OBJECTIVETo investigate the expressions and the role of Notch signaling-associated proteins in esophageal squamous cell carcinoma (ESCC).

METHODSFifty patients with ESCC were included in this study. The expressions of Notch signaling-associated protein (4 receptors: Notch1, Notch2, Notch3, Notch4; 5 ligands: Dll1, Dll3, Dll4, Jagged1, Jagged2) in cancer foci and adjacent normal tissues (5 cm distance to cancer) were examined by immunohistochemitry. Correlations of these proteins with cancer cell proliferation(Ki-67 index) and clinicopathologic features were investigated.

RESULTSHigher levels of Notch1 and Notch2 were measured in cancer foci compared with adjacent tissues (all P<0.05). There were no differences in the expressions of Notch3, Dll1 and Dll3 (all P>0.05). Notch4, Dll4 and Jagged2 were not detected in both cancer foci and adjacent tissues. Notch1 expression was negatively correlated with lymph node metastasis and TNM staging (all P<0.01). Jagged 1 expression was positively correlated with TNM staging (P<0.01). Ki-67 index was obviously higher in cancer foci, while it was negatively correlated with Notch1 and Notch3 (all P<0.01) and positively correlated with Dll1 and Jagged 1 (all P<0.01).

CONCLUSIONNotch signaling path may act as tumor suppressive gene in the pathogenesis of esophageal squamous cell cancer, in which Notch1 protein plays an important role.

Carcinoma, Squamous Cell ; metabolism ; Esophageal Neoplasms ; metabolism ; Genes, Tumor Suppressor ; Humans ; Lymphatic Metastasis ; Neoplasm Staging ; Receptor, Notch1 ; metabolism ; Receptor, Notch2 ; metabolism ; Receptor, Notch3 ; Receptors, Notch ; metabolism ; Signal Transduction

OBJECTIVETo explore the mechanism of Notch signaling transduction system and its effects on hematopoietic system.

METHODSNotch ligands transfected CHO cells were added into Notch1 and Notch2 transfected CHO cells, which were transiently transfected with reporter gene TP1. PGL-100 was used as substrate to test the interaction between Notch and Notch ligands. CHO, Jagged2-CHO and Delta 4-CHO cells were seeded in the petri dish containing G-CSF, and then Notch 1-32D cells were added in it to observe the differentiation of Notch1-32D cell after incubation and staining.

RESULTSAll of the five Notch ligands binding to Notch1 could induce TP1 activity, it increased significantly the Jagged2-CHO, Delta 4-CHO1-4 and Delta 4-CHO1-5 cells. For Notch2, the TP1 activity induced by the five ligands in these cells was much higher than that of CHO. At the presence of G-CSF, Notch1-32D could differentiate to mature granulocyte. Jagged2 could inhibit G-CSF induced Notch1-32D cell differentiation, but Delta 4 could not.

CONCLUSIONJagged2 and Delta 4 are the ligands of Notch1. Jagged2 can inhibit G-CSF induced Notch1-32D cell differentiation, but Delta 4 can not.

Animals ; CHO Cells ; Calcium-Binding Proteins ; genetics ; metabolism ; physiology ; Cell Differentiation ; physiology ; Cricetinae ; Cricetulus ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; physiology ; Membrane Proteins ; genetics ; metabolism ; physiology ; Receptor, Notch1 ; genetics ; metabolism ; physiology ; Receptor, Notch2 ; genetics ; metabolism ; physiology ; Receptors, Notch ; genetics ; metabolism ; physiology ; Serrate-Jagged Proteins ; Signal Transduction ; physiology ; Transfection

OBJECTIVETo investigate the expression of Notch gene in chronic lymphocytic leukemia cells and to explore the change of Notch protein after the therapy with cytosine arabinoside or dexmethasone, and the mechanism of Notch mediated anti-apoptosis and drug-resistance in chronic lymphocytic leukemia cells.

METHODSThe mononuclear cells from bone marrow or peripheral blood of chronic lymphocytic leukemia patients (24 cases) and healthy donors (14 cases) were collected, then the expression of Notch gene, BCL-2, as well as NF-κB gene were detected by real-time fluorescent quantitative PCR (qRT-PCR) at the level of transcription. The change of Notch protein in L1210 cell lines after therapy with cytosine arabinoside and dexmethasone was determined by Western blot.

RESULTSmRNA expression levels of Notch1, Notch2, BCL-2 and NF-κB gene in CLL group were significantly higher than those in healthy control group (0.8556 ± 0.8726 vs 0.6731 ± 0.5334, P = 0.0182; 1.2273 ± 0.8207 vs 0.6577 ± 0.6424, P < 0.0001; 8.0960 ± 7.5661 vs 0.5969 ± 0.4976, P < 0.0001; 1.0966 ± 0.6925 vs 0.5373 ± 0.7180, P < 0.0001, respectively), but no significant difference was found between Notch3 and Notch4 gene (1.1914 ± 2.4219 vs 0.8713 ± 0.7937, P = 0.3427; 0.8174 ± 1.0869 vs 0.9752 ± 1.3446, P = 0.2402, respectively). Notch1 protein expression in L1210 cells were significantly decreased after treating with cytosine arabinoside of low and middle concentrations, but increased after treating with cytosine arabinoside of high concentration or prolonging time of cytosine arabinoside of middle con-centration. Notch1 protein expression in L1210 cells dereased after treating with dexamethasone, but did not be changed with the different concentrations and different times of dexmethason.

CONCLUSIONThe transcription level of Notch gene in CLL patients significantly higher than that in normal controls. The Notch1 protein expression is down-regulated in process of inhibiting L1210 cell proliferation by Ara-C and dexmethason. Notch signaling pathway may mediated anti-apoptosis and drug resistance of CLL cells. Notch molecule possibly plays an important role in the anti-apoptosis and drug-resistance of CLL cells.

Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cytarabine ; Down-Regulation ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Lymphocytic, Chronic, B-Cell ; NF-kappa B ; Receptor, Notch1 ; Receptors, Notch ; Signal Transduction ; Tumor Cells, Cultured

OBJECTIVE: Notch receptors are heterodimeric transmembrane proteins that regulate cell fate, such as differentiation, proliferation, and apoptosis. Dysregulated Notch pathway signaling has been observed in glioblastomas, as well as in other human malignancies. Nerve growth factor (NGF) is essential for cell growth and differentiation in the nervous system. Recent reports suggest that NGF stimulates glioblastoma proliferation. However, the relationship between NGF and Notch1 in glioblastomas remains unknown. Therefore, we investigated expression of Notch1 in a glioblastoma cell line (U87-MG), and examined the relationship between NGF and Notch1 signaling.METHODS: We evaluated expression of Notch1 in human glioblastomas and normal brain tissues by immunohistochemical staining. The effect of NGF on glioblastoma cell line (U87-MG) was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. To evaluate the relationship between NGF and Notch1 signaling, Notch1 and Hes1 expression were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. To confirm the effects of NGF on Notch1 signaling, Notch1 and Hes1 small interfering RNAs (siRNAs) were used.RESULTS: In immunohistochemistry, Notch1 expression was higher in glioblastoma than in normal brain tissue. MTT assay showed that NGF stimulates U87-MG cells in a dose-dependent manner. RT-PCR and Western blot analysis demonstrated that Notch1 and Hes1 expression were increased by NGF in a dose-dependent manner. After transfection with Notch1 and Hes1 siRNAs, there was no significant difference between controls and 100 nM NGF-β, which means that U87-MG cell proliferation was suppressed by Notch1 and Hes1 siRNAs.CONCLUSION: These results indicate that NGF stimulates glioblastoma cell proliferation via Notch1 signaling through Hes 1.
Apoptosis ; Blotting, Western ; Brain ; Cell Line ; Cell Proliferation ; Glioblastoma ; Humans ; Immunohistochemistry ; Nerve Growth Factor ; Nervous System ; Polymerase Chain Reaction ; Receptor, Notch1 ; Receptors, Notch ; Reverse Transcription ; RNA, Small Interfering ; Transfection

Humans ; Psoriasis ; metabolism ; Receptors, Notch ; metabolism ; Signal Transduction

Notch signaling pathway is a main pathway through cell-cell interactions, which regulates the programmed cell death, cellular proliferation and differentiation in multiple cell systems, and also is an important signaling pathway to modulate the balance between proliferation and differentiation in hematopoietic environment, and is related with the incidence of multiple hematologic malignancies. Multiple myeloma (MM) is malignant in B cell lineage and characterized by clonal proliferative plasma cells. It is very difficult to cure MM patients with a low proliferation rate of the MM cell and drug resistance to the standard dosage of chemotherapy. In recent years, research has shown that in the malignant plasma cells of the patients with multiple myeloma (MM) and the cell lines, but not in normal plasma cells or tumor cells from patients with other malignancies, the Notch ligand Jagged2 was found to be overexpressed. Jagged2 can induce stromal cells to secrete IL-6, VEGF and IGF-1. Notch activation can interact with NF-kappaB and C-myc to promote the proliferation and to inhibit the apoptosis of MM cells, showing in the relationship between the incidence of myeloma and drug resistance. Inhibition of the Notch signaling pathway may induce the apoptosis of MM cells and enhance the effect of chemotherapy. Study indicated that the specific inhibition of Notch signaling by treatment with a gamma-secretase inhibitor (GSI) alone, a specific pharmacologic inhibitor of Notch signaling, induces the apoptosis of myeloma cells and improves sensitivity of myeloma cell to chemotherapy when combined. In this article the composition of Notch signalling pathway, the mechanism of Notch signalling pathway and the relation of Notch signalling pathway to multiple myeloma were reviewed.
Humans ; Multiple Myeloma ; metabolism ; Receptors, Notch ; metabolism ; Signal Transduction

The Notch signaling pathway has been implicated in the regulation of cell-fate decisions such as differentiation of embryo stem cells and neural stem cells into neurons. We cultured human mesenchymal stem cells (hMSCs) in vitro and induced hMSCs to differentiate into neural cells by beta-mercaptoethanol (beta-ME), DMSO and 3-tert-butyl-4-hydroxyanisole (BHA). Immunocytochemistry was utilized to detect neuron-specific enolase (NSE) and Nissl body, and flow cytometry was used to determine cell growth phases. The expressions of signal molecules involved in the Notch pathway such as Notch1, Jagged 1 (JAG1), presenilin 1 (PS1) and hairy and enhancer of split 1(HES1) were observed by RT-PCR and immunofluorescent techniques. The results were as follows: (1) Before induction, the percentage of hMSCs at G(0)/G(1) was 58.5%, and the percentage at S+G(2)/M was 41.5%. After induction, the percentage of hMSCs at G(0)/G(1) increased to 73.1%, 76.2% and 78.1%, respectively on days 2, 4 and 6, and the percentage at S+G(2)/M decreased to 26.8%, 24.8% and 21.9%, respectively; The percentage of NSE-positive cells reached (77+/-0.35) %; Nisslos staining was positive in cytoplasm. (2) Notch1 and JAG1 were both expressed in hMSCs before and after induction, but the mRNA expressions of both Notch1 and JAG1, detected by RT-PCR, decreased obviously after induction(P<0.05). Notch1 mRNA/beta-actin was 1.157, 0.815, 0.756 and 0.570, and JAG1 mRNA/beta-actin was 0.437, 0.350, 0.314 and 0.362, respectively, on days 0, 2, 4 and 6 after induction. The Notch pathway activation participant PS1 mRNA and Notch pathway target gene HES1 mRNA also decreased apparently after induction (P<0.05), and their mRNA/beta-actin was 0.990, 0.449, 0.441, 0.454 and 0.370, 0.256, 0.266, 0.240 on days 0, 2, 4 and 6, respectively. These observations indicate that the expressions of Notch signal molecules were suppressed when hMSCs were induced to differentiate into neural cells. Based on these findings, we propose that low level of Notch signaling activation may contribute to neural cell differentiation.
Basic Helix-Loop-Helix Transcription Factors ; genetics ; Calcium-Binding Proteins ; genetics ; Cell Cycle ; Cell Differentiation ; Flow Cytometry ; Homeodomain Proteins ; genetics ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; Jagged-1 Protein ; Membrane Proteins ; genetics ; Mesenchymal Stromal Cells ; cytology ; Neurons ; cytology ; Receptor, Notch1 ; genetics ; Receptors, Notch ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Serrate-Jagged Proteins ; Signal Transduction ; Transcription Factor HES-1

This study was aimed to explore the inhibitory effect of pumpkin protein (cucurmosin, CUS) on proliferation of RPMI8226 myeloma cells in vitro and its mechanism. Western blot was used to detect the expression level of Notch-1, Jagged-2, P-Akt and NF-KB in the myeloma cells treated by different concentrations of CUS. The results demonstrated that CUS could down-regulate the protein expression levels of Notch1, Jagged-2, P-Akt and NF-KB in the myeloma cells and with time-and concentration-dependent way, at the same time CUS could also decrease the expressions of BCL-2 and P-Akt. It is concluded that CUS can obviously inhibit the RPMI8226 cell proliferation in vitro, down-regulate the expression levels of Notch signal and its down-stream target genes. Therefore, Notch signaling pathway can be used as a new treatment target for multiple myeloma, and CUS may be become a potential new drug for regulating Notch signaling pathway.
Cell Line, Tumor ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Jagged-2 Protein ; Membrane Proteins ; metabolism ; Multiple Myeloma ; metabolism ; NF-kappa B ; metabolism ; Plant Proteins ; pharmacology ; Proto-Oncogene Proteins c-akt ; metabolism ; Receptor, Notch1 ; metabolism ; Receptors, Notch ; metabolism ; Signal Transduction ; drug effects

Ex vivo expansion of hematopoietic progenitor cells (HPCs) is valuable for clinical application, however, traditional ex vivo culture negatively affects long-term hematopoietic reconstitution ability. In the hematopoietic system, the expression of Notch receptors and their ligands has been widely reported. Active Notch signal inhibits the differentiation of HSCs while promotes their expansion, suggesting that ex vivo expansion of hematopoietic progenitor cells could be enhanced by manipulating Notch signal pathways. In this article the Notch signal pathways, Notch signal and maintenance of hematopoietic progenitor cells, Notch signal and expansion of hematopoietic progenitor cells and molecular mechanism of Notch signal maintaining undifferentiation of hematopoietic progenitor cells were reviewed.
Animals ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; Receptors, Notch ; metabolism ; Signal Transduction

The occurrence and development of many tumors all relate with abnormal expression of the Notch receptor. The role of different Notch receptors may be different, even contrary in different tissues at different stages of tumor development, as well as in the same system tumors. Notch signaling pathway plays an important role in cell proliferation, differentiation, apoptosis and tumor angiogenesis, and is as a meeting point for many important cell signaling pathway. Angiogenesis is regulated by complex interactions of multiple activators and inhibitors. Vascular endothelial growth factor (VEGF) and Notch signaling pathway are involved in such process. Many studies have confirmed that Notch signaling pathway plays a key role in the embryonic development and tumour angiogenesis. Recent studies have also revealed that Notch signaling pathway has many potential drug targets. Based on study of Notch signaling pathway and its molecular mechanism of leukemia, to design drugs effecting these targets to block and activate Notch signaling pathway for therapy of leukemia and angiogenesis diseases has a broad application prospects. This review summarises the components of Notch signaling pathway and the role of Notch signaling pathway in occurrence of leukemia and angiogenesis.
Animals ; Humans ; Leukemia ; metabolism ; pathology ; Neovascularization, Pathologic ; metabolism ; pathology ; Receptors, Notch ; metabolism ; Signal Transduction