Project description:In this study, we describe a novel relationship between glioblastoma CSCs and the Notch pathway, which involves the constitutive activation of STAT3 and NF-κB signaling. We demonstrate that adherent glioma CSCs exhibit characteristics previously described for CSCs grown in suspension culture. The expression of CD133, Sox2 and Nestin increased when compared to glioma cells grown in monolayer, and the adherent CSCs were ~100 times more tumorigenic in vivo than monolayer cultured glioma cells. We also found that while the STAT3 and NF-κB signaling pathways are constitutively activated in glioma lines, these pathways are dramatically activated in glioma CSCs. Treatment with STAT3 inhibitors led to a loss of nuclear activation of STAT3 signaling and suppression of growth in both monolayer and CSC conditions. There was a markedly greater growth suppressive effect on glioma CSCs, suggesting that targeted therapy of these key pathways in glioma CSCs may be possible. To further investigate potential biomarkers in glioma CSCs, microarray analysis was performed and revealed deregulation of the Notch signaling pathway. This constitutive activation of STAT3, NF-κB, and Notch pathways in glioma CSCs helps identify novel therapeutic targets for the treatment of glioma. GBM6 cells were continuously maintained as subcutaneous xenografts in NSG mice, and monolayer and CSC cultures were derived from freshly harvested tumor tissue. A total of 6 samples were subjected to microarray analysis, with three biological replicates for each experimental condition.
Project description:In this study, we describe a novel relationship between glioblastoma CSCs and the Notch pathway, which involves the constitutive activation of STAT3 and NF-κB signaling. We demonstrate that adherent glioma CSCs exhibit characteristics previously described for CSCs grown in suspension culture. The expression of CD133, Sox2 and Nestin increased when compared to glioma cells grown in monolayer, and the adherent CSCs were ~100 times more tumorigenic in vivo than monolayer cultured glioma cells. We also found that while the STAT3 and NF-κB signaling pathways are constitutively activated in glioma lines, these pathways are dramatically activated in glioma CSCs. Treatment with STAT3 inhibitors led to a loss of nuclear activation of STAT3 signaling and suppression of growth in both monolayer and CSC conditions. There was a markedly greater growth suppressive effect on glioma CSCs, suggesting that targeted therapy of these key pathways in glioma CSCs may be possible. To further investigate potential biomarkers in glioma CSCs, microarray analysis was performed and revealed deregulation of the Notch signaling pathway. This constitutive activation of STAT3, NF-κB, and Notch pathways in glioma CSCs helps identify novel therapeutic targets for the treatment of glioma.
Project description:The activated B cell-like (ABC) subgroup of diffuse large B cell lymphoma (DLBCL) is characterized by constitutive activation of the NF-êB pathway. Here we show that the NF- êB pathway induces the expression of the cytokines IL-6 and IL-10 in ABC DLBCL cell lines, which also have high levels of total and phosphorylated STAT3 protein, suggesting autocrine signaling. Using RNA interference for STAT3, we defined a gene expression signature of IL-6 and IL-10 signaling through STAT3. Based on this signature, we constructed a molecular predictor of STAT3 signaling that defined a subset of ABC DLBCL tumors with high expression of STAT3, IL-6 and/or IL-10, and their downstream targets. Although the STAT3-high and STAT3-low subsets had equivalent expression of genes that distinguish ABC DLBCL from GCB DLBCL, STAT3-high ABC DLBCLs had higher expression of signatures that reflected NF-kB activity, proliferation, and glycolysis. A smallmolecule inhibitor of JAK signaling, which blocked STAT3 signature expression, was toxic only for ABC DLBCL lines, and synergized with an inhibitor of NF-kB signaling. These findings suggest that the biological interplay between the STAT3 and NF-kB pathways may be exploited for the treatments of a subset of ABC DLBCLs. Keywords: time series design
Project description:The activated B cell-like (ABC) subgroup of diffuse large B cell lymphoma (DLBCL) is characterized by constitutive activation of the NF-êB pathway. Here we show that the NF- êB pathway induces the expression of the cytokines IL-6 and IL-10 in ABC DLBCL cell lines, which also have high levels of total and phosphorylated STAT3 protein, suggesting autocrine signaling. Using RNA interference for STAT3, we defined a gene expression signature of IL-6 and IL-10 signaling through STAT3. Based on this signature, we constructed a molecular predictor of STAT3 signaling that defined a subset of ABC DLBCL tumors with high expression of STAT3, IL-6 and/or IL-10, and their downstream targets. Although the STAT3-high and STAT3-low subsets had equivalent expression of genes that distinguish ABC DLBCL from GCB DLBCL, STAT3-high ABC DLBCLs had higher expression of signatures that reflected NF-kB activity, proliferation, and glycolysis. A smallmolecule inhibitor of JAK signaling, which blocked STAT3 signature expression, was toxic only for ABC DLBCL lines, and synergized with an inhibitor of NF-kB signaling. These findings suggest that the biological interplay between the STAT3 and NF-kB pathways may be exploited for the treatments of a subset of ABC DLBCLs. Activated B cell-like (ABC) subgroup of diffuse large B cell lymphoma (DLBCL) cell lines were used as model systems to study the cytokine pathways in these cells. We expressed inducible IkB super-repressor for 1 to 24 hours to identify NF-kB target genes in OCI-Ly3 and OCI-Ly10 cells for a total of 13 arrays with replicates of each time point. We treated OCI-Ly3 cells with IL-10 for 1 to 96 hours for a total of 10 arrays with replicates of each time point. We treated OCI-Ly10 cells with IL-6 for 30 minutes to 24 hours for a total of 8 arrays with replicates of each time point. OCI-Ly10 cells transfected with no siRNA versus STAT3-siRNA for 8, 24, or 48 hours for a total of 5 arrays with replicates for 24 and 48 hours. We treated OCI-Ly10 cells with JAK inhibitor I for 3 and 6 hours for a total of 4 arrays with replicates of each time point.
Project description:Sivakumar2011 - Notch Signaling Pathway
Notch is a transmembrane receptor that mediates local cell-cell communication and coordinates a signaling cascade. It plays a key role in modulating cell fate decisions throughout the development of invertebrate and vertebrate species and the misregulation leads to a number of human diseases.
References:
Notch signaling: from the outside in.
Notch signaling in hematopoiesis and early lymphocyte development.
An overview of the Notch signalling pathway.
Notch and cancer: best to avoid the ups and downs.
Notch signaling: control of cell communication and cell fate.
This model is described in the article:
A systems biology approach to model neural stem cell regulation by notch, shh, wnt, and EGF signaling pathways.
Sivakumar KC, Dhanesh SB, Shobana S, James J, Mundayoor S.
Omics: a Journal of Integrative Biology. 2011; 15(10):729-737
Abstract:
The Notch, Sonic Hedgehog (Shh), Wnt, and EGF pathways have long been known to influence cell fate specification in the developing nervous system. Here we attempted to evaluate the contemporary knowledge about neural stem cell differentiation promoted by various drug-based regulations through a systems biology approach. Our model showed the phenomenon of DAPT-mediated antagonism of Enhancer of split [E(spl)] genes and enhancement of Shh target genes by a SAG agonist that were effectively demonstrated computationally and were consistent with experimental studies. However, in the case of model simulation of Wnt and EGF pathways, the model network did not supply any concurrent results with experimental data despite the fact that drugs were added at the appropriate positions. This paves insight into the potential of crosstalks between pathways considered in our study. Therefore, we manually developed a map of signaling crosstalk, which included the species connected by representatives from Notch, Shh, Wnt, and EGF pathways and highlighted the regulation of a single target gene, Hes-1, based on drug-induced simulations. These simulations provided results that matched with experimental studies. Therefore, these signaling crosstalk models complement as a tool toward the discovery of novel regulatory processes involved in neural stem cell maintenance, proliferation, and differentiation during mammalian central nervous system development. To our knowledge, this is the first report of a simple crosstalk map that highlights the differential regulation of neural stem cell differentiation and underscores the flow of positive and negative regulatory signals modulated by drugs.
This model is hosted on BioModels Database and identified by: BIOMD0000000396.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication for more information.
Project description:Sivakumar2011_NeuralStemCellDifferentiation_Crosstalk
This model is generated by integrating
BIOMD0000000394
(EGFR),
BIOMD0000000395
(Hedgehog),
BIOMD0000000396
(Notch) and
BIOMD0000000397
(Wnt), to investigate the signalling crosstalk between the four
pathways.
This model is described in the article:
A systems biology approach
to model neural stem cell regulation by notch, shh, wnt, and
EGF signaling pathways.
Sivakumar KC, Dhanesh SB, Shobana S,
James J, Mundayoor S.
OMICS 2011 Oct; 15(10): 729-737
Abstract:
The Notch, Sonic Hedgehog (Shh), Wnt, and EGF pathways have
long been known to influence cell fate specification in the
developing nervous system. Here we attempted to evaluate the
contemporary knowledge about neural stem cell differentiation
promoted by various drug-based regulations through a systems
biology approach. Our model showed the phenomenon of
DAPT-mediated antagonism of Enhancer of split [E(spl)] genes
and enhancement of Shh target genes by a SAG agonist that were
effectively demonstrated computationally and were consistent
with experimental studies. However, in the case of model
simulation of Wnt and EGF pathways, the model network did not
supply any concurrent results with experimental data despite
the fact that drugs were added at the appropriate positions.
This paves insight into the potential of crosstalks between
pathways considered in our study. Therefore, we manually
developed a map of signaling crosstalk, which included the
species connected by representatives from Notch, Shh, Wnt, and
EGF pathways and highlighted the regulation of a single target
gene, Hes-1, based on drug-induced simulations. These
simulations provided results that matched with experimental
studies. Therefore, these signaling crosstalk models complement
as a tool toward the discovery of novel regulatory processes
involved in neural stem cell maintenance, proliferation, and
differentiation during mammalian central nervous system
development. To our knowledge, this is the first report of a
simple crosstalk map that highlights the differential
regulation of neural stem cell differentiation and underscores
the flow of positive and negative regulatory signals modulated
by drugs.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000398.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Developmental signals are known to modulate inflammation. How ever, the mechanistic insight that links developmental and inflammatory signaling remains elusive. In the current study, we identifya critical role of NF-kB system in mediating stimulus specific crosstalk that allows developmental LTbR signals to sustain inflammatory TLR4 induced RelA/NF-kB response and gene expression. LTbR activated non-canonical signaling targets canonical TLR4 induced, nfkb2 encoded p100 not only to deplete inhibitory IkBd/(p100)2, but also to supplement RelA:p52/NF-kB dimers. Robust crosstalk in the gut epithelial cells are important, as crosstalk-defective nfkb2-/- mice succumbed to gut infection by Citrobacter rodentium due to hypo-inflammatory responses. Finally, we present evidence for a crosstalk motif that integrates tissue microenvironment derived developmental cues to ameliorate the pathogen response. Total RNA from WT early passage MEFs stimulated with ligands LPS, LTbR and LPS+LTbR for 24hrs were analyzed for global gene expression levels
Project description:Sivakumar2011 - Hedgehog Signaling Pathway
This is the current model for the Hedgehog signaling pathway. The best data for mechanism of signaling has been worked out in Drosophila, so this model is based largely on Drosophila data. Hedgehog target genes vary from tissue to tissue, so the identities of individual target genes have not been listed. The main difference between the Drosophila and mammalian Hedgehog signaling pathways is the fact that there are three mammalian homologs of Cubitus interruptus, Gli1 Gli2 and Gli3. Some or all of the mammalian homologs may be proteolytically processed, but the data are controversial. There are two mammalian Ptc genes and three mammalian Hedgehog genes as well. The pathway for Sonic Hedgehog appears to be most similar to the Drosophila hedgehog pathway.
References:
Hedgehog signaling in animal development: paradigms and principles.
Sonic hedgehog in the nervous system: functions, modifications and mechanisms.
Hedgehog signal transduction: recent findings.
Hedgehog signaling: Costal-2 bridges the transduction gap.
This model is described in the article:
A systems biology approach to model neural stem cell regulation by notch, shh, wnt, and EGF signaling pathways.
Sivakumar KC, Dhanesh SB, Shobana S, James J, Mundayoor S.
Omics: a Journal of Integrative Biology. 2011; 15(10):729-737
Abstract:
The Notch, Sonic Hedgehog (Shh), Wnt, and EGF pathways have long been known to influence cell fate specification in the developing nervous system. Here we attempted to evaluate the contemporary knowledge about neural stem cell differentiation promoted by various drug-based regulations through a systems biology approach. Our model showed the phenomenon of DAPT-mediated antagonism of Enhancer of split [E(spl)] genes and enhancement of Shh target genes by a SAG agonist that were effectively demonstrated computationally and were consistent with experimental studies. However, in the case of model simulation of Wnt and EGF pathways, the model network did not supply any concurrent results with experimental data despite the fact that drugs were added at the appropriate positions. This paves insight into the potential of crosstalks between pathways considered in our study. Therefore, we manually developed a map of signaling crosstalk, which included the species connected by representatives from Notch, Shh, Wnt, and EGF pathways and highlighted the regulation of a single target gene, Hes-1, based on drug-induced simulations. These simulations provided results that matched with experimental studies. Therefore, these signaling crosstalk models complement as a tool toward the discovery of novel regulatory processes involved in neural stem cell maintenance, proliferation, and differentiation during mammalian central nervous system development. To our knowledge, this is the first report of a simple crosstalk map that highlights the differential regulation of neural stem cell differentiation and underscores the flow of positive and negative regulatory signals modulated by drugs.
This model is hosted on BioModels Database and identified by: BIOMD0000000395.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication for more information.