Transcription factors in colorectal cancer: molecular mechanism and therapeutic implications

Colorectal cancer (CRC) is a major cause of cancer mortality worldwide, however, the molecular mechanisms underlying the pathogenesis of CRC remain largely unclear. Recent studies have revealed crucial roles of transcription factors in CRC development. Transcription factors essential for the regulation of gene expression by interacting with transcription corepressor/enhancer complexes and they orchestrate downstream signal transduction. Deregulation of transcription factors is a frequent occurrence in CRC, and the accompanying drastic changes in gene expression profiles play fundamental roles in multistep process of tumorigenesis, from cellular transformation, disease progression to metastatic disease. Herein, we summarized current and emerging key transcription factors that participate in CRC tumorigenesis, and highlighted their oncogenic or tumor suppressive functions. Moreover, we presented critical transcription factors of CRC, emphasized the major molecular mechanisms underlying their effect on signal cascades associated with tumorigenesis, and summarized of their potential as molecular biomarkers for CRC prognosis therapeutic response, as well as drug targets for CRC treatment. A better understanding of transcription factors involved in the development of CRC will provide new insights into the pathological mechanisms and reveal novel prognostic biomarkers and therapeutic strategies for CRC.

The value of five blood markers in differentiating mycosis fungoides and Sézary syndrome: a validation cohort

BACKGROUND

Clinical and histological diagnosis of Sézary syndrome (SS) and mycosis fungoides (MF) is challenging in clinical routine.

OBJECTIVES

We investigated five blood markers previously described for SS (T-plastin, Twist, KIR3DL2, NKp46 and Tox) in a prospective validation cohort of patients.

METHODS

We included 447 patients in this study and 107 patients were followed up for prognosis. The markers were analysed by reverse transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) on peripheral blood leucocytes and CD4⁺ T cells in a cohort of consecutive patients with early MF, erythrodermic MF and SS and compared with patients presenting with benign inflammatory dermatoses (BID) and erythrodermic BID. The markers were assessed in parallel to gold standard values such as CD4/CD8 ratio, loss of CD7 and CD26 membrane expression and CD4 absolute values. Sensitivity and specificity were analysed by receiver operator characteristic curves. The prognostic value of selected markers was analysed on a subset of patients. This study was conducted in one centre.

RESULTS

We defined cut-off values for each marker. T-plastin, Twist and KIR3DL2 had the best validity. SS may be overrepresented. The combination of T-plastin and Twist was able to differentiate between erythrodermic MF or BID and SS. The additional analysis of KIR3DL2 may be useful to predict the prognosis.

CONCLUSIONS

We propose T-plastin, Twist and KIR3DL2 measured by RT-qPCR as new diagnostic markers for Sézary syndrome.

AKT1 E17K Inhibits Cancer Cell Migration by Abrogating β-Catenin Signaling

Mutational activation of the PI3K/AKT pathway is among the most common pro-oncogenic events in human cancers. The clinical utility of PI3K and AKT inhibitors has, however, been modest to date. Here, we used CRISPR-mediated gene editing to study the biological consequences of AKT1 E17K mutation by developing an AKT1 E17K-mutant isogenic system in a TP53-null background. AKT1 E17K expression under the control of its endogenous promoter enhanced cell growth and colony formation, but had a paradoxical inhibitory effect on cell migration and invasion. The mechanistic basis by which activated AKT1 inhibited cell migration and invasion was increased E-cadherin expression mediated by suppression of ZEB1 transcription via altered β-catenin subcellular localization. This phenotypic effect was AKT1-specific, as AKT2 activation had the opposite effect, a reduction in E-cadherin expression. Consistent with the opposing effects of AKT1 and AKT2 activation on E-cadherin expression, a pro-migratory effect of AKT1 activation was not observed in breast cancer cells with PTEN loss or expression of an activating PIK3CA mutation, alterations which induce the activation of both AKT isoforms. The results suggest that the use of AKT inhibitors in patients with breast cancer could paradoxically accelerate metastatic progression in some genetic contexts and may explain the frequent coselection for CDH1 mutations in AKT1-mutated breast tumors. IMPLICATIONS: AKT1 E17K mutation in breast cancer impairs migration/invasiveness via sequestration of β-catenin to the cell membrane leading to decreased ZEB1 transcription, resulting in increased E-cadherin expression and a reversal of epithelial-mesenchymal transition.

PIK3CA Is Regulated by CUX1, Promotes Cell Growth and Metastasis in Bladder Cancer via Activating Epithelial-Mesenchymal Transition

PIK3CA is a key component of phosphatidylinositol 3-kinase (PI3K) pathway that its involvement in tumorigenesis has been revealed by previous research. However, its functions and potential mechanisms in bladder cancer are still largely undiscovered. Tissue microarray (TMA) with 66 bladder cancer patients was surveyed via immunohistochemistry to evaluate the level of PIK3CA and CUX1 and we found upregulation of PIK3CA in bladder cancer tissue and patients with higher level of PIK3CA presented with poorer prognosis. Overly expressed PIK3CA promoted growth, migration, invasion, and metastasis of bladder cancer cells and knockdown of PIK3CA had the opposite effect. Gain-of-function and loss-of-function studies showed that PIK3CA expression was facilitated by CUX1, leading to activation of epithelial-mesenchymal transition (EMT), accompanied by upregulated expression of Snail, β-catenin, Vimentin and downregulated expression of E-cadherin in the bladder cancer cell lines. Besides, over-expressed CUX1 could restore the expression of downregulated Snail, β-catenin, Vimentin and E-cadherin which was induced by PIK3CA knockdown. These results revealed that PIK3CA overexpression in bladder cancer was regulated by the transcription factor CUX1, and PIK3CA exerted its biological effects by activating EMT.

PTEN and Other PtdIns(3,4,5)P3 Lipid Phosphatases in Breast Cancer

The phosphoinositide 3-kinase (PI3K)/AKT signalling pathway is hyperactivated in ~70% of breast cancers. Class I PI3K generates PtdIns(3,4,5)P₃ at the plasma membrane in response to growth factor stimulation, leading to AKT activation to drive cell proliferation, survival and migration. PTEN negatively regulates PI3K/AKT signalling by dephosphorylating PtdIns(3,4,5)P₃ to form PtdIns(4,5)P₂. PtdIns(3,4,5)P₃ can also be hydrolysed by the inositol polyphosphate 5-phosphatases (5-phosphatases) to produce PtdIns(3,4)P₂. Interestingly, while PTEN is a bona fide tumour suppressor and is frequently mutated/lost in breast cancer, 5-phosphatases such as PIPP, SHIP2 and SYNJ2, have demonstrated more diverse roles in regulating mammary tumourigenesis. Reduced PIPP expression is associated with triple negative breast cancers and reduced relapse-free and overall survival. Although PIPP depletion enhances AKT phosphorylation and supports tumour growth, this also inhibits cell migration and metastasis in vivo, in a breast cancer oncogene-driven murine model. Paradoxically, SHIP2 and SYNJ2 are increased in primary breast tumours, which correlates with invasive disease and reduced survival. SHIP2 or SYNJ2 overexpression promotes breast tumourigenesis via AKT-dependent and independent mechanisms. This review will discuss how PTEN, PIPP, SHIP2 and SYNJ2 distinctly regulate multiple functional targets, and the mechanisms by which dysregulation of these distinct phosphoinositide phosphatases differentially affect breast cancer progression.

Proteome-wide Analysis Reveals Substrates of E3 Ligase RNF146 Targeted for Degradation

Specific E3 ligases target tumor suppressors for degradation. Inhibition of such E3 ligases may be an important approach to cancer treatment. RNF146 is a RING domain and PARylation-dependent E3 ligase that functions as an activator of the β-catenin/Wnt and YAP/Hippo pathways by targeting the degradation of several tumor suppressors. Tankyrases 1 and 2 (TNKS1/2) are the only known poly-ADP-ribosyltransferases that require RNF146 to degrade their substrates. However, systematic identification of RNF146 substrates have not yet been performed. To uncover substrates of RNF146 that are targeted for degradation, we generated RNF146 knockout cells and TNKS1/2-double knockout cells and performed proteome profiling with label-free quantification as well as transcriptome analysis. We identified 160 potential substrates of RNF146, which included many known substrates of RNF146 and TNKS1/2 and 122 potential TNKS-independent substrates of RNF146. In addition, we validated OTU domain-containing protein 5 and Protein mono-ADP-ribosyltransferase PARP10 as TNKS1/2-independent substrates of RNF146 and SARDH as a novel substrate of TNKS1/2 and RNF146. Our study is the first proteome-wide analysis of potential RNF146 substrates. Together, these findings not only demonstrate that proteome profiling can be a useful general approach for the systemic identification of substrates of E3 ligases but also reveal new substrates of RNF146, which provides a resource for further functional studies.

Structure based peptide design, molecular dynamics and MM-PBSA studies for targeting C terminal dimerization of NFAT5 DNA binding domain

NFAT5 as a transcription factor with an established role in osmotic stress response, has also been revealed to be active under numerous settings, including pathological conditions such as diabetic microvascular complications, chronic arthritis and cancer. Despite these links, current strategies for downregulating NFAT5 activity only relies on indirect modulators, not directly targeting NFAT5, itself. With this study, through using a computational approach, an original peptide was explored to directly target C terminal dimerization of NFAT5 RHR, located in its DNA binding domain. At first, homodimeric NFAT5 RHR bound to its consensus DNA was used for prediction of a preliminary peptide sequence. Possible amino acid replacements for this preliminary peptide were predicted for optimization, which was followed by addition of a cell penetrating peptide sequence. These attempts yielded a small peptide library, which was further investigated for peptide affinities towards C terminal of NFAT5 RHR through molecular docking, 50 ns and 250 ns molecular dynamics simulations, followed by estimation of MM-PBSA based relative binding free energies. Results indicated that after receiving mutations on the preliminary peptide sequence for optimization, a unique peptide could target C terminal dimerization region of NFAT5 RHR through using its cell penetrating peptide sequence. In conclusion, this is the first study presenting computational evidence on identification of a novel peptide capable of directly targeting NFAT5 dimerization. Besides, future implications of these observations were also discussed in terms of methodology and possible applications.

NFAT Overexpression Correlates with CA72-4 and Poor Prognosis of Ovarian Clear-Cell Carcinoma Subtype

Current biomarkers did not overcome the limitations of clinical application due to the heterogeneity of ovarian tumors. The role of nuclear factor of activated T cells (NFAT) in the prognosis of different histological subtypes of ovarian cancer remains unclear. NFAT expression was analyzed in 302 ovarian tumors from The Cancer Genome Atlas (TCGA) dataset and was further confirmed by 88 ovarian tumor specimens, including 30 clear-cell carcinoma, 34 serous carcinoma, and 24 papillary serous cystadenocarcinoma. The correlations between NFAT expression, cancer biomarkers, and clinical characteristics in different subtypes of ovarian tumors were analyzed. ALGGEN PROMO, reporter assay, and NFAT overexpression and knockdown were used to identify chondroadherin (CHAD) as the downstream target of NFAT. NFAT was significantly upregulated only in late-stage clear-cell carcinoma, but not in other two subtypes. NFAT levels were correlated with CA72-4 levels and poor overall survival and disease-free survival (P < 0.05), suggesting that NFAT together with CA72-4 were specific prognostic markers for clear-cell carcinoma. Pathological stage and lymph node metastasis were the prognostic factors affecting serous carcinoma (P < 0.05), while CA-125 was the prognostic factor affecting papillary serous cystadenocarcinoma (P < 0.05). PROMO and reporter assay indicated that CHAD was the downstream target of NFAT. In addition, NFAT overexpression and silencing increased and reduced CHAD expression, respectively. NFAT together with CA72-4 were specific tumor markers for risk assessment of unique clear-cell subtype of ovarian tumors. CHAD was identified as the downstream target gene of NAFT and was associated with poor survival of ovarian cancer.

Genistein inhibits radiation-induced invasion and migration of glioblastoma cells by blocking the DNA-PKcs/Akt2/Rac1 signaling pathway

BACKGROUND AND PURPOSE

Radiotherapy is the most important therapeutic measure against glioblastoma multiforme (GBM), which is regarded as the most common and highly lethal type of brain cancer. Nevertheless, most relapses originate in the close vicinity of the irradiated target volume. Genistein is a natural product that can suppress the invasive potential of cancer cells. In this study, DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-proficient and -deficient GBM cells were selected for in vitro and in vivo studies to investigate the inhibiting effects of genistein on radiation-induced invasion and migration and the corresponding mechanism.

MATERIALS AND METHODS

GBM cell lines with or without genistein pre-treatment were irradiated with X-rays. Cell survival was determined using colony formation assay and the rate of cellular proliferation was analyzed with a real-time cell electronic sensing system. For in vitro study, invasion and migration abilities were evaluated via wound-healing and transwell assays, while protein expression was determined with western blotting. Genistein interaction with DNA-PKcs was estimated with pull-down, recombinant and binding assays. For in vivo study, cells were stereotactically injected into NOD-SCID mice to establish tumors. Hematoxylin and eosin and immunohistochemistry were used to assess the invasive potential of GBM.

RESULTS

X-ray irradiation enhanced the migration and invasion of DNA-PKcs-positive but not DNA-PKcs-negative GBM cells. It also activated the DNA-PKcs/Akt2/Rac1 signaling pathway, which contributed to GBM malignant progression by aggravating GBM cell invasive potential. The study successfully demonstrated that genistein can specifically bind to DNA-PKcs and block the DNA-PKcs/Akt2/Rac1 pathway, thereby effectively inhibiting radiation-induced invasion and migration of GBM cells in vitro and in vivo. The present study emphasized that radiation-induced invasive potential is initiated by DNA-PKcs, which is a well-known double strand breaks (DSB) repair protein, and determined the exact site for genistein binding to DNA-PKcs.

CONCLUSION

DNA-PKcs is not only a potential target for cancer therapy, but also a reliable biomarker for predicting radiation-induced invasion and migration of GBM cells. Thus, genistein might serve as a novel therapeutic strategy for treating GBM.

Posttranscriptional Gene Regulatory Networks in Chronic Airway Inflammatory Diseases: In silico Mapping of RNA-Binding Protein Expression in Airway Epithelium

Background: Posttranscriptional gene regulation (PTGR) contributes to inflammation through alterations in messenger RNA (mRNA) turnover and translation rates. RNA-binding proteins (RBPs) coordinate these processes but their role in lung inflammatory diseases is ill-defined. We evaluated the expression of a curated list of mRNA-binding RBPs (mRBPs) in selected Gene Expression Omnibus (GEO) transcriptomic databases of airway epithelium isolated from chronic obstructive pulmonary disease (COPD), severe asthma (SA) and matched control subjects, hypothesizing that global changes in mRBPs expression could be used to infer their pathogenetic roles and identify novel disease-related regulatory networks.

Methods: A published list of 692 mRBPs [Nat Rev Genet 2014] was searched in GEO datasets originated from bronchial brushings of stable COPD patients (C), smokers (S), non-smokers (NS) controls with normal lung function (n = 6/12/12) (GEO ID: GSE5058) and of (SA) and healthy control (HC) (n = 6/12) (GSE63142). Fluorescence intensity data were extracted and normalized on the medians for fold change (FC) comparisons. FCs were set at ≥ |1.5| with a false discovery rate (FDR) of ≤ 0.05. Pearson correlation maps and heatmaps were generated using tMEV tools v4_9_0.45. DNA sequence motifs were searched using PScan-ChIP. Gene Ontology (GO) was performed with Ingenuity Pathway Analysis (IPA) tool.

Results: Significant mRBP expression changes were detected for S/NS, COPD/NS and COPD/S (n = 41, 391, 382, respectively). Of those, 32% of genes changed by FC ≥ |1.5| in S/NS but more than 60% in COPD/NS and COPD/S (n = 13, 267, 257, respectively). Genes were predominantly downregulated in COPD/NS (n = 194, 73%) and COPD/S (n = 202, 79%), less so in S/NS (n = 4, 31%). Unsupervised cluster analysis identified in 4 out of 12 S the same mRBP pattern seen in C, postulating subclinical COPD. Significant DNA motifs enrichment for transcriptional regulation was found for downregulated RBPs. Correlation analysis identified five clusters of co-expressed mRBPs. GO analysis revealed significant enrichments in canonical pathways both specific and shared among comparisons. Unexpectedly, no significant mRBPs modulation was found in SA compared to controls.

Conclusions: Airway epithelial mRBPs profiling reveals a COPD-specific global downregulation of RBPs shared by a subset of control smokers, the potential of functional cooperation by coexpressed RBPs and significant impact on relevant pathogenetic pathways in COPD. Elucidation of PTGR in COPD could identify disease biomarkers or pathways for therapeutic targeting.

Effect of AKT1 (p. E17K) Hotspot Mutation on Malignant Tumorigenesis and Prognosis

The substitution of the seventeenth amino acid glutamate by lysine in the homologous structural domain of the Akt1 gene pleckstrin is a somatic cellular mutation found in breast, colorectal, and ovarian cancers, named p. Glu17Lys or E17K. In recent years, a growing number of studies have suggested that this mutation may play a unique role in the development of tumors. In this review article, we describe how AKT1(E17K) mutations stimulate downstream signals that cause cells to emerge transformed; we explore the differential regulation and function of E17K in different physiological and pathological settings; and we also describe the phenomenon that E17K impedes tumor growth by interfering with growth-promoting and chemotherapy-resistant AKT1^lowQCC generation, an intriguing finding that mutants may prolong tumor patient survival by activating feedback mechanisms and disrupting transcription. This review is intended to provide a better understanding of the role of AKT1(E17K) in cancer and to inform the development of AKT1(E17K)-based antitumor strategies.

Osteolytic metastasis in breast cancer: effective prevention strategies

INTRODUCTION

Breast cancer is the most common cancer in women throughout the world. Patients who are diagnosed early generally have better prognosis and survivability. Indeed, advanced stage breast cancer often develops osteolytic metastases, leading to bone destruction. Although there are select drugs available to treat bone metastatic disease, these drugs have shown limited success.

AREA COVERED

This paper emphasizes updated mechanisms of bone remodeling and osteolytic bone metastases of breast cancer. This article also aims to explore the potential of novel natural and synthetic therapeutics in the effective prevention of breast cancer-induced osteolysis and osteolytic metastases of breast cancer.

EXPERT OPINION

Targeting TGFβ and BMP signaling pathways, along with osteoclast activity, appears to be a promising therapeutic strategy in the prevention of breast cancer-induced osteolytic bone destruction and metastatic growth at bone metastatic niches. Pilot studies in animal models suggest various natural and synthetic compounds and monoclonal antibodies as putative therapeutics in the prevention of breast cancer stimulated osteolytic activity. However, comprehensive pre-clinical studies demonstrating the PK/PD and in-depth understanding of molecular mechanism(s) by which these potential molecules exhibit anti-tumor growth and anti-osteolytic activity are still required to develop effective therapies against breast cancer-induced osteolytic bone disease.

Gene Expression Comparison between Sézary Syndrome and Lymphocytic-Variant Hypereosinophilic Syndrome Refines Biomarkers for Sézary Syndrome

Sézary syndrome (SS), an aggressive cutaneous T-cell lymphoma (CTCL) with poor prognosis, is characterized by the clinical hallmarks of circulating malignant T cells, erythroderma and lymphadenopathy. However, highly variable clinical skin manifestations and similarities with benign mimickers can lead to significant diagnostic delay and inappropriate therapy that can lead to disease progression and mortality. SS has been the focus of numerous transcriptomic-profiling studies to identify sensitive and specific diagnostic and prognostic biomarkers. Benign inflammatory disease controls (e.g., psoriasis, atopic dermatitis) have served to identify chronic inflammatory phenotypes in gene expression profiles, but provide limited insight into the lymphoproliferative and oncogenic roles of abnormal gene expression in SS. This perspective was recently clarified by a transcriptome meta-analysis comparing SS and lymphocytic-variant hypereosinophilic syndrome, a benign yet often clonal T-cell lymphoproliferation, with clinical features similar to SS. Here we review the rationale for selecting lymphocytic-variant hypereosinophilic syndrome (L-HES) as a disease control for SS, and discuss differentially expressed genes that may distinguish benign from malignant lymphoproliferative phenotypes, including additional context from prior gene expression studies to improve understanding of genes important in SS.

CircFOXO3 promotes glioblastoma progression by acting as a competing endogenous RNA for NFAT5

BACKGROUND

Circular RNAs (circRNAs), a newly discovered type of endogenous noncoding RNA, have been proposed to mediate the progression of diverse types of tumors. Systematic studies of circRNAs have just begun, and the physiological roles of circRNAs remain largely unknown. Here, we focused on elucidating the potential role and molecular mechanism of circular forkhead box O3 (circFOXO3) in glioblastoma (GBM) progression.

METHODS

First, we analyzed circFOXO3 alterations in GBM and noncancerous tissues through real-time quantitative reverse transcription PCR (qRT-PCR). Next, we used loss- and gain-of-function approaches to evaluate the effect of circFOXO3 on GBM cell proliferation and invasion. Mechanistically, fluorescent in situ hybridization, RNA pull-down, dual luciferase reporter, and RNA immunoprecipitation assays were performed to confirm the interaction between circFOXO3 and miR-138-5p/miR-432-5p in GBM. An animal model was used to verify the in vitro experimental findings.

RESULTS

CircFOXO3 expression was significantly higher in GBM tissues than in noncancerous tissues. GBM cell proliferation and invasion were reduced by circFOXO3 knockdown and enhanced by circFOXO3 overexpression. Further biochemical analysis showed that circFOXO3 exerted its pro-tumorigenic activity by acting as a competing endogenous RNA (ceRNA) to increase expression of nuclear factor of activated T cells 5 (NFAT5) via sponging both miR-138-5p and miR-432-5p. Notably, tumor inhibition by circFOXO3 downregulation could be reversed by miR-138-5p/miR-432-5p inhibitors in GBM cells. Moreover, GBM cells with lower circFOXO3 expression developed less aggressive tumors in vivo.

CONCLUSIONS

Our data demonstrate that circFOXO3 can exert regulatory functions in GBM and that ceRNA-mediated microRNA sequestration might be a potential strategy for GBM therapy.

Profound Reprogramming towards Stemness in Pancreatic Cancer Cells as Adaptation to AKT Inhibition

Cancer cells acquire resistance to cytotoxic therapies targeting major survival pathways by adapting their metabolism. The AKT pathway is a major regulator of human pancreatic adenocarcinoma progression and a key pharmacological target. The mechanisms of adaptation to long-term silencing of AKT isoforms of human and mouse pancreatic adenocarcinoma cancer cells were studied. Following silencing, cancer cells remained quiescent for long periods of time, after which they recovered proliferative capacities. Adaptation caused profound proteomic changes largely affecting mitochondrial biogenesis, energy metabolism and acquisition of a number of distinct cancer stem cell (CSC) characteristics depending on the AKT isoform that was silenced. The adaptation to AKT1 silencing drove most de-differentiation and acquisition of stemness through C-MYC down-modulation and NANOG upregulation, which were required for survival of adapted CSCs. The changes associated to adaptation sensitized cancer cells to inhibitors targeting regulators of oxidative respiration and mitochondrial biogenesis. In vivo pharmacological co-inhibition of AKT and mitochondrial metabolism effectively controlled pancreatic adenocarcinoma growth in pre-clinical models.

Genetic and Epigenetic Modulation of Drug Resistance in Cancer: Challenges and Opportunities

Cancer is a complex disease that has the ability to develop resistance to traditional therapies. The current chemotherapeutic treatment has become increasingly sophisticated, yet it is not 100% effective against disseminated tumours. Anticancer drugs resistance is an intricate process that ascends from modifications in the drug targets suggesting the need for better targeted therapies in the therapeutic arsenal. Advances in the modern techniques such as DNA microarray, proteomics along with the development of newer targeted drug therapies might provide better strategies to overcome drug resistance. This drug resistance in tumours can be attributed to an individual's genetic differences, especially in tumoral somatic cells but acquired drug resistance is due to different mechanisms, such as cell death inhibition (apoptosis suppression) altered expression of drug transporters, alteration in drug metabolism epigenetic and drug targets, enhancing DNA repair and gene amplification. This review also focusses on the epigenetic modifications and microRNAs, which induce drug resistance and contributes to the formation of tumour progenitor cells that are not destroyed by conventional cancer therapies. Lastly, this review highlights different means to prevent the formation of drug resistant tumours and provides future directions for better treatment of these resistant tumours.

AP-1 activity induced by co-stimulation is required for chromatin opening during T cell activation

Activation of T cells is dependent on the organized and timely opening and closing of chromatin. Herein, we identify AP-1 as the transcription factor that directs most of this remodeling. Chromatin accessibility profiling showed quick opening of closed chromatin in naive T cells within 5 h of activation. These newly opened regions were strongly enriched for the AP-1 motif, and indeed, ChIP-seq demonstrated AP-1 binding at >70% of them. Broad inhibition of AP-1 activity prevented chromatin opening at AP-1 sites and reduced the expression of nearby genes. Similarly, induction of anergy in the absence of co-stimulation during activation was associated with reduced induction of AP-1 and a failure of proper chromatin remodeling. The translational relevance of these findings was highlighted by the substantial overlap of AP-1-dependent elements with risk loci for multiple immune diseases, including multiple sclerosis, inflammatory bowel disease, and allergic disease. Our findings define AP-1 as the key link between T cell activation and chromatin remodeling.

Intracellular Fate and Impact on Gene Expression of Doxorubicin/Cyclodextrin-Graphene Nanomaterials at Sub-Toxic Concentration

The graphene road in nanomedicine still seems very long and winding because the current knowledge about graphene/cell interactions and the safety issues are not yet sufficiently clarified. Specifically, the impact of graphene exposure on gene expression is a largely unexplored concern. Herein, we investigated the intracellular fate of graphene (G) decorated with cyclodextrins (CD) and loaded with doxorubicin (DOX) and the modulation of genes involved in cancer-associated canonical pathways. Intracellular fate of GCD@DOX, tracked by FLIM, Raman mapping and fluorescence microscopy, evidenced the efficient cellular uptake of GCD@DOX and the presence of DOX in the nucleus, without graphene carrier. The NanoString nCounter™ platform provided evidence for 34 (out of 700) differentially expressed cancer-related genes in HEp-2 cells treated with GCD@DOX (25 µg/mL) compared with untreated cells. Cells treated with GCD alone (25 µg/mL) showed modification for 16 genes. Overall, 14 common genes were differentially expressed in both GCD and GCD@DOX treated cells and 4 of these genes with an opposite trend. The modification of cancer related genes also at sub-cytotoxic G concentration should be taken in consideration for the rational design of safe and effective G-based drug/gene delivery systems. The reliable advantages provided by NanoString^® technology, such as sensibility and the direct RNA measurements, could be the cornerstone in this field.

Cross‑validation of genes potentially associated with neoadjuvant chemotherapy and platinum‑based chemoresistance in epithelial ovarian carcinoma

Ovarian carcinomas have the poorest prognosis and the highest mortality among gynecological malignancies. Neoadjuvant chemotherapy (NACT) is considered as a novel therapeutic strategy and an alternative treatment for advanced epithelial ovarian cancer (AEOC). The aim of the present study was to identify the core genes related to platinum‑based NACT resistance in AEOC and to allow screening at the molecular level for the most appropriate ovarian cancer patients for NACT. We obtained three drug‑resistant microarrays GSE114206, GSE41499 and GSE33482 from the Gene Expression Omnibus (GEO) database as well as a microarray representing NACT, GSE109934. Bioinformatics analysis revealed the nature of the four potential candidate genes for using in functional enrichment analyses and interaction network construction. The potential associations and possible genetic alterations among the DEGs were summarized using the STRING database in Cytoscape and the cBioPortal visualization tool, respectively. A total of 63 genes were identified as DEGs from GSE109934 representing NACT. From the drug‑resistant GSE114206 and GSE41499 datasets, 106 DEGs containing 36 upregulated genes and 70 downregulated genes were selected, and from the drug‑resistant GSE114206 and GSE33482 datasets, 406 DEGs with 157 upregulated genes and 249 downregulated genes were selected. The 36 upregulated DEGs and the 70 downregulated genes were notably abundant in the different categories. In KEGG pathway analysis, the 157 upregulated genes and the 249 downregulated genes were concentrated in distinctive signaling pathways. Four potential genes associated with NACT and platinum‑based chemoresistance were screened, including nuclear factor of activated T‑cells, cytoplasmic 1 (NAFTc1), Kruppel‑like factor 4 (KLF4), nuclear receptor subfamily 4 group A member 3 (NR4A3) and hepatocyte growth factor (HGF). Our study showed that the mRNA expression levels of NAFTc1, NR4A3 and HGF were increased in drug‑resistant OC cell lines (all P<0.01), whereas the mRNA expression levels of KLF4 were notably lower in the SKOV3‑CDDP and HeyA8‑CDDP cell line (all P<0.01) but higher in the A2780‑CBP cell line. The NAFTc1, KLF4, NR4A3 and HGF genes may be potential therapeutic targets for NACT and platinum‑based chemoresistance factors as well as candidate biomarkers in AEOC. Determination of the expression levels of these four genes in tumor tissues before planning NACT treatment or initial surgery would be beneficial for AEOC patients.

Implications of lipid droplets in lung cancer: Associations with drug resistance

Cancer cells usually show different metabolic patterns compared with healthy cells due to the reprogramming of metabolic processes. The process of lipid metabolism undergoes notable changes, leading to the accumulation of lipid droplets in cells. Additionally, this phenotype is considered an important marker of cancer cells. Lipid droplets are a highly dynamic type of organelle in the cell, which is composed of a neutral lipid core, a monolayer phospholipid membrane and lipid droplet-related proteins. Lipid droplets are involved in several biological processes, including cell proliferation, apoptosis, lipid metabolism, stress, immunity, signal transduction and protein trafficking. Epidermal growth factor receptor (EGFR)-activating mutations are currently the most effective therapeutic targets for non-small cell lung cancer. Several EGFR tyrosine kinase inhibitors (EGFR-TKIs) that target these mutations, including gefitinib, erlotinib, afatinib and osimertinib, have been widely used clinically. However, the development of acquired resistance has a major impact on the efficacy of these drugs. A number of previous studies have reported that the expression of lipid droplets in the tumor tissues of patients with lung cancer are elevated, whereas the association between elevated numbers of lipid droplets and drug resistance has received little attention. The present review describes the potential association between lipid droplets and drug resistance. Furthermore, the mechanisms and implications of lipid droplet accumulation in cancer cells are analyzed, as wells as the mechanism by which lipid droplets suppress endoplasmic reticulum stress and apoptosis, which are essential for the development and treatment of lung cancer.

Extracellular vesicles produced by NFAT3-expressing cells hinder tumor growth and metastatic dissemination

Metastases are the main cause of cancer-induced deaths worldwide. To block tissue invasion, development of extracellular vesicles (EVs) as therapeutic carriers, appears as an exciting challenge. To this aim, we took advantage of the anti-invasive function of NFAT3 transcription factor we identified previously in breast cancer and addressed the opportunity to transfer this inhibitory function by EVs. We show here that EVs produced by poorly invasive NFAT3-expressing breast cancer cell lines are competent to block in vitro invasion of aggressive cancer cells from different origins and, in cooperation with macrophages, inhibit cell proliferation and induce apoptosis. Moreover, this inhibitory effect can be improved by overexpression of NFAT3 in the EVs-producing cells. These results were extended in a mouse breast cancer model, with clear impact of inhibitory EVs on tumor growth and metastases spreading. This work identifies EVs produced by NFAT3-expressing breast cancer cells as an anti-tumoral tool to tackle cancer development and metastases dissemination.

Recurrent Amplification of the Osmotic Stress Transcription Factor NFAT5 in Adrenocortical Carcinoma

Tumorigenesis requires mitigation of osmotic stress and the transcription factor nuclear factor of activated T cells 5 (NFAT5) coordinates this response by inducing transcellular transport of ions and osmolytes. NFAT5 modulates in vitro behavior in several cancer types, but a potential role of NFAT5 in adrenocortical carcinoma (ACC) has not been studied. A discovery cohort of 28 ACCs was selected for analysis. Coverage depth analysis of whole-exome sequencing reads assessed NFAT5 copy number alterations in 19 ACCs. Quantitative real-time PCR measured NFAT5 mRNA expression levels in 11 ACCs and 23 adrenocortical adenomas. Immunohistochemistry investigated protein expression in representative adrenal samples. The Cancer Genome Atlas database was analyzed to corroborate NFAT5 findings from the discovery cohort and to test whether NFAT5 expression correlated with ion/osmolyte channel and regulatory protein expression patterns in ACC. NFAT5 was amplified in 10 ACCs (52.6%) and clustered in the top 6% of all amplified genes. mRNA expression levels were 5-fold higher compared with adrenocortical adenomas (P < 0.0001) and NFAT5 overexpression had a sensitivity and specificity of 81.8% and 82.7%, respectively, for malignancy. Increased protein expression and nuclear localization occurred in representative ACCs. The Cancer Genome Atlas analysis demonstrated concomitant NFAT5 amplification and overexpression (P < 0.0001) that correlated with increased expression of sodium/myo-inositol transporter SLC5A3 (r² = 0.237, P < 0.0001) and 14 other regulatory proteins (P < 0.05) previously shown to interact with NFAT5. Amplification and overexpression of NFAT5 and associated osmotic stress response related genes may play an important role adrenocortical tumorigenesis.

Identification of prognostic biomarkers and drug target prediction for colon cancer according to a competitive endogenous RNA network

Colorectal cancer is one of the commoner digestive tract malignant tumor types, and its incidence and mortality rate are high. Accumulating evidence indicates that long‑chain non‑coding RNAs (lncRNAs) and protein‑coding RNAs interact with each other by competing with the same micro(mi)RNA response element (MREs) and serve an important role in the regulation of gene expression in a variety of tumor types. However, the regulatory mechanism and prognostic role of lncRNA‑mediated competing endogenous (ce)RNA networks in colon cancer have yet to be elucidated. The expression profiles of mRNAs, lncRNAs and miRNAs from 471 colon cancer and 41 paracancerous tissue samples were downloaded from The Cancer Genome Atlas database. A lncRNA‑miRNA‑mRNA ceRNA network in colon cancer was constructed and comprised 17 hub lncRNAs, 87 hub miRNA and 144 hub mRNAs. The topological properties of the network were analyzed, and the random walk algorithm was used to identify the nodes significantly associated with colon cancer. Survival analysis using the UALCAN database indicated that 2/17 lncRNAs identified [metastasis‑associated lung adenocarcinoma transcript (MALAT1) and maternally expressed gene 3 (MEG3)] and 5/144 mRNAs [FES upstream region (FURIN), nuclear factor of activated T‑cells 5 (NFAT5), RNA Binding Motif Protein 12B (RBM12B), Ras related GTP binding A (RRAGA) and WD repeat domain phosphoinositide‑interacting protein 2 (WIPI2)] were significantly associated with the overall survival of patients with colon cancer, and may therefore be used as potential prognostic biomarkers of colon cancer. According to extracted lncRNA‑miRNA‑mRNA interaction pairs, the GSE26334 dataset was used to confirm that the lncRNA MALAT1/miR‑129‑5p/NFAT5 axis may represent a novel regulatory mechanism concerning the progression of colon cancer. The clusterProfiler package was used to analyze Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in colon cancer. Finally, drugs that significantly interact with the core genes identified in colon cancer were predicted using a hypergeometric test. Of these, fostamatinib was identified to be a targeted drug for colon cancer therapy. The present findings provide a novel perspective for improved understanding of the lncRNA‑associated ceRNA network and may facilitate the development of novel targeted therapeutics in colon cancer.

Osteogenesis imperfecta mutations in plastin 3 lead to impaired calcium regulation of actin bundling

Mutations in actin-bundling protein plastin 3 (PLS3) emerged as a cause of congenital osteoporosis, but neither the role of PLS3 in bone development nor the mechanisms underlying PLS3-dependent osteoporosis are understood. Of the over 20 identified osteoporosis-linked PLS3 mutations, we investigated all five that are expected to produce full-length protein. One of the mutations distorted an actin-binding loop in the second actin-binding domain of PLS3 and abolished F-actin bundling as revealed by cryo-EM reconstruction and protein interaction assays. Surprisingly, the remaining four mutants fully retained F-actin bundling ability. However, they displayed defects in Ca2+ sensitivity: two of the mutants lost the ability to be inhibited by Ca2+, while the other two became hypersensitive to Ca2+. Each group of the mutants with similar biochemical properties showed highly characteristic cellular behavior. Wild-type PLS3 was distributed between lamellipodia and focal adhesions. In striking contrast, the Ca2+-hyposensitive mutants were not found at the leading edge but localized exclusively at focal adhesions/stress fibers, which displayed reinforced morphology. Consistently, the Ca2+-hypersensitive PLS3 mutants were restricted to lamellipodia, while chelation of Ca2+ caused their redistribution to focal adhesions. Finally, the bundling-deficient mutant failed to co-localize with any F-actin structures in cells despite a preserved F-actin binding through a non-mutation-bearing actin-binding domain. Our findings revealed that severe osteoporosis can be caused by a mutational disruption of the Ca2+-controlled PLS3's cycling between adhesion complexes and the leading edge. Integration of the structural, biochemical, and cell biology insights enabled us to propose a molecular mechanism of plastin activity regulation by Ca2+.

Metabolomics and lipidomics study unveils the impact of polybrominated diphenyl ether-47 on breast cancer mice

Polybrominated diphenyl ether-47 (BDE-47) is a congener of polybrominated diphenyl ethers (PBDEs) and relates to different health risks. However, in vivo study of the association between BDE-47 and breast cancer was scarce. In this study, we performed in vivo exposure of BDE-47 to breast cancer nude mice and conducted mass spectrometry-based metabolomics and lipidomics analysis to investigate the metabolic changes in mice. Results showed that the tumor sizes were positively associated with the dosage of BDE-47. Metabolomics and lipidomics profiling analysis indicated that BDE-47 induced significant alterations of metabolic pathways in livers, including glutathione metabolism, ascorbate and aldarate metabolism, and lipids metabolism, etc. The upregulations of phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) suggested the membrane remodeling, and the downregulations of Lyso-PCs and Lyso-PEs might be associated with the tumor growth. Targeted metabolomics analysis revealed that BDE-47 inhibited fatty acid β-oxidation (FAO) and induced incomplete FAO. The inhibition of FAO and downregulation of PPARγ would contribute to inflammation, which could promote tumor growth. In addition, BDE-47 elevated the expression of the cytokines TNFRSF12A, TNF-α, IL-1β and IL-6, and lowered the cytokines SOCS3 and the nuclear receptor PPARα. The changes of cytokines and receptor may contribute to the tumor growth of mice.

Two Birds with One Stone: NFAT1-MDM2 Dual Inhibitors for Cancer Therapy

The tumor suppressor p53 is believed to be the mostly studied molecule in modern biomedical research. Although p53 interacts with hundreds of molecules to exert its biological functions, there are only a few modulators regulating its expression and function, with murine double minute 2 (MDM2) playing a key role in this regard. MDM2 also contributes to malignant transformation and cancer development through p53-dependent and -independent mechanisms. There is an increasing interest in developing MDM2 inhibitors for cancer prevention and therapy. We recently demonstrated that the nuclear factor of activated T cells 1 (NFAT1) activates MDM2 expression. NFAT1 regulates several cellular functions in cancer cells, such as cell proliferation, migration, invasion, angiogenesis, and drug resistance. Both NFAT isoforms and MDM2 are activated and overexpressed in several cancer subtypes. In addition, a positive correlation exists between NFAT1 and MDM2 in tumor tissues. Our recent clinical study has demonstrated that high expression levels of NFAT1 and MDM2 are independent predictors of a poor prognosis in patients with hepatocellular carcinoma. Thus, inhibition of the NFAT1-MDM2 pathway appears to be a novel potential therapeutic strategy for cancer. In this review, we summarize the potential oncogenic roles of MDM2 and NFAT1 in cancer cells and discuss the efforts of discovery and the development of several newly identified MDM2 and NFAT1 inhibitors, focusing on their potent in vitro and in vivo anticancer activities. This review also highlights strategies and future directions, including the need to focus on the development of more specific and effective NFAT1-MDM2 dual inhibitors for cancer therapy.

Cyclooxygenase 2-Regulated Genes an Alternative Avenue to the Development of New Therapeutic Drugs for Colorectal Cancer

Colorectal cancer (CRC) is one of the most common and recurrent types of cancer, with high mortality rates. Several clinical trials and meta-analyses have determined that the use of pharmacological inhibitors of cyclooxygenase 2 (COX-2), the enzyme that catalyses the rate-limiting step in the synthesis of prostaglandins (PG) from arachidonic acid, can reduce the incidence of CRC as well as the risk of recurrence of this disease, when used together with commonly used chemotherapeutic agents. These observations suggest that inhibition of COX-2 may be useful in the treatment of CRC, although the current drugs targeting COX-2 are not widely used since they increase the risk of health complications. To overcome this difficulty, a possibility is to identify genes regulated by COX-2 activity that could give an advantage to the cells to form tumors and/or metastasize. The modulation of those genes as effectors of COX-2 may cancel the beneficial effects of COX-2 in tumor transformation and metastasis. A review of the available databases and literature and our own data have identified some interesting molecules induced by prostaglandins or COX-2 that have been also described to play a role in colon cancer, being thus potential pharmacological targets in colon cancer. Among those mPGES-1, DUSP4, and 10, Programmed cell death 4, Trop2, and many from the TGFβ and p53 pathways have been identified as genes upregulated in response to COX-2 overexpression or PGs in colon carcinoma lines and overexpressed in colon tumor tissue. Here, we review the available evidence of the potential roles of those molecules in colon cancer in the context of PG/COX signaling pathways that could be critical mediators of some of the tumor growth and metastasis advantage induced by COX-2. At the end, this may allow defining new therapeutic targets/drugs against CRC that could act specifically against tumor cells and would be effective in the prevention and treatment of CRC, lacking the unwanted side effects of COX-2 pharmacological inhibitors, providing alternative approaches in colon cancer.

miR-29c-3p inhibits microglial NLRP3 inflammasome activation by targeting NFAT5 in Parkinson's disease

Microglial inflammation is identified as a key process associated with Parkinson's disease (PD) pathogenesis. Our previous study showed that miR-29c-3p (miR-29c) exhibited anti-inflammatory properties in PD animal and neuronal models. However, the specific role and regulatory mechanism of miR-29c played in microglia are still unclear. In this study, lipopolysaccharide (LPS)-stimulated BV-2 cells were used to establish a cellular model of microglial activation for investigating PD. The results showed a decreased expression of miR-29c in LPS-induced BV-2 cells. Over-expression of miR-29c suppressed LPS-triggered Iba-1 increment, pro-inflammatory cytokine release, and NF-кB and TXNIP/NLRP3 inflammasome activation. Silence of miR-29c induced similar effects with LPS on microglial inflammation. In addition, we found that NFAT5 was negatively correlated with miR-29c. Knockdown of NFAT5 blocked the aggravated inflammation in microglia treated by miR-29c inhibitor. Thus, these findings suggest that miR-29c modulates NLRP3 inflammasome to impair microglial inflammatory responses by targeting NFAT5, which represents a promising therapeutic target for PD.

Inhibition of NFAT Signaling Restores Microvascular Endothelial Function in Diabetic Mice

Central to the development of diabetic macro- and microvascular disease is endothelial dysfunction, which appears well before any clinical sign but, importantly, is potentially reversible. We previously demonstrated that hyperglycemia activates nuclear factor of activated T cells (NFAT) in conduit and medium-sized resistance arteries and that NFAT blockade abolishes diabetes-driven aggravation of atherosclerosis. In this study, we test whether NFAT plays a role in the development of endothelial dysfunction in diabetes. NFAT-dependent transcriptional activity was elevated in skin microvessels of diabetic Akita (Ins2 ^+/- ) mice when compared with nondiabetic littermates. Treatment of diabetic mice with the NFAT blocker A-285222 reduced NFATc3 nuclear accumulation and NFAT-luciferase transcriptional activity in skin microvessels, resulting in improved microvascular function, as assessed by laser Doppler imaging and iontophoresis of acetylcholine and localized heating. This improvement was abolished by pretreatment with the nitric oxide (NO) synthase inhibitor l-N ^G-nitro-l-arginine methyl ester, while iontophoresis of the NO donor sodium nitroprusside eliminated the observed differences. A-285222 treatment enhanced dermis endothelial NO synthase expression and plasma NO levels of diabetic mice. It also prevented induction of inflammatory cytokines interleukin-6 and osteopontin, lowered plasma endothelin-1 and blood pressure, and improved mouse survival without affecting blood glucose. In vivo inhibition of NFAT may represent a novel therapeutic modality to preserve endothelial function in diabetes.

ZIC2 is downregulated and represses tumor growth via the regulation of STAT3 in breast cancer

Although early detection and systemic therapies have improved the diagnosis and clinical cure rate of breast cancer, breast cancer remains the most frequently occurring malignant cancer in women due to a lack of sufficiently effective treatments. Thus, to develop potential targeted therapies and thus benefit more patients, it is helpful to understand how cancer cells work. ZIC family members have been shown to play important roles in neural development and carcinogenesis. In our study, we found that ZIC2 is downregulated in breast cancer tissues at both the mRNA and protein levels. Low expression of ZIC2 was correlated with poor outcome in breast cancer patients and serves as an independent prognostic marker. Furthermore, overexpression of ZIC2 repressed, whereas knockdown of ZIC2 promoted, cell proliferation and colony formation ability in vitro and tumor growth in vivo. Using ChIP-seq and RNA-seq analysis, we screened and identified STAT3 as a potential target for ZIC2. ZIC2 bound to the STAT3 promoter and repressed the promoter activities of STAT3. ZIC2 knockdown induced the expression of STAT3, increasing the level of phosphorylated STAT3. These results suggest that ZIC2 regulates the transcription of STAT3 by directly binding to the STAT3 promoter. Additionally, interfering STAT3 with siRNAs or inhibitors abrogated the oncogenic effects induced by decreased ZIC2. Taken together, our results indicate that ZIC2 serves as a useful prognostic marker in breast cancer and acts as a tumor suppressor by regulating STAT3, implying that STAT3 inhibitors might provide an alternative treatment option for breast cancer patients with ZIC2 downregulation.

Co-expression of glycosylated aquaporin-1 and transcription factor NFAT5 contributes to aortic stiffness in diabetic and atherosclerosis-prone mice

Increased stiffness characterizes the early change in the arterial wall with subclinical atherosclerosis. Proteins inducing arterial stiffness in diabetes and hypercholesterolaemia are largely unknown. This study aimed at determining the pattern of protein expression in stiffening aorta of diabetic and hypercholesterolaemic mice. Male Ins^2+/Akita mice were crossbred with ApoE^−/− (Ins^2+/Akita: ApoE^−/−) mice. Relative aortic distension (relD) values were determined by ultrasound analysis and arterial stiffness modulators by immunoblotting. Compared with age‐ and sex‐matched C57/BL6 control mice, the aortas of Ins^2+/Akita, ApoE^−/− and Ins^2+/Akita:ApoE^−/− mice showed increased aortic stiffness. The aortas of Ins^2+/Akita, ApoE^−/− and Ins^2+/Akita:ApoE^−/− mice showed greater expression of VCAM‐1, collagen type III, NADPH oxidase and iNOS, as well as reduced elastin, with increased collagen type III‐to‐elastin ratio. The aorta of Ins^2+/Akita and Ins^2+/Akita:ApoE^−/− mice showed higher expression of eNOS and cytoskeletal remodelling proteins, such as F‐actin and α‐smooth muscle actin, in addition to increased glycosylated aquaporin (AQP)‐1 and transcription factor NFAT5, which control the expression of genes activated by high glucose‐induced hyperosmotic stress. Diabetic and hypercholesterolaemic mice have increased aortic stiffness. The association of AQP1 and NFAT5 co‐expression with aortic stiffness in diabetes and hypercholesterolaemia may represent a novel molecular pathway or therapeutic target.

Implication and role of neutrophil gelatinase-associated lipocalin in cancer: lipocalin-2 as a potential novel emerging comprehensive therapeutic target for a variety of cancer types

Cancer is a leading cause of mortalities worldwide. Over the past few decades, exploration of molecular mechanisms behind cancer initiation and progression has been of great interest in the viewpoint of both basic and clinical scientists. It is generally believed that identification of key molecules implicated in cancer pathology not only improves our understanding of the disease, but also could result in introduction of novel therapeutic strategies. Neutrophil gelatinase-associated lipocalin (NGAL)/lipocalin-2 (LCN2) is a member of lipocalin superfamily with a variety of functions. Although the main function of LCN2 is still unknown, many studies confirmed its significant role in the initiation, progression, and metastasis of various types of cancer. Furthermore, aberrant expression of LCN2 is also concerned with the chemo- and radio-resistant phenotypes of tumors. Here, we will review the contribution of known functions of LCN2 to the pathophysiology of cancer. We also highlight how the deregulated expression of LCN2 is associated with a variety of fatal types of cancer for which there are no effective therapeutic modalities. The unique and multiple functions of LCN2 and its widespread expression in different types of cancer prompted us to suggest LCN2 could be considered either as a valuable diagnostic and prognostic biomarker or as a potential novel therapeutic target.

Gliomas display distinct sex-based differential methylation patterns based on molecular subtype

Background

Gliomas are the most common type of primary brain tumor and one of many cancers where males are diagnosed with greater frequency than females. However, little is known about the sex-based molecular differences in glioblastomas (GBMs) or lower grade glioma (non-GBM) subtypes. DNA methylation is an epigenetic mechanism involved in regulating gene transcription. In glioma and other cancers, hypermethylation of specific gene promoters downregulates transcription and may have a profound effect on patient outcome. The purpose of this study was to determine if sex-based methylation differences exist in different glioma subtypes.

Methods

Molecular and clinical data from glioma patients were obtained from The Cancer Genome Atlas and grouped according to tumor grade and molecular subtype (IDH1/2 mutation and 1p/19q chromosomal deletion). Sex-specific differentially methylated probes (DMPs) were identified in each subtype and further analyzed to determine if they were part of differentially methylated regions (DMRs) or associated with differentially methylated DNA transcription regulatory binding motifs.

Results

Analysis of methylation data in 4 glioma subtypes revealed unique sets of both sex-specific DMPs and DMRs in each subtype. Motif analysis based on DMP position also identified distinct sex-based sets of DNA-binding motifs that varied according to glioma subtype. Downstream targets of 2 of the GBM-specific transcription binding sites, NFAT5 and KLF6, showed differential gene expression consistent with increased methylation mediating downregulation.

Conclusion

DNA methylation differences between males and females in 4 glioma molecular subtypes suggest an important, sex-specific role for DNA methylation in epigenetic regulation of gliomagenesis.

Identification of novel interacting regions involving calcineurin and nuclear factor of activated T cells

Nuclear factor of activated T cells (NFAT) leads to the transcription of diverse inducible genes involved in many biological processes; therefore, aberrant NFAT expression is responsible for the development and exacerbation of various disorders. Since five isoforms of NFAT (NFATc1-c4, NFAT5) exhibit distinct and overlapping functions, selective control of a part, but not all, of NFAT family members is desirable. By comparing the binding activity of each NFATc1-c4 with its regulatory enzyme, calcineurin (CN), using a quantitative immunoprecipitation assay, we found a new CN-binding region (CNBR) selectively functioning in NFATc1 and NFATc4. This region, termed CNBR3, is located between two preexisting CNBR1 and CNBR2, within the Ca²⁺ regulatory domain. The nuclear translocation of NFATc1 but not NFATc2 in T cells was suppressed by ectopic expression of CNBR3 and, accordingly, NFATc1-dependent cytokine expression was downregulated. Through competition assays using NFATc1-derived partial peptides and mass spectrometry with photoaffinity technology, we identified 18 amino acids in NFATc1 (Arg²⁵⁸ to Pro²⁷⁵ ) and 13 amino acids in CN catalytic subunit (CNA) (Asn⁷⁷ to Gly⁸⁹ ) responsible for CNA/CNBR3 binding in which Cys²⁶³ and Asp⁸² , respectively, played crucial roles. The possible selective regulation of NFAT-mediated biological processes by targeting this new CN/NFAT-binding region is suggested.

Inflammatory bowel disease-associated ubiquitin ligase RNF183 promotes lysosomal degradation of DR5 and TRAIL-induced caspase activation

RNF183 is a ubiquitin ligase containing RING-finger and transmembrane domains, and its expression levels are increased in patients with inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, and in 2,4,6-trinitrobenzene sulfonic acid-induced colitis mice. Here, we further demonstrate that RNF183 was induced to a greater degree in the dextran sulfate sodium (DSS)-treated IBD model at a very early stage than were inflammatory cytokines. In addition, fluorescence-activated cell sorting and polymerase chain reaction analysis revealed that RNF183 was specifically expressed in epithelial cells of DSS-treated mice, which suggested that increased levels of RNF183 do not result from the accumulation of immune cells. Furthermore, we identified death receptor 5 (DR5), a member of tumour necrosis factor (TNF)-receptor superfamily, as a substrate of RNF183. RNF183 mediated K63-linked ubiquitination and lysosomal degradation of DR5. DR5 promotes TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis signal through interaction with caspase-8. Inhibition of RNF183 expression was found to suppress TRAIL-induced activation of caspase-8 and caspase-3. Thus, RNF183 promoted not only DR5 transport to lysosomes but also TRAIL-induced caspase activation and apoptosis. Together, our results provide new insights into potential roles of RNF183 in DR5-mediated caspase activation in IBD pathogenesis.

Relationship between polycomb-group protein BMI-1 and phosphatases regulating AKT phosphorylation level in endometrial cancer

The PI3K/AKT pathway is frequently activated in endometrial carcinoma. BMI‐1 (B‐lymphoma Mo‐MLV insertion region 1) protein affects expression of PTEN (phosphatase and tensin homolog) in some cancers, but its significance for endometrial tumorigenesis is not known. The objective of this study was to determine the relationship between BMI‐1 and expression of factors affecting AKT (protein kinase B) phosphorylation level in endometrial cancer. The expression of proteins and mRNAs was investigated in endometrial cancer specimens and samples of non‐neoplastic endometrial tissue by Western blot and RT‐PCR, respectively. The impact of BMI‐1 down‐regulation on AKT phosphorylation and expression of genes coding for several phosphatases were studied in HEC1A cells. The results showed that BMI‐1 depletion caused increase in PHLPP1 and PHLPP2 (PH domain and leucine‐rich repeat protein phosphatases 1/2) expression and decrease in phospho‐AKT (pAKT) level. In more advanced tumours with higher metastatic potential, the expression of BMI‐1 was lower compared to tumours less advanced and without lymph node metastasis. There were significant inverse correlations between BMI‐1 and PHLPPs, especially PHLPP1 in normal endometrial samples. The inverse correlation between BMI‐1 and PHLPP1/PHLPP2 expression was observed in PTEN positive but not PTEN negative cancers. Low PHLPP2 expression in tumours predicted poorer overall survival. BMI‐1 impacts on AKT phosphorylation level in endometrial cells by regulation of PHLPP expression.

MiR-338 regulates NFATc1 expression and inhibits the proliferation and epithelial-mesenchymal transition of human non-small-cell lung cancer cells

BACKGROUND

It is well known that nuclear factor of activated T cells c1 (NFATc1) expression is closely associated with progression of many cancers. And we found that miR-338 could directly target the NFATc1. However, the precise mechanisms of miR-338 in non-small-cell lung cancer (NSCLC) have not been well clarified. Our study aimed to explore the interaction between NFATc1 and miR-338 in NSCLC.

METHODS

Quantitative RT-PCR was utilized to determine the expressions of NFATc1 and miR-338 in NSCLC tissues and cell lines. And the cell proliferation and epithelial-mesenchymal transition (EMT) were assessed to determine the functional roles of miR-338 and NFATc1 in NSCLC cells. NFATc1 expression was detected using quantitative RT-PCR and western blotting, respectively. Luciferase reporter assays were performed to validate NFATc1 as a target of miR-338 in NSCLC cells.

RESULTS

In this study, our results showed that NFATc1 expression was significantly up-regulated in NSCLC tissues and cell lines, and the miR-338 level was dramatically down-regulated. Moreover high NFATc1 expression was closely associated with low miR-338 level in NSCLC tissues. Moreover introduction of miR-338 significantly inhibited proliferation and EMT of NSCLC cells. Bioinformatics analysis predicted that the NFATc1 was a potential target gene of miR-338. We demonstrated that miR-338 could directly target NFATc1 by using luciferase reporter assay. Besides, knockdown of NFATc1 had the similar effects with miR-338 overexpression on NSCLC cells. Up-regulation of NFATc1 in NSCLC cells partially abolished the inhibitory effects of miR-338 mimic.

CONCLUSIONS

Overexpression of miR-338 inhibited cell proliferation and EMT of NSCLC cells by directly down-regulating NFATc1 expression.

Arsenic sulfide induces RAG1-dependent DNA damage for cell killing by inhibiting NFATc3 in gastric cancer cells

Background

Arsenic sulfide was found to have potential anti-cancer activities, especially in gastric cancer. However, the underlying mechanism need to be further explored. This study was aimed to investigate the mechanism of arsenic compounds on gastric cancer.

Methods

Gastric cancer cell lines were infected with lentiviral vector carrying shNFATc3 and/or treated with arsenic sulfide. MTT assay were performed to assess cell growth. Flow cytometer assays were used to detect cell cycle and reactive oxygen species (ROS) level of gastric cancer cells. Western blot was carried out to detect nuclear factor of activated T-cells, cytoplasmic 3 (NFATc3), cell cycle markers, DNA damage pathway protein expression as well as other protein expression in gastric cancer cell lines. The expression of recombination activating gene 1 (RAG1) in gastric cancer cell lines was determined by RNA-sequencing analyses and Real-Time qPCR. The effect of NFATc3 on RAG1 were determined by CHIP-qPCR assay. The effect of arsenic sulfide on AGS cells was evaluated in vivo.

Results

We show that arsenic sulfide as well as knockdown of NFATc3 resulted in increased double-strand DNA damage in gastric cancer cells by increasing the expression of RAG1, an endonuclease essential for immunoglobulin V(D) J recombination. Overexpression of NFATc3 blocked the expression of RAG1 expression and DNA damage induced by arsenic sulfide. Arsenic sulfide induced cellular oxidative stress to redistribute NFATc3, thereby inhibiting its transcriptional function, which can be reversed by N-acetyl-L-cysteine (NAC). We show that NFATc3 targets the promoter of RAG1 for transcriptional inhibition. We further showed that NFATc3 upregulation and RAG1 downregulation significantly associated with poor prognosis in patients with gastric cancer. Our in vivo experiments further confirmed that arsenic sulfide exerted cytotoxic activity against gastric cancer cells through inhibiting NFATc3 to activate RAG1 pathway.

Conclusion

These results demonstrate that arsenic sulfide targets NFATc3 to induce double strand DNA break (DSB) for cell killing through activating RAG1 expression. Our results link arsenic compound to the regulation of DNA damage control and RAG1 expression as a mechanism for its cytotoxic effect.

Sodium homeostasis in the tumour microenvironment

The concentration of sodium ions (Na+) is raised in solid tumours and can be measured at the cellular, tissue and patient levels. At the cellular level, the Na+ gradient across the membrane powers the transport of H+ ions and essential nutrients for normal activity. The maintenance of the Na+ gradient requires a large proportion of the cell's ATP. Na+ is a major contributor to the osmolarity of the tumour microenvironment, which affects cell volume and metabolism as well as immune function. Here, we review evidence indicating that Na+ handling is altered in tumours, explore our current understanding of the mechanisms that may underlie these alterations and consider the potential consequences for cancer progression. Dysregulated Na+ balance in tumours may open opportunities for new imaging biomarkers and re-purposing of drugs for treatment.

Distinct functions of AKT isoforms in breast cancer: a comprehensive review

BACKGROUND

AKT, also known as protein kinase B, is a key element of the PI3K/AKT signaling pathway. Moreover, AKT regulates the hallmarks of cancer, e.g. tumor growth, survival and invasiveness of tumor cells. After AKT was discovered in the early 1990s, further studies revealed that there are three different AKT isoforms, namely AKT1, AKT2 and AKT3. Despite their high similarity of 80%, the distinct AKT isoforms exert non-redundant, partly even opposing effects under physiological and pathological conditions. Breast cancer as the most common cancer entity in women, frequently shows alterations of the PI3K/AKT signaling.

MAIN CONTENT

A plethora of studies addressed the impact of AKT isoforms on tumor growth, metastasis and angiogenesis of breast cancer as well as on therapy response and overall survival in patients. Therefore, this review aimed to give a comprehensive overview about the isoform-specific effects of AKT in breast cancer and to summarize known downstream and upstream mechanisms. Taking account of conflicting findings among the studies, the majority of the studies reported a tumor initiating role of AKT1, whereas AKT2 is mainly responsible for tumor progression and metastasis. In detail, AKT1 increases cell proliferation through cell cycle proteins like p21, p27 and cyclin D1 and impairs apoptosis e.g. via p53. On the downside AKT1 decreases migration of breast cancer cells, for instance by regulating TSC2, palladin and EMT-proteins. However, AKT2 promotes migration and invasion most notably through regulation of β-integrins, EMT-proteins and F-actin. Whilst AKT3 is associated with a negative ER-status, findings about the role of AKT3 in regulation of the key properties of breast cancer are sparse. Accordingly, AKT1 is mutated and AKT2 is amplified in some cases of breast cancer and AKT isoforms are associated with overall survival and therapy response in an isoform-specific manner.

CONCLUSIONS

Although there are several discussed hypotheses how isoform specificity is achieved, the mechanisms behind the isoform-specific effects remain mostly unrevealed. As a consequence, further effort is necessary to achieve deeper insights into an isoform-specific AKT signaling in breast cancer and the mechanism behind it.

Phosphorylation of NFATC1 at PIM1 target sites is essential for its ability to promote prostate cancer cell migration and invasion

Background

Progression of prostate cancer from benign local tumors to metastatic carcinomas is a multistep process. Here we have investigated the signaling pathways that support migration and invasion of prostate cancer cells, focusing on the role of the NFATC1 transcription factor and its post-translational modifications. We have previously identified NFATC1 as a substrate for the PIM1 kinase and shown that PIM1-dependent phosphorylation increases NFATC1 activity without affecting its subcellular localization. Both PIM kinases and NFATC1 have been reported to promote cancer cell migration, invasion and angiogenesis, but it has remained unclear whether the effects of NFATC1 are phosphorylation-dependent and which downstream targets are involved.

Methods

We used mass spectrometry to identify PIM1 phosphorylation target sites in NFATC1, and analysed their functional roles in three prostate cancer cell lines by comparing phosphodeficient mutants to wild-type NFATC1. We used luciferase assays to determine effects of phosphorylation on NFAT-dependent transcriptional activity, and migration and invasion assays to evaluate effects on cell motility. We also performed a microarray analysis to identify novel PIM1/NFATC1 targets, and validated one of them with both cellular expression analyses and in silico in clinical prostate cancer data sets.

Results

Here we have identified ten PIM1 target sites in NFATC1 and found that prevention of their phosphorylation significantly decreases the transcriptional activity as well as the pro-migratory and pro-invasive effects of NFATC1 in prostate cancer cells. We observed that also PIM2 and PIM3 can phosphorylate NFATC1, and identified several novel putative PIM1/NFATC1 target genes. These include the ITGA5 integrin, which is differentially expressed in the presence of wild-type versus phosphorylation-deficient NFATC1, and which is coexpressed with PIM1 and NFATC1 in clinical prostate cancer specimens.

Conclusions

Based on our data, phosphorylation of PIM1 target sites stimulates NFATC1 activity and enhances its ability to promote prostate cancer cell migration and invasion. Therefore, inhibition of the interplay between PIM kinases and NFATC1 may have therapeutic implications for patients with metastatic forms of cancer.

Graphical abstract

TonEBP-deficiency accelerates intervertebral disc degeneration underscored by matrix remodeling, cytoskeletal rearrangements, and changes in proinflammatory gene expression

The tonicity-responsive enhancer binding protein (TonEBP) plays an important role in intervertebral disc and axial skeleton embryogenesis. However, the contribution of this osmoregulatory transcription factor in postnatal intervertebral disc homeostasis is not known in vivo. Here, we show for the first time that TonEBP-deficient mice have pronounced age-related degeneration of the intervertebral disc with annular and endplate herniations. Using FTIR-imaging spectroscopy, quantitative immunohistochemistry, and tissue-specific transcriptomic analysis, we provide morphological and molecular evidence that the overall phenotype is driven by a replacement of water-binding proteoglycans with fibrocartilaginous matrix. Whereas TonEBP deficiency in the AF compartment caused tissue fibrosis associated with alterations in actin cytoskeleton and adhesion molecules, predominant changes in pro-inflammatory pathways were seen in the NP compartment of mutants, underscoring disc compartment-specific effects. Additionally, TonEBP-deficient mice presented with compromised trabecular bone properties of vertebrae. These results provide the first in vivo support to the long-held hypothesis that TonEBP is crucial for postnatal homeostasis of the spine and controls a multitude of functions in addition to cellular osmoadaptation.

Emergence of Polyfunctional Cytotoxic CD4+ T Cells in Mycobacterium avium Immune Reconstitution Inflammatory Syndrome in Human Immunodeficiency Virus-Infected Patients

Background

Immune reconstitution inflammatory syndrome (IRIS) is an aberrant inflammatory response in individuals with advanced human immunodeficiency virus (HIV) infection, after antiretroviral therapy (ART) initiation. The pathogenesis of Mycobacterium avium complex (MAC)-associated IRIS has not been fully elucidated.

Methods

We investigated monocyte and CD4+ T-cell responses in vitro, tumor necrosis factor (TNF) expression in tissues, and plasma cytokines and inflammatory markers, in 13 HIV-infected patients with MAC-IRIS and 14 HIV-uninfected patients with pulmonary MAC infection.

Results

Prior to ART, HIV-infected compared with HIV-uninfected patients, had reduced TNF+ monocytes (P = .013), although similar cytokine (interferon gamma [IFN-γ], TNF, interleukin 2 [IL-2], and interleukin 17 [IL-17])-expressing CD4+ T cells. During IRIS, monocyte cytokine production was restored. IFN-γ+ (P = .027), TNF+ (P = .004), and polyfunctional CD4+ T cells (P = 0.03) also increased. These effectors were T-betlow, and some expressed markers of degranulation and cytotoxic potential. Blockade of cytotoxic T-lymphocyte associated protein 4 and lymphocyte activation gene-3 further increased CD4+ T-cell cytokine production. Tissue immunofluorescence showed higher proportions of CD4+ and CD68+ (monocyte/macrophage) cells expressed TNF during IRIS compared with HIV-uninfected patients. Plasma IFN-γ (P = .048), C-reactive protein (P = .008), and myeloperoxidase (P < .001) levels also increased, whereas interleukin 10 decreased (P = .008) during IRIS.

Conclusions

Advanced HIV infection was associated with impaired MAC responses. Restoration of monocyte responses and expansion of polyfunctional MAC-specific T-betlow CD4+ T cells with cytotoxic potential after ART initiation may overwhelm existing regulatory and inhibitory mechanisms, leading to MAC-IRIS.

DDX17 promotes hepatocellular carcinoma progression via inhibiting Klf4 transcriptional activity

DEAD box RNA helicase 17 (DDX17) is a transcriptional regulator of several transcription factors, which is more appreciated than its role in RNA metabolism. However, prognostic value and biofunction of DDX17 in HCC remain unclear. Illuminating the mechanism underlying the regulating HCC progression by DDX17 may contribute to therapeutic strategies. In our study, we report for the first time that DDX17 was overexpressed in HCC specimens by using The Cancer Genome Atlas (TCGA) and immunohistochemistry (IHC) and correlated to clinical pathological characteristics and patients' survival. In vitro, DDX17 was ascertained to alter HCC migratory and invasive capacities after overexpression and knockdown in HCC cell lines. Moreover, by performing co-immunoprecipitation (Co-IP) and GST-pull down assay, the physical association between DDX17 and Klf4 was discovered and validated. Additionally, DDX17 could modulate expressions of Klf4 target genes including E-cadherin, MMP2 by inhibiting the promoter activity. The potent correlation between DDX17 and Klf4 target gene expressions was further appraised by a same set of 30 HCC tissues. Besides, we discovered that DDX17 could not deploy its function in regulating Klf4 target gene expressions and HCC progression in Klf4-depletion condition. Intriguingly, DDX17 failed to interact with Klf4 once the zinc-finger domain was deleted and inhibited the binding of Klf4 on MMP-2 promoter. Collectively, our study enucleates novel mechanism of DDX17-mediated oncogenesis by suppressing the transcriptional activity of Klf4 thus is likely to be a therapeutic target in HCC.

The critical role of calcineurin/NFAT (C/N) pathways and effective antitumor prospect for colorectal cancers

Transcription factors (TFs) like a nuclear factor of activated T-cells (NFAT) and its controller calcineurin are highly expressed in primary intestinal epithelial cells (IECs) due to delamination, damage by tumor-associated flora and selective activation in the intestinal tract tumor are crucial in the progression and growth of colorectal cancer (CRC). This study sought to summarize the current findings concerning the dysregulated calcineurin/NFAT (C/N) signaling involved in CRC initiation and progression. These signalings include proliferation, T-cell functions, and glycolysis with high lactate production that remodels the acidosis, which genes in tumor cells provide an evolutionary advantage, or even increased their attack phenotype. Moreover, the relationship between C/N and gut microbiome in CRC, especially role of NFAT and toll-like receptor signaling in regulating intestinal microbiota are also discussed. Furthermore, this review will discuss the proteins and genes relating to C/N induced acidosis in CRC, which includes ASIC2 regulated C/N1 and TFs associated with the glycolytic by-product that affect T-cell functions and CRC cell growth. It is revealed that calcineurin or NFAT targeting to antitumor, selective calcineurin inhibition or targets in NFAT signaling may be useful for clinical treatment of CRC. This can further aid in the identification of specific targets via cancer patient-personalized approach. Future studies should be focused on targeting to C/N or TLR signaling by the combination of therapeutic agents to regulate T-cell functions and gut microbiome for activating potent anticancer property with the prospect of potentiating the antitumor therapy for CRC.

Calcineurin regulates cyclin D1 stability through dephosphorylation at T286

The Calcineurin/NFAT (nuclear factor of activated T cells) pathway plays an essential role in the tumorigenic and metastatic properties in breast cancer. The molecular mechanism of the antiproliferative effect of calcineurin inhibition, however, is poorly understood. We found that calcineurin inhibition delayed cell cycle progression at G1/S, and promoted cyclin D1 degradation by inhibiting dephosphorylation at T286. Importantly, overexpression of cyclin D1 partially rescued delayed G1/S progression, thereby revealing cyclin D1 as a key factor downstream of calcineurin inhibition. Cyclin D1 upregulation is observed in human invasive breast cancers, and our findings indicate that dysregulation of T286 phosphorylation could play a role in this phenomenon. We therefore propose that targeting site specific phosphorylation of cyclin D1 could be a potential strategy for clinical intervention of invasive breast cancer.

Calcium-sensing stromal interaction molecule 2 upregulates nuclear factor of activated T cells 1 and transforming growth factor-β signaling to promote breast cancer metastasis

Background

Stromal interaction molecule (STIM) 2 is a key calcium-sensing molecule that regulates the stabilization of calcium ions (Ca²⁺) and therefore regulates downstream Ca²⁺-associated signaling and cellular events. We hypothesized that STIM2 regulates epithelial-mesenchymal transition (EMT) to promote breast cancer metastasis.

Methods

We determined the effects of gain, loss, and rescue of STIM2 on cellular motility, levels of EMT-related proteins, and secretion of transforming growth factor-β (TGF-β). We also conducted bioinformatics analyses and in vivo assessments of breast cancer growth and metastasis using xenograft models.

Results

We found a significant association between STIM2 overexpression and metastatic breast cancer. STIM2 overexpression activated the nuclear factor of activated T cells 1 (NFAT1) and TGF-β signaling. Knockdown of STIM2 inhibited the motility of breast cancer cells by inhibiting EMT via specific suppression of NFAT1 and inhibited mammary tumor metastasis in mice. In contrast, STIM2 overexpression promoted metastasis. These findings were validated in human tissue arrays of 340 breast cancer samples for STIM2.

Conclusion

Taken together, our results demonstrated that STIM2 specifically regulates NFAT1, which in turn regulates the expression and secretion of TGF-β1 to promote EMT in vitro and in vivo, leading to metastasis of breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1185-1) contains supplementary material, which is available to authorized users.

Transcriptome analysis of Sézary syndrome and lymphocytic-variant hypereosinophilic syndrome T cells reveals common and divergent genes

Sézary syndrome (SS) is an aggressive cutaneous T cell lymphoma with pruritic skin inflammation and immune dysfunction, driven by neoplastic, clonal memory T cells in both peripheral blood and skin. To gain insight into abnormal gene expression promoting T cell dysfunction, lymphoproliferation and transformation in SS, we first compared functional transcriptomic profiles of both resting and activated CD4⁺CD45RO⁺ T cells from SS patients and normal donors to identified differential expressed genes. Next, a meta-analysis was performed to compare our SS data to public microarray data from a novel benign disease control, lymphocytic-variant hypereosinophilic syndrome (L-HES). L-HES is a rare, clonal lymphoproliferation of abnormal memory T cells that produces similar clinical symptoms as SS, including severe pruritus and eosinophilia. Comparison revealed gene sets specific for either SS (370 genes) or L-HES (519 genes), and a subset of 163 genes that were dysregulated in both SS and L-HES T cells compared to normal donor T cells. Genes confirmed by RT-qPCR included elevated expression of PLS3, TWIST1 and TOX only in SS, while IL17RB mRNA was increased only in L-HES. CDCA7 was increased in both diseases. In an L-HES patient who progressed to peripheral T cell lymphoma, the malignant transformation identified increases in the expression of CDCA7, TIGIT, and TOX, which are highly expressed in SS, suggesting that these genes contribute to neoplastic transformation. In summary, we have identified gene expression biomarkers that implicate a common transformative mechanism and others that are unique to differentiate SS from L-HES.

NFAT5 mediates hypertonic stress-induced atherosclerosis via activating NLRP3 inflammasome in endothelium

BACKGROUND

How high-salt intake leads to the occurrence of many cardiovascular diseases such as atherosclerosis is a fundamental question in pathology. Here we postulated that high-salt-induced NFAT5 controls the inflammasome activation by directly regulating NLRP3, which mediates the expression of inflammatory- and adhesion-related genes in vascular endothelium, resulting in the formation of atherosclerosis.

METHODS

Atherosclerosis-prone apolipoprotein E-deficient (ApoE-/-) mice which accumulate cholesterol ester-enriched particles in the blood due to poor lipoprotein clearance capacity were used as the atherosclerosis model in vivo. Cultured endothelial cells (ECs) and monocytes under high-salt condition were used to explore the atheroprone role of the activation of NFAT5-NLRP3 inflammasome in vascular endothelium in vitro. Bioinformatic analysis and chromatin immunoprecipitation assay were used to identify the DNA binding sites of NFAT5 on promoters of NLRP3 and IL-1β.

RESULTS

We first observe that high-salt intake promotes atherosclerosis formation in the aortas of ApoE^-/- mice, through inducing the expression of NFAT5, NLRP3, and IL-1β in endothelium. Overexpression of NFAT5 activates NLRP3-inflammasome and increases the secretion of IL-1β in ECs partly via ROS. Chromatin immunoprecipitation assay demonstrates that NFAT5 directly binds to the promoter regions of NLRP3 and IL-1β in endothelial cells subjected to the high-salt environment.

CONCLUSIONS

Our study identifies NFAT5 as a new and essential transcription factor that is required for the early activation of NLRP3-inflammasome-mediated endothelium innate immunity, contributing to the formation of atherosclerosis under hypertonic stress induction.