Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA149831 | ENA |
REPOSITORIES: ENA
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Project description:Neuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the PI3K/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have not been determined. Here, we identify the forkhead transcription factor FOXO3a as a key target of the PI3K/AKT pathway in neuroblastoma. FOXO3a expression was elevated in low stage neuroblastoma tumors and normal embryonal neuroblasts, but reduced in late stage neuroblastoma. Inactivation of FOXO3a by AKT was essential for neuroblastoma cell survival. Treatment of neuroblastoma cells with the dual PI3K/mTOR inhibitor PI-103 activated FOXO3a and triggered apoptosis. This effect was rescued by FOXO3a silencing. Conversely, apoptosis induced by PI-103 or the AKT inhibitor MK-2206 was potentiated by FOXO3a overexpression. Further, levels of total or phosphorylated FOXO3a correlated closely with apoptotic sensitivity to MK-2206. In clinical specimens, there was an inverse relationship between gene expression signatures regulated by PI3K signaling and FOXO3a transcriptional activity. Moreover, high PI3K activity and low FOXO3a activity were each associated with an extremely poor prognosis. Our work indicates that expression of FOXO3a and its targets offer useful prognostic markers as well as biomarkers for PI3K/AKT inhibitor efficacy in neuroblastoma. Affymetrix U133 Plus 2.0 profiling of SY5Y-TetR-FOXO3A cells treated with doxycycline and/or the PI3K/mTOR inhibitor PI-103. Each condition profiled in triplicate.
2013-05-01 | E-GEOD-42762 | biostudies-arrayexpress
Project description:Neuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the PI3K/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have not been determined. Here, we identify the forkhead transcription factor FOXO3a as a key target of the PI3K/AKT pathway in neuroblastoma. FOXO3a expression was elevated in low stage neuroblastoma tumors and normal embryonal neuroblasts, but reduced in late stage neuroblastoma. Inactivation of FOXO3a by AKT was essential for neuroblastoma cell survival. Treatment of neuroblastoma cells with the dual PI3K/mTOR inhibitor PI-103 activated FOXO3a and triggered apoptosis. This effect was rescued by FOXO3a silencing. Conversely, apoptosis induced by PI-103 or the AKT inhibitor MK-2206 was potentiated by FOXO3a overexpression. Further, levels of total or phosphorylated FOXO3a correlated closely with apoptotic sensitivity to MK-2206. In clinical specimens, there was an inverse relationship between gene expression signatures regulated by PI3K signaling and FOXO3a transcriptional activity. Moreover, high PI3K activity and low FOXO3a activity were each associated with an extremely poor prognosis. Our work indicates that expression of FOXO3a and its targets offer useful prognostic markers as well as biomarkers for PI3K/AKT inhibitor efficacy in neuroblastoma.
2013-05-01 | GSE42762 | GEO
Project description:Inflammatory responses must be tightly coordinated with the activation of emergency myelopoiesis to produce potent myeloid cells that fight infection without causing self-damage. Here we show that GM-CSF programs myeloid committed progenitors to produce trained macrophages (increased cytokine response), but programs the upstream non-committed LKS+ progenitors to produce tolerized macrophages (decreased cytokine response). In myeloid progenitors, GM-CSF strongly activates STAT5, ERK and Akt-mTOR signaling pathways which are essential to establish a training program, whereas in LKS+ progenitors GM-CSF induces NF-κB translocation to the nucleus to establish a tolerization program. These differences arise from higher GM-CSF receptor expression in myeloid progenitors compared to LKS+ cells. We demonstrate that β-catenin regulation of NF-κB nuclear translocation is central in this process. Glycogen synthase kinase 3 (GSK3) inactivation by strong ERK and PI3K-Akt signaling increases cytoplasmic β-catenin levels to block NF-κB nuclear translocation in myeloid progenitors. In contrast, when ERK and PI3K-Akt signaling is weak, active GSK3 decreases β-catenin to allow NF-κB nuclear translocation in LKS+ progenitors. Finally, GM-CSF-induced LKS+ tolerization can be reversed and takes place in several murine models of trained immunity and in human CD34+ CD38– progenitors. Our study reveals that in addition to activating myelopoiesis, GM-CSF also programs early and immediate myeloid progenitors to produce opposing immune memory phenotypes. We propose that the inflammatory response from immediate myeloid progenitors may be balanced by the tolerized phenotype of early progenitors, thus providing a mechanism for appropriate resolution of inflammation and protection against prolonged cytokine storm.
2023-08-01 | GSE239650 | GEO
Project description:We established a model system in human DLD1 colon cancer cells to study the transcriptional crosstalk between FOXO3A and beta-Catenin. Thereby, translocation to the nucleus of a AKT-insensitive mutant (T32A, S253A, S315A) of human FOXO3A fused to the ligand binding domain of human estrogen receptor can be induced by exposure to 4-hydroxy-tamoxifen. Furthermore, expression of a stable mutant (S33Y) of human beta-catenin is doxycycline inducible. Addition of those drugs separately or in combination allows identification of common or excusive target gene sets.
2012-05-01 | E-MEXP-3262 | biostudies-arrayexpress
Project description:BRD4 assembles transcriptional machinery at gene super-enhancer regions and governs the expression of genes that are critical for cancer progression. However, it remains unclear whether BRD4-mediated gene transcription is required for tumor cells to develop drug resistance. Our data show that prolonged treatment of luminal breast cancer cells with AKT inhibitors induces FOXO3a de-phosphorylation, nuclear translocation, and disrupts its association with SIRT6, eventually leading to FOXO3a acetylation as well as BRD4 recognition. Acetylated FOXO3a recognizes the BD2 domain of BRD4, recruits the BRD4/RNAPII complex to the CDK6 gene promoter and induces its transcription. Pharmacological inhibition of either BRD4/FOXO3a association or CDK6 significantly overcomes the resistance of luminal breast cancer cells to AKT inhibitors in vitro and in vivo. Our study reports the involvement of BRD4/FOXO3a/CDK6 axis in AKTi resistance and provides potential therapeutic strategies for treating resistant breast cancer.
2019-02-21 | GSE118148 | GEO
Project description:Pre-mRNA splicing is regulated by developmental and environmental cues, but little is known about how specific signals are transduced in mammalian cells to regulate this critical gene expression step. Here, we report massive reprogramming of alternative splicing in response to EGF signaling. By blocking individual branches in EGF signaling, we found that Akt activation plays a major role, while other branches, such as the JAK/STAT and ERK pathways, make minor contributions to EGF-induced splicing. Activated Akt next branches to the SRPK family of kinases specific for SR proteins, rather than mTOR, by inducing SRPK autophosphorylation that switches the splicing kinases from Hsp70- to Hsp90-containing complexes. This leads to enhanced SRPK nuclear translocation and SR protein phosphorylation. These findings reveal a major signal transduction pathway for regulated splicing and place SRPKs in a central position in the pathway, consistent with their reputed roles in a large number of human cancers. Examination of EGF induced AKT-SRPK-SR pathway in the regulation of splicing in HEK293T cells with RASL-seq
2012-08-17 | E-GEOD-37731 | biostudies-arrayexpress
Project description:c-Jun N-terminal kinase (JNK) plays a pivotal role in the regulation of cancer cell apoptosis. Previous studies have revealed that forkhead transcription factor (Foxo3a) is a critical effector of JNK-mediated tumor suppression. However, it is not clear whether caveolin-1 (CAV1) mediated JNK/Foxo3a pathway is involved in cancer cell apoptosis. We found that cordycepin upregulates CAV1 expression, which was accompanied by JNK phosphorylation (p-JNK), which induced Foxo3a translocation into the nucleus, resulting in the upregulation of levels of Bax protein. Furthermore, we found that CAV1 overexpression upregulated p-JNK, whereas siRNA mediated inhibition of CAV1 downregulated p-JNK, and that JNK inhibition by SP600125, a specific JNK inhibitor, significantly increased Foxo3a phosphorylation (p-Foxo3a), which attenuated Foxo3a translocation into the nucleus, indicating caveolin-1 mediated JNK’s regulation of Foxo3a. siRNA mediated inhibition of Foxo3a downregulated levels of Bax protein, attenuated A549 cell apoptosis, indicating that CAV1 mediated JNK/Foxo3a pathway induce the apoptosis of A549 lung cancer cells. Taken, together, these results indicate that cordycepin promotes CAV1 upregulation to enhance JNK/Foxo3a signaling pathway activation to induce apoptosis in lung cancer cells and support the potential of cordycepin as a therapeutic agent for lung cancer.
2016-05-24 | GSE81727 | GEO
Project description:FOXO3a Is A Major Target Of Inactivation By PI3K/AKT Signaling In Aggressive Neuroblastoma
| PRJNA183072 | ENA
Project description:Objective Oncogenic Kras-activated robust Mek/Erk signals phosphorylate to the tuberous sclerosis complex (Tsc) and deactivates mammalian target of rapamycin (mTOR) suppression in pancreatic ductal adenocarcinoma (PDAC); however, Mek and mTOR inhibitors alone have demonstrated minimal clinical antitumor activity. Design We generated transgenic mouse models in which mTOR was hyperactivated either through the Kras/Mek/Erk cascade, by loss of Pten or through Tsc1 haploinsufficiency. Primary cancer cells were isolated from mouse tumours. Oncogenic signalling was assessed in vitro and in vivo, with and without single or multiple targeted molecule inhibition. Transcriptional profiling was used to identify biomarkers predictive of the underlying pathway alterations and of therapeutic response. Results from the preclinical models were confirmed on human material. Results Reduction of Tsc1 function facilitated activation of Kras/Mek/Erk-mediated mTOR signalling, which promoted the development of metastatic PDACs. Single inhibition of mTOR or Mek elicited strong feedback activation of Erk or Akt, respectively. Only dual inhibition of Mek and PI3K reduced mTOR activity and effectively induced cancer cell apoptosis. Analysis of downstream targets demonstrated that oncogenic activity of the Mek/Erk/Tsc/mTOR axis relied on Aldh1a3 function. Moreover, in clinical PDAC samples, ALDH1A3 specifically labelled an aggressive subtype. Conclusions These results advance our understanding of Mek/Erk-driven mTOR activation and its downstream targets in PDAC, and provide a mechanistic rationale for effective therapeutic matching for Aldh1a3-positive PDACs.
2015-10-05 | GSE48643 | GEO
Project description:Activation of the AKT and ERK signaling pathway is a major contributor to cell proliferation. However, the integrated regulation of this multistep process, involving signal processing, cell growth and cell-cycle progression, is poorly understood. Here we study three cell types of hematopoietic origin, in which AKT and ERK signaling is triggered by erythropoietin (Epo). We find that the different cell types exhibit distinct proliferative responses, despite sharing the molecular network for pro-proliferative signaling. Iterating quantitative experiments and mathematical modeling, we show that the cell-type-specific regulation of proliferation emerges from two sources: (1) the protein abundance patterns of signaling components that cause differential flow of signals along the AKT and ERK pathways, and (2) the differential impact of the downstream regulators for protein synthesis and for cell-cycle progression on proliferation. Our integrated mathematical model of Epo-driven proliferation explains cell-type-specific effects of targeted AKT and ERK inhibitors and correctly predicts whether their combined application results in synergy.
2017-01-20 | GSE72317 | GEO