Diphthamide modification of eEF2 is required for gut tumor-like hyperplasia induced by oncogenic Ras
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ABSTRACT:
PROVIDER: PRJNA592564 | ENA |
REPOSITORIES: ENA
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Project description:Eukaryotic elongation factor 2 (eEF2) undergoes a unique post-translational modification called diphthamidation. Although eEF2 diphthamidation is highly conserved, its pathophysiological function is still largely unknown. To elucidate the function of diphthamidation in tumor, we examined the involvement of diphthamidation pathway enzyme Dph5 in tumor progression in Drosophila adult gut. Expression of oncogenic RasV12 in gut intestinal stem cells (ISCs) and enteroblasts (EBs) causes hypertrophy and disruption of gut epithelia, and shortened lifespan. Knockdown of dph5 ameliorated these pathogenic phenotypes. Dph5 is required for gross translation activation and high dMyc protein level in RasV12 tumor-like hyperplasia. Transcriptome analysis revealed that Dph5 is involved in the regulation of ribosome biogenesis genes. These results suggest that diphthamidation is required for translation activation partly through the regulation of ribosome biogenesis in Ras-induced tumor-like hyperplasia model in Drosophila gut.
2020-05-01 | GSE141201 | GEO
Project description:Ephexin1 was initially identified as a neuronal guanine nucleotide exchange factor involved in the control of neuronal development and synaptic homeostasis. Here, we demonstrate that the induction of Ephexin1 expression by an oncogenic K-Ras mutation amplifies the MAPK signaling via direct interaction with oncogenic Ras and contributes to colon and lung tumorigenesis. Ephexin1 cooperates with mutant Ras to accelerate skin tumorigenesis in vivo. In addition, we have demonstrated that the functionally relevant interaction between oncogenic K-Ras and Ephexin1. Together, these findings suggest that Ephexin1 serves as a positive regulator of Ras-driven oncogenesis and potentially represents a novel target for therapeutic intervention.
2021-10-27 | GSE147809 | GEO
Project description:Ephexin1 cooperates with K-Ras to promote oncogenic Ras-driven tumorigenesis
| PRJNA619876 | ENA
Project description:Oncogenic K-Ras suppresses global miRNA function
| PRJNA784250 | ENA
Project description:RAS mutations are frequently found among AML patients, generating a constitutively active signaling protein changing cellular proliferation, differentiation and apoptosis. We previously showed that treatment of AML patients with high-dose cytarabine (HDAC) is preferentially beneficial for those with an oncogenic RAS mutation. By applying a murine AML model, we could ascribe this effect to a RAS-driven, p53-dependent induction of differentiation. Here, we sought to confirm the correlation between RAS status and differentiation of blasts obtained from AML patients. The expression signature of primary AML blasts expressing oncogenic RAS where compared to blasts with wtRAS. Blasts where obtained from peripheral blood or bone marrow samples from patients with CBFbeta-MYH11 translocations and with or without an additional NRAS point mutation. As a reference, the Kasumi-1 acute myeloid leukemia cell line was used.
2015-11-20 | E-MTAB-2090 | biostudies-arrayexpress
Project description:Constitutively active RAS plays a central role in the development of skin cancer in the classical two stage skin carcinogenesis in mice and in a number of human cancers. Ras-mediated tumor formation is commonly associated with upregulation of cytokines and chemokines that mediate an inflammatory response considered relevant to oncogenesis. MyD88 is a crucial intermediate in the expression of multiple innate immune responders through signaling from the Toll-like/IL-1R family. We report that mice ablated for MyD88 or the IL-1R are resistant to topical skin carcinogenesis, and cultured MyD88-/- keratinocytes transduced with an oncogenic ras vector form only a few small tumors in orthotopic grafts. Initiated keratinocytes arising from oncogenic activation of ras are hyperproliferative but also resist signals for induced differentiation and upregulate a host of pro-inflammatory genes. Ras-transduced MyD88-/- keratinocytes are also hyperproliferative but the differentiation response is intact and pro-inflammatory genes are not upregulated. Using both genetic and pharmacological approaches, we find that in keratinocytes, the differentiation and immune regulation functions mediated by oncogenic ras require the establishment of an autocrine loop through IL-1α and its receptor leading to NF-κB activation. In the absence of MyD88 or IL-1R, this loop cannot be established. Further, blocking the IL-1a mediated NF-κB activation in ras-transduced wildtype keratinocytes corrects the defect in both differentiation response and proinflammatory gene expression. Collectively, these results demonstrate that ras activation converts normal keratinocytes to an initiated phenotype through a series of potentially reversible feedback signals that provide therapeutic opportunities through inhibition of IL-1 signaling. Gene expression comparison of wild type ras-transformed keratinocytes untreated (n=3) or treated (n=3) in vitro with the IL1R antagonist Anakinra.
2011-08-28 | E-GEOD-22777 | biostudies-arrayexpress
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations. ChIP sequencing two transcription factors in PC3 cells, four transcription factors plus a FLAG control in RWPE-1 cells and input DNA sequencing from each cell line.
2011-10-19 | E-GEOD-29808 | biostudies-arrayexpress
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations.
2011-10-20 | GSE29808 | GEO
Project description:Constitutively active RAS plays a central role in the development of skin cancer in the classical two stage skin carcinogenesis in mice and in a number of human cancers. Ras-mediated tumor formation is commonly associated with upregulation of cytokines and chemokines that mediate an inflammatory response considered relevant to oncogenesis. MyD88 is a crucial intermediate in the expression of multiple innate immune responders through signaling from the Toll-like/IL-1R family. We report that mice ablated for MyD88 or the IL-1R are resistant to topical skin carcinogenesis, and cultured MyD88-/- keratinocytes transduced with an oncogenic ras vector form only a few small tumors in orthotopic grafts. Initiated keratinocytes arising from oncogenic activation of ras are hyperproliferative but also resist signals for induced differentiation and upregulate a host of pro-inflammatory genes. Ras-transduced MyD88-/- keratinocytes are also hyperproliferative but the differentiation response is intact and pro-inflammatory genes are not upregulated. Using both genetic and pharmacological approaches, we find that in keratinocytes, the differentiation and immune regulation functions mediated by oncogenic ras require the establishment of an autocrine loop through IL-1α and its receptor leading to NF-κB activation. In the absence of MyD88 or IL-1R, this loop cannot be established. Further, blocking the IL-1a mediated NF-κB activation in ras-transduced wildtype keratinocytes corrects the defect in both differentiation response and proinflammatory gene expression. Collectively, these results demonstrate that ras activation converts normal keratinocytes to an initiated phenotype through a series of potentially reversible feedback signals that provide therapeutic opportunities through inhibition of IL-1 signaling.
2011-08-29 | GSE22777 | GEO
Project description:Oncolytic viruses exploit common molecular changes in cancer cells, which are not present in normal cells, to target and kill cancer cells. Ras transformation and defects in type I interferon (IFN)-mediated antiviral responses are known to be the major mechanisms underlying viral oncolysis. Previously, we demonstrated that oncogenic RAS/Mitogen-activated protein kinase kinase (Ras/MEK) activation suppresses the transcription of many IFN-inducible genes in human cancer cells, suggesting that Ras transformation underlies type I IFN defects in cancer cells. Here, we investigated how Ras/MEK downregulates IFN-induced transcription. By conducting promoter deletion analysis of IFN-inducible genes, namely guanylate-binding protein 2 and IFN gamma inducible protein 47 (Ifi47), we identified the IFN regulatory factor 1 (IRF1) binding site as the promoter region responsible for the regulation of transcription by MEK. MEK inhibition promoted transcription of the IFN-inducible genes in wild type mouse embryonic fibroblasts (MEFs), but not in IRF1?/? MEFs, showing that IRF1 is involved in MEK-mediated downregulation of IFN-inducible genes. Furthermore, IRF1 protein expression was lower in RasV12 cells compared with vector control NIH3T3 cells, but was restored to equivalent levels by inhibition of MEK. Similarly, the restoration of IRF1 expression by MEK inhibition was observed in human cancer cells. IRF1 re-expression in human cancer cells caused cells to become resistant to infection by the oncolytic vesicular stomatitis virus strain. Together, this work demonstrates that Ras/MEK activation in cancer cells downregulates transcription of IFN-inducible genes by targeting IRF1 expression, resulting in increased susceptibility to viral oncolysis. RNA was isolated from RasV12 transformed NIH/3T3 cells (RasV12 cells) treated with 20?M U0126 or 500U/ml IFN-?, or left untreated, for 6 hours, triplicate biological samples (9 samples).
2014-11-13 | E-GEOD-49469 | biostudies-arrayexpress