PI3K-Akt-mTORC1 in peripheral nerve myelination
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB20661 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR1958090.fastq.gz | Fastqsanger.gz | |||
| ERR1958091.fastq.gz | Fastqsanger.gz | |||
| ERR1958092.fastq.gz | Fastqsanger.gz | |||
| ERR1958093.fastq.gz | Fastqsanger.gz | |||
| ERR1958094.fastq.gz | Fastqsanger.gz |
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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.
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Project description:G protein accelerates epidermal cell migration via activation of PI3K/Akt-dependent mTORC1 signaling under hypoxia
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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.
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Project description:When skin tissue is damaged, the wound microenvironment is hypoxic or anoxic due to the rupture of blood vessels and the high oxygen consumption of related cells; so far, it is not clear whether such hypoxic microenvironment will promote epidermal cell migration and the underlying molecular regulatory mechanisms of this effect remains unclear. Studies to date have shown that, immortal keratinocyte cell line HaCaT and primary human keratinocytes are maintained under conditions of hypoxia (1% oxygen) or normoxia. The researchers would adopt methods such as live cell imaging system, Western blotting, transwell assays and wound scratch assays etc. to study the changes of cell migration. Expression profile of mRNAs in HaCaT cells from 3 hypoxia and 3 normoxic conditions were analyzed by the Clariom D microarray assay. Gene Ontology (GO) and KEGG genomics analyses were performed to identify significant functions, pathways, and the associations of differentially expressed mRNAs. Moreover, the potential mechanism is discussed and studied. According to relevant results, the epidermal cell migration is promoted in the early hypoxia. Furthermore, experiment showed that 1456 mRNAs showed differential expression between the hypoxia and normoxic conditions, which included 537 upregulated and 919 downregulated mRNAs. These results also shown that all G proteins are upregulated. At the same time, GO analysis indicated that most upregulated mRNA are in connection with cell inflammation and migration. Pathway analysis indicated that 20 pathways corresponded to the upregulated mRNA and 6 pathways corresponded to the upregulated mRNA. These pathway analyses have indicated that genes involved in inflammation, migration and PI3K-Akt signaling are potentially regulated. Combine with microarray assay, we further shown that G protein accelerates epidermal cell migration via activation of PI3K/Akt-dependent mTORC1 signaling under the condition of hypoxia. Based on this evidence, researchers can further reveal the molecular and cellular mechanisms of local wound hypoxia, and for improving the wound healing.
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