Ephexin1 cooperates with K-Ras to promote oncogenic Ras-driven tumorigenesis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE147809 | GEO | 2021/10/27
REPOSITORIES: GEO
Similar Datasets
Project description:Ephexin1 cooperates with K-Ras to promote oncogenic Ras-driven tumorigenesis
| PRJNA619876 | ENA
Project description:-7/del(7q) is genetic event prevalent in high-risk myeloid neoplasms. For reasons that are unclear, gain-of-function mutations in the RAS pathway frequently co-occur with monosomy 7. Here we identify a genetic interaction between RAS and the 7q-encoded transcription factor, CUX1. Concomitant mutations in RAS genes and CUX1 are wide-spread across tumor types, suggesting cooperativity in tumorigenesis. To test this, we generated mice with oncogenic NrasG12D and Cux1 knockdown. Double mutant mice developed myeloid malignancies with higher penetrance and faster onset than either single allele alone, with leukemic transformation in one third of cases. Oncogenic RAS imparts increased self-renewal on CUX1-deficient hematopoietic stem and progenitor cells (HSPCs). Reciprocally, CUX1 knockdown amplifies RAS signaling through decreased transcriptional expression of negative regulators of RAS and PI3K signaling. Accordingly, NrasG12D;Cux1-knockdown HSPCs have heighted growth factor-sensitivity and downstream RAS pathway activation. Double mutant HSPCs were responsive to PIK3 or MEK inhibition, suggesting that these may be promising therapeutic targets in patients with 7/del(7q) malignancies. Our results implicate the loss of CUX1 as the underlying explanation for the association of -7/del(7q) with oncogenic RAS. Furthermore, we report the unexpected convergence of an oncogene and tumor suppressor gene on the same pathway.
2021-11-16 | GSE161614 | GEO
Project description:Aberrant Ras signaling is linked to a wide spectrum of hyperproliferative diseases, and components of the signaling pathway, including Ras, have been the subject of intense and ongoing drug discovery efforts. The cellular activity of Ras is modulated by its association with the guanine nucleotide exchange factor Sos, and the high-resolution crystal structure of the Ras-Sos complex provides a basis for the rational design of orthosteric Ras ligands. We constructed a synthetic Sos protein mimic that engages the wild-type and oncogenic forms of nucleotide-bound Ras and modulates downstream kinase signaling. The Sos mimic was designed to capture the conformation of the Sos helix-loop-helix motif that makes critical contacts with Ras in its switch region. Chemoproteomics studies illustrate that the proteomimetic engages Ras and other cellular GTPases. The synthetic proteomimetic resists proteolytic degradation and enters cells through macropinocytosis. As such, it is selectively toxic to cancer cells with upregulated macropinocytosis, including those that feature oncogenic Ras mutations.
2021-03-02 | MSV000086972 | MassIVE
Project description:Ras proteins are GTPases that regulate a wide range of cellular processes. The activity of Ras is dependent on its nucleotide-binding status, which is modulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Previously, we demonstrated that mutation of lysine 104 to glutamine (K104Q) attenuates the transforming capacity of oncogenic K-Ras by interrupting GEF induced nucleotide exchange. To assess the effect of this mutation in vivo, we used CRISPR/Cas9 to generate mouse models carrying the K104Q point mutation in wild-type and conditional K- RasLSL-G12D alleles. Homozygous animals for K104Q were viable, fertile, and arose at Mendelian frequency, indicating that K104Q is not a complete loss of function mutation. Consistent with our previous findings from in vitro studies, however, the oncogenic activity of K-RasG12D was significantly attenuated by mutation at K104. These data demonstrate that lysine at position 104 is critical for the full oncogenic activity of mutant K-Ras and suggest that modification at K104, for example acetylation, may also regulate its activity. Using biochemical and structural analysis, we found that the G12D and K104Q mutations cooperate to suppress GEF-mediated nucleotide exchange, explaining the preferential effect of K104Q on oncogenic K-Ras. Furthermore, we found that K104 site forms allosteric network with three residues (M72, R73 and G75) on 2 helix at switch II. Intriguingly, point mutation at glutamine 75 to alanine (G75A) showed strong negative regulatory effect on K-RasG12D. Collectively, modulating these sites may provide a unique therapeutic approach in cancer expressing mutant K-Ras.
2023-06-01 | GSE233945 | GEO
Project description:MAPK scaffolds, such as IQGAP1, assemble pathway kinases together to effect signal transmission and disrupting scaffold function therefore offers a potentially orthogonal approach to MAPK cascade inhibition. Consistent with this possibility, we observed an IQGAP1 requirement in Ras-driven tumorigenesis in mouse and human tissue. Delivery of the IQGAP1 WW peptide sequence that mediates Erk1/4 binding, moreover, disrupted IQGAP1-Erk1/2 interactions, abolished Ras/Raf-driven tumorigenesis, bypassed acquired resistance to the B-Raf inhibitor vemurafinib (PLX- 4032), and acts as a systemically deliverable therapeutic to significantly increase lifespan of tumor bearing mice. Scaffold-kinase interaction blockade (SKIB) acts by a mechanism distinct from direct kinase inhibition and represents a strategy to target over-active oncogenic kinase cascades in cancer. Gene expression profiling: Fragmented cRNA was hybridized to the Mouse Gene 1.0 ST Array (Affymetrix). Iqgap1 wild-type and Iqgap1 knockout mouse treated with topical 4OHT for 0 days and 6 days days are compared.
2013-04-01 | E-GEOD-44967 | biostudies-arrayexpress
Project description:MAPK scaffolds, such as IQGAP1, assemble pathway kinases together to effect signal transmission and disrupting scaffold function therefore offers a potentially orthogonal approach to MAPK cascade inhibition. Consistent with this possibility, we observed an IQGAP1 requirement in Ras-driven tumorigenesis in mouse and human tissue. Delivery of the IQGAP1 WW peptide sequence that mediates Erk1/4 binding, moreover, disrupted IQGAP1-Erk1/2 interactions, abolished Ras/Raf-driven tumorigenesis, bypassed acquired resistance to the B-Raf inhibitor vemurafinib (PLX- 4032), and acts as a systemically deliverable therapeutic to significantly increase lifespan of tumor bearing mice. Scaffold-kinase interaction blockade (SKIB) acts by a mechanism distinct from direct kinase inhibition and represents a strategy to target over-active oncogenic kinase cascades in cancer.
2013-04-01 | GSE44967 | GEO
Project description:Several aspects of a Western lifestyle such as increased obesity and decreased physical activity are associated with increased risk for gastrointestinal cancers1. Although high-fat diet (HFD) induced low-grade inflammation has been closely linked to tumorigenesis2, however, the microbial shift that occurs due to diet and consequent alterations in host immunity have merely been considered to play a critical role during carcinogenesis. Here we show that HFD promotes tumor progression in the small intestine of genetically susceptible mice, however, independently of obesity and diet-induced chronic inflammation. HFD consumption cooperates with mutant K-Ras to mediate a shift in the composition of microbiota, which is associated with a decrease in Paneth cell antimicrobial host defense that compromises dendritic cell (DC) recruitment and MHCII presentation in the gut-associated lymphoid tissues (GALTs). DC recruitment in GALTs can be normalized and tumor progression attenuated completely when K-Ras mutant mice are supplemented with the short chain fatty acid butyrate, a bacterial fermentation end product, or partially when provided with probiotics. Importantly, Myd88-deficiency completely blocks tumor progression in K-ras mutants, however, rather by substantial changes in the microbiota than host-mediated signaling mechanisms. Strikingly, transfer of fecal samples from diseased donors into healthy adult K-ras mutants is sufficient to enhance tumor progression in the absence of HFD suggesting a pivotal role for distinct microbiota shifts in aggravating disease in the small intestine. Collectively, these data underscore the reciprocal interaction between host and environmental factors for the composition of intestinal microbiota that favors carcinogenesis and suggest tumor progression could potentially be “transmitted” in genetically predisposed individuals. 13 samples; S103_396_GroupA_Arkan and S104_429_GroupA_Arkan represent the controls of the first group, S105_394_GroupB_Arkan and S106_429_GroupB_Arkan represent ViRas (mutated) mice of the first group. S982_groupA_ 1 and S983_groupA_2 represent the cotrols of the second group, S984_groupB_3, S985_groupB_4 and S986_groupB_5 represent ViRas (mutant) mice of the second group, S563_CO1979 represent the control of the third group, S564_KO1_1231, S565_KO2_1984 and S566_KO3_2013 represent the ViRas (mutant) mice of the third group. The first group are mice kept on HFD, second group kept on ND and third group kept on HFD plus treated with butyrate
2013-07-01 | E-GEOD-42840 | biostudies-arrayexpress
Project description:Several aspects of a Western lifestyle such as increased obesity and decreased physical activity are associated with increased risk for gastrointestinal cancers1. Although high-fat diet (HFD) induced low-grade inflammation has been closely linked to tumorigenesis2, however, the microbial shift that occurs due to diet and consequent alterations in host immunity have merely been considered to play a critical role during carcinogenesis. Here we show that HFD promotes tumor progression in the small intestine of genetically susceptible mice, however, independently of obesity and diet-induced chronic inflammation. HFD consumption cooperates with mutant K-Ras to mediate a shift in the composition of microbiota, which is associated with a decrease in Paneth cell antimicrobial host defense that compromises dendritic cell (DC) recruitment and MHCII presentation in the gut-associated lymphoid tissues (GALTs). DC recruitment in GALTs can be normalized and tumor progression attenuated completely when K-Ras mutant mice are supplemented with the short chain fatty acid butyrate, a bacterial fermentation end product, or partially when provided with probiotics. Importantly, Myd88-deficiency completely blocks tumor progression in K-ras mutants, however, rather by substantial changes in the microbiota than host-mediated signaling mechanisms. Strikingly, transfer of fecal samples from diseased donors into healthy adult K-ras mutants is sufficient to enhance tumor progression in the absence of HFD suggesting a pivotal role for distinct microbiota shifts in aggravating disease in the small intestine. Collectively, these data underscore the reciprocal interaction between host and environmental factors for the composition of intestinal microbiota that favors carcinogenesis and suggest tumor progression could potentially be “transmitted” in genetically predisposed individuals.
2013-07-01 | GSE42840 | GEO
Project description:K-Ras is frequently hyperactivated in human cancers through gain-of-function mutations that drive tumorigenesis. K-RasG12D, the most common oncogenic K-Ras allele, triggers massive transcriptomic and proteomic changes in the murine colon. Here, we report a comprehensive profile of physiological miRNA targets in murine colonic epithelium and tumor expressing K-RasG12D. Combining it with transcriptional, transcriptomic, and proteomic landscapes, we uncover a K-RasG12D-induced global suppression of miRNA activity that up-regulates hundreds of genes post-transcriptionally. K-RasG12D suppresses Csnk1a1 and Csnk2a1, which can decrease Ago2 phosphorylation at Ser825/829/831/835. Hypo-phosphorylated Ago2 increases binding with mRNA, reducing its regulatory activity by locking Ago2 in a small set of target transcripts. While expanding the repertoire of miRNA targets identified, it functionally decreases active Ago2, resulting in global de-repression of miRNA targets. Our findings establish a regulatory relationship among K-Ras, Csnk1a1/Csnk2a1, and Ago2 that provides a mechanistic link between oncogenic K-Ras and the up-regulation of hundreds of miRNA targets.
2022-05-13 | GSE189704 | GEO
Project description:K-Ras is frequently hyperactivated in human cancers through gain-of-function mutations that drive tumorigenesis. K-RasG12D, the most common oncogenic K-Ras allele, triggers massive transcriptomic and proteomic changes in the murine colon. Here, we report a comprehensive profile of physiological miRNA targets in murine colonic epithelium and tumor expressing K-RasG12D. Combining it with transcriptional, transcriptomic, and proteomic landscapes, we uncover a K-RasG12D-induced global suppression of miRNA activity that up-regulates hundreds of genes post-transcriptionally. K-RasG12D suppresses Csnk1a1 and Csnk2a1, which can decrease Ago2 phosphorylation at Ser825/829/831/835. Hypo-phosphorylated Ago2 increases binding with mRNA, reducing its regulatory activity by locking Ago2 in a small set of target transcripts. While expanding the repertoire of miRNA targets identified, it functionally decreases active Ago2, resulting in global de-repression of miRNA targets. Our findings establish a regulatory relationship among K-Ras, Csnk1a1/Csnk2a1, and Ago2 that provides a mechanistic link between oncogenic K-Ras and the up-regulation of hundreds of miRNA targets.
2022-05-13 | GSE189702 | GEO