the role of LSH in orchestrating chromatin rearrangements, such as DNA methylation and histone modifications, as well as in DNA-damage repair. Changes in chromatin structure may facilitate gene expression signatures that cause malignant transformation. We summarise recent findings of LSH in cancers and raise critical open questions for further studies.

Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer

The switch/sucrose non-fermentable (SWI/SNF) complex has a crucial role in chromatin remodelling1 and is altered in over 20% of cancers2,3. Here we developed a proteolysis-targeting chimera (PROTAC) degrader of the SWI/SNF ATPase subunits, SMARCA2 and SMARCA4, called AU-15330. Androgen receptor (AR)+ forkhead box A1 (FOXA1)+ prostate cancer cells are exquisitely sensitive to dual SMARCA2 and SMARCA4 degradation relative to normal and other cancer cell lines. SWI/SNF ATPase degradation rapidly compacts cis-regulatory elements bound by transcription factors that drive prostate cancer cell proliferation, namely AR, FOXA1, ERG and MYC, which dislodges them from chromatin, disables their core enhancer circuitry, and abolishes the downstream oncogenic gene programs. SWI/SNF ATPase degradation also disrupts super-enhancer and promoter looping interactions that wire supra-physiologic expression of the AR, FOXA1 and MYC oncogenes themselves. AU-15330 induces potent inhibition of tumour growth in xenograft models of prostate cancer and synergizes with the AR antagonist enzalutamide, even inducing disease remission in castration-resistant prostate cancer (CRPC) models without toxicity. Thus, impeding SWI/SNF-mediated enhancer accessibility represents a promising therapeutic approach for enhancer-addicted cancers.

Genomic landscape of a mouse model of diffuse-type gastric adenocarcinoma

BACKGROUND

There is a need for a model of diffuse-type gastric cancer that captures the features of the disease, facilitates the study of its mechanisms, and aids the development of potential therapies. One such model may be Cdh1 and Trp53 double conditional knockout (DCKO) mice, which have histopathological features similar to those of human diffuse-type gastric cancer. However, a genomic profile of this mouse model has yet to be completed.

METHODS

Whole-genome sequences of tumors from eight DCKO mice were analyzed and their molecular features were compared with those of human gastric adenocarcinoma.

RESULTS

DCKO mice gastric cancers harbored single nucleotide variations and indel patterns comparable to those of human genomically stable gastric cancers, whereas their copy number variation fraction and ploidy were more similar to human chromosomal instability gastric cancers (perhaps due to Trp53 knockout). Copy number variations dominated changes in cancer-related genes in DCKO mice, with typical high-level amplifications observed for oncogenic drivers, e.g., Myc, Ccnd1, and Cdks, as well as gastrointestinal transcription factors, e.g., Gata4, Foxa1, and Sox9. Interestingly, frequent alterations in gastrointestinal transcription factors in DCKO mice indicated their potential role in tumorigenesis. Furthermore, mouse gastric cancer had a reproducible but smaller number of mutational signatures than human gastric cancer, including the potentially acid-related signature 17, indicating shared tumorigenic etiologies in humans and mice.

CONCLUSIONS

Cdh1/Trp53 DCKO mice have similar genomic features to those found in human gastric cancer; hence, this is a suitable model for further studies of diffuse-type gastric cancer mechanisms and therapies.

Pioneering the developmental frontier

Coordinated changes in gene expression allow a single fertilized oocyte to develop into a complex multi-cellular organism. These changes in expression are controlled by transcription factors that gain access to discrete cis-regulatory elements in the genome, allowing them to activate gene expression. Although nucleosomes present barriers to transcription factor occupancy, pioneer transcription factors have unique properties that allow them to bind DNA in the context of nucleosomes, define cis-regulatory elements, and facilitate the subsequent binding of additional factors that determine gene expression. In this capacity, pioneer factors act at the top of gene-regulatory networks to control developmental transitions. Developmental context also influences pioneer factor binding and activity. Here we discuss the interplay between pioneer factors and development, their role in driving developmental transitions, and the influence of the cellular environment on pioneer factor binding and activity.

FoxA factors: the chromatin key and doorstop essential for liver development and function

This Outlook discusses the findings by Reizel et al. describing FOXA as a key, opening regions of chromatin during development, and as a doorstep, maintaining the established euchromatic structure in adult tissues.

Pioneer factors are transcriptional regulators with the capacity to bind inactive regions of chromatin and induce changes in accessibility that underpin cell fate decisions. The FOXA family of transcription factors is well understood to have pioneer capacity. Indeed, researchers have uncovered numerous examples of FOXA-dependent epigenomic modulation in developmental and disease processes. Despite the presence of FOXA being essential for correct epigenetic patterning, the need for continued FOXA presence postchromatin modulation has been debated. In a recent study in this issue of Genes & Development, Reizel and colleagues (pp. 1039–1050) show that the tissue-specific ablation of FOXA1/2/3 in the adult mouse liver results in the collapse of the epigenetic profile that maintains the hepatic gene expression profile. Thus, FOXA functions as a key, opening regions of chromatin during development, and as a doorstep, maintaining the established euchromatic structure in adult tissue.

Nucleosome allostery in pioneer transcription factor binding

While recent experiments revealed that some pioneer transcription factors (TFs) can bind to their target DNA sequences inside a nucleosome, the binding dynamics of their target recognitions are poorly understood. Here we used the latest coarse-grained models and molecular dynamics simulations to study the nucleosome-binding procedure of the two pioneer TFs, Sox2 and Oct4. In the simulations for a strongly positioning nucleosome, Sox2 selected its target DNA sequence only when the target was exposed. Otherwise, Sox2 entropically bound to the dyad region nonspecifically. In contrast, Oct4 plastically bound on the nucleosome mainly in two ways. First, the two POU domains of Oct4 separately bound to the two parallel gyres of the nucleosomal DNA, supporting the previous experimental results of the partial motif recognition. Second, the POU_S domain of Oct4 favored binding on the acidic patch of histones. Then, simulating the TFs binding to a genomic nucleosome, the LIN28B nucleosome, we found that the recognition of a pseudo motif by Sox2 induced the local DNA bending and shifted the population of the rotational position of the nucleosomal DNA. The redistributed DNA phase, in turn, changed the accessibility of a distant TF binding site, which consequently affected the binding probability of a second Sox2 or Oct4. These results revealed a nucleosomal DNA-mediated allosteric mechanism, through which one TF binding event can change the global conformation, and effectively regulate the binding of another TF at distant sites. Our simulations provide insights into the binding mechanism of single and multiple TFs on the nucleosome.

Dynamic changes in cis-regulatory occupancy by Six1 and its cooperative interactions with distinct cofactors drive lineage-specific gene expression programs during progressive differentiation of the auditory sensory epithelium

The transcription factor Six1 is essential for induction of sensory cell fate and formation of auditory sensory epithelium, but how it activates gene expression programs to generate distinct cell-types remains unknown. Here, we perform genome-wide characterization of Six1 binding at different stages of auditory sensory epithelium development and find that Six1-binding to cis-regulatory elements changes dramatically at cell-state transitions. Intriguingly, Six1 pre-occupies enhancers of cell-type-specific regulators and effectors before their expression. We demonstrate in-vivo cell-type-specific activity of Six1-bound novel enhancers of Pbx1, Fgf8, Dusp6, Vangl2, the hair-cell master regulator Atoh1 and a cascade of Atoh1's downstream factors, including Pou4f3 and Gfi1. A subset of Six1-bound sites carry consensus-sequences for its downstream factors, including Atoh1, Gfi1, Pou4f3, Gata3 and Pbx1, all of which physically interact with Six1. Motif analysis identifies RFX/X-box as one of the most significantly enriched motifs in Six1-bound sites, and we demonstrate that Six1-RFX proteins cooperatively regulate gene expression through binding to SIX:RFX-motifs. Six1 targets a wide range of hair-bundle regulators and late Six1 deletion disrupts hair-bundle polarity. This study provides a mechanistic understanding of how Six1 cooperates with distinct cofactors in feedforward loops to control lineage-specific gene expression programs during progressive differentiation of the auditory sensory epithelium.

Non-coding RNAs and nuclear architecture during epithelial-mesenchymal transition in lung cancer and idiopathic pulmonary fibrosis

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. On the other hand, idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease showing a prevalence of 20 new cases per 100,000 persons per year. Despite differences in cellular origin and pathological phenotypes, LC and IPF are lung diseases that share common features, including hyperproliferation of specific cell types in the lung, involvement of epithelial-mesenchymal transition (EMT) and enhanced activity of signaling pathways, such as tissue growth factor (TGFB), epidermal growth factor (EGF), fibroblast growth factor (FGF), wingless secreted glycoprotein (WNT) signaling, among others. EMT is a process during which epithelial cells lose their cell polarity and cell-cell adhesion, and acquire migratory and invasive properties to become mesenchymal cells. EMT involves numerous morphological hallmarks of hyperproliferative diseases, like cell plasticity, resistance to apoptosis, dedifferentiation and proliferation, thereby playing a central role during organ fibrosis and cancer progression. EMT was considered as an "all-or-none" process. In contrast to these outdated dichotomist interpretations, recent reports suggest that EMT occurs gradually involving different epithelial cell intermediate states with mesenchyme-like characteristics. These cell intermediate states of EMT differ from each other in their cell plasticity, invasiveness and metastatic potential, which in turn are induced by signals from their microenvironment. EMT is regulated by several transcription factors (TFs), which are members of prominent families of master regulators of transcription. In addition, there is increasing evidence for the important contribution of noncoding RNAs (ncRNAs) to EMT. In our review we highlight articles dissecting the function of different ncRNAs subtypes and nuclear architecture in cell intermediate states of EMT, as well as their involvement in LC and IPF.

Inactivation of nuclear histone deacetylases by EP300 disrupts the MiCEE complex in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and highly lethal lung disease with unknown etiology and poor prognosis. IPF patients die within 2 years after diagnosis mostly due to respiratory failure. Current treatments against IPF aim to ameliorate patient symptoms and to delay disease progression. Unfortunately, therapies targeting the causes of or reverting IPF have not yet been developed. Here we show that reduced levels of miRNA lethal 7d (MIRLET7D) in IPF compromise epigenetic gene silencing mediated by the ribonucleoprotein complex MiCEE. In addition, we find that hyperactive EP300 reduces nuclear HDAC activity and interferes with MiCEE function in IPF. Remarkably, EP300 inhibition reduces fibrotic hallmarks of in vitro (patient-derived primary fibroblast), in vivo (bleomycin mouse model), and ex vivo (precision-cut lung slices, PCLS) IPF models. Our work provides the molecular basis for therapies against IPF using EP300 inhibition.

Idiopathic pulmonary fibrosis (IPF) is a lethal disease with insufficient treatment strategies. Here the authors show that reduction of the microRNA MIRLET7D and hyperactivation of EP300 contribute to impaired epigenetic silencing by the MiCEE complex in pulmonary fibroblasts of IPF patients, and demonstrate the benefit of inhibiting EP300 for the treatment of IPF.