Downregulation Of Notch Signaling Research Articles

A Novel Flow Cytometric Assay to Identify Inhibitors of RBPJ-DNA Interactions.

Notch signaling is often involved in cancer cell initiation and proliferation. Aberrant Notch activation underlies more than 50% of T-cell acute lymphoblastic leukemia (T-ALL); accordingly, chemicals disrupting Notch signaling are of potential to treat Notch-dependent cancer. Here, we developed a flow cytometry-based high-throughput assay to identify compounds that disrupt the interactions of DNA and RBPJ, the major downstream effector of Notch signaling. From 1492 compounds, we identified 18 compounds that disrupt RBPJ-DNA interactions in a dose-dependent manner. Cell-based assays further revealed that auranofin downregulates Notch-dependent transcription and decreases RBPJ-chromatin interactions in cells. Most strikingly, T-ALL cells that depend on Notch signaling for proliferation are more sensitive to auranofin treatment, supporting the notion that auranofin downregulates Notch signaling by disrupting RBPJ-DNA interaction. These results validate the feasibility of our assay scheme to screen for additional Notch inhibitors and provide a rationale to further test the use of auranofin in treating Notch-dependent cancer.

429 Risk of keratinocyte carcinoma among patients with hidradenitis suppurativa

Recent studies have implicated the role of the Notch pathway in keratinocyte carcinomas (KCs). Notch signaling is often upregulated in basal cell carcinoma (BCC) but downregulated in squamous cell carcinoma (SCC). Hidradenitis suppurativa (HS) is an inflammatory disorder of the apocrine glands whose pathogenesis has also been associated with downregulation of Notch signaling. Given the role of Notch in the pathogenesis of HS and KCs, we hypothesized that HS patients could be at decreased risk for BCC and increased risk for SCC. To test our hypothesis, we examined the association between HS and KC risk by comparing the incidence of BCC and SCC in HS patients to controls (patients with acne vulgaris, an inflammatory disorder of pilosebaceous glands that is not known to involve the Notch pathway). Using an age, sex, and race matched 1:2 case-control study design, we derived KC outcomes and covariates through chart review of an institutional database (Partners Healthcare, 2000-2019) and determined incident BCC and SCC risk by performing multivariate logistic regression adjusted for disease duration, BMI, smoking, immunosuppression, and number of dermatology visits. The study population consisted of 13,812 patients (4,604 HS and 9,208 acne patients), of which 59% were white, 74.7% female, and mean (SD) age was 43.7 (15.4) years. Adjusted odds ratio (OR) for incident BCC risk in HS was OR 0.51 (95% CI 0.37-0.71, P<0.001) whereas adjusted OR for incident SCC risk was 0.79 (95% CI 0.54-1.17, P=0.238). There were no statistical differences in age, gender, and race among those who developed BCC or SCC between groups (all P>0.05). Our results suggest that HS patients have reduced risk of BCC, and similar risk of SCC, compared with controls (acne patients). Further studies are needed to investigate whether decreased Notch signaling in HS patients plays a protective role in BCC tumorigenesis or whether inflammation of the pilosebaceous unit in acne affects follicular bulge cells to increase risk of BCCs.

CHK1/2 Inhibitor Prexasertib Suppresses NOTCH Signaling and Enhances Cytotoxicity of Cisplatin and Radiation in Head and Neck Squamous Cell Carcinoma.

Platinum-based chemoradiotherapy is a mainstay of organ-preserving therapy for patients with head and neck squamous cell carcinoma cancer (HNSCC). However, the disease eventually becomes resistant to treatment necessitating new therapies. Checkpoint kinase 1 and 2 (CHK1/2) are serine/threonine kinases that activate cell-cycle checkpoints and serve a critical role in the DNA-damage response (DDR). As resistance to cisplatin and radiation may involve a heightened DDR, we hypothesized that prexasertib, an inhibitor of CHK1/2, may enhance the cytotoxicity induced by cisplatin and irradiation in HNSCC. In this study, we found that combining prexasertib with cisplatin and radiation significantly decreased the in vitro survival fraction in HNSCC cell lines both with and without radiotherapy. Reduced survival was accompanied by inhibition of DNA repair checkpoint activation, which resulted in persistent DNA damage and increased apoptosis. In addition, NanoString analysis with the PanCancer Pathways Panel revealed that prexasertib downregulated NOTCH signaling target genes (NOTCH1, NOTCH2, and NOTCH3) and their associated ligands (JAG1, JAG2, SKP2, MAML2, and DLL1). Prexasertib also reduced NOTCH1, NOTCH3 and HES1 protein expression. Importantly, a significant tumor growth delay was observed in vivo in both human papillomavirus (HPV)-positive UM-SCC47 and HPV-negative UM-SCC1 cell line xenografts treated with prexasertib, cisplatin, and radiotherapy without increased toxicity as measured by mouse body weight. Taken together, prexasertib reduced NOTCH signaling and enhanced the in vitro and in vivo response of HNSCCs to cisplatin and radiation, suggesting combination therapy may increase clinical benefit. A clinical trial has recently completed accrual (NCT02555644).

Antiproliferative effect of Moringa oleifera methanolic leaf extract by down-regulation of Notch signaling in DU145 prostate cancer cells

ObjectiveRecent research suggested that Notch signaling pathway may be abnormally activated and thus leads to the development and progression of several carcinomas including prostate cancer. Various parts of Moringa oleifera and their phytochemicals are widely used in the treatment of various types of disorders including cancer. The present work designed to evaluate the anticancer effect of Moringa oleifera methanolic leaves extract mediated by inhibition of Notch signaling pathway in human prostate cancer DU145 cell line. MethodsThe human prostate cancer DU145 cell line was cultured and maintained in RPMI-1640 media. The cell viability was measured by MTT assay and phase-contrast microscopy after treatment with various concentrations of Moringa oleifera methanolic leaves extract. Nuclear morphology, the percentage of apoptotic cells were analyzed by DAPI staining and FITC-Annexin V/PI double staining methods respectively. Gene expression analysis of Bax, Bcl-2, and Notch signaling related genes were determined using real-time PCR. ResultsMoringa oleifera methanolic leaves extract significantly inhibits cell survival, marked morphological and nuclear alterations in a concentration-dependent manner. Apoptotic induction was associated with marked upregulation of Bax expression with concurrent downregulation of the Bcl-2 gene. Additionally, extract treatment results in suppression of abnormal Notch signaling pathway via downregulating Notch-1 and Hes-1 expression. ConclusionThese observations clearly revealed that the antiproliferative effect of Moringa oleifera methanolic leaves extract against prostate cancer DU145 is mediated through apoptotic induction and suppression of the aberrant Notch signaling pathway.

Development of Therapeutic Anti-JAGGED1 Antibodies for Cancer Therapy.

The role of Notch signaling and its ligand JAGGED1 (JAG1) in tumor biology has been firmly established, making them appealing therapeutic targets for cancer treatment. Here, we report the development and characterization of human/rat-specific JAG1-neutralizing mAbs. Epitope mapping identified their binding to the Notch receptor interaction site within the JAG1 Delta/Serrate/Lag2 domain, where E228D substitution prevented effective binding to the murine Jag1 ortholog. These antibodies were able to specifically inhibit JAG1-Notch binding in vitro, downregulate Notch signaling in cancer cells, and block the heterotypic JAG1-mediated Notch signaling between endothelial and vascular smooth muscle cells. Functionally, in vitro treatment impaired three-dimensional growth of breast cancer cell spheroids, in association with a reduction in cancer stem cell number. In vivo testing showed variable effects on human xenograft growth when only tumor-expressed JAG1 was targeted (mouse models) but a more robust effect when stromal-expressed Jag1 was also targeted (rat MDA-MB-231 xenograft model). Importantly, treatment of established triple receptor-negative breast cancer brain metastasis in rats showed a significant reduction in neoplastic growth. MRI imaging demonstrated that this was associated with a substantial improvement in blood-brain barrier function and tumor perfusion. Lastly, JAG1-targeting antibody treatment did not cause any detectable toxicity, further supporting its clinical potential for cancer therapy.

MS05.03 Notch Signalling

The Notch signaling pathway is a highly conserved pathway that has a vital role in embryonic development and post-embryonic functions such as hematopoiesis, neural cell development and angiogenesis (1). The signaling pathway is activated by the interaction of 4 Notch receptors and their interactions with 5 different ligands. Signaling is characterized by juxtacrine interaction between ligands and receptors on neighboring cells or within the same cell. Alterations in this pathway have been detected in several tumors both as tumor promoter and tumor suppressor. Notch signaling does appear to have relevance in non-small cell lung cancers (NSCLC) (2). In approximately 30% of NSCLCs loss of Numb, a negative regulator of Notch1, leads to increased Notch activity and about 10% of NSCLCs have gain of function mutations in Notch1. A meta-analysis demonstrated that higher expression of Notch1 was correlated with more advanced tumors (3). In addition, higher expressions of both Notch1 and Notch3 were associated with poor prognosis (4,5). In pre-clinical studies inhibition of Notch3 signaling has reduced growth of lung cancers. In addition, it has been demonstrated that there is cross talk between Notch3 and EGFR pathways and inhibition of both pathways can induce expression of anti-apoptotic protein BIM. Finally, Notch signaling may have a role in induction of the epithelial to mesenchymal phenotype (EMT) in cancers (6). EMT is known to be associated with resistance to both cytotoxic agents and targeted agents and inhibition of Notch signaling can not only reverse EMT but also can enhance the anti-tumor activity of cytotoxic agents such as cisplatin and targeted agents such as erlotinib. The EMT phenotype is frequently observed in a sub-population of cancer cells with self-renewal capacity or cancer stem cells. Notch signaling may be crucial to survival of cancer stem cells and persistence of this population may contribute to resistance to therapeutic agents. In squamous cell lung cancers Notch signaling may have tumor suppressive properties (7). Loss of function mutations in Notch family of genes, predominantly in Notch receptors, are frequently identified in several squamous cell cancers including squamous cell cancer of the lung. Similarly, loss of function mutations in Notch genes, particularly Notch1 have been identified in small cell lung cancer (SCLC). Expression of Notch receptor in a mouse model of SCLC reduced tumor burden, suggesting its tumor suppressive properties. The expression of DLL3, one of the Notch ligands is induced in SCLC by a key transcription factor ASCL1.DLL3 is shown to downregulate Notch signaling in SCLCs and enhance the carcinogenic phenotype. All the above data suggest that Notch signaling is highly contextual. In some tumors this pathway may have tumor suppressive properties but in others tumor promoting properties. Defining the role of this pathway in tumor types may guide development of therapeutic strategies targeting the Notch signaling pathway. Bigas A, Espinosa L. The multiple usages of Notch signaling in development, cell differentiation and cancer. Curr Opin Cell Biol 2018;55:1-7. Westhoff B, Colaluca IN, D’Ario G, et al. Alterations of the Notch pathway in lung cancer. Proc Natl Acad Sci 2009;106:22293-8. Yuan X, Wu H, Xu H, et al. Meta-analysis reveals the correlation of Notch signaling with non-small cell lung cancer progression and prognosis. Sci Rep 2015;5:10338. Donnem T, Andersen S, Al-shibili K, et al. Prognostic impact of Notch ligands and receptors in nonsmall cell lung cancer: coexpression of Notch-1 and vascular endothelial growth factor-A predicts poor survival. Cancer 2010:116:5674-85. Hassan WA, Yoshida R, Kudoh S, et al. Evaluation of role of Notch3 signaling pathway in human lung cancer cells. J Cancer Res Clin Oncol 2016;142:981-93. Yuan X, Wu H, Han N, et al. Notch signaling and EMT in non-small cell lung cancer: biological significance and therapeutic application. J Hematol Oncol 2014;7:87. Nowell CS, Radtke F. Notch as a tumor suppressor. Nat Rev Cancer 2017;17:145-159. squamous, Tumor suppressor, NOTCH

Curcumin attenuates hypoxia/reoxygenation‑induced cardiomyocyte injury by downregulating Notch signaling.

Recovery of the blood supply is the most effective treatment against ischemic heart disease; however, it is also a major cause of myocardial ischemia/reperfusion injury in clinical therapy. Curcumin has been reported to possess beneficial effects against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury by regulating cell proliferation, apoptosis and antioxidant enzyme activity. The aim of the present study was to investigate the molecular mechanisms underlying the effects of curcumin on H/R-injured cardiomyocytes. H9C2 cardiomyocytes were pretreated with curcumin, and then cultured under H/R conditions. The viability of H9C2 cells was measured using a Cell Counting kit-8 assay, and the levels of intracellular lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured to assess cell injury. Levels of reactive oxygen species (ROS) and apoptosis were evaluated by flow cytometry. The expression levels of Notch intracellular domain (NICD) and numerous downstream genes were analyzed via reverse transcription-quantitative polymerase chain reaction and western blotting. The results revealed that curcumin protected H9C2 cells against H/R-induced injury, reversing the H/R-induced increases in LDH and MDA levels, and decreases in SOD levels. ROS levels in H/R-induced cells were also significantly downregulated by curcumin treatment (P<0.01), and the apoptotic rate was significantly decreased from 15.13% in the H/R group to 7.7% in the H/R + curcumin group (P<0.01). The expression levels of NICD, hairy and enhancer of split (Hes)-1, Hes-5 and hairy/enhancer-of-split related with YRPW motif protein 1 (Hey-1) were significantly decreased in H/R-treated cells following curcumin treatment. Treatment with Jagged1 attenuated the effects of curcumin on cell viability, ROS levels and apoptosis; the Notch pathway was also reactivated. The present study indicated that there was a role for the Notch pathway in the protective effects of curcumin against H/R-induced cardiomyocyte injury, suggesting that downregulation of the Notch pathway may alleviate H/R-induced injury in H9C2 cells.

Inhibition of microRNA-34a Suppresses Epileptiform Discharges Through Regulating Notch Signaling and Apoptosis in Cultured Hippocampal Neurons

Epilepsy is characterized by recurrent unprovoked seizures and some seizures can cause neuronal apoptosis, which is possible to make contributions to the epilepsy phenotype, impairments in cognitive function or even epileptogenesis. Moreover, many studies have indicated that microRNA-34a (miRNA-34a) is involved in apoptosis through regulating Notch signaling. However, whether miRNA-34a participates in neuronal apoptosis after seizures remain unclear. Therefore, we aimed to explore the expression of miRNA-34a and its effects on the epileptiform discharge in spontaneous recurrent epileptiform discharges (SREDs) rat hippocampal neuronal pattern. Mg2+-free medium was used to induce SREDs, quantitative reverse-transcription polymerase chain reaction was used to detect the expression of miRNA-34a, western blot was used to determine the expression of Notch pathway and apoptosis-related proteins, and whole cell current clamp recordings was used to observe the alteration of epileptiform discharge. We found obvious apoptosis, increased expression of miRNA-34a and decreased expression of Notch signaling in Mg2+-free-treated neurons. Treatment with miRNA-34a inhibitor decreased the frequency of action potentials, activated Notch signaling and prevented neuronal apoptosis in Mg2+-free-treated neurons. However, treatment with miRNA-34a mimics increased the frequency of action potentials, down-regulated Notch signaling and promoted neuronal apoptosis in Mg2+-free-treated neurons. Furthermore, γ-secretase inhibitor N-[N-(3,5-di-uorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester (DAPT), an inhibitor of Notch signaling, could weaken anti-apoptosis effect of miRNA-34a inhibitor. These results suggest that inhibition of miRNA-34a could suppress epileptiform discharges through regulating Notch signaling and apoptosis in the rat hippocampal neuronal model of SREDs.

Synergistic interaction of Deltex and Hrp48 leads to JNK activation.

The communication among the cells plays a seminal role in metazoan development by coordinating multiple cellular processes that, in turn, helps in the maintenance of biological homeostasis. Our previous study demonstrated that Dx and Hrp48 together downregulate Notch signaling and induce cell death in Drosophila. To understand the signaling events behind the Dx and Hrp48-induced cell death in a greater detail, we performed a set of genetic experiments followed by immunocytochemical analyses. Our data revealed that Dx along with Hrp48 induced JNK activation and consequently cell death in the eye tissue. Additionally, using genetic and molecular approaches, we identified the domain of Dx protein responsible for its synergistic activity with Hrp48. Altogether, our analyses suggest that coexpression of Dx and Hrp48 activates JNK pathway to induce cell death in eye disc of Drosophila melanogaster.

Notch pathway inhibition using DAPT, a γ-secretase inhibitor (GSI), enhances the antitumor effect of cisplatin in resistant osteosarcoma.

Overcoming platinum drug resistance represents a major clinical challenge in osteosarcoma (OS) treatment. The high rates and patterns of therapeutic failure seen in patients are consistent with a steady accumulation of drug-resistant cancer stem cells (CSCs). Notch signaling is implicated in regulating CSCs and tumor resistance to platinum. Thus, we attempt to investigate whether inhibiting of Notch pathway could sensitize cisplatin (CDDP) to CDDP-resistant OS cells and the underlying molecular mechanisms. OS cell lines resistant to CDDP were treated with DAPT, CDDP or combination, we present evidences that DAPT enhances the cytotoxic effect of CDDP in resistant OS by inhibiting proliferation, resulting in G0/G1 cell-cycle arrest, inducing apoptosis, and reducing motility. In addition, DAPT targeting depletes OS stem cells (OSCs), thus increasing tumor sensitivity to platinum, which indicating that a dual combination targeting both OSCs and the bulk of tumor cells are needed for tumor eradication. We also found that the combination of CDDP and DAPT exhibit additive suppression on phosphorylated AKT and ERK, contributing to the anti-cancer effects. In animal model, this combination therapy inhibits the growth and metastasis of CDDP resistant tumor xenografts in nude mice to a greater extent than treatment with either reagent alone. Based on these results, we conclude that CDDP plus DAPT was able to sensitize CDDP-resistant human OS cells to CDDP by downregulation of Notch signaling. CDDP and DAPT combination treatment may be effective and promising for advanced OS.

Rer1-mediated quality control system is required for neural stem cell maintenance during cerebral cortex development.

Rer1 is a retrieval receptor for endoplasmic reticulum (ER) retention of various ER membrane proteins and unassembled or immature components of membrane protein complexes. However, its physiological functions during mammalian development remain unclear. This study aimed to investigate the role of Rer1-mediated quality control system in mammalian development. We show that Rer1 is required for the sufficient cell surface expression and activity of γ-secretase complex, which modulates Notch signaling during mouse cerebral cortex development. When Rer1 was depleted in the mouse cerebral cortex, the number of neural stem cells decreased significantly, and malformation of the cerebral cortex was observed. Rer1 loss reduced γ-secretase activity and downregulated Notch signaling in the developing cerebral cortex. In Rer1-deficient cells, a subpopulation of γ-secretase complexes and components was transported to and degraded in lysosomes, thereby significantly reducing the amount of γ-secretase complex on the cell surface. These results suggest that Rer1 maintains Notch signaling by maintaining sufficient expression of the γ-secretase complex on the cell surface and regulating neural stem cell maintenance during cerebral cortex development.

Downregulating Notch counteracts KrasG12D-induced ERK activation and oxidative phosphorylation in myeloproliferative neoplasm.

The Notch signaling pathway contributes to the pathogenesis of a wide spectrum of human cancers, including hematopoietic malignancies. Its functions are highly dependent on the specific cellular context. Gain-of-function NOTCH1 mutations are prevalent in human T cell leukemia, while loss of Notch signaling is reported in myeloid leukemias. Here, we report a novel oncogenic function of Notch signaling in oncogenic Kras-induced myeloproliferative neoplasm (MPN). We find that downregulation of Notch signaling in hematopoietic cells via DNMAML expression or Pofut1 deletion significantly blocks MPN development in KrasG12D mice in a cell-autonomous manner. Further mechanistic studies indicate that inhibition of Notch signaling significantly upregulates Dusp1, a dual phosphatase that inactivates p-ERK, and downregulates cytokine-evoked ERK activation in KrasG12D cells. Moreover, mitochondrial metabolism is greatly enhanced in KrasG12D cells but significantly reprogrammed by DNMAML close to that in control cells. Consequently, cell proliferation and expanded myeloid compartment in KrasG12D mice are significantly reduced. Consistent with these findings, combined inhibition of the MEK/ERK pathway and mitochondrial oxidative phosphorylation effectively inhibited the growth of human and mouse leukemia cells in vitro. Our study provides a strong rational to target both ERK signaling and aberrant metabolism in oncogenic Ras-driven myeloid leukemia.

Light-sheet Fluorescence Microscopy to Capture 4-Dimensional Images of the Effects of Modulating Shear Stress on the Developing Zebrafish Heart.

The hemodynamic forces experienced by the heart influence cardiac development, especially trabeculation, which forms a network of branching outgrowths from the myocardium. Genetic program defects in the Notch signaling cascade are involved in ventricular defects such as Left Ventricular Non-Compaction Cardiomyopathy or Hypoplastic Left Heart Syndrome. Using this protocol, it can be determined that shear stress driven trabeculation and Notch signaling are related to one another. Using Light-sheet Fluorescence Microscopy, visualization of the developing zebrafish heart was possible. In this manuscript, it was assessed whether hemodynamic forces modulate the initiation of trabeculation via Notch signaling and thus, influence contractile function occurs. For qualitative and quantitative shear stress analysis, 4-D (3-D+time) images were acquired during zebrafish cardiac morphogenesis, and integrated light-sheet fluorescence microscopy with 4-D synchronization captured the ventricular motion. Blood viscosity was reduced via gata1a-morpholino oligonucleotides (MO) micro-injection to decrease shear stress, thereby, down-regulating Notch signaling and attenuating trabeculation. Co-injection of Nrg1 mRNA with gata1a MO rescued Notch-related genes to restore trabeculation. To confirm shear stress driven Notch signaling influences trabeculation, cardiomyocyte contraction was further arrested via tnnt2a-MO to reduce hemodynamic forces, thereby, down-regulating Notch target genes to develop a non-trabeculated myocardium. Finally, corroboration of the expression patterns of shear stress-responsive Notch genes was conducted by subjecting endothelial cells to pulsatile flow. Thus, the 4-D light-sheet microscopy uncovered hemodynamic forces underlying Notch signaling and trabeculation with clinical relevance to non-compaction cardiomyopathy.

Abstract LB-182: Notch signaling pathway is transcriptionally elevated in anaplastic thyroid cancer

Abstract Anaplastic thyroid cancer (ATC), contrary to well-differentiated papillary thyroid cancer (PTC), is one of the most aggressive human malignancies. Anaplastic thyroid cancer is responsible for more than half of all thyroid cancer deaths, with an overall mortality rate about 70% at 6 months and 81% at 12 months, despite only accounting for &amp;lt;2% of thyroid cancer incidence [1]. Both PTC and ATC are MAPK-driven cancers that have two mutually exclusive drivers with distinct signaling consequences: BRAF V600E mutation and RAS mutation [2-3]. In PTC, BRAF (V600E)-like tumors showed higher MAPK transcriptional output and lower expression of genes related with iodine metabolism, and RAS-like tumors showed lower MAPK signaling and comparatively higher expression of iodine metabolism genes. However, in ATC both BRAF mutant and RAS mutant tumors showed BRAF-like tumor transcriptional output. Down-regulation of Notch signaling by gamma-secretase inhibitor (GSI) or Notch1 RNAi reduced PTC cell proliferation [3]. Here by combining multiple gene expression microarray studies (TCGA, GSE27155, GSE29265 and GSE33630), we showed that compared with normal thyroid tissue the Notch signaling pathway was up-regulated in both PTC and ATC. However, ATC and PTC showed different activation patterns in terms of expression of Notch receptors, ligands and downstream targets. Compared with normal thyroid tissue, Notch1, Notch3 and JAG1 were up-regulated in both ATC and PTC, but were much higher in ATC. Compared with normal thyroid tissue, HEY1, HES4 and NRARP were up-regulated in both ATC and PTC. Comparing with PTC, HEY1 was also higher in ATC. However, HES1 was down-regulated in ATC but up-regulated in PTC. It was also reported that both Notch1 and Hes1 were up-regulated by activation of MAPK signaling in thyroid follicular cells with RET/PTC3 or BRAF (T1799A) [4]. Notch1 protein level was also higher in PTC [3]. All of the evidence above supports the hypothesis that Notch pathway may be a key signaling component along with aberrant activation of MAPK pathway in ATC. These data suggest inhibition of Notch signaling alone and/or combination with MAPK signaling inhibitors, such as BRAF inhibitor or ERK inhibitor, may be of benefit in ATC, and support investigation in a clinical trial. 1. Anaplastic Thyroid Carcinoma: Treatment Outcome and Prognostic Factors. Cancer 103 1330-1335,2015. 2. Integrated Genomic Characterization of Papillary Thyroid Carcinoma. Cell 159, 676-690, 2014. 3. Notch Pathway is activated by MAPK signaling and influences papillary thyroid cancer proliferation. Translational oncology, 6,197-205, 2013. 4. Genomic and transcriptomic hallmarks of poorly differentiated and anaplastic thyroid cancers. JCI, 126, 1052-1066, 2016. Citation Format: Yan Ding, Hui-Rong Qian, Bharvin K R Patel, Gerald Joseph Oakley, Karim A. Benhadji, Emma Bowden, Amit Aggarwal. Notch signaling pathway is transcriptionally elevated in anaplastic thyroid cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-182.

Abstract 4343: Molecular identification of bladder cancer gene expression subtypes

Abstract Bladder urothelial carcinoma (BLCA) comprises two main types: non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). To discovery the subtype of BLCA, we used gene expression data from 165 patient cohort (102 NMIBC, 63 MIBC). Three other gene expression data sets including the Sweden 1 cohort (97 NMIBC, 45 MIBC), the Sweden 2 cohort (213 NMIBC, 93 MIBC), and 408 MIBC sample from The Cancer Genome Atlas (TCGA) and 476 sample (460 NMIBC, 16 MIBC, the multicenter European UROMOL consortium). For selection of subtype-specific gene set, we used significance analysis of microarrays (SAM). Then, subtype-specific genes were trained by prediction analysis for microarrays (PAM) to build a classifier. Clustering analyses were applied to gene expression data of training set identified four molecular subtypes with different clinical outcomes. The majority of patients with class 1 were the low-grade NMIBC and associated with the prognosis of NMIBC, for cancer-specific survival (P =0.003, log-rank test). Class 2 patients, characterized by FGFR3 overexpression and downregulated immune pathways, showed the intermediate prognosis. Class 3 tumors showed high expression of cell-cycle genes and downregulated notch signaling pathway. Furthermore, high-grade NMIBC were predominantly found in class 3, indicating that NMIBC patients classified as class 3 would be more likely to progress to MIBC. Class 4 tumors, mainly composed of MIBC, were characterized by high expression of immune-related genes which is positively associated with potential response to immunotherapy. We further validated the BLCA subtypes in four independent data sets (n = 1,471), including the RNA-seq data set, by applying the 786-gene classifier onto the data sets. As expected, the progression rate of NMIBC patients classified as class 3 was significantly increased compared with other three classes in the RNA-seq data set (P &amp;lt; 0.001, log-rank test). Citation Format: In-Sun Chu, Bic-Na Song, Sun-Hee Leem. Molecular identification of bladder cancer gene expression subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4343.

Deltex interacts with Eiger and consequently influences the cell death in Drosophila melanogaster

TNF-JNK signaling is one of the highly conserved signaling pathways that regulate a broad spectrum of cellular processes including proliferation and apoptosis. Eiger, the sole homologue of TNF in Drosophila, initiates the TNF-JNK pathway to induce cell death. Previously, Deltex (Dx) has been identified as a Notch signaling component that regulates vesicular trafficking of Notch. In the present study, we have investigated the interaction between these two proteins in order to identify how Dx influences the activity of Eiger. Dx is found to act as a novel modulator of JNK-mediated cell death inducing activity of Eiger. Additionally, we observe that dx genetically interacts with eiger during wing development, and these two proteins, Dx and Eiger, colocalize in the cytoplasm. Our analysis reveals that Dx is involved in the cytoplasmic relocalization of Eiger from the cell membrane, thereby influencing Eiger-mediated JNK-activation process. Moreover, we demonstrate that Dx potentiates the activity of Eiger to downregulate Notch signaling pathway by retaining the Notch protein in the cytoplasm. Together, our findings reveal a novel role of Dx to modulate the signaling activity of Eiger and subsequent JNK-mediated cell death.

HepaCAM inhibits the malignant behavior of castration-resistant prostate cancer cells by downregulating Notch signaling and PF-3084014 (a γ-secretase inhibitor) partly reverses the resistance of refractory prostate cancer to docetaxel and enzalutamide in vitro.

Castration-resistant prostate cancer (CRPC) continues to be a major challenge in the treatment of prostate cancer (PCa). The expression of hepatocyte cell adhesion molecule (HepaCAM), a novel tumor suppressor, is frequently downregulated or lost in PCa. Overactivated Notch signaling is involved in the development and progression of PCa, including CRPC. In this study, we found that the activities of Notch signaling were elevated, while HepaCAM expression was decreased in CRPC tissues compared with matched primary prostate cancer (PPC) tissues. In addition, HepaCAM negativity was found to be associated with a worse progression-free survival (PFS). Furthermore, the overexpression of HepaCAM induced by transfection with a HepaCAM overexpression vector (Ad-HepaCAM) exerted antitumor effects by decreasing the proliferation, and suppressing the invasion and migration of bicalutamide-resistant (Bica-R) cells and enzalutamide-resistant (Enza-R) cells. Importantly, we found that the antitumor effects of HepaCAM on the resistant cells were associated with the downregulation of Notch signaling. Moreover, we revealed that PF-3084014 (a γ-secretase inhibitor) re-sensitized Enza-R cells to enzalutamide, and sequential dual-resistant (E+D-R) cells to docetaxel. Additionally, the findings of this study demonstrated that the use of PF-3084014 alone exerted potent antitumor effect on the resistant cells in vitro. On the whole, this study indicates that HepaCAM potentially represents a therapeutic target and PF-3084014 may prove to a promising agent for use in the treatment of refractory PCa.

KIAA0247 inhibits growth, migration, invasion of non-small-cell lung cancer through regulating the Notch pathway.

Lung cancer remains the leading cause of cancer‐related death worldwide. Previous studies have shown that the novel KIAA0247 gene potentially targeted by the tumor suppressor p53 may inhibit the development of several cancers. However, the exact function of KIAA0247 in non‐small‐cell lung cancer (NSCLC) is unknown. The purpose of the present study was to clarify the role of KIAA0247 in NSCLC. KIAA0247 expression was evaluated in tumors and adjacent normal tissues of 197 NSCLC patients by immunohistochemistry and real‐time PCR and analyzed for association with clinicopathological parameters. Results indicated that KIAA0247 levels positively correlated with cell differentiation (P < .001) and patient survival (P < .0001) and negatively correlated with lymph node metastasis (P < .001) and advanced p‐TNM stage (P < .001). In cultured NSCLC cell lines, KIAA0247 overexpression inhibited cell migration, invasion, and proliferation and downregulated the expression of Jagged1, Notch1 intracellular domain (NICD), Snail, cyclin D1, RhoA, RhoC, and MMP9, while upregulating that of E‐cadherin and p21. The Notch inhibitor DAPT reduced the biological effects of KIAA0247 knockdown, suggesting that KIAA0247 decreased the carcinogenic activity of NSCLC cells through downregulation of Notch signaling. Our results indicate that KIAA0247 inhibits NSCLC progression by reducing the metastatic potential of cancer cells through downregulation of the Notch pathway, which may underlie the association of KIAA0247 expression with favorable clinicopathological characteristics of NSCLC patients. These findings suggest that KIAA0247 is a candidate prognostic biomarker and potential therapeutic target in NSCLC.

BMI1 Inhibitors Down-regulate NOTCH Signaling and Suppress Proliferation of Acute Leukemia Cells.

B cell-specific Moloney murine leukemia virus integration site 1 (BMI1) is up-regulated in several cancers; therefore, we investigated the effects of BMI1 inhibitors on leukemia cells. Four acute myeloid leukemia and two T-lymphoblastic leukemia cell lines were treated with BMI1 inhibitors artemisinin, PRT4165, and PTC-209 and analyzed for cell proliferation and gene expression by microarray and immunoblotting. PTC-209 and PRT4165 suppressed the growth of all cell lines through apoptosis.Artemisinin acted only on Jurkat cells. BMI1 inhibitors and BMI1-specific siRNA down-regulated the expression of NOTCH signaling proteins NOTCH1, HES1, and MYC. All but one cell lines did not have the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene targeted by BMI1, thus the inhibitors acted through CDKN2A-independent pathways. BMI1 inhibition suppressed proliferation of leukemia cells through NOTCH signaling which functions downstream of BMI1, suggesting that BMI1 inhibitors can be candidate targeted drugs against leukemia.

Down-regulated notch signaling in arpe-19 cells Cultured on denuded human Amniotic membrane.

Down-regulated notch signaling in arpe-19 cells Cultured on denuded human Amniotic membrane.