Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

BRAF-induced tumorigenesis is IKKalpha dependent but NFκB independent

ABSTRACT: Tumor cells carrying KRAS mutations activate the NF-κB pathway by different mechanisms, which contribute to the acquisition of essential cancer properties. The BRAF kinase, a downstream mediator of KRAS, is also mutated in a subset of colorectal cancers (CRC), which predicts bad prognosis and therapy resistance. However, nothing is known on whether NF-κB participates of BRAF-mediated tumorigenesis. We here found that in CRC cells, mutant BRAF does not trigger canonical or alternative NF-κB signaling but induces p45-IKKα activation. Moreover, IKKα activity is required for BRAF-induced transformation and to support BRAF-dependent transcription in CRC cells. Activation of p45-IKKα downstream of BRAF requires the TAK1 kinase, and is associated to the endosomal compartment. Inhibition of endosomal V-ATPase abolished p45-IKKα phosphorylation, and induced apoptosis of BRAF mutated CRC cells. Pharmacologic inhibition of endosome acidification reduced the in vivo growth of tumors carrying mutant BRAF, and abrogated the metastatic capacity of a primary human CRC tumor with acquired resistance to standard chemotherapy in an orthotopic xenograft model.

ORGANISM(S): Homo sapiens

PROVIDER: GSE57979 | GEO | 2015/05/08

SECONDARY ACCESSION(S): PRJNA248640

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

BRAF-induced tumorigenesis is IKKalpha dependent but NF?B independent

Project description:Tumor cells carrying KRAS mutations activate the NF-?B pathway by different mechanisms, which contribute to the acquisition of essential cancer properties. The BRAF kinase, a downstream mediator of KRAS, is also mutated in a subset of colorectal cancers (CRC), which predicts bad prognosis and therapy resistance. However, nothing is known on whether NF-?B participates of BRAF-mediated tumorigenesis. We here found that in CRC cells, mutant BRAF does not trigger canonical or alternative NF-?B signaling but induces p45-IKK? activation. Moreover, IKK? activity is required for BRAF-induced transformation and to support BRAF-dependent transcription in CRC cells. Activation of p45-IKK? downstream of BRAF requires the TAK1 kinase, and is associated to the endosomal compartment. Inhibition of endosomal V-ATPase abolished p45-IKK? phosphorylation, and induced apoptosis of BRAF mutated CRC cells. Pharmacologic inhibition of endosome acidification reduced the in vivo growth of tumors carrying mutant BRAF, and abrogated the metastatic capacity of a primary human CRC tumor with acquired resistance to standard chemotherapy in an orthotopic xenograft model. 18 samples were analyzed: HT29 controls (n=3); HT28 BRAF inhibited (n=3), WiDr controls (n=3); WiDr BRAF inhibited (n=3); WiDr transduced with control shRNA (n=3) and WiDr transduced with shRNA against IKKalpha (n=3)

2015-05-08 | E-GEOD-57979 | biostudies-arrayexpress

Inhibition of NF-κB signaling by a novel siRNA sequence induces apoptosis and suppresses tumor growth in KRAS mutant colorectal cancer.

Project description:KRAS mutation is one of the major genetic alterations in colorectal cancer (CRC). Treating patients with KRAS mutant CRC remains one of the biggest challenges in oncology. In this study, we aimed to discover an effective therapeutic microRNA (miRNA) that could target KRAS mutant CRC. For this purpose, we investigated the functional relevance of dysregulated miRNAs in KRAS mutant cancers. We transfected exogenous KRASG12V into human embryonic kidney 293 (HEK293) cells and human lung fibroblasts (MRC5) cells, and performed comprehensive microRNA expression profiling by microarray analysis. The results showed that 6 miRNAs are significantly upregulated in KRAS-transfected HEK293 and MRC5 cells. Among 6 miRNAs, we identified mature miRNA-29b-1-5p as potent growth inhibitor in CRC cell proliferation. However, miRNA-29b-1-5p was found to be a passenger strand with a star form (miRNA-29b-1-5p*), and did not function in CRC cells. Proliferation assay revealed that completely opposite complementary strand to miRNA-29b-1-5p possessed a potent anti-tumor effect. We named this novel anti-tumor siRNA sequence “MIRTX”. MIRTX induced apoptosis and significantly inhibited cell proliferation in KRAS mutant CRC in vitro. In addition, MIRTX suppressed NF-κB signaling pathway, which is downstream effector of KRAS in CRC. Furthermore, MIRTX directly targeted 3'-UTR of PIK3R1 and CXCR2 mRNA, and indirectly suppressed KRAS itself. In vivo xenograft mouse models, systemic administration of MIRTX significantly inhibited the tumor growth with no particular toxicity, using carbonate apatite as a vehicle. These findings indicate that inhibition of NF-κB signaling by siRNA-based therapeutic could be a promising strategy against KRAS mutant CRC.

2018-03-17 | GSE83634 | GEO

TLR4-NFkB-phospho-NF-kB signaling in BMDM

Project description:The model was constructed to describe TLR4 induced NF-κB activation in native bone marrow-derived macrophages. It included processes of ligand (lipopolysaccharide) recognition, formation of dimer receptor complex and further signal transduction through TRAF6/TAK1 complex that leads to the activation of IKKα/β kinase, which in turn enables the NF-κB transcription factor phosphorylation and translocation in the cell nucleus, and induction of IkB and WIP1 (as an example of induced protein that promotes NF-κB dephosphorylation 2) gene transcription. Models were based on the current knowledge of TLR signaling framework, protein interactions within the TLR4 pathway, and up-to-date mathematical models describing Toll receptor activation. The major important additions were made to TLR4 signaling description: 1) Receptor dimerization process 2) The existence of a basal nuclear NF-κB level (translocation) 3) NF-κB phosphorylation by IKK complex

2019-03-27 | MODEL1809230001 | BioModels

Treg cell by tumor-associated macrophage ROS and inflammatory signaling through T-cell NF-κB c-Rel drives pathogenesis of lung adenocarcinomas

Project description:IKKα, one subunit of the IKK complex composed of IKKα, IKKβ, and IKKγ (NEMO), is essential for canonical and noncanonical NF-κB pathways involved in the development of lymphoid organs, leukocytes, immunity, and epithelial organs. Deletions of the CHUK locus that encodes IKKα significantly reduce survival for both KRAS-mutation lung adenocarcinoma (ADC) patients and mice, but the question of whether IKKα regulates immune responses remains unanswered. Here, we show that tumor-IKKα reduction elicits an immunosuppressive tumor-microenvironment associated with macrophage and Treg cell induction, which are maintained through elevated reactive oxygen species (ROS) and cytokines important for macrophage and Treg cell development in human and mouse lung ADCs. Enhanced macrophage-ROS and inflammatory cytokine signaling, mediated by tumor-cell IKKα reduction, enforces Treg cell differentiation via a ROS/TNFα/TNFR2/c-Rel pathway in CD4 T-cells. The blockage of each crucial step, including ROS, macrophages, Treg cells, and TNFα/c-Rel, impairs lung ADC development. To explore the molecular mechanism, we performed ChIP-Seq to check some important immunoregulatory genes including TNF, IL-23A CSF1, and CCL22 were regulated transcriptionally by IKKα. Therefore, IKKα serves as a specific surveillant that suppresses immunosuppressive responses and antagonizes lung carcinogenesis in humans and mice.

2022-01-31 | GSE132460 | GEO

Hepatitis C Virus Infection Activates a Novel Innate Pathway Involving IKKα in Lipogenesis and Viral Assembly

Project description:Hepatitis C virus interacts extensively with host factors not only to establish productive infection but also to trigger unique pathological processes. Our recent genome-wide siRNA screen demonstrated that IKKα is a critical host factor for HCV. Here we describe a novel NF-κB-independent and kinase-mediated nuclear function of IKKα in HCV assembly. HCV infection, through its 3’-untranslated region, interacts with DDX3X to activate IKKα, which translocates to the nucleus and induces a CBP/p300-mediated transcriptional program involving SREBPs. This novel innate pathway induces lipogenic genes and enhances core-associated lipid droplet formation to facilitate viral assembly. Chemical inhibitors of IKKα suppress HCV infection and IKKα-induced lipogenesis, offering a proof-of-concept approach for novel HCV therapeutic development. Our results show that HCV commands a novel mechanism to its advantage by exploiting intrinsic innate response and hijacking lipid metabolism, which likely contributes to a high chronicity rate and the pathological hallmark of steatosis in HCV infection. Cells were treated with either non-targeting control siRNA or siRNA against IKKalpha. After 72 h, cells were either mock infected or infected with HCV JFH-1 strain with the M.O.I. of 0.5.

2013-05-08 | E-GEOD-46528 | biostudies-arrayexpress

Profiling of epithelial and stromal cells in early proximal colon preneoplasia with matched normals.

Project description:Progression of nonmalignant colonic cells harboring somatic mutations depends upon interactions with surrounding stroma; however, details of this interaction are poorly understood. We performed targeted transcriptional profiling of laser-captured epithelial and stromal cells from ACF, the earliest detectable human colonic pre-neoplastic lesion. Within ACF epithelium carrying non-overlapping mutations in KRAS, BRAF, or APC, we observed broad NF-kB-related inflammatory changes and specific differences associated with each mutation, including BRAFV600E-mediated senescence. Additionally, we identified ACF-associated stromal changes indicative of immune cell infiltration and fibroblast activation. Our results provide new insight into intercellular signaling changes that control the earliest stages of CRC development.

2016-11-23 | GSE77312 | GEO

GEMM CRC collection analysis

Project description:A collection of genetically engineered mouse models (GEMM) of colorectal cancer (CRC) were created, and primary tumors from these GEMMs were analyzed. Primary CRC tumors from these GEMMs were genotyped to confirm that they contain the core genetic lesions of interest, including APC, P53, KRAS, and BRAF. Primary tumors from GEMMs with combinations of lesions of interest were analyzed by whole genome expression, and their expression profiles were compared to determine how they segregate. Signatures were then generated from GEMM tumors of interest and compared to human clinical datasets with expression and outcome data. Primary tumors from CRC GEMMs with different combinations of mutant alleles of interested were generated and analyzed. Alleles include mutant forms of APC (A), P53 (P), KRAS (K) and BRAF (B).

2014-07-01 | E-GEOD-50794 | biostudies-arrayexpress

Transcriptome Signature Post Reovirus Treatment In KRAS Mutated Colorectal Cancer

Project description:Reovirus propagates with high efficiency in KRAS mutated colorectal cancer (CRC). About 45-50% of CRC patients possess KRAS mutation. Oncolytic reovirus treatment in combination with chemotherapy was tested in patient samples possessing KRAS mutated metastatic CRC. This is the raw data from the peripheral mononuclear cell (PBMC) samples at 4 timepoints (pre treatment, 48 hours, day 8, and day 15).

2021-05-01 | GSE173636 | GEO

Expression data from tumors generated from genome-engineered mice

Project description:Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are found in 30–40% of human colorectal cancers (CRC). However, specific therapeutics against KRAS-mutated CRC have not been established. We have previously reported mouse models for colon cancer with and without Kras mutations (CDX2P-G22Cre;Apcflox/flox; KrasG12D and CDX2P-G22Cre;Apcflox/flox mice, respectively). Herein, we aimed to identify candidate genes as novel therapeutic targets or biomarkers for KRAS-mutated CRC by comparing the gene expression profiles of these two mouse models.

2015-12-25 | GSE75435 | GEO

IKKα is essential for the development and maintenance of Marginal zone and Follicular B cells

Project description:IKKα kinase is essential for the B cell maturation and secondary lymphoid organ development. In the current study, we evaluated the role of IKKα in the marginal zone and follicular B lymphocyte development by genetically deleting IKKα from the B cell lineage using CD19-Cre mice. The loss of IKKα did not affect the normal development of early B cell progenitors. However, a significant decline was observed in the percentage of immature B lymphocytes, mature marginal zone and follicular B cells along with a severe disruption of splenic marginal and follicular B cell zones. A gene expression analysis performed on the RNA extracted from the newly formed B cells (B220+IgMhi) revealed that IKKα deficiency produces significant changes in the expression of genes involved in MZ and FO B lymphocyte survival, homing and migration. And several among those genes identified belong to G protein family. Specifically, we validated the upregulated expression of regulator of G protein signaling 13 (RGS13), which is a GTPase activating protein (GAP) that negatively regulates G protein signaling and impede B cell migration. Likewise, promigratory B lymphocyte receptor, the sphingosine-1-phosphate receptor 3 (SIPR3) that couple to Gαi showed significantly reduced expression. In addition, an in silico analysis of gene product interactions revealed NF-κB signaling pathways to be a major gene regulating networks perturbed with IKKα deletion. Taken together, this study reveals IKKαNF-κB and G protein signaling axis to be central for the MZ and FO B cells survival, maintenance, homing and migration.

2017-09-14 | GSE102587 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data