hes1-protein--human and Glioma

Glioma stem cells (GSCs) have been proven to be resistant to various therapeutic strategies, such as temozolomide chemotherapy and radiotherapy, leading to glioma recurrence. Isoliquiritigenin (ISL), a menber of the flavonoids isolated from liquorice has been found to be a potent stimulator of cell differentiation and has potential application for treating various types of cancer including human brain glioma. However, the antitumor activity of ISL on GSCs and the signaling pathway underlying its therapeutic effects are poorly understood. In the present study, GSCs were isolated from SHG44 human glioma cells by serum-free culture and treated with ISL or DAPT (a Notch/γ-secretase inhibitor). It was found that ISL dose-dependently inhibited GSC growth after 72 h of treatment and decreased the formation of tumor spheres. Meanwhile, GSCs differentiated into astrocytes and neurons. Furthermore, these therapeutic effects were accompanied by downregulation of Notch1 and Hes1 at the protein and mRNA levels. Taken together, our results demonstrated that ISL exhibits antitumor effects on GSCs by inhibiting proliferation and inducing differentiation. The therapeutic effect may be related to downregulation of the Notch1 signaling pathway. Application of ISL presents potential benefits for the treatment of human brain glioma.

Topics: Antineoplastic Agents; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Chalcones; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Glioma; Humans; Neoplastic Stem Cells; Receptor, Notch1; Signal Transduction; Transcription Factor HES-1; Tumor Cells, Cultured

Tigecycline is a broad-spectrum, first-in-class glycylcycline antibiotic currently used to treat complicated skin infections and community-acquired pneumonia. However, there is accumulating evidence showing that tigecycline has anticancer properties. In this study, we found tigecycline could inhibit cell proliferation by inducing cell-cycle arrest, but not apoptosis in glioma. To find the underlying mechanism of how tigecycline inhibits cell proliferation, the expression of miRNAs, which were related to regulating cell-cycle progression, was detected with miRNA assay. We found that miR-199b-5p expression was significantly increased after tigecycline treatment, and miR-199b-5p target gene HES1 was downregulated. In addition, the PI3K/AKT pathway was inhibited and p21 expression was increased. When treated with tigecycline and miR-199b-5p antagomir simultaneously in glioma cells, we found that miR-199b-5p antagomir could partly block the effects induced by tigecycline. Tigecycline effectively upregulated miR-199b-5p expression and inhibited tumor growth in the xenograft tumor model of U87 glioma cells. These results suggest that tigecycline may induce cell-cycle arrest and inhibit glioma growth by regulating miRNA-199b-5p-HES1-AKT pathway. Thus, tigecycline is a promising agent in the treatment of malignant gliomas.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Glioma; Humans; Male; MicroRNAs; Minocycline; Proto-Oncogene Proteins c-akt; Rats; RNA Interference; Signal Transduction; Tigecycline; Transcription Factor HES-1; Tumor Burden

Glioma is the most common malignant tumors in adult brains, and Notch signaling pathway plays an important role in cell differentiation. The aim of the present study is to investigate the role of Notch1 in the progression of glioma cancers and clarify the mechanism of Notch1 silencing on inhibiting the proliferation of glioma cancer cells. First, endogenous Notch1 expression was interfered with a lentiviral vector of Notch1 shRNA. RT-PCR and western blotting were used for detecting the expression of Notch1 mRNA and protein, respectively. MTT assay results demonstrated that transfection with Notch1 shRNA and treatment with MRK003, a Notch1 inhibitor, both inhibited the proliferation of glioma cancer cells (p < 0.01). The lentiviral vector of Notch1 shRNA transfected into U251 cells induced cell cycle arrest at G0/G1 phase by FACS with PI staining analysis. Meanwhile, the expression levels of LC3-II and Beclin1 significantly increase in Notch1 shRNA-transfected U251 cells, suggesting that cell autophagy was induced when interfering with Notch1 in glioma cells. The downstream transcription factors were also detected by RT-PCR and western blotting analysis, and the data showed that interference with Notch1 increased the expression level of Hes-1, but not Hes-5. Taken together, all the data obviously revealed that Notch1 played an important role in the progression of glioma cancers. The clarification of the mechanism will be helpful for the diagnosis of glioma cancer and would provide new clues to molecular targets for cancer therapy.

Topics: Autophagy; Basic Helix-Loop-Helix Transcription Factors; Cell Line, Tumor; Cell Proliferation; Down-Regulation; G1 Phase Cell Cycle Checkpoints; Glioma; Homeodomain Proteins; Humans; Receptor, Notch1; Resting Phase, Cell Cycle; RNA, Messenger; Signal Transduction; Transcription Factor HES-1

Glioma stemness has been recognized as the most important reason for glioma relapse and drug resistance. Differentiation of glioma stem cells (GSCs) has been implicated as a novel approach to target recurrent glioma. However, the detailed molecular mechanism involved in the differentiation of GSCs has not yet been elucidated. This study identified CPEB1 as the key modulator that induces the differentiation of GSCs at the post-transcriptional level. Gain and loss of function experiments showed that CPEB1 expression reduced sphere formation ability and the expression of stemness markers such as Nestin and Notch. To elucidate the detailed molecular mechanism underlying the action of CPEB1, we investigated the interacting ribonome of the CPEB1 complex using a Ribonomics approach. CPEB1 specifically suppressed the translation of HES1 and SIRT1 by interacting with a cytoplasmic polyadenylation element. The expression profile of CPEB1 negatively correlated with overall survival in glioma patients. Overexpression of CPEB1 decreased the number of GSCs in an orthotopically implanted glioma animal model. These results suggest that CPEB1-mediated translational control is essential for the differentiation of GSCs and provides novel therapeutic concepts for differentiation therapy.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Brain Neoplasms; Cell Differentiation; Down-Regulation; Female; Glioma; HEK293 Cells; Heterografts; Homeodomain Proteins; Humans; Mice; Mice, Inbred BALB C; mRNA Cleavage and Polyadenylation Factors; Neoplastic Stem Cells; Sirtuin 1; Transcription Factor HES-1; Transcription Factors; Transcription, Genetic; Transfection

Notch pathway plays critical role in stem cell maintenance and angiogenesis, as well as cell fate decisions of cancer. However, concrete mechanisms of notch pathway regulation in glioma were not well known, especially mediated by microRNAs. In this study, we identified a brain-specific miRNA, miR-524-5p, which was associated with the pathological grade and overall survival of gliomas. Restorated expression of miR-524-5p in glioma suppressed cell proliferation and invasion both in vitro and in vivo. Using bioinformatics and biological approaches, we found that Jagged-1 and Hes-1, two key components of notch pathway, were direct targets of miR-524-5p. Knocking down of Jagged-1 or Hes-1 partially phenocopied miR-524-5p re-expression, whereas forced expression of Jagged-1 or Hes-1 reversed the effects of miR-524-5p on proliferation and invasion of glioma. Moreover, miR-524-5p levels in glioma samples were inversely correlated with Jagged-1 and Hes-1 and their overexpressions were associated with poor survival. Thus, we have identified that miR-524-5p behaves as a tumor suppressor by negatively targeting Jagged-1 and Hes-1 and provides an additional option to inhibit this oncogene in gliomas.

Topics: Animals; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Blotting, Western; Brain Neoplasms; Calcium-Binding Proteins; Cell Movement; Cell Proliferation; Chromatin Immunoprecipitation; Female; Gene Expression Profiling; Genes, Tumor Suppressor; Glioma; Homeodomain Proteins; Humans; Immunoenzyme Techniques; Intercellular Signaling Peptides and Proteins; Jagged-1 Protein; Luciferases; Membrane Proteins; Mice; Mice, Nude; MicroRNAs; Oligonucleotide Array Sequence Analysis; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Serrate-Jagged Proteins; Transcription Factor HES-1

Both the Notch-signaling pathway and extracellular signal regulated kinase (ERK) cascade are involved in a wide variety of biological processes, such as proliferation, differentiation, survival, and tumorigenesis. Their dysregulation in recent studies have been shown to be associated with glioma formation. Here, we show that transforming growth factor-alpha (TGF-alpha) stimulated glioma cell line U251 growth and can partly compensate for the inhibitory effect of Notch-signaling inhibitor DAPT. The effect of TGF-alpha on ERK1/2 phosphorylation was prompt and transient and could be inhibited by mitogen-activated/extracellular signal-regulated kinase kinase 1/2 (MEK1/2) specific inhibitor PD98059. Moreover, TGF-alpha was capable of up-regulating Hairy-enhancer of split1 (Hes1) expression which was independent of Notch1 activation, and of introducing Hes1 nuclear import in the presence of ERK1/2 activation. Collectively, our data suggest a potential linkage between ERK activation and the Notch-signaling pathway.

Topics: Active Transport, Cell Nucleus; Amyloid Precursor Protein Secretases; Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Dipeptides; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Gene Expression Regulation, Neoplastic; Glioma; Homeodomain Proteins; Humans; Immunoglobulin J Recombination Signal Sequence-Binding Protein; Phosphorylation; Protease Inhibitors; Protein Kinase Inhibitors; Protein Transport; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Transcription Factor HES-1; Transforming Growth Factor alpha; Up-Regulation

Polypyrimidine tract binding protein (PTB) is expressed in developing mammalian astrocytes, absent in mature adult astrocytes, and aberrantly elevated in gliomas. It is unclear whether PTB is a coincidental marker of tumor progression or a significant mediator of tumorigenesis. In developing Drosophila, the absence of the PTB homolog, hephaestus, results in increased Notch activity. Since Notch is a well-known inducer of glial cell fate, we determined whether overexpression of PTB in glial cell tumors provides a selective growth advantage by inhibiting activated Notch (Notch1IC)-mediated differentiation. To do this, we performed an immunohistochemical analysis for expression of PTB, activated Notch1 (Notch1IC), Hes1 (a Notch target), and GFAP on an extensive human tissue microarray that included 246 gliomas, 10 gliosarcomas, and 10 normal brains. Statistically significant PTB overexpression was seen in all glioma grades, with the highest increase in grade IV tumors. Notch1IC was also abnormally expressed in gliomas except in a subset of grade IV tumors in which it was absent. This decrease in Notch1IC was not associated with increased PTB expression. We conclude that PTB, and Notch1 serve as independent and functionally unlinked markers of glioma progression.

Topics: Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Brain Neoplasms; Glial Fibrillary Acidic Protein; Glioma; Homeodomain Proteins; Humans; Immunoenzyme Techniques; Neoplasm Staging; Polypyrimidine Tract-Binding Protein; Receptor, Notch1; Tissue Array Analysis; Transcription Factor HES-1