Role Of Notch Signaling Pathway Research Articles

The role of Notch signaling in diabetic endothelial progenitor cells dysfunction

AimsTo investigate the role of Notch signaling pathway in vasculogenic dysfunction of diabetic EPCs (DM-EPCs). MethodsThe study was performed in mice and diabetes was induced with Streptozotocin. The functional consequences of Notch pathway modulation were studied by assessment of colony forming capacity (EPC colony forming assay), EPC differentiation capacity (% of definitive EPC-CFU (dEPC-CFU)), circulating EPCs (EPC culture assay) and migrated cells (migration assay); in the presence of Notch inhibitor (γ-secretase inhibitors (GSI)) compared to control. Notch pathway and VEGF involvement in DM- EPCs were assessed by gene expression (RT-qPCR). ResultsDM demonstrated to increase Notch pathway expression in bone marrow (BM) EPCs followed by lower EPC-CFU number, EPCs differentiation capacity, number of circulating EPCs, migrated cells and VEGF expression compared to control (p<0.05). Inhibition of Notch pathway by GSI rescued vasculogenic dysfunction in DM-EPCs as represented by increase in EPC-CFU number, differentiation capacity and number of circulating EPCs (p<0.05). ConclusionOur findings indicate the involvement of Notch pathway in mediating DM-EPCs dysfunction including less number of EPC-CFU, circulating EPCs and migrated cell number compared to control. Further in vitro inhibition of Notch pathway by GSI rescued DM-EPC dysfunction. Therefore targeting Notch pathway in DM may provide a target to restore DM-EPC dysfunction.

Notch signaling regulates osteogenic differentiation through different roles played by different Notch molecular components

Osteogenic differentiation process consists of integration of several signaling pathways such as TGF-β, BMP, Wnt/β-catenin (1,2) and Notch which orchestrate to regulate differentiation of mesenchymal stem cells. To date, the role of Notch signaling pathway, which is known to regulate cell fate decision and differentiation in several cell types is still poorly understood in osteogenic differentiation, as controversial results have been described. Notch signaling is initiated by binding a Notch ligand (JAGGED and Delta-Like) to a cell surface Notch receptor (NOTCH 1–4), resulting in a multistep cleavage of receptor and releasing Notch intracellular domain (NICD) which translocates to the nucleus and activates transcription of downstream Notch target genes, such as the Hes/Hey family (3). The aim of this study was to investigate the involvement of Notch signaling in the osteogenic dif- ferentiation. To this purpose, we stimulated human immature osteoblast cell line (MG-63) with osteogenic medium for 28 days, in the absence and in the presence of DAPT, a gamma-secretase inhibitor used to block Notch signaling. At different days during differentia- tion, we investigated biochemical osteogenic markers such as Alkaline phosphatase (ALP) activity, osteocalcin (OC) levels, mineralization as well as gene expression of osteogenic transcription factors including Runx2, DLX5, Osterix and the gene Collagen I (CollI). Further, the gene expression of Notch receptors (Notch1-4), their ligands (Jagged1 and DLL4) and nuclear target genes (Hey1, Hey2, hes1, Hes5) was evaluated. As expected, our results showed that during osteogenic differentiation of MG63, osteogenic markers and transcription factors were upregulated. In addition, Notch2, Notch4 and Hey1 were overexpressed in different stages of differentiation. Differently, Notch1, Notch3 and Hes5 were down-regulated. No differences were observed about Notch ligands. Treatment of cells with DAPT, impaired osteogenic differentiation by reducing the main osteogenic markers such as ALP, OC, Coll I, , Runx2, DLX5 and Osterix as well as Hey1 nuclear gene. These results appear to confirm a significant role of Notch signaling during osteogenic differentiation by the activation of the canonical pathway with the main involvement of Notch 2 and Notch 4 receptors and Hey1 as nuclear target gene. In clinics these data may be relevant as they propose that Notch pathway can be used as a therapeutic target during bone defects and pathologies.

Clinical role of Notch signaling pathway in intraductal papillary mucinous neoplasm of the pancreas.

This study was performed to elucidate the expression of the Notch signaling pathway and its correlations to clinicopathological factors of intraductal papillary mucinous neoplasms (IPMNs). It is incontrovertible that regulatory T cells (Tregs) play an important role in tumor immunity. However, the whole mechanism of control of peripheral Tregs remains unclear. It is also known that the Notch signaling pathway is involved in Treg suppressor function. Moreover, IPMNs have a high malignant potential. Peripheral blood samples and resected specimens from 18 patients with IPMN were evaluated. All patients were pathologically diagnosed with IPMN. Resected specimens were immunohistochemically evaluated (anti-Notch1, anti-Notch2, and anti-Notch2-intracellular domain antibody staining) and compared in terms of clinicopathological factors. Peripheral Treg populations were analyzed with an automated flow cytometer. Disease-free survival was significantly worse in the Notch1 high-expression group (P = 0.023). Notch2 family expressions were higher in intraductal papillary mucinous carcinoma (IPMC) than in intraductal papillary mucinous adenoma (IPMA) (Notch2, P = 0.012; Notch2-intracellular domain, P = 0.036). Jagged1 expression was significantly higher in IPMC than in IPMA (P < 0.05) and was significantly related to recurrence. The Treg population in peripheral blood was higher in patients with IPMC than in those with IPMA (P < 0.01). Notch signaling, especially Jagged1 expression, reflects IPMN aggressiveness. Our data may suggest that the Notch signaling pathway is a key pathway that determines IPMN pathological aggressiveness and reflects the peripheral Treg population.

Role of Notch signaling pathway in gastric cancer: a meta-analysis of the literature.

To perform a meta-analysis to quantitatively summarize the evidence for the association between the Notch signaling pathway and gastric cancer (GC). An electronic search of the MEDLINE, EMBASE and Chinese National Knowledge Infrastructure, which contain articles published from 1966 onwards, was conducted to select studies for this meta-analysis. Fifteen studies with a total of 1547 gastric cancer cases and 450 controls were included in this meta-analysis. Overall, the expression of Notch1, Notch2, Delta-like 4 and Hes1 was significantly higher in tumor tissues of GC compared to normal tissues. Specifically, stratified analyses showed that significantly increased expression of Notch1 was associated with non-cardia location, > 5 cm size, diffuse type, positive lymphovascular invasion and distal metastasis. Statistically significant higher expression of Notch3 was found in diffuse type GC. Jagged1 was also significantly over-expressed in diffuse type and poor differentiation type of GC. DLL4 was significantly over-expressed in advanced T stage, N stage and TNM stage in GC patients. However, the stratified analysis showed that there was no statistically significant difference in Hes1 expression between different subgroups. Sporadic reports showed that Notch1 and Jagged1 were independent poor prognostic predictors in GC. The Notch signaling pathway plays an important role in tumor progression of gastric cancer.

Notch signaling pathway in 1-methyl-4-phenylpyridinium-induced apoptosis of SH-SY5Y cell

To explore the role of Notch signaling pathway and the effect of γ-secretase inhibitor (DAPT) on the apoptosis induced by 1-methyl-4-phenylpyridinium (MPP(+)) in differentiated SH-SY5Y cell. SH-SY5Y cell were incubated with various concentrations (0, 0.5, 1, 1.5, 2 mmol/L) of MPP(+) for 0, 24, 48 and 72 h respectively. Flow cytometry with Annexin V-FITC/PI double staining was used for apoptotic analysis. The protein expressions of Notch-1, Jagged-1 and Hes-1 were detected by Western blot. SH-SY5Y cell were preincubated with 10 µmol/L DAPT for 15 min before 1.5 mmol/L MPP(+) treatment for 48 h. Flow cytometry and Western blot were performed to analyze the cell apoptosis and protein expressions of Notch-1, Jagged-1 and Hes-1. MPP(+) induced the apoptosis of SH-SY5Y cell in a dose (3.20% ± 0.19% vs 10.00% ± 1.72%, 20.60% ± 3.76%, 32.80% ± 5.12%, 46.00% ± 5.06%, all P < 0.05) and time- (2.80% ± 0.21% vs 12.30% ± 1.82%, 19.60% ± 2.89%, 35.00% ± 4.78%, all P < 0.05) dependent manner. MPP(+) up-regulated the expressions of Notch-1, Jagged-1 and Hes-1 in a dose- and time-dependent manner in SH-SY5Y cell. DAPT treatment decreased MPP(+)-induced apoptosis (3.10% ± 0.21% vs 35.50% ± 4.98%, 19.20% ± 2.98%, both P < 0.05) and the expressions of Notch-1, Jagged-1 and Hes-1 in SH-SY5Y cell. The activation of Notch signaling pathway plays an important role in MPP(+)-induced apoptosis of SH-SY5Y cell. DAPT inhibits Notch signaling pathway and protects SH-SY5Y cell from MPP(+)-induced apoptosis.

Regulation of EMT by Notch Signaling Pathway in Tumor Progression

Notch signaling pathway has been reported to play critical roles in the development and progression of human cancers because Notch signaling pathway is critically involved in many cellular processes including cell proliferation, survival, apoptosis, migration, invasion, angiogenesis, and metastasis. Emerging evidence suggests that Notch regulates EMT (Epithelial-to-Mesenchymal Transition), leading to tumor invasion and metastasis. Thus, this mini-review is focused on discussing the novel role of Notch signaling pathway in the regulation of EMT. Moreover, we summarized that Notch signaling pathway could be down-regulated by its inhibitors or natural compounds, resulting in the reversal of EMT to MET (Mesenchymal-to-Epithelial Transition), which could be a promising strategy for achieving better treatment outcome in patients diagnosed with cancer.

Role of Notch signalling pathway in cancer and its association with DNA methylation

The Notch signalling pathway is an evolutionarily conserved cell signalling pathway involved in the development of organisms as diverse as humans and fruit flies. It plays a pivotal role in cell fate determination. Dysregulated Notch signalling is oncogenic, inhibits apoptosis and promotes cell survival. Abnormal Notch signalling is seen in many cancers like T-cell acute lymphoblastic leukaemia, acute myeloid leukaemia and cancers of the breast, cervix, colon, pancreas, skin and brain. Inhibition of Notch signalling leads to growth arrest and differentiation in those cells in which Notch pathway is activated and this represents a new target for cancer therapy. Cancer develops from genome defects, including both genetic and epigenetic alterations. Epigenetics deals with heritable changes in gene function that occur without a change in the DNA sequence. Among various epigenetic alterations such as acetylation, phosphorylation, ubiquitylation and sumoylation, promoter region methylation is considered as an important component in cancer development. Epigenetic alterations can be used as biomarkers in screening, detection, diagnosis, staging and risk stratification of various cancers. DNA methylation can be therapeutically reversed and demethylating drugs have proven to be promising in cancer treatment. This review focusses on the methylation status of genes in Notch signalling pathway from various cancers and how this epigenetic alteration can be used as a biomarker for cancer diagnosis and subsequent treatment.

Role of Notch signaling pathway in gastric cancer pathogenesis

Notch signaling pathway is activated dynamically during evolution playing significant role in cell fate determination and differentiation. It has been known that alterations of this pathway may lead to human malignancies, including gastric cancer. Despite a decline in the overall incidence, this disease still remains an important global health problem. Therefore, a better understanding of the molecular alterations underlying gastric cancer may contribute to the development of rationally designed molecular targeted therapies. It has been reported that Notch1 receptor could become a prognostic marker of gastric cancer and novel target for gastric cancer therapy. Among the novel and targeted approaches for the treatment of gastric cancer is also the process of Notch receptors regulation by specific microRNA. γ-secretase inhibitors are also taken into consideration.

Therapeutic effect of obestatin in ischemia/reperfusion-induced acute pancreatitis

s / Pancreatology 12 (2012) 502–597 509 Introduction: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Early diagnosis is rare and treatment options are limited. The Notch pathway has recently emerged as a candidate drug target. Notch signalling is important in PDAC initiation and maintenance. This provides a rationale for further analysis of Notch signalling in PDAC carcinogenesis Aims: Based on the known roles of Notch in development and stem cell biology, we investigated the effects of GSI IX on epithelial mesenchymal transition (EMT) and on pancreatic tumor initiating CD44+/EpCAM+ cells. Methods: We analyzed the effect of the GSI IX on growth and epithelial plasticity of human pancreatic cancer cell lines, and on the tumorigenicity of pancreatic tumor initiating CD44+/EpCAM+ cells. In addition, sorted CD44+/EpCAM+ cells were subcutaneously injected into the nude mice (NMRI-nu/nu) and treated with vehicle or with GSI IX. The effect of GSI on Xenograft tumors, EMT markers, and cell proliferation was evaluated. Results: GSI IX inhibited pancreatic cancer cell proliferation, migration and invasion in a dose-dependent manner. Apoptosis was induced after GSI IX treatment and EMT markers reversed partially. GSI IX significantly inhibited the growth of pancreatic tumor initiating CD44+/EpCAM+ cells in vitro and in a xenograft mouse model. Conclusion: Our data support the central role of Notch signalling pathway in pancreatic cancer pathogenesis and identifies an effective approach to inhibit EMT and suppress tumorigenesis by eliminating pancreatic tumor initiating CD44+/EpCAM+ cells.

Acenocoumarol increases the severity of cerulein-induced acute pancreatitis in rats

s / Pancreatology 12 (2012) 502–597 509 Introduction: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Early diagnosis is rare and treatment options are limited. The Notch pathway has recently emerged as a candidate drug target. Notch signalling is important in PDAC initiation and maintenance. This provides a rationale for further analysis of Notch signalling in PDAC carcinogenesis Aims: Based on the known roles of Notch in development and stem cell biology, we investigated the effects of GSI IX on epithelial mesenchymal transition (EMT) and on pancreatic tumor initiating CD44+/EpCAM+ cells. Methods: We analyzed the effect of the GSI IX on growth and epithelial plasticity of human pancreatic cancer cell lines, and on the tumorigenicity of pancreatic tumor initiating CD44+/EpCAM+ cells. In addition, sorted CD44+/EpCAM+ cells were subcutaneously injected into the nude mice (NMRI-nu/nu) and treated with vehicle or with GSI IX. The effect of GSI on Xenograft tumors, EMT markers, and cell proliferation was evaluated. Results: GSI IX inhibited pancreatic cancer cell proliferation, migration and invasion in a dose-dependent manner. Apoptosis was induced after GSI IX treatment and EMT markers reversed partially. GSI IX significantly inhibited the growth of pancreatic tumor initiating CD44+/EpCAM+ cells in vitro and in a xenograft mouse model. Conclusion: Our data support the central role of Notch signalling pathway in pancreatic cancer pathogenesis and identifies an effective approach to inhibit EMT and suppress tumorigenesis by eliminating pancreatic tumor initiating CD44+/EpCAM+ cells.

Epithelial mesenchymal transition and pancreatic tumor initiating CD44+/EpCAM+ cells are inhibited by γ-secretase inhibitor IX.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Recent studies have indicated that the Notch signalling pathway is important in PDAC initiation and maintenance, although the specific cell biological roles of the pathway remain to be established. Here we sought to examine this question in established pancreatic cancer cell lines using the γ-secretase inhibitor IX (GSI IX) to inactivate Notch. Based on the known roles of Notch in development and stem cell biology, we focused on effects on epithelial mesenchymal transition (EMT) and on pancreatic tumor initiating CD44+/EpCAM+ cells. We analyzed the effect of the GSI IX on growth and epithelial plasticity of human pancreatic cancer cell lines, and on the tumorigenicity of pancreatic tumor initiating CD44+/EpCAM+ cells. Notably, apoptosis was induced after GSI IX treatment and EMT markers were selectively targeted. Furthermore, under GSI IX treatment, decline in the growth of pancreatic tumor initiating CD44+/EpCAM+ cells was observed in vitro and in a xenograft mouse model. This study demonstrates a central role of Notch signalling pathway in pancreatic cancer pathogenesis and identifies an effective approach to inhibit selectively EMT and suppress tumorigenesis by eliminating pancreatic tumor initiating CD44+/EpCAM+ cells.

Involvement of notch in activation of human γδ T cells (45.22)

Abstract γδ T cells recognize phosphorylated antigens and play an important role in tumor immunity. The aim of the present study was to investigate the role of Notch signaling pathway in antigen specific responses of γδ T cells. Expression of mRNA for Notch1 and Notch2 genes was predominantly observed in peripheral γδ T cells. The presence of active Notch intracellular domain in γδ T cells was confirmed by confocal microscopy and western blotting. Proliferation of γδ T cells and IFN-γ release in response to phosphoantigens was inhibited in the presence of γ-secretase inhibitor confirming involvement of Notch signal. Delta like ligands 1 and 4 activated γδ T cells while Jagged1 inhibited the γδ T cell response. Oral and breast cancer cells showed dominant expression of Jagged1 ligand which may exert inhibitory signal as a way to evade immune recognition by γδ T cells. Decreased expression of CD107a and diminished lysis of tumor targets in the presence of γ-secretase inhibitor confirmed that Notch was involved in cytotoxic effector functions of γδ T cells. Thus, our data for the first time demonstrates that Notch signal plays an indispensable role in antigen specific responses of γδ T cells. Future immunotherapeutic strategies can exploit Notch signaling in γδ T cells to achieve therapeutic benefits in cancer patients.

Abstract 3336: The role of Notch signaling in esophageal adenocarcinoma

Abstract Background: The Notch signaling pathway plays a critical role in embryonic development and carcinogenesis. Aberrant Notch signaling has been linked to a wide variety of cancers. Activation of Notch pathway can either suppress or promote tumors depending on the cell type and context. However, the role of the Notch pathway in the pathogenesis and development of esophageal adenocarcinoma (EAC) is poorly understood. Objective: Elucidate the role of NOTCH signaling pathway in EAC. Methodology: In this study, the expression of Notch components in EAC tissues, matched non-tumor esophageal mucosa and normal esophagus tissues, EAC cell lines (FLO-1, JH-EsoAd1, OE19 and OE33) and 3 primary esophageal normal epithelial cells were assessed by quantitative RT- PCR, western blot analysis, immunofluorescence and immunohistochemistry. The effect of blocking as well as ectopic activation of the Notch pathway on the proliferation, colony formation, and gene expression were also characterized. Results: The aberrant activation of Notch signaling was observed in human EAC clinical samples. Expression of most Notch pathway components was elevated in EAC. The expression of activated NOTCH1 also associated with the differentiation grade of EAC. We found that blocking Notch activity by gamma-secretase inhibitors(GSI) affects the proliferation and/or survival of EAC cell lines and human EAC samples ex vivo cultures. In contrast, this effect was not observed in human esophageal epithelial cell line, Het-1A. However, we observed that activation of Notch signaling by NOTCH1icd could promote colony formation in Het-1A cells. Conclusions: Our results showed that Notch signaling promotes the growth and pathogenesis of EAC. Therefore, Notch signaling pathway could be a promising therapeutic target for treatment of human EAC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3336. doi:1538-7445.AM2012-3336

Identification of a Potential Ovarian Cancer Stem Cell Gene Expression Profile from Advanced Stage Papillary Serous Ovarian Cancer

Identification of gene expression profiles of cancer stem cells may have significant implications in the understanding of tumor biology and for the design of novel treatments targeted toward these cells. Here we report a potential ovarian cancer stem cell gene expression profile from isolated side population of fresh ascites obtained from women with high-grade advanced stage papillary serous ovarian adenocarcinoma. Affymetrix U133 Plus 2.0 microarrays were used to interrogate the differentially expressed genes between side population (SP) and main population (MP), and the results were analyzed by paired T-test using BRB-ArrayTools. We identified 138 up-regulated and 302 down-regulated genes that were differentially expressed between all 10 SP/MP pairs. Microarray data was validated using qRT-PCR and17/19 (89.5%) genes showed robust correlations between microarray and qRT-PCR expression data. The Pathway Studio analysis identified several genes involved in cell survival, differentiation, proliferation, and apoptosis which are unique to SP cells and a mechanism for the activation of Notch signaling is identified. To validate these findings, we have identified and isolated SP cells enriched for cancer stem cells from human ovarian cancer cell lines. The SP populations were having a higher colony forming efficiency in comparison to its MP counterpart and also capable of sustained expansion and differentiation in to SP and MP phenotypes. 50,000 SP cells produced tumor in nude mice whereas the same number of MP cells failed to give any tumor at 8 weeks after injection. The SP cells demonstrated a dose dependent sensitivity to specific γ-secretase inhibitors implicating the role of Notch signaling pathway in SP cell survival. Further the generated SP gene list was found to be enriched in recurrent ovarian cancer tumors.

Notch Signaling Pathway and Human Placenta

Notch signaling was evolutionarily conserved and critical for cell-fate determination, differentiation and many other biological processes. Growing evidences suggested that Notch signaling pathway played an important role in the mammalian placental development. All of the mammalian Notch family proteins had been identified in human placenta except Delta-like 3, which appeared to affect the axial skeletal system. However the molecular mechanisms that regulated the Notch signaling pathway remained largely unknown in human placenta. Therefore, additional research was needed to investigate expression pattern of Notch family members and the mechanisms for activation of Notch signaling pathway in human placenta, which might help elucidate the roles of Notch signaling pathway in human placentation. This review would focus on the roles of Notch receptors and ligands in the human placental trophoblasts function and placental angiogenesis. It might hopefully provide perspectives for future research about human placentation of pregnancy complicated by preeclampsia and other placenta associated diseases.

The Role of EMT in Pancreatic Cancer Progression

The Role of EMT in Pancreatic Cancer Progression

Role of Notch signaling pathway in retina development and angiogenesis

Retina degeneration and neovascularization are present in many common retinal diseases, which can cause vision disability and blindness. Recent studies have demonstrated that the Notch signaling involves in regulating the development and differentiation of various tissues and cells. In this review, we discuss the compositions of the Notch signaling and its effects in the processes of retina development and angiogenesis. The Notch signaling pathway provides us a novel drug target for the treatment of retinal disease.

Notch signaling pathway regulates adult mammalian central nervous system

Physiologically, Notch signaling pathway is not only to be implicated in the maintenance and self-renewal of adult NSC, but also can inhibit differentiation of NSC to neuron and promotes to neural gila cells. After cerebral ischemia occurs, Notch signaling pathway is activated to regulate the reconstitution of the brain lesion and functional restoration. Here,we review the roles of Notch signaling pathway in the adult mammalian CNS in physiological and pathological conditions. Key words: Notch signaling pathway; Neural stem cells; Neural glia cells; Differentiation; Proliferation

The Role of Notch Signaling Pathway in Epithelial-Mesenchymal Transition (EMT) During Development and Tumor Aggressiveness

The Notch signaling pathway maintains a balance between cell proliferation and apoptosis, and thus it is believed that Notch signaling pathways may play an important role in the development and progression of several malignancies. However, the functions of Notch signaling in EMT are largely unknown. This mini review describes the role of Notch signaling pathway in EMT, and cataloging how its deregulation is involved in EMT and tumor aggressiveness. Further attempts have been made to summarize the role of several chemopreventive agents that could be useful for targeted inactivation of Notch signaling, and thus it may cause reversal of EMT, which could become a novel approach for cancer prevention and treatment.

The Role of Notch Signaling Pathway in Epithelial-Mesenchymal Transition (EMT) During Development and Tumor Aggressiveness

The Role of Notch Signaling Pathway in Epithelial-Mesenchymal Transition (EMT) During Development and Tumor Aggressiveness