scholarly journals Notch activation inhibits AML growth and survival: a potential therapeutic approach

2013 ◽  
Vol 210 (2) ◽  
pp. 321-337 ◽  
Author(s):  
Sankaranarayanan Kannan ◽  
Robert M. Sutphin ◽  
Mandy G. Hall ◽  
Leonard S. Golfman ◽  
Wendy Fang ◽  
...  
Keyword(s):  
Therapeutic Approach ◽  
Growth Arrest ◽  
B Cell Lymphoma ◽  
Receptor Activation ◽  
Notch Receptor ◽  
Myelogenous Leukemia ◽  
Growth And Survival ◽  
Notch Receptors ◽  
Notch Activation

Although aberrant Notch activation contributes to leukemogenesis in T cells, its role in acute myelogenous leukemia (AML) remains unclear. Here, we report that human AML samples have robust expression of Notch receptors; however, Notch receptor activation and expression of downstream Notch targets are remarkably low, suggesting that Notch is present but not constitutively activated in human AML. The functional role of these Notch receptors in AML is not known. Induced activation through any of the Notch receptors (Notch1–4), or through the Notch target Hairy/Enhancer of Split 1 (HES1), consistently leads to AML growth arrest and caspase-dependent apoptosis, which are associated with B cell lymphoma 2 (BCL2) loss and enhanced p53/p21 expression. These effects were dependent on the HES1 repressor domain and were rescued through reexpression of BCL2. Importantly, activated Notch1, Notch2, and HES1 all led to inhibited AML growth in vivo, and Notch inhibition via dnMAML enhanced proliferation in vivo, thus revealing the physiological inhibition of AML growth in vivo in response to Notch signaling. As a novel therapeutic approach, we used a Notch agonist peptide that led to significant apoptosis in AML patient samples. In conclusion, we report consistent Notch-mediated growth arrest and apoptosis in human AML, and propose the development of Notch agonists as a potential therapeutic approach in AML.

scholarly journals Effect of Hes1 on AML Cells: A Potential Therapeutic Target

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5208-5208
Author(s):  
Chen Tian ◽  
Yongsheng Jia ◽  
Dongzhi Hu ◽  
Yizhuo Zhang
Keyword(s):  
Conflicts Of Interest ◽  
Growth Arrest ◽  
Notch Pathway ◽  
Growth And Survival ◽  
Downstream Effector ◽  
Cancer Types ◽  
Notch Signal Pathway ◽  
Notch Activation

Abstract Notch signal pathway is an important mediator of growth and survival in several cancer types, while Notch pathway genes function as oncogenes or tumor suppressors in different cancers. Although aberrant Notch activation contributes to leukemogenesis in T cells, the role of Notch pathway in acute myeloid leukemia (AML) remains unclear. To address this problem, we investigated the expression levels of its downstream effector Hes1 and p21 in primary AML cells and cell lines by realtime PCR and western, and found that both of them was weak in these cells. Induced activation of Hes1 consisently led to AML growth arrest and apoptosis, which was associated with enhanced p21 expression. Besides, overexpression of Hes1 inhibited growth of AML cells in vivo. In conclusion, we reported that Hes1 mediated growth arrest and apoptosis of human AML cells, and demonstrated a novel tumor suppressor role for Hes1 in AML. Disclosures No relevant conflicts of interest to declare.

scholarly journals TspanC8 tetraspanins regulate ADAM10/Kuzbanian trafficking and promote Notch activation in flies and mammals

2012 ◽  
Vol 199 (3) ◽  
pp. 481-496 ◽  
Author(s):  
Emmanuel Dornier ◽  
Franck Coumailleau ◽  
Jean-François Ottavi ◽  
Julien Moretti ◽  
Claude Boucheix ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Endoplasmic Reticulum ◽  
Cell Migration ◽  
Surface Expression ◽  
Receptor Activation ◽  
Notch Receptor ◽  
Ectodomain Shedding ◽  
Border Cells ◽  
Notch Receptors ◽  
Notch Activation

The metalloprotease ADAM10/Kuzbanian catalyzes the ligand-dependent ectodomain shedding of Notch receptors and activates Notch. Here, we show that the human tetraspanins of the evolutionary conserved TspanC8 subfamily (Tspan5, Tspan10, Tspan14, Tspan15, Tspan17, and Tspan33) directly interact with ADAM10, regulate its exit from the endoplasmic reticulum, and that four of them regulate ADAM10 surface expression levels. In an independent RNAi screen in Drosophila, two TspanC8 genes were identified as Notch regulators. Functional analysis of the three Drosophila TspanC8 genes (Tsp3A, Tsp86D, and Tsp26D) indicated that these genes act redundantly to promote Notch signaling. During oogenesis, TspanC8 genes were up-regulated in border cells and regulated Kuzbanian distribution, Notch activity, and cell migration. Furthermore, the human TspanC8 tetraspanins Tspan5 and Tspan14 positively regulated ligand-induced ADAM10-dependent Notch1 signaling. We conclude that TspanC8 tetraspanins have a conserved function in the regulation of ADAM10 trafficking and activity, thereby positively regulating Notch receptor activation.

scholarly journals Current Views on the Roles of O-Glycosylation in Controlling Notch-Ligand Interactions

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 309
Author(s):  
Wataru Saiki ◽  
Chenyu Ma ◽  
Tetsuya Okajima ◽  
Hideyuki Takeuchi
Keyword(s):  
Notch Signaling ◽  
100Th Anniversary ◽  
Notch Receptor ◽  
Notch Receptors ◽  
Evolutionarily Conserved ◽  
Future Challenges ◽  
Ligand Interactions ◽  
Epidermal Growth ◽  
Notch Activation ◽  
Human Specific

The 100th anniversary of Notch discovery in Drosophila has recently passed. The Notch is evolutionarily conserved from Drosophila to humans. The discovery of human-specific Notch genes has led to a better understanding of Notch signaling in development and diseases and will continue to stimulate further research in the future. Notch receptors are responsible for cell-to-cell signaling. They are activated by cell-surface ligands located on adjacent cells. Notch activation plays an important role in determining the fate of cells, and dysregulation of Notch signaling results in numerous human diseases. Notch receptors are primarily activated by ligand binding. Many studies in various fields including genetics, developmental biology, biochemistry, and structural biology conducted over the past two decades have revealed that the activation of the Notch receptor is regulated by unique glycan modifications. Such modifications include O-fucose, O-glucose, and O-N-acetylglucosamine (GlcNAc) on epidermal growth factor-like (EGF) repeats located consecutively in the extracellular domain of Notch receptors. Being fine-tuned by glycans is an important property of Notch receptors. In this review article, we summarize the latest findings on the regulation of Notch activation by glycosylation and discuss future challenges.

scholarly journals POS0042 NOTCH 1 INHIBITION INCREASES OSTEOCLAST PROGENITOR ACTIVITY IN THE MOUSE MODEL OF RHEUMATOID ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 226.3-226
Author(s):  
M. Filipović ◽  
A. Šućur ◽  
D. Flegar ◽  
Z. Jajić ◽  
M. Ikić Matijašević ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Notch Signaling ◽  
Neutralizing Antibodies ◽  
Osteoclast Differentiation ◽  
Notch Receptor ◽  
Notch 1 ◽  
Collagen Induced Arthritis ◽  
Notch Receptors

Background:Osteoclasts mediate periarticular and systemic bone loss in rheumatoid arthritis (RA). Osteoclast progenitor cells (OCPs) derived from the myeloid lineage are susceptible to regulation through Notch signaling. Murine bone marrow and splenic OCPs, identified as CD45+Ly6G-CD3-B220-NK1.1-CD11blo/+CD115+CCR2+ cells, are specifically increased in arthritis. We previously identified an increased frequency of OCPs expressing Notch receptors in arthritic mice.Objectives:Several studies suggested that Notch signaling modulation affects the course of experimental arthritis. We aimed to determine the effects of Notch receptor signaling inhibition on OCP activity and arthritis severity in murine collagen-induced arthritis (CIA).Methods:Male C57/Bl6 and DBA mice were immunized with chicken type II collagen and treated with i.p. injections of anti-Notch 1 neutralizing antibodies (1mg/kg). Notch receptor 1 through 4 expression on OCPs was analyzed by flow cytometry in periarticular bone marrow (PBM) and spleen (SPL). Gene expression of Notch receptors, ligands and transcription targets as well as osteoclast differentiation genes RANK, cFos and cFms was determined by qPCR from tissues and sorted OCPs. FACS sorted OCPs were stimulated by osteoclastogenic factors (M-CSF and RANKL), in control, IgG, Jagged (Jag)1 or Delta-like (DLL)1 coated wells, with or without anti-Notch 1 antibodies. Research was approved by the Ethics Committee.Results:We confirmed the expression of Notch receptors on OCPs by flow cytometry with Notch 1 and 2 being most abundantly expressed (around 25% and 40% positive OCPs in PBM and 35% and 20% in SPL respectively), with a significant increase of Notch 2 expression in arthritis. Seeding OCPs on DLL1 coated wells significantly increased while seeding on Jag1 coated wells significantly decreased osteoclastogenesis as reflected on the number of TRAP+ osteoclasts and expression of osteoclast differentiation genes. The addition of anti-Notch 1 antibodies to ligand-stimulated OCPs resulted in an increased number of TRAP+ osteoclasts, partially reversing Jag1 inhibition. In vivo treatment with anti-Notch 1 antibodies did not affect total OCP frequency, but increased expression of Notch 4 both in PBM and SPL as seen by flow cytometry and qPCR. Additionally, anti-Notch 1 treatment stimulated Notch transcription factors HES and HEY. Both PBM and SPL cultured OCPs from anti-Notch 1 treated mice produced a higher number of large TRAP+ osteoclasts, doubling the area covered with osteoclasts in the latter compared to untreated mice. Increased osteoclastogenesis in vitro was further confirmed by an increased expression of osteoclast differentiation genes in the treated group.Conclusion:Our results confirm that Notch signaling may represent an important therapeutic target for the regulation of osteoclast activity in arthritis. Both in vitro and in vivo anti-Notch 1 neutralizing antibodies enhanced osteoclastogenesis in CIA model, implying an inhibitory role of Notch 1 signaling in osteoclast differentiation. As Notch 2 expression is increased on OCPs of arthritic mice, we next plan to determine the effects of Notch 2 neutralization on osteoclast activity and arthritis severity.References:[1]Ikić Matijašević M, Flegar D, Kovačić N, Katavić V, Kelava T, Šućur A, et al. Increased chemotaxis and activity of circulatory myeloid progenitor cells may contribute to enhanced osteoclastogenesis and bone loss in the C57BL/6 mouse model of collagen-induced arthritis. Clin Exp Immunol. 2016;186(3):321–35.[2]Šućur A, Filipović M, Flegar D, Kelava T, Šisl D, Lukač N, et al. Notch receptors and ligands in inflammatory arthritis – a systematic review. Immunology Letters 2020 Vol. 223, p. 106–14.Acknowledgements:The work has been supported by Croatian Science Foundation projects IP-2018-01-2414, UIP-2017-05-1965 and DOK-2018-09-4276.Disclosure of Interests:None declared.

Serrate expression can functionally replace Delta activity during neuroblast segregation in the Drosophila embryo

Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 855-865 ◽  
Author(s):  
Y. Gu ◽  
N.A. Hukriede ◽  
R.J. Fleming
Keyword(s):  
Ectopic Expression ◽  
Notch Receptor ◽  
Drosophila Embryo ◽  
Notch Ligand ◽  
Receptor Molecule ◽  
Extracellular Region ◽  
Delta Activity ◽  
Related Proteins ◽  
Notch Activation

Serrate and Delta encode structurally related proteins in D. melanogaster that bind within a common extracellular region on the NOTCH receptor molecule. We used ectopic expression to determine if SERRATE could mediate in vivo functions parallel or antagonistic to those proposed for the putative NOTCH ligand DELTA. Our results demonstrate that Serrate can replace Delta gene function during embryonic neuroblast segregation and that expression of Serrate leads to a NOTCH-dependent suppression of achaete expression in proneural clusters. Our findings strongly suggest that SERRATE functions as an alternative ligand capable of NOTCH activation.

scholarly journals Notch Subunit Heterodimerization and Prevention of Ligand-Independent Proteolytic Activation Depend, Respectively, on a Novel Domain and the LNR Repeats

2004 ◽  
Vol 24 (21) ◽  
pp. 9265-9273 ◽  
Author(s):  
Cheryll Sanchez-Irizarry ◽  
Andrea C. Carpenter ◽  
Andrew P. Weng ◽  
Warren S. Pear ◽  
Jon C. Aster ◽  
...  
Keyword(s):  
Cell Surface ◽  
Target Genes ◽  
Receptor Activation ◽  
Notch Receptor ◽  
Gamma Secretase ◽  
Prior Work ◽  
Proteolytic Activation ◽  
Transmembrane Receptors ◽  
Notch Receptors ◽  
Proteolytic Cleavages

ABSTRACT Notch proteins are transmembrane receptors that participate in a highly conserved signaling pathway that regulates morphogenesis in metazoans. Newly synthesized Notch receptors are proteolytically cleaved during transit to the cell surface, creating heterodimeric mature receptors comprising noncovalently associated extracellular (NEC) and transmembrane (NTM) subunits. Ligand binding activates Notch by inducing two successive proteolytic cleavages, catalyzed by metalloproteases and gamma-secretase, respectively, that permit the intracellular portion of NTM to translocate to the nucleus and activate transcription of target genes. Prior work has shown that the presence of NEC prevents ligand-independent activation of NTM, but the mechanisms involved are poorly understood. Here, we define the roles of two regions at the C-terminal end of NEC that participate in maintaining the integrity of resting Notch receptors through distinct mechanisms. The first region, a hydrophobic, previously uncharacterized portion of NEC, is sufficient to form stable complexes with the extracellular portion of NTM. The second region, consisting of the three Lin12/Notch repeats, is not needed for heterodimerization but acts to protect NTM from ligand-independent cleavage by metalloproteases. Together, these two contiguous regions of NEC impose crucial restraints that prevent premature Notch receptor activation.

scholarly journals Notch ligand activity is modulated by glycosphingolipid membrane composition in Drosophila melanogaster

2010 ◽  
Vol 188 (4) ◽  
pp. 581-594 ◽  
Author(s):  
Sophie Hamel ◽  
Jacques Fantini ◽  
François Schweisguth
Keyword(s):  
Protein Interactions ◽  
Receptor Activation ◽  
Notch Receptor ◽  
Binding Motif ◽  
Membrane Composition ◽  
Notch Receptors ◽  
Notch Ligands ◽  
Ligand Activity ◽  
Signaling Activity

Endocytosis of the transmembrane ligands Delta (Dl) and Serrate (Ser) is required for the proper activation of Notch receptors. The E3 ubiquitin ligases Mindbomb1 (Mib1) and Neuralized (Neur) regulate the ubiquitination of Dl and Ser and thereby promote both ligand endocytosis and Notch receptor activation. In this study, we identify the α1,4-N-acetylgalactosaminyltransferase-1 (α4GT1) gene as a gain of function suppressor of Mib1 inhibition. Expression of α4GT1 suppressed the signaling and endocytosis defects of Dl and Ser resulting from the inhibition of mib1 and/or neur activity. Genetic and biochemical evidence indicate that α4GT1 plays a regulatory but nonessential function in Notch signaling via the synthesis of a specific glycosphingolipid (GSL), N5, produced by α4GT1. Furthermore, we show that the extracellular domain of Ser interacts with GSLs in vitro via a conserved GSL-binding motif, raising the possibility that direct GSL–protein interactions modulate the endocytosis of Notch ligands. Together, our data indicate that specific GSLs modulate the signaling activity of Notch ligands.

scholarly journals The Role of Intracellular Trafficking of Notch Receptors in Ligand-Independent Notch Activation

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1369 ◽  
Author(s):  
Judith Hounjet ◽  
Marc Vooijs
Keyword(s):  
Notch Signaling ◽  
Intracellular Trafficking ◽  
Current Knowledge ◽  
Unmet Need ◽  
Receptor Activation ◽  
Notch Receptor ◽  
Comprehensive Overview ◽  
Normal Tissues ◽  
Notch Receptors

Aberrant Notch signaling has been found in a broad range of human malignancies. Consequently, small molecule inhibitors and antibodies targeting Notch signaling in human cancers have been developed and tested; however, these have failed due to limited anti-tumor efficacy because of dose-limiting toxicities in normal tissues. Therefore, there is an unmet need to discover novel regulators of malignant Notch signaling, which do not affect Notch signaling in healthy tissues. This review provides a comprehensive overview of the current knowledge on the role of intracellular trafficking in ligand-independent Notch receptor activation, the possible mechanisms involved, and possible therapeutic opportunities for inhibitors of intracellular trafficking in Notch targeting.

A Novel Notch Pathway Inhibitor Blocks Osteoclast Activity and Synergistically Induces Apoptosis with the Proteasome Inhibitor Bortezomib in Multiple Myeloma Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1522-1522
Author(s):  
Franziska Jundt ◽  
Rolf Schwarzer ◽  
Martin Kaiser ◽  
Oezlem Acikgoez ◽  
Ulrike Heider ◽  
...  
Keyword(s):  
Cell Growth ◽  
Notch Signaling ◽  
Proteasome Inhibitor ◽  
Notch Pathway ◽  
Growth And Survival ◽  
Osteoclast Activity ◽  
Notch Receptors ◽  
Induced Apoptosis

Abstract Notch pathway inhibition in multiple myeloma (MM) cells is a promising new therapeutic approach since it controls myeloma cell growth as we previously demonstrated (Blood. 2004; 103:3511–3515). Notch signaling is involved in the tight interactions between myeloma cells and the bone marrow microenvironment and induces tumor cell growth in MM. We provided evidence that Notch receptors are expressed on MM cells and that Notch ligands on MM and bone marrow stromal cells activate Notch signaling through homotypic as well as heterotypic interactions in MM cells. In this study, we analyzed whether Notch signaling might be activated in osteoclasts, which express Notch receptors but not the ligands. To that end, we co-cultured MM cells and human osteoclasts, which were generated from mononuclear hematopoietic precursors of healthy donors using in vitro RANKL/M-CSF stimulation. Co-cultivation specifically activated Notch in osteoclasts and induced osteoclast activity as measured by mRNA expression of the tartrate-resistant acid phosphatase. The novel Notch pathway inhibitor, so called γ-secretase inhibitor 1 (GSI1), that we recently identified by structural comparison of known inhibitors with unknown compounds by data bank screening, specifically inhibited Notch signaling in osteoclasts and blocked their activity in this co-cultivation assay. In addition, GSI1 induced apoptosis in osteoclasts in higher concentrations. We suggest from our data that GSI treatment controls MM cell growth and concomitantly aberrant osteoclast activity in vitro and possibly in vivo, that is under current investigation. We further hypothesized that GSI1 can be combined with the proteasome inhibitor bortezomib, which has been known to have in vitro and in vivo activity against MM. We evaluated the activity of the combination of GSI1 and bortezomib against MM cell growth and survival. Proliferation of MM cell lines treated with GSI, bortezomib and their combination was determined by CellTiter-Glo® luminescent cell viability assay. AnnexinV-FITC/PI staining and cleaved poly (ADP-ribose) polymerase (PARP) staining were used to determine the degree of apoptosis. Although treatment of MM cell lines (OPM2, LP1) with either drug alone significantly inhibited proliferation and induced apoptosis with concentrations of GSI1 (30–60 μM) and bortezomib (1–4 nM), the combination resulted in synergistic inhibition of cell growth and survival. Our data suggest that combination of GSI1 and bortezomib is a rational novel treatment option in MM that simultaneously targets different proliferative and anti-apoptotic pathways. Whether this combination might also have synergistic activity against aberrant osteoclast activity in MM will be further investigated.

scholarly journals Systematic Evaluation for the Influences of the SOX17/Notch Receptor Family Members on Reversing Enzalutamide Resistance in Castration-Resistant Prostate Cancer Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhongbo Du ◽  
Luo Li ◽  
Wei Sun ◽  
Pingyu Zhu ◽  
Shulin Cheng ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Notch Receptor ◽  
Systematic Evaluation ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Notch Receptors ◽  
Molecular Therapeutic ◽  
Molecular Therapeutic Targets

The treatment of castration-resistant prostate cancer (CRPC) remains challenging due to the failure of androgen deprivation therapy (ADT); hence the search for other molecular therapeutic targets besides androgen receptor signaling is ongoing. This study systematically investigated the expression of SOX17 and Notch receptors in CRPC tissues and cells in vitro, showing that consistent clinical CRPC, SOX17/Notch1, and Notch4 were responsible for enzalutamide resistance in CRPC cells. The γ secretase inhibitors, BMS-708163, GSI-IX, PF-3084014, and RO4929097 abrogated the enzalutamide resistance by inhibiting Notch1 or/and Notch4 in vitro, with GSI-IX and RO4929097 being more effective than BMS-708163 and PF-3084014 in reliving bone metastasis in vivo. In conclusion, the Notch1 and Notch4 inhibitors GSI-IX and RO4929097 are promising therapeutic agents for the treatment of CRPC.

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