NOTCH4ΔL12_16 sensitizes lung adenocarcinomas to EGFR-TKIs through transcriptional down-regulation of HES1.

Resistance to epidermal growth factor tyrosine kinase inhibitors (EGFR-TKI) remains one of the major challenges in lung adenocarcinoma (LUAD) therapy. Here, we find an increased frequency of the L12_16 amino acid deletion mutation in the signal peptide region of NOTCH4 (NOTCH4ΔL12_16) in EGFR-TKI-sensitive patients. Functionally, exogenous induction of NOTCH4ΔL12_16 in EGFR-TKI -resistant LUAD cells sensitizes them to EGFR-TKIs. This process is mainly mediated by the reduction of the intracellular domain of NOTCH4 (NICD4) caused by the NOTCH4ΔL12_16 mutation, which results in a lower localization of NOTCH4 in the plasma membrane. Mechanistically, NICD4 transcriptionally upregulates the expression of HES1 by competitively binding to the gene promoter relative to p-STAT3. Because p-STAT3 can downregulate the expression of HES1 in EGFR-TKI-resistant LUAD cells, the reduction of NICD4 induced by NOTCH4ΔL12_16 mutation leads to a decrease in HES1. Moreover, inhibition of the NOTCH4-HES1 pathway using inhibitors and siRNAs abolishes the resistance of EGFR-TKI. Overall, we report that the NOTCH4ΔL12_16 mutation sensitizes LUAD patients to EGFR-TKIs through transcriptional down-regulation of HES1 and that targeted blockade of this signaling cohort could reverse EGFR-TKI -resistance in LUAD, providing a potential approach to overcome resistance to EGFR-TKI -therapy.

Notch1 and Notch4 core binding domain peptibodies exhibit distinct ligand-binding and anti-angiogenic properties.

The Notch signaling pathway is an important therapeutic target for the treatment of inflammatory diseases and cancer. We previously created ligand-specific inhibitors of Notch signaling comprised of Fc fusions to specific EGF-like repeats of the Notch1 extracellular domain, called Notch decoys, which bound ligands, blocked Notch signaling, and showed anti-tumor activity with low toxicity. However, the study of their function depended on virally mediated expression, which precluded dosage control and limited clinical applicability. We have refined the decoy design to create peptibody-based Notch inhibitors comprising the core binding domains, EGF-like repeats 10-14, of either Notch1 or Notch4. These Notch peptibodies showed high secretion properties and production yields that were improved by nearly 100-fold compared to previous Notch decoys. Using surface plasmon resonance spectroscopy coupled with co-immunoprecipitation assays, we observed that Notch1 and Notch4 peptibodies demonstrate strong but distinct binding properties to Notch ligands DLL4 and JAG1. Both Notch1 and Notch4 peptibodies interfere with Notch signaling in endothelial cells and reduce expression of canonical Notch targets after treatment. While prior DLL4 inhibitors cause hyper-sprouting, the Notch1 peptibody reduced angiogenesis in a 3-dimensional in vitro sprouting assay. Administration of Notch1 peptibodies to neonate mice resulted in reduced radial outgrowth of retinal vasculature, confirming anti-angiogenic properties. We conclude that purified Notch peptibodies comprising EGF-like repeats 10-14 bind to both DLL4 and JAG1 ligands and exhibit anti-angiogenic properties. Based on their secretion profile, unique Notch inhibitory activities, and anti-angiogenic properties, Notch peptibodies present new opportunities for therapeutic Notch inhibition.

NOTCH4 mutation as predictive biomarker for immunotherapy benefits in NRAS wildtype melanoma.

Background: NRAS wildtype melanoma accounts for approximately 80% of melanomas. Previous studies have shown that NRAS wildtype melanoma had higher response rates and better prognoses than NRAS-mutant patients following immunotherapy, while as major actors in tumor cells and tumor microenvironment (TME), the association between NOTCH family genes and response to immunotherapy in NRAS wildtype melanoma remains indistinct. Objective: We aim to explore whether NOTCH family gene variation is associated with genomic factors in immune checkpoint inhibitor (ICI) response in NRAS wildtype melanoma and with clinical results in these patients. Method: This research used genomic data of 265 NRAS wildtype ICI-pretreatment samples from five ICI-treated melanoma cohorts to analyze the relationship between NOTCH family gene mutation and the efficacy of ICI therapy. Results: NRAS wildtype melanomas with NOTCH4-Mut were identified to be associated with prolonged overall survival (OS) in both the discovery (HR: 0.30, 95% CI: 0.11-0.83, P = 0.01) and validation cohorts(HR: 0.21, 95% CI: 0.07-0.68, P = 0.003). Moreover, NOTCH4-Mut melanoma had a superior clinical response in the discovery cohort (ORR, 40.0% vs 13.11%, P = 0.057) and validation cohort (ORR, 68.75% vs 30.07%, P = 0.004). Further exploration found that NOTCH4-Mut tumors had higher tumor mutation burden (TMB) and tumor neoantigen burden (TNB) (P <0.05). NOTCH4-Mut tumors had a significantly increased mutation in the DNA damage response (DDR) pathway. Gene set enrichment analysis revealed NOTCH4-Mut tumor enhanced anti-tumor immunity. Conclusion: NOTCH4 mutation may promote tumor immunity and serve as a biomarker to predict good immune response in NRAS wildtype melanoma and guide immunotherapeutic responsiveness.

The NOTCH4-GATA4-IRG1 axis as a novel target in early-onset colorectal cancer.

The early onset of colorectal cancer (CRC) in individuals younger than 50 years is an emerging phenomenon, and obesity is a strong risk factor. Inflammatory mechanisms are mediated by immune cells, with macrophages and their phenotypical changes playing a significant role in CRC. Obesity-related hormones, such as leptin and adiponectin, affect macrophage polarization and cytokine expression. Macrophage metabolism, and therefore polarization, directly affects tumor progression and survival in patients with CRC. Altered obesity-related hormone levels induce phosphoinositide kinase-3 (PI3K)/serine-threonine-protein kinase (AKT) activation in colon cancer, causing increased cell survival, hyperplasia, and proliferation. Investigating the effects of obesity-related mechanisms on PI3K/Akt signaling can provide new insights for targeting mechanisms in CRC and obesity among the young. Central molecules for the control of cell proliferation, differentiation, and tumorigenesis within the gastrointestinal tract include downstream targets of the PI3K/AKT pathway, such as Neurogenic locus notch homolog 4 (Notch4) and GATA binding proteins (GATA). Leptin and adiponectin both alter gene expression within this pathway, thereby affecting TAM-mediated CRC progression. Our goal is to introduce the NOTCH4-GATA4-IRG1 axis as a link between inflammation and sporadic CRC and to discuss this pathway as a new potential immunotherapeutic target in individuals affected with obesity and early-onset CRC.

Expression of NOTCH1, NOTCH4, HLA-DMA and HLA-DRA is synergistically associated with T cell exclusion, immune checkpoint blockade efficacy and recurrence risk in ER-negative breast cancer.

PURPOSE: Reliable biomarkers to predict the outcome and treatment response of estrogen receptor (ER)-negative breast cancer (BC) are urgently needed. Since immune-related signaling plays an important role in the tumorigenesis of ER-negative BC, we asked whether Notch genes, alone or in combination with other immune genes, can be used to predict the clinical outcome and immune checkpoint blockade (ICB) for this type of cancer. METHODS: We analyzed transcriptome data of 6918 BC samples from five independent cohorts, 81 xenograft triple-negative BC tumors that respond differently to ICB treatment and 754 samples of different cancer types from patients treated with ICB agents. RESULTS: We found that among four Notch genes, the expression levels of NOTCH1 and NOTCH4 were positively associated with recurrence of ER-negative BC, and that combined expression of these two genes (named Notch14) further enhanced this association, which was comparable with that of the Notch pathway signature. Analysis of 1182 immune-related genes revealed that the expression levels of most HLA genes, particularly HLA-DMA and -DRA, were reversely associated with recurrence in ER-negative BC with low, but not high Notch14 expression. A combined expression signature of NOTCH1, NOTCH4, HLA-DMA and HLA-DRA was more prognostic for ER-negative and triple-negative BCs than previously reported immune-related signatures. Furthermore, we found that the expression levels of these four genes were also synergistically associated with T cell exclusion score, infiltration of specific T cells and ICB efficacy in ER-negative BC, thereby providing a potential molecular mechanism for the synergistic effect of these genes on BC. CONCLUSIONS: Our data indicate that a gene signature composed of NOTCH1, NOTCH4, HLA-DMA and HLA-DRA may serve as a potential promising biomarker for predicting ICB therapy efficacy and recurrence in ER-negative/triple-negative BCs.

Notch4 mediates vascular remodeling via ERK/JNK/P38 MAPK signaling pathways in hypoxic pulmonary hypertension.

BACKGROUND: Hypoxic pulmonary hypertension (HPH) is a chronic progressive advanced disorder pathologically characterized by pulmonary vascular remodeling. Notch4 as a cell surface receptor is critical for vascular development. However, little is known about the role and mechanism of Notch4 in the development of hypoxic vascular remodeling. METHODS: Lung tissue samples were collected to detect the expression of Notch4 from patients with HPH and matched controls. Human pulmonary artery smooth muscle cells (HPASMCs) were cultured in hypoxic and normoxic conditions. Real-time quantitative PCR and western blotting were used to examine the mRNA and protein levels of Notch4. HPASMCs were transfected with small interference RNA (siRNA) against Notch4 or Notch4 overexpression plasmid, respectively. Cell viability, cell proliferation, apoptosis, and migration were assessed using Cell Counting Kit-8, Edu, Annexin-V/PI, and Transwell assay. The interaction between Notch4 and ERK, JNK, P38 MAPK were analyzed by co-immunoprecipitation. Adeno-associated virus 1-mediated siRNA against Notch4 (AAV1-si-Notch4) was injected into the airways of hypoxic rats. Right ventricular systolic pressure (RVSP), right ventricular hypertrophy and pulmonary vascular remodeling were evaluated. RESULTS: In this study, we demonstrate that Notch4 is highly expressed in the media of pulmonary vascular and is upregulated in lung tissues from patients with HPH and HPH rats compared with control groups. In vitro, hypoxia induces the high expression of Delta-4 and Notch4 in HPASMCs. The increased expression of Notch4 promotes HPASMCs proliferation and migration and inhibits cells apoptosis via ERK, JNK, P38 signaling pathways. Furthermore, co-immunoprecipitation result elucidates the interaction between Notch4 and ERK/JNK/P38. In vivo, silencing Notch4 partly abolished the increase in RVSP and pulmonary vascular remodeling caused by hypoxia in HPH rats. CONCLUSIONS: These findings reveal an important role of the Notch4-ERK/JNK/P38 MAPK axis in hypoxic pulmonary remodeling and provide a potential therapeutic target for patients with HPH.

NOTCH Single Nucleotide Polymorphisms in the Predisposition of Breast and Colorectal Cancers in Saudi Patients.

Breast cancer (BC) is a heterogeneous disease and is one of the most common malignancy affecting women worldwide while colorectal cancer (CRC) is estimated to be the third common cancer and second leading cause of cancer related death globally. Both BC and CRC involve multiple genetic and epigenetic alterations in genes belonging to various signaling pathways including NOTCH that has been implicated in the development of these cancers. We investigated four single nucleotide polymorphisms, each in genes encoding NOTCH1-4 receptors for their role in susceptibility to breast and colorectal cancers in Saudi population. In this case-control study, TaqMan genotypic analysis of rs3124591 in NOTCH1 and rs3820041 in NOTCH4 did not exhibit association with breast as well as colorectal cancers. However, a strong association of rs11249433 which is in close proximity to NOTCH2 was observed with breast cancer susceptibility especially with those having an early onset of the disease. Interestingly, the rs1043994 located in NOTCH3 showed gender preference and was found to be significantly associated with colorectal cancers in males. Validation of these findings in bigger populations of different ethnicities may prove beneficial in identifying rs11249433 and rs1043994 as genetic screening markers for early detection of breast and colorectal carcinomas, respectively.

Notch4 signaling limits regulatory T-cell-mediated tissue repair and promotes severe lung inflammation in viral infections.

A cardinal feature of COVID-19 is lung inflammation and respiratory failure. In a prospective multi-country cohort of COVID-19 patients, we found that increased Notch4 expression on circulating regulatory T (Treg) cells was associated with disease severity, predicted mortality, and declined upon recovery. Deletion of Notch4 in Treg cells or therapy with anti-Notch4 antibodies in conventional and humanized mice normalized the dysregulated innate immunity and rescued disease morbidity and mortality induced by a synthetic analog of viral RNA or by influenza H1N1 virus. Mechanistically, Notch4 suppressed the induction by interleukin-18 of amphiregulin, a cytokine necessary for tissue repair. Protection by Notch4 inhibition was recapitulated by therapy with Amphiregulin and, reciprocally, abrogated by its antagonism. Amphiregulin declined in COVID-19 subjects as a function of disease severity and Notch4 expression. Thus, Notch4 expression on Treg cells dynamically restrains amphiregulin-dependent tissue repair to promote severe lung inflammation, with therapeutic implications for COVID-19 and related infections.

Reciprocal activation of HEY1 and NOTCH4 under SOX2 control promotes EMT in head and neck squamous cell carcinoma.

Several comprehensive studies have demonstrated that the NOTCH pathway is altered in a bimodal manner in head and neck squamous cell carcinoma (HNSCC). In a previous study, it was found that the NOTCH4/HEY1 pathway was specifically upregulated in HNSCC and promoted epithelial­mesenchymal transition (EMT), and that HEY1 activation supported SOX2 expression. However, the interactions in this pathway have not yet been fully elucidated. The present study investigated the NOTCH4/HEY1/SOX2 axis in HNSCC using in vitro models and the Cancer Genome Atlas (TCGA) database. To explore the association, reporter and ChIP RT­qPCR assays using SOX2­overexpressing (SOX2­OE) cells were performed. The association between NOTCH4 and HEY1 was examined in the same manner using HEY1­overexpressing (HEY1­OE) cells. The results of the in vitro experiments indicated that HEY1 promoted EMT in the HNSCC cells. Furthermore, the overexpression of HEY1 also promoted sphere formation and increased murine xenograft tumorigenicity. Reporter assays and ChIP RT­qPCR experiments indicated that SOX2 regulated HEY1 expression via direct binding of the HEY1 promoter. HEY1 expression significantly correlated with SOX2 expression in primary lung SCC and other SCCs using the TCGA database. HEY1 also regulated NOTCH4 expression to create a positive reciprocal feedback loop. On the whole, the present study demonstrates that HEY1 expression in HNSCC is regulated via the promotion of SOX2 and promotes EMT. The NOTCH4/HEY1 pathway is specifically upregulated via a positive reciprocal feedback loop mediated by the HEY1­medaited regulation of NOTCH4 transcription, and SOX2 correlates with HEY1 expression in SCC from other primary sites.

Methylation status of CpG sites in the NOTCH4 promoter region regulates NOTCH4 expression in patients with tetralogy of Fallot.

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease (CHD). Although a lower methylation level of whole genome has been demonstrated in TOF patients, little is known regarding the DNA methylation changes in specific gene and its associations with TOF development. NOTCH4 is a mediator of the Notch signalling pathway that plays an important role in normal cardiac development. However, the role of epigenetic regulation of the NOTCH4 gene in the pathogenesis of TOF remains unclear. Considering the NOTCH4 low mutation frequency and reduced expression in the TOF patients, we hypothesized that abnormal DNA methylation change of NOTCH4 gene may influence its expression and responsible for TOF development. In this study, we measured the promoter methylation status of NOTCH4 and was measured and its regulation mechanism was explored, which may be related to TOF disease. Additionally, the promoter methylation statuses of NOTCH4 was measured in order to further understand epigenetic mechanisms that may serve a role in the development of TOF. Immunohistochemical analysis was used to examine NOTCH4 expression in right ventricular outflow tract myocardial tissues in patients with TOF. Compared with healthy controls, patients with TOF displayed significantly reduced in NOTCH4 expression (P=0.0055). Moreover, bisulphite sequencing suggested that the methylation levels of CpG site 2 in the NOTCH4 promoter was significantly higher in the patients than in the controls (P=0.0459). NOTCH4 expression was negatively associated with CpG site 2 methylation levels (r=­0.51; P=0.01). ETS1 transcription factor can serve as transcriptional activators by binding to specific DNA sequences of target genes, such as DLL4 and NOTCH4, which serves an important role in normal heart development. Dual­luciferase reporter and electrophoretic mobility shift assays indicated that the ETS1 transcription factor could bind to the NOTCH4 promoter region. However, binding of ETS1 to the NOTCH4 promoter was abrogated by methylation at the putative ETS1 binding sites. These findings suggested that decreased NOTCH4 expression in patients with TOF may be associated with hypermethylation of CpG site 2 in the NOTCH4 promoter region, due to impaired binding of ETS1.

NOTCH4 maintains quiescent mesenchymal-like breast cancer stem cells via transcriptionally activating SLUG and GAS1 in triple-negative breast cancer.

Rationale: NOTCH4 receptor has been implicated in triple-negative breast cancer (TNBC) development and breast cancer stem cell (BCSC) regulation. However, the potential of NOTCH4 as a BCSC marker and the underlying mechanisms remain unclear. Methods: In this study, we determined the expression and activation of NOTCH4 in breast cancer cell lines and tumor samples by qRT-PCR, western blotting and immunohistochemistry. Subsequently, in vitro and in vivo serial dilution experiments were performed to demonstrate the application of NOTCH4 as an efficient mesenchymal-like (ML)-BCSC marker in TNBC. Stable overexpression of activated NOTCH4 and knockdown cell lines were established using lentivirus. RNA-seq and qRT-PCR were employed to reveal the downstream effectors of NOTCH4, followed by dual-luciferase reporter and chromatin immunoprecipitation assays to identify the genuine binding sites of NOTCH4 on SLUG and GAS1 promoters. Transwell assay, mammosphere formation and chemoresistance experiments were performed to determine the effects of SLUG, GAS1 and NOTCH4 on the mesenchymal-like characteristics of TNBC cells. Survival analysis was used to study the relation of NOTCH4, SLUG and GAS1 with prognosis of breast cancer. Results: NOTCH4 is aberrantly highly expressed and activated in TNBC, which contributes to the maintenance of ML-BCSCs. Furthermore, NOTCH4 shows significantly higher efficiency in labeling ML-BCSCs than the currently commonly used CD24-CD44+ marker. Mechanistically, NOTCH4 transcriptionally upregulates SLUG and GAS1 to promote EMT and quiescence in TNBC, respectively. The effects of NOTCH4 can be mimicked by simultaneous overexpression of SLUG and GAS1. Moreover, SLUG is also involved in harnessing GAS1, a known tumor suppressor gene, via its anti-apoptotic function. Conclusions: Our findings reveal that the NOTCH4-SLUG-GAS1 circuit serves as a potential target for tumor intervention by overcoming stemness of ML-BCSCs and by conquering the lethal chemoresistance and metastasis of TNBC.

NOTCH and DNA repair pathways are more frequently targeted by genomic alterations in inflammatory than in non-inflammatory breast cancers.

Inflammatory breast cancer (IBC) is the most pro-metastatic form of breast cancer. Better understanding of its pathophysiology and identification of actionable genetic alterations (AGAs) are crucial to improve systemic treatment. We aimed to define the DNA profiles of IBC vs noninflammatory breast cancer (non-IBC) clinical samples in terms of copy number alterations (CNAs), mutations, and AGAs. We applied targeted next-generation sequencing (tNGS) and array-comparative genomic hybridization (aCGH) to 57 IBC and 50 non-IBC samples and pooled these data with four public datasets profiled using NGS and aCGH, leading to a total of 101 IBC and 2351 non-IBC untreated primary tumors. The respective percentages of each molecular subtype [hormone receptor-positive (HR+)/HER2-, HER2+, and triple-negative] were 68%, 15%, and 17% in non-IBC vs 25%, 35%, and 40% in IBC. The comparisons were adjusted for both the molecular subtypes and the American Joint Committee on Cancer (AJCC) stage. The 10 most frequently altered genes in IBCs were TP53 (63%), HER2/ERBB2 (30%), MYC (27%), PIK3CA (21%), BRCA2 (14%), CCND1 (13%), GATA3 (13%), NOTCH1 (12%), FGFR1 (11%), and ARID1A (10%). The tumor mutational burden was higher in IBC than in non-IBC. We identified 96 genes with an alteration frequency (p < 5% and q < 20%) different between IBC and non-IBC, independently from the molecular subtypes and AJCC stage; 95 were more frequently altered in IBC, including TP53, genes involved in the DNA repair (BRCA2) and NOTCH pathways, and one (PIK3CA) was more frequently altered in non-IBC. Ninety-seven percent of IBCs displayed at least one AGA. This percentage was higher than in non-IBC (87%), notably for drugs targeting DNA repair, NOTCH signaling, and CDK4/6, whose pathways were more frequently altered (DNA repair) or activated (NOTCH and CDK4/6) in IBC than in non-IBC. The genomic landscape of IBC is different from that of non-IBC. Enriched AGAs in IBC may explain its aggressiveness and provide clinically relevant targets.

All-trans retinoic acid enhances, and a pan-RAR antagonist counteracts, the stem cell promoting activity of EVI1 in acute myeloid leukemia.

Ecotropic virus integration site 1 (EVI1), whose overexpression characterizes a particularly aggressive subtype of acute myeloid leukemia (AML), enhanced anti-leukemic activities of all-trans retinoic acid (atRA) in cell lines and patient samples. However, the drivers of leukemia formation, therapy resistance, and relapse are leukemic stem cells (LSCs), whose properties were hardly reflected in these experimental setups. The present study was designed to address the effects of, and interactions between, EVI1 and retinoids in AML LSCs. We report that Evi1 reduced the maturation of leukemic cells and promoted the abundance, quiescence, and activity of LSCs in an MLL-AF9-driven mouse model of AML. atRA further augmented these effects in an Evi1 dependent manner. EVI1 also strongly enhanced atRA regulated gene transcription in LSC enriched cells. One of their jointly regulated targets, Notch4, was an important mediator of their effects on leukemic stemness. In vitro exposure of leukemic cells to a pan-RAR antagonist caused effects opposite to those of atRA. In vivo antagonist treatment delayed leukemogenesis and reduced LSC abundance, quiescence, and activity in Evi1high AML. Key results were confirmed in human myeloid cell lines retaining some stem cell characteristics as well as in primary human AML samples. In summary, our study is the first to report the importance of EVI1 for key properties of AML LSCs. Furthermore, it shows that atRA enhances, and a pan-RAR antagonist counteracts, the effects of EVI1 on AML stemness, thus raising the possibility of using RAR antagonists in the therapy of EVI1high AML.

Vascular endothelial growth factor 165 inhibits pro-fibrotic differentiation of stromal cells via the DLL4/Notch4/smad7 pathway.

Endometrial fibrosis is the main pathological feature of Asherman's syndrome (AS), which is the leading cause of uterine infertility. Much is known about the expression of VEGF165 in luminal/glandular epithelial cells and stromal cells of the endometrium in normal menstrual cycles; however, less is known about the role and mechanism of VEGF165 in endometrial fibrosis. Herein, we report that VEGF165 is a key regulator in endometrial stromal cells to inhibit α-SMA and collagen 1 expression. Compared to human control subjects, patients with AS exhibited decreased VEGF165 expression in the endometrium along with increased fibrotic marker expression and collagen production. A fibrotic phenotype was shown in both mice with conditional VEGF reduction and VEGF165-deleted endometrial stromal cells. Exogenous VEGF165 could suppress TGFß1-induced α-SMA and collagen 1 expression in human primary endometrial stromal cells. However, this beneficial effect was hindered when the expression of smad7 or Notch4 was inhibited or when Notch signaling was blocked, suggesting that smad7 and Notch4 are essential downstream molecules for VEGFA functioning. Overall, our results uncover a clinical targeting strategy for VEGF165 to inhibit pro-fibrotic differentiation of stromal cells by inducing DLL4/Notch4/smad7, which paves the way for AS treatment.

Evaluation of the correlation of vasculogenic mimicry, Notch4, DLL4, and KAI1/CD82 in the prediction of metastasis and prognosis in non-small cell lung cancer.

Vasculogenic mimicry (VM) is a new blood supply style in tumors and has long been treated as a useful factor in malignant tumor metastasis and prognosis. Notch4 (a marker of Notch signaling pathway receptors), DLL4 (a marker of Notch signaling pathway ligands) and KAI1/CD82 (a suppressor gene of tumor metastasis) are all effective predictive factors for tumor metastasis. In this study, we analyzed correlations among VM, Notch4, DLL4, and KAI1/CD82 in non-small cell lung cancer (NSCLC), and their respective associations with patients' clinicopathological parameters and survival rate in NSCLC.Positive rates of VM, Notch4, DLL4, and KAI1/CD82 in 189 whole NSCLC specimens were detected by histochemical and immunohistochemical staining. Moreover, patients' clinicopathological information was also collected.Positive rates of VM, Notch4, and DLL4 were significantly higher, and levels of KAI1/CD82 were significantly lower in NSCLC than in normal lung tissues. Positive rates of VM, Notch4, and DLL4 were positively associated with tumor size, lymph node metastasis (LNM), distant metastasis (DM) and tumor-node-metastasis (TNM) stage, and inversely with patients, overall survival (OS) time and positive rate of DLL4 were positively associated with tumor grade. Levels of KAI1/CD82 were negatively associated with tumor size, LNM, DM, and TNM stage. The KAI1/CD82+ subgroup had significantly longer OS time than did the KAI1/CD82- subgroup. In multivariate analysis, high VM, Notch4, DLL4 levels, tumor size, LNM, DM, TNM stage, and low KAI1/CD82 levels were potential to be independent prognostic factors for overall survival time (OST) in NSCLC patients.VM and the expression of Notch4, DLL4, and KAI1/CD82 represent promising markers for tumor metastasis and prognosis, and maybe potential therapeutic targets for NSCLC.

Increased expression of miR-1179 inhibits breast cancer cell metastasis by modulating Notch signaling pathway and correlates with favorable prognosis.

OBJECTIVE: MicroRNAs (miRNAs) play a key role in the regulation of gene expression. In this study, we aimed to identify the clinical values of miR-1179 and to investigate the potential molecular mechanisms in breast cancer (BC). MATERIALS AND METHODS: RT-PCR was used to detect the expression levels of miR-1179 in both BC tissues and cell lines. We analyzed the association between the miR-1179 levels and clinicopathological factors and patient prognosis. The proliferation ability of miR-1179 on BC cells was assessed by MTT and colony formation assay. The role of miR-1179 in BC cells migration and invasion was measured by transwell assays. Western blot analysis was used to quantify the expression of the molecular biomarkers of the Notch signaling pathway. RESULTS: Our results showed that miR-1179 expression was frequently downregulated in BC tissues and cell lines. Clinicopathologic analysis revealed that low miR-1179 expression is correlated with lymph node metastasis, advanced clinical stage and shorter overall survival. Multivariable Cox proportional hazards regression analysis suggested that increased miR-1179 expression was an independent prognostic factor of overall survival in BC patients. Gain-of-function assay indicated that the overexpression of miR-1179 significantly suppressed BC cells proliferation, migration and invasion. Mechanistically, miR-1179 up-regulation inhibited the expression of Notch 1, Notch 4 and Hes1, indicating that miR-1179 could suppress the activation of the Notch signaling pathway. CONCLUSIONS: We showed that miR-1179 was a tumor suppressor that may serve as a novel potential prognostic biomarker or molecular therapeutic target for BC.

Exosome markers associated with immune activation and oxidative stress in HIV patients on antiretroviral therapy.

Exosomes are nanovesicles released from most cell types including immune cells. Prior studies suggest exosomes play a role in HIV pathogenesis, but little is known about exosome cargo in relation to immune responses and oxidative stress. Here, we characterize plasma exosomes in HIV patients and their relationship to immunological and oxidative stress markers. Plasma exosome fractions were isolated from HIV-positive subjects on ART with suppressed viral load and HIV-negative controls. Exosomes were characterized by electron microscopy, nanoparticle tracking, immunoblotting, and LC-MS/MS proteomics. Plasma exosomes were increased in HIV-positive subjects compared to controls, and correlated with increased oxidative stress markers (cystine, oxidized cys-gly) and decreased PUFA (DHA, EPA, DPA). Untargeted proteomics detected markers of exosomes (CD9, CD63, CD81), immune activation (CD14, CRP, HLA-A, HLA-B), oxidative stress (CAT, PRDX1, PRDX2, TXN), and Notch4 in plasma exosomes. Exosomal Notch4 was increased in HIV-positive subjects versus controls and correlated with immune activation markers. Treatment of THP-1 monocytic cells with patient-derived exosomes induced expression of genes related to interferon responses and immune activation. These results suggest that exosomes in ART-treated HIV patients carry proteins related to immune activation and oxidative stress, have immunomodulatory effects on myeloid cells, and may have pro-inflammatory and redox effects during pathogenesis.

Human NOTCH4 is a key target of RUNX1 in megakaryocytic differentiation.

Megakaryocytes (MKs) in adult marrow produce platelets that play important roles in blood coagulation and hemostasis. Monoallelic mutations of the master transcription factor gene RUNX1 lead to familial platelet disorder (FPD) characterized by defective MK and platelet development. However, the molecular mechanisms of FPD remain unclear. Previously, we generated human induced pluripotent stem cells (iPSCs) from patients with FPD containing a RUNX1 nonsense mutation. Production of MKs from the FPD-iPSCs was reduced, and targeted correction of the RUNX1 mutation restored MK production. In this study, we used isogenic pairs of FPD-iPSCs and the MK differentiation system to identify RUNX1 target genes. Using integrative genomic analysis of hematopoietic progenitor cells generated from FPD-iPSCs, and mutation-corrected isogenic controls, we identified 2 gene sets the transcription of which is either up- or downregulated by RUNX1 in mutation-corrected iPSCs. Notably, NOTCH4 expression was negatively controlled by RUNX1 via a novel regulatory DNA element within the locus, and we examined its involvement in MK generation. Specific inactivation of NOTCH4 by an improved CRISPR-Cas9 system in human iPSCs enhanced megakaryopoiesis. Moreover, small molecules known to inhibit Notch signaling promoted MK generation from both normal human iPSCs and postnatal CD34+ hematopoietic stem and progenitor cells. Our study newly identified NOTCH4 as a RUNX1 target gene and revealed a previously unappreciated role of NOTCH4 signaling in promoting human megakaryopoiesis. Our work suggests that human iPSCs with monogenic mutations have the potential to serve as an invaluable resource for discovery of novel druggable targets.

The NOTCH4-HEY1 Pathway Induces Epithelial-Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma.

Purpose: Recently, several comprehensive genomic analyses demonstrated NOTCH1 and NOTCH3 mutations in head and neck squamous cell carcinoma (HNSCC) in approximately 20% of cases. Similar to other types of cancers, these studies also indicate that the NOTCH pathway is closely related to HNSCC progression. However, the role of NOTCH4 in HNSCC is less well understood.Experimental Design: We analyzed NOTCH4 pathway and downstream gene expression in the TCGA data set. To explore the functional role of NOTCH4, we performed in vitro proliferation, cisplatin viability, apoptosis, and cell-cycle assays. We also compared the relationships among NOTCH4, HEY1, and epithelial-mesenchymal transition (EMT)-related genes using the TCGA data set and in vitro assays.Results:HEY1 is specifically upregulated in HNSCC compared with normal tissues in the TCGA data set. NOTCH4 is more significantly related to HEY1 activation in HNSCC in comparison with other NOTCH receptors. NOTCH4 promotes cell proliferation, cisplatin resistance, inhibition of apoptosis, and cell-cycle dysregulation. Furthermore, NOTCH4 and HEY1 upregulation resulted in decreased E-cadherin expression and increased Vimentin, Fibronectin, TWIST1, and SOX2 expression. NOTCH4 and HEY1 expression was associated with an EMT phenotype as well as increased invasion and cell migration.Conclusions: In HNSCC, the NOTCH4-HEY1 pathway is specifically upregulated, induces proliferation and cisplatin resistance, and promotes EMT. Clin Cancer Res; 24(3); 619-33. ©2017 AACR.

Protective effect of Shouwu Yizhi decoction against vascular dementia by promoting angiogenesis.

Shouwu is a traditional Chinese medicine (TCM) with neuroprotective effect. Shouwu Yizhi decoction (SYD) was designed based on TCM theory. However, little is known about the roles of SYD in Vascular dementia (VaD). The present study aimed to evaluate the potential effects of SYD on the vascular cognitive impairment and explore the underlying mechanism by establishing focal cerebral ischemia/reperfusion (I/R) rat model to induce VaD. SYD administration (54 mg·kg-1) for 40 days obviously improved the vascular cognitive impairment in the middle cerebral artery occlusion (MCAO) rats as evidenced by the declined neurological deficit score and shortened escape latency via neurological deficit assessment and Morris water maze test. Moreover, SYD decreased neuron damage-induced cell death and ameliorated the ultrastructure of endothelial cells in the MCAO rats, thereby alleviating VaD. Mechanistically, SYD caused increases in the expression of vascular endothelial growth factor (VEGF), CD34 and CD31, compared with the MCAO rats in coronal hippocampus. Simultaneously, the expression level of miR-210 was elevated significantly after SYD administration, compared with the vehicle rats (P < 0.01). The expression of Notch 4 at both mRNA and protein levels was upregulated remarkably along with the notably downregulated DLL4 expression under SYD administration compared with the vehicle rats (P < 0.05). Overall, the above results indicated that SYD promoted angiogenesis by upregulating VEGF-induced miR210 expression to activate Notch pathway, and further alleviated neuron damage and ameliorated the ultrastructure of endothelial cells in the MCAO rats, ultimately enhancing the cognition and memory of MCAO rats. Therefore, our findings preliminarily identified the effect and the mechanism of action for SYD on VaD in rats. SYD could be a potential candidate in treatment of VaD.