High-density lipoprotein mediates anti-inflammatory reprogramming of macrophages via the transcriptional regulator ATF3.

High-density lipoprotein (HDL) mediates reverse cholesterol transport and is known to be protective against atherosclerosis. In addition, HDL has potent anti-inflammatory properties that may be critical for protection against other inflammatory diseases. The molecular mechanisms of how HDL can modulate inflammation, particularly in immune cells such as macrophages, remain poorly understood. Here we identify the transcriptional regulator ATF3, as an HDL-inducible target gene in macrophages that downregulates the expression of Toll-like receptor (TLR)-induced proinflammatory cytokines. The protective effects of HDL against TLR-induced inflammation were fully dependent on ATF3 in vitro and in vivo. Our findings may explain the broad anti-inflammatory and metabolic actions of HDL and provide the basis for predicting the success of new HDL-based therapies.

SUMOylation of the ubiquitin ligase component KEAP1 at K39 upregulates NRF2 and its target function in lung cancer cell proliferation.

Nuclear Factor Erythroid 2-Related Factor 2 (NRF2) is important for the expression of genes associated with oxidative stress. The levels of NRF2 are controlled by Kelch-like ECH-associated protein 1 (KEAP1)-dependent degradation. Although oxidative stress is known to suppress KEAP1 activity to stabilize the levels of NRF2, the mechanism for this control is unclear. Here, we identify that KEAP1 is modified by SUMO1 at the lysine residue position 39 (K39). Arginine replacement of this lysine (K39R) in KEAP1 did not affect its stability, subcellular localization, or dimerization but promoted the formation of the Cullin 3 ubiquitin ligase and increased NRF2 ubiquitination. This was accompanied by decreased NRF2 expression. Gene reporter assays showed that the transcription of antioxidant response elements was heightened in KEAP1-WT cells compared to cells expressing the KEAP1-K39R SUMO1 substrate mutant. Consistent with this, chromatin immunoprecipitation assays revealed higher NRF2 binding to the promoter regions of antioxidant genes in cells expressing the KEAP1-WT compared to the KEAP1-K39R mutant protein in H1299 lung cancer cell. The significance of this suppression of KEAP1 activity by its SUMOylation was tested in a subcutaneous tumor model of H1299 lung cancer cell lines that differentially expressed the WT and K39R KEAP1 constructs. This model showed that mutating the SUMOylation site on KEAP1 altered the production of reactive oxygen species and suppressed tumor growth. Taken together, our study recognizes that NRF2-dependent redox control is regulated by the SUMOylation of KEAP1. These findings identify a potential new therapeutic option to counteract oxidative stress.

Proinflammatory phenotype of B10 and B10pro cells elicited by TNF-α in rheumatoid arthritis.

OBJECTIVES: B10 and B10pro cells suppress immune responses via secreting interleukin (IL)-10. However, their regulators and underlying mechanisms, especially in human autoimmune diseases, are elusive. This study aimed to address these questions in rheumatoid arthritis (RA), one of the most common highly disabling autoimmune diseases. METHODS: The frequencies and functions of B10 and B10pro cells in healthy individuals and patients with RA were first analysed. The effects of proinflammatory cytokines, particularly tumour necrosis factor (TNF)-α on the quantity, stability and pathogenic phenotype of these cells, were then assessed in patients with RA before and after anti-TNF therapy. The underlying mechanisms were further investigated by scRNA-seq database reanalysis, transcriptome sequencing, TNF-α-/- and B cell-specific SHIP-1-/- mouse disease model studies. RESULTS: TNF-α was a key determinant for B10 cells. TNF-α elicited the proinflammatory feature of B10 and B10pro cells by downregulating IL-10, and upregulating interferon-γ and IL-17A. In patients with RA, B10 and B10pro cells were impaired with exacerbated proinflammatory phenotype, while anti-TNF therapy potently restored their frequencies and immunosuppressive functions, consistent with the increased B10 cells in TNF-α-/- mice. Mechanistically, TNF-α diminished B10 and B10pro cells by inhibiting their glycolysis and proliferation. TNF-α also regulated the phosphatidylinositol phosphate signalling of B10 and B10pro cells and dampened the expression of SHIP-1, a dominant phosphatidylinositol phosphatase regulator of these cells. CONCLUSIONS: TNF-α provoked the proinflammatory phenotype of B10 and B10pro cells by disturbing SHIP-1 in RA, contributing to the disease development. Reinstating the immunosuppressive property of B10 and B10pro cells might represent novel therapeutic approaches for RA.

HDAC6 inhibitor promotes reactive oxygen species-meditated clearance of Staphylococcus aureus in macrophage.

Staphylococcus aureus (S. aureus) pneumonia has become an increasingly important public health problem. Recent evidence suggests that epigenetic modifications are critical in the host immune defence against pathogen infection. In this study, we found that S. aureus infection induces the expression of histone deacetylase 6 (HDAC6) in a dose-dependent manner. Furthermore, by using a S. aureus pneumonia mouse model, we showed that the HDAC6 inhibitor, tubastatin A, demonstrates a protective effect in S. aureus pneumonia, decreasing the mortality and destruction of lung architecture, reducing the bacterial burden in the lungs and inhibiting inflammatory responses. Mechanistic studies in primary bone marrow-derived macrophages demonstrated that the HDAC6 inhibitors, tubastatin A and tubacin, reduced the intracellular bacterial load by promoting bacterial clearance rather than regulating phagocytosis. Finally, N-acetyl-L- cysteine, a widely used reactive oxygen species (ROS) scavenger, antagonized ROS production and significantly inhibited tubastatin A-induced S. aureus clearance. These findings demonstrate that HDAC6 inhibitors promote the bactericidal activity of macrophages by inducing ROS, an important host factor for S. aureus clearance and production. Our study identified HDAC6 as a suitable epigenetic modification target for preventing S. aureus infection, and tubastatin A as a useful compound in treating S. aureus pneumonia.

Tumor-secreted exosomal miR-141 activates tumor-stroma interactions and controls premetastatic niche formation in ovarian cancer metastasis.

BACKGROUND: Metastatic colonization is one of the critical steps in tumor metastasis. A pre-metastatic niche is required for metastatic colonization and is determined by tumor-stroma interactions, yet the mechanistic underpinnings remain incompletely understood. METHODS: PCR-based miRNome profiling, qPCR, immunofluorescent analyses evaluated the expression of exosomal miR-141 and cell-to-cell communication. LC-MS/MS proteomic profiling and Dual-Luciferase analyses identified YAP1 as the direct target of miR-141. Human cytokine profiling, ChIP, luciferase reporter assays, and subcellular fractionation analyses confirmed YAP1 in modulating GROα production. A series of in vitro tumorigenic assays, an ex vivo model and Yap1 stromal conditional knockout (cKO) mouse model demonstrated the roles of miR-141/YAP1/GROα/CXCR1/2 signaling cascade. RNAi, CRISPR/Cas9 and CRISPRi systems were used for gene silencing. Blood sera, OvCa tumor tissue samples, and tissue array were included for clinical correlations. RESULTS: Hsa-miR-141-3p (miR-141), an exosomal miRNA, is highly secreted by ovarian cancer cells and reprograms stromal fibroblasts into proinflammatory cancer-associated fibroblasts (CAFs), facilitating metastatic colonization. A mechanistic study showed that miR-141 targeted YAP1, a critical effector of the Hippo pathway, reducing the nuclear YAP1/TAZ ratio and enhancing GROα production from stromal fibroblasts. Stromal-specific knockout (cKO) of Yap1 in murine models shaped the GROα-enriched microenvironment, facilitating in vivo tumor colonization, but this effect was reversed after Cxcr1/2 depletion in OvCa cells. The YAP1/GROα correlation was demonstrated in clinical samples, highlighting the clinical relevance of this research and providing a potential therapeutic intervention for impeding premetastatic niche formation and metastatic progression of ovarian cancers. CONCLUSIONS: This study uncovers miR-141 as an OvCa-derived exosomal microRNA mediating the tumor-stroma interactions and the formation of tumor-promoting stromal niche through activating YAP1/GROα/CXCRs signaling cascade, providing new insight into therapy for OvCa patients with peritoneal metastases.

Survival prediction of stomach cancer using expression data and deep learning models with histopathological images.

Accurately predicting patient survival is essential for cancer treatment decision. However, the prognostic prediction model based on histopathological images of stomach cancer patients is still yet to be developed. We propose a deep learning-based model (MultiDeepCox-SC) that predicts overall survival in patients with stomach cancer by integrating histopathological images, clinical data, and gene expression data. The MultiDeepCox-SC not only automatedly selects patches with more information for survival prediction, without manual labeling for histopathological images, but also identifies genetic and clinical risk factors associated with survival in stomach cancer. The prognostic accuracy of the MultiDeepCox-SC (C-index = 0.744) surpasses the result only based on histopathological image (C-index = 0.660). The risk score of our model was still an independent predictor of survival outcome after adjustment for potential confounders, including pathologic stage, grade, age, race, and gender on The Cancer Genome Atlas dataset (hazard ratio 1.555, p = 3.53e-08) and the external test set (hazard ratio 2.912, p = 9.42e-4). Our fully automated online prognostic tool based on histopathological images, clinical data, and gene expression data could be utilized to improve pathologists' efficiency and accuracy (https://yu.life.sjtu.edu.cn/DeepCoxSC).

Large-scale comparative assessment of computational predictors for lysine post-translational modification sites.

Lysine post-translational modifications (PTMs) play a crucial role in regulating diverse functions and biological processes of proteins. However, because of the large volumes of sequencing data generated from genome-sequencing projects, systematic identification of different types of lysine PTM substrates and PTM sites in the entire proteome remains a major challenge. In recent years, a number of computational methods for lysine PTM identification have been developed. These methods show high diversity in their core algorithms, features extracted and feature selection techniques and evaluation strategies. There is therefore an urgent need to revisit these methods and summarize their methodologies, to improve and further develop computational techniques to identify and characterize lysine PTMs from the large amounts of sequence data. With this goal in mind, we first provide a comprehensive survey on a large collection of 49 state-of-the-art approaches for lysine PTM prediction. We cover a variety of important aspects that are crucial for the development of successful predictors, including operating algorithms, sequence and structural features, feature selection, model performance evaluation and software utility. We further provide our thoughts on potential strategies to improve the model performance. Second, in order to examine the feasibility of using deep learning for lysine PTM prediction, we propose a novel computational framework, termed MUscADEL (Multiple Scalable Accurate Deep Learner for lysine PTMs), using deep, bidirectional, long short-term memory recurrent neural networks for accurate and systematic mapping of eight major types of lysine PTMs in the human and mouse proteomes. Extensive benchmarking tests show that MUscADEL outperforms current methods for lysine PTM characterization, demonstrating the potential and power of deep learning techniques in protein PTM prediction. The web server of MUscADEL, together with all the data sets assembled in this study, is freely available at http://muscadel.erc.monash.edu/. We anticipate this comprehensive review and the application of deep learning will provide practical guide and useful insights into PTM prediction and inspire future bioinformatics studies in the related fields.

Regulation of actin dynamics by protein kinase R control of gelsolin enforces basal innate immune defense.

Primary resistance to pathogens is reliant on both basal and inducible immune defenses. To date, research has focused upon inducible innate immune responses. In contrast to resistance via cytokine induction, basal defense mechanisms are less evident. Here we showed that the antiviral protein kinase R (PKR) inhibited the key actin-modifying protein gelsolin to regulate actin dynamics and control cytoskeletal cellular functions under homeostatic conditions. Through this mechanism, PKR controlled fundamental innate immune, actin-dependent processes that included membrane ruffling and particle engulfment. Accordingly, PKR counteracted viral entry into the cell. These findings identify a layer of host resistance, showing that the regulation of actin-modifying proteins during the innate immune response bolsters first-line defense against intracellular pathogens and has a sustained effect on virus production. Moreover, these data provide proof of principle for a concept in which the cell cytoskeleton could be targeted to elicit broad antiviral protection.

MAP30 protein from Momordica charantia is therapeutic and has synergic activity with cisplatin against ovarian cancer in vivo by altering metabolism and inducing ferroptosis.

Increasing evidence shows that Traditional Chinese Medicine (TCM) has an obvious appeal for cancer treatment, but there is still a lack of scientific investigation of its underlying molecular mechanisms. Bitter melon or bitter gourd (Momordica charantia) is an edible fruit that is commonly consumed, and it is used to cure different diseases in various ancient folk medical practices. We report that a bioactive protein, MAP30, isolated from bitter melon seeds exhibited potent anticancer and anti-chemoresistant effects on ovarian cancer cells. Functional studies revealed that MAP30 inhibited cancer cell migration, cell invasion, and cell proliferation in various ovarian cancer cells but not normal immortalized ovarian epithelial cells. When administered with cisplatin, MAP30 produced a synergistic effect on cisplatin-induced cell cytotoxicity in ovarian cancer cells. When low doses of cisplatin and MAP30 were co-injected intraperitoneally, a remarkable reduction of tumor dissemination and tumor growth was observed in an ovarian cancer ascites mouse model. Notably, blood tests confirmed that MAP30 did not cause any adverse effects on liver and kidney functions in the treated mice. MAP30 activated AMP-activated protein kinase (AMPK) signaling via CaMKKß and induced cell cycle arrest in the S-phase. MAP30 modulated cell metabolism of ovarian cancer cells via suppression of GLUT-1/-3-mediated glucose uptake, adipogenesis, and lipid droplet formation in tumor development and progression. MAP30 also induced an increase in intracellular Ca2+ ion concentration, which triggered ROS-mediated cancer cell death via apoptosis and ferroptosis. Collectively, these findings suggest that natural MAP30 is a non-toxic supplement that may enhance chemotherapeutic outcomes and benefit ovarian cancer patients with peritoneal metastases.

A non-canonical function of Ezh2 preserves immune homeostasis.

Enhancer of zeste 2 (Ezh2) mainly methylates lysine 27 of histone-H3 (H3K27me3) as part of the polycomb repressive complex 2 (PRC2) together with Suz12 and Eed. However, Ezh2 can also modify non-histone substrates, although it is unclear whether this mechanism has a role during development. Here, we present evidence for a chromatin-independent role of Ezh2 during T-cell development and immune homeostasis. T-cell-specific depletion of Ezh2 induces a pronounced expansion of natural killer T (NKT) cells, although Ezh2-deficient T cells maintain normal levels of H3K27me3. In contrast, removal of Suz12 or Eed destabilizes canonical PRC2 function and ablates NKT cell development completely. We further show that Ezh2 directly methylates the NKT cell lineage defining transcription factor PLZF, leading to its ubiquitination and subsequent degradation. Sustained PLZF expression in Ezh2-deficient mice is associated with the expansion of a subset of NKT cells that cause immune perturbation. Taken together, we have identified a chromatin-independent function of Ezh2 that impacts on the development of the immune system.

Promyelocytic leukemia zinc finger protein regulates interferon-mediated innate immunity.

Interferons (IFNs) direct innate and acquired immune responses and, accordingly, are used therapeutically to treat a number of diseases, yet the diverse effects they elicit are not fully understood. Here, we identified the promyelocytic leukemia zinc finger (PLZF) protein as a previously unrecognized component of the IFN response. IFN stimulated an association of PLZF with promyelocytic leukemia protein (PML) and histone deacetylase 1 (HDAC1) to induce a decisive subset of IFN-stimulated genes (ISGs). Consequently, PLZF-deficient mice had a specific ISG expression defect and as a result were more susceptible to viral infection. This susceptibility correlated with a marked decrease in the expression of the key antiviral mediators and an impaired IFN-mediated induction of natural killer cell function. These results provide new insights into the regulatory mechanisms of IFN signaling and the induction of innate antiviral immunity.

(-)-Epigallocatechin-3-gallate and EZH2 inhibitor GSK343 have similar inhibitory effects and mechanisms of action on colorectal cancer cells.

Epigallocatechin-3-gallate (EGCG) is a type of catechin. It exhibits excellent antioxidant effects and anti-tumour activities for cancer chemoprevention. The mechanism of anti-tumour effects of EGCG on different cancers has been studied for the past few decades, but remains controversial. To investigate the potential role that EGCG may play in the epigenetic regulation of colorectal cancer (CRC) cell line, we integrated bioinformatics analysis with experimental validation. We found that levels of the enhancer of zeste homologue 2 (EZH2) were significantly higher in CRC tissues compared to normal adjacent tissues, based on the Genomic Data Commons (GDC) data portal. Different human CRC cell lines exhibited differing expression of levels of the EZH2 protein. In RKO cells, EGCG and the EZH2 inhibitor GSK343 exhibited similar inhibitory efficacy on the proliferation, invasion and migration abilities of the cells, and suppressed protein expression of trimethylated lysine 27 on histone H3 (H3K27me3), which may be caused by the loss of the enzymatic function of EZH2. EGCG and GSK343 were found to have a synergistic effect on the growth of RKO cells in lower concentrations. EZH2-correlated genes were enriched in the cell cycle pathway, the top-ranking up-regulated pathway in tumour tissues, based on pathway analyses using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA). In accord with this, we confirmed that EGCG and GSK343 could both significantly arrest the G0/G1 phase in RKO cell cycle, suggesting EGCG and EZH2 inhibitor share a common mechanism of action in RKO cells.

BTB-ZF transcriptional regulator PLZF modifies chromatin to restrain inflammatory signaling programs.

Inflammation is critical for host defense, but without appropriate control, it can cause chronic disease or even provoke fatal responses. Here we identify a mechanism that limits the inflammatory response. Probing the responses of macrophages to the key sensory Toll-like receptors, we identify that the Broad-complex, Tramtrack and Bric-a-brac/poxvirus and zinc finger (BTB/POZ), transcriptional regulator promyelocytic leukemia zinc finger (PLZF) limits the expression of inflammatory gene products. In accord with this finding, PLZF-deficient animals express higher levels of potent inflammatory cytokines and mount exaggerated inflammatory responses to infectious stimuli. Temporal quantitation of inflammatory gene transcripts shows increased gene induction in the absence of PLZF. Genome-wide analysis of histone modifications distinguish that PLZF establishes basal activity states of early response genes to maintain immune homeostasis and limit damaging inflammation. We show that PLZF stabilizes a corepressor complex that encompasses histone deacetylase activity to control chromatin. Together with our previous demonstration that PLZF promotes the antiviral response, these results suggest a strategy that could realize one of the major goals of immune therapy to retain immune resistance to pathogens while curbing damaging inflammation.

Understanding immune phenotypes in human gastric disease tissues by multiplexed immunohistochemistry.

BACKGROUND: Understanding immune phenotypes and human gastric disease in situ requires an approach that leverages multiplexed immunohistochemistry (mIHC) with multispectral imaging to facilitate precise image analyses. METHODS: We developed a novel 4-color mIHC assay based on tyramide signal amplification that allowed us to reliably interrogate immunologic checkpoints, including programmed death-ligand 1 (PD-L1), cytotoxic T cells (CD8+T) and regulatory T cells (Foxp3), in formalin-fixed, paraffin-embedded tissues of various human gastric diseases. By observing cell phenotypes within the disease tissue microenvironment, we were able to determine specific co-localized staining combinations and various measures of cell density. RESULTS: We found that PD-L1 was expressed in gastric ulcer and in tumor cells (TCs), as well as in tumor-infiltrating immune cells (TIICs), but not in normal gastric mucosa or other gastric intraepithelial neoplastic tissues. Furthermore, we found no significant reduction in CD8+T cells, whereas the ratio of CD8+T:Foxp3 cells and CD8+T:PD-L1 cells was suppressed in tumor tissues and elevated in adjacent normal tissues. An unsupervised hierarchical analysis also identified correlations between CD8+T and Foxp3+ tumor-infiltrating lymphocyte (TIL) densities and average PD-L1 levels. Three main groups were identified based on the results of CD8+T:PD-L1 ratios in gastric tumor tissues. Furthermore, integrating CD8+T:Foxp3 ratios, which increased the complexity for immune phenotype status, revealed 6-7 clusters that enabled the separation of gastric cancer patients at the same clinical stage into different risk-group subsets. CONCLUSIONS: Characterizing immune phenotypes in human gastric disease tissues via multiplexed immunohistochemistry may help guide PD-L1 clinical therapy. Observing unique disease tissue microenvironments can improve our understanding of immune phenotypes and cell interactions within these microenvironments, providing the ability to predict safe responses to immunotherapies.

Emerging Roles for Epigenetic Programming in the Control of Inflammatory Signaling Integration in Heath and Disease.

Macrophages and dendritic cells initiate the innate immune response to infection and injury and contribute to inflammatory signaling to maintain the homeostasis of various tissues, which includes resident macrophages for the elimination of invading microorganisms and tissue damage. Inappropriate inflammatory signaling can lead to persistent inflammation and further develop into autoimmune and inflammation-associated diseases. Inflammatory signaling pathways have been well characterized, but how these signaling pathways are converted into sustained and diverse patterns of expression of cytokines, chemokines, and other genes in response to environmental challenges is unclear. Emerging evidence suggests the important role of epigenetic mechanisms in finely tuning the outcome of the host innate immune response. An understanding of epigenetic regulation of innate immune cell identity and function will enable the identification of the mechanism between gene-specific host defenses and inflammatory disease and will also allow for exploration of the program of innate immune memory in health and disease. This information could be used to develop therapeutic agents to enhance the host response, preventing chronic inflammation through preserving tissues and signaling integrity.

Telomerase Deficiency Causes Alveolar Stem Cell Senescence-associated Low-grade Inflammation in Lungs.

Mutations of human telomerase RNA component (TERC) and telomerase reverse transcriptase (TERT) are associated with a subset of lung aging diseases, but the mechanisms by which TERC and TERT participate in lung diseases remain unclear. In this report, we show that knock-out (KO) of the mouse gene Terc or Tert causes pulmonary alveolar stem cell replicative senescence, epithelial impairment, formation of alveolar sacs, and characteristic inflammatory phenotype. Deficiency in TERC or TERT causes a remarkable elevation in various proinflammatory cytokines, including IL-1, IL-6, CXCL15 (human IL-8 homolog), IL-10, TNF-α, and monocyte chemotactic protein 1 (chemokine ligand 2 (CCL2)); decrease in TGF-ß1 and TGFßRI receptor in the lungs; and spillover of IL-6 and CXCL15 into the bronchoalveolar lavage fluids. In addition to increased gene expressions of α-smooth muscle actin and collagen 1α1, suggesting myofibroblast differentiation, TERC deficiency also leads to marked cellular infiltrations of a mononuclear cell population positive for the leukocyte common antigen CD45, low-affinity Fc receptor CD16/CD32, and pattern recognition receptor CD11b in the lungs. Our data demonstrate for the first time that telomerase deficiency triggers alveolar stem cell replicative senescence-associated low-grade inflammation, thereby driving pulmonary premature aging, alveolar sac formation, and fibrotic lesion.

Regulatory T cells in rheumatoid arthritis showed increased plasticity toward Th17 but retained suppressive function in peripheral blood.

OBJECTIVE: Regulatory T cells (Tregs) with the plasticity of producing proinflammatory cytokine IL-17 have been demonstrated under normal and pathogenic conditions. However, it remains unclear whether IL-17-producing Tregs lose their suppressive functions because of their plasticity toward Th17 in autoimmunity. The aim of this study was to investigate IL-17-producing Tregs from patients with rheumatoid arthritis (RA), and characterise their regulatory capacity and clinical significance. METHODS: Foxp3 and IL-17 coexpression were evaluated in CD4 T lymphocytes from RA patients. An in vitro T cell polarisation assay was performed to investigate the role of proinflammatory cytokines in IL-17-producing Treg polarisation. The suppressive function of IL-17-producing Tregs in RA was assessed by an in vitro suppression assay. The relationship between this Treg subset and clinical features in RA patients was analysed using Spearman's rank correlation test. RESULTS: A higher frequency of IL-17-producing Tregs was present in the peripheral blood of RA patients compared with healthy subjects. These cells from peripheral blood showed phenotypic characteristics of Th17 and Treg cells, and suppressed T cell proliferation in vitro. Tregs in RA synovial fluid lost suppressive function. The Th17 plasticity of Tregs could be induced by IL-6 and IL-23. An increased ratio of this Treg subset was associated with decreased levels of inflammatory markers, including the erythrocyte sedimentation rate and C-reactive protein level, in patients with RA. CONCLUSIONS: Increased levels of IL-17-producing Tregs were identified in RA patients. This Treg subset with Th17 plasticity in peripheral blood retained suppressive functions and was associated with milder inflammatory conditions, suggesting that this Treg population works as a negative regulator in RA, but in RA synovial site it may be pathogenic.

The polycomb group protein enhancer of zeste 2 is a novel therapeutic target for cervical cancer.

Enhancer of zeste 2 (EZH2), a polycomb histone methyltransferase, is overexpressed in various cancers, including cervical cancer. Gene expression analysis revealed that increased expression of EZH2 is associated with cervical cancer progression, particularly the progression to invasive squamous cell carcinoma. Enhancer of zeste 2 is known to trimethylate lysine 27 on histone H3, leading to gene silencing that contributes to the progression of tumours into a more aggressive form of cancer. However, the specific molecular mechanisms by which EZH2 contributes to the development of cervical cancer remain largely unknown. Recently, an EZH2 inhibitor was reported to selectively inhibit trimethylated lysine 27 on histone H3 and to reactivate silenced genes in cancer cells. In this study, we found that GSK343 (a specific inhibitor of EZH2 methyltransferase) induces phenotypic reprogramming of cancer cells from mesenchymal to epithelial cells, reducing proliferation and cell motility and blocking the invasion of cervical cancer cell lines both in vitro and in vivo. Treatment with the EZH2 inhibitor led to increased levels of the epithelial marker E-cadherin and decreased levels of mesenchymal markers such as N-cadherin and vimentin. The observed reprogramming is associated with restrained cervical cancer progression and provides direct evidence in support of EZH2 as a therapeutic target.

A miR-19 regulon that controls NF-κB signaling.

Fine-tuning of inflammatory responses by microRNAs (miRNAs) is complex, as they can both enhance and repress expression of pro-inflammatory mediators. In this study, we investigate inflammatory responses following global miRNA depletion, to better define the overall contribution of miRNAs to inflammation. We demonstrate that miRNAs positively regulate Toll-like receptor signaling using inducible Dicer1 deletion and global miRNA depletion. We establish an important contribution of miR-19b in this effect, which potentiates nuclear factor-κB (NF-κB) activity in human and mouse cells. Positive regulation of NF-κB signaling by miR-19b involves the coordinated suppression of a regulon of negative regulators of NF-κB signaling (including A20/Tnfaip3, Rnf11, Fbxl11/Kdm2a and Zbtb16). Transfection of miR-19b mimics exacerbated the inflammatory activation of rheumatoid arthritis primary fibroblast-like synoviocytes, demonstrating its physiological importance in the pathology of this disease. This study constitutes, to our knowledge, the first description of a miR-19 regulon that controls NF-κB signaling, and suggests that targeting this miRNA and linked family members could regulate the activity of NF-κB signaling in inflammation.

Identifying the Spatial Architecture That Restricts the Proximity of CD8+ T Cells to Tumor Cells in Pancreatic Ductal Adenocarcinoma.

The anti-tumor function of CD8+ T cells is dependent on their proximity to tumor cells. Current studies have focused on the infiltration level of CD8+ T cells in the tumor microenvironment, while further spatial information, such as spatial localization and inter-cellular communication, have not been defined. In this study, co-detection by indexing (CODEX) was designed to characterize PDAC tissue regions with seven protein markers in order to identify the spatial architecture that regulates CD8+ T cells in human pancreatic ductal adenocarcinoma (PDAC). The cellular neighborhood algorithm was used to identify a total of six conserved and distinct cellular neighborhoods. Among these, one unique spatial architecture of CD8+ T and CD4+ T cell-enriched neighborhoods enriched the majority of CD8+ T cells, but heralded a poor prognosis. The proximity analysis revealed that the CD8+ T cells in this spatial architecture were significantly closer to themselves and the CD4+ T cells than to the tumor cells. Collectively, we identified a unique spatial architecture that restricted the proximity of CD8+ T cells to tumor cells in the tumor microenvironment, indicating a novel immune evasion mechanism of pancreatic ductal adenocarcinoma in a topologically regulated manner and providing new insights into the biology of PDAC.