RAC-GEF function as a critical factor in intestinal tumourigenesis
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB25520 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Here we investigate the transcription changes in the murine intestine 4 days following loss of APC under the control of Vil-CreErT2 driver. We compare the RNAseq data from epithelial organoids generated from control (APC loss) intestines to organoids generated from lacking VAV2, VAV3 and TIAM1. We show that loss of these GEFs supress the APC WNT driven intestinal phenotype in a RAC-dependent manner.
2019-12-31 | GSE112261 | GEO
Project description:RAC1 activity is critical for intestinal homeostasis, and is required for hyperproliferation driven by loss of the tumour suppressor gene Apc in the murine intestine. To avoid the impact of direct targeting upon homeostasis, we reasoned that indirect targeting of RAC1 via RAC-GEFs might be effective. Transcriptional profiling of Apc deficient intestinal tissue identified Vav3 and Tiam1 as key targets. Deletion of these indicated that while TIAM1 deficiency could suppress Apc-driven hyperproliferation, it had no impact upon tumourigenesis, while VAV3 deficiency had no effect. Intriguingly, deletion of either gene resulted in upregulation of Vav2, with subsequent targeting of all three (Vav2-/- Vav3-/- Tiam1-/-), profoundly suppressing hyperproliferation, tumourigenesis and RAC1 activity, without impacting normal homeostasis. Critically, the observed RAC-GEF dependency was negated by oncogenic KRAS mutation. Together, these data demonstrate that while targeting RAC-GEF molecules may have therapeutic impact at early stages, this benefit may be lost in late stage disease.
| S-EPMC7782582 | biostudies-literature
Project description:RAC-GEF function as a critical factor in intestinal tumourigenesis
| PRJNA445428 | ENA
Project description:Rac GTPases are required for neutrophil adhesion and migration, and for the neutrophil effector responses that kill pathogens. These Rac-dependent functions are impaired when neutrophils lack the activators of Rac, Rac-GEFs from the Prex, Vav and Dock families. In this study, we demonstrate that Tiam1 is also expressed in neutrophils, governing focal complexes, actin cytoskeletal dynamics, polarisation and migration, in a manner depending on the integrin ligand to which the cells adhere. Tiam1 is dispensable for the generation of reactive oxygen species but mediates degranulation and NETs release in adherent neutrophils, as well as the killing of bacteria. In vivo, Tiam1 is required for neutrophil recruitment during aseptic peritonitis and for the clearance of Streptococcus pneumoniae during pulmonary infection. However, Tiam1 functions differently to other Rac-GEFs. Instead of promoting neutrophil adhesion to ICAM1 and stimulating β2 integrin activity as could be expected, Tiam1 restricts these processes. In accordance with these paradoxical inhibitory roles, Tiam1 limits the fMLP-stimulated activation of Rac1 and Rac2 in adherent neutrophils, rather than activating Rac as expected. Tiam1 promotes the expression of several regulators of small GTPases and cytoskeletal dynamics, including αPix, Psd4, Rasa3 and Tiam2. It also controls the association of Rasa3, and potentially αPix, Git2, Psd4 and 14‐3‐3ζ/δ, with Rac. We propose these latter roles of Tiam1 underlie its effects on Rac and β2 integrin activity and on cell responses. Hence, Tiam1 is a novel regulator of Rac-dependent neutrophil responses that functions differently to other known neutrophil Rac-GEFs.
2024-01-26 | PXD046791 | Pride
Project description:Cutaneous squamous tumors rely on autocrine/paracrine loops for proper fitness. Targeting this Achilles’ heel is therefore considered a potential avenue for patient treatment. However, the mechanisms that engage and sustain such programs during tumor ontogeny are poorly understood. Here, we show that two Rho/Rac activators, the exchange factors Vav2 and Vav3, control the expression of an epithelial autocrine/paracrine program that regulates keratinocyte survival and proliferation as well as the creation of an inflammatory microenvironment. Vav proteins are also critically involved in some of the subsequent autocrine signaling loops activated in keratinocytes. The genetic inactivation of both Vav proteins reduces tumor multiplicity without hampering skin homeostasis, thus suggesting that pan-specific Vav therapies may be useful in skin tumor prevention and treatment. The dorsal skin of WT and DKO mice (Vav2-/-;Vav3-/-) were treated with either one or four applications of phorbol ester 12-O-tetradecanoylphorbol-13 acetate (TPA) (6.8 nmol in 200 μl acetone) two days after shaving. As control, we applied 200 μl of acetone. Animals were euthanized 24 hours after treatment.
2013-07-30 | E-GEOD-40849 | biostudies-arrayexpress
Project description:The guanosine triphosphatases of the Rho and Rac subfamilies regulate protumorigenic pathways and are activated by guanine nucleotide exchange factors (Rho GEFs), which could be potential targets for anticancer therapies. We report that two Rho GEFs, Vav2 and Vav3, play synergistic roles in breast cancer by sustaining tumor growth, neoangiogenesis, and many of the steps involved in lung-specific metastasis. The involvement of Vav proteins in these processes did not correlate with Rac1 and RhoA activity or cell migration, implying the presence of additional biological programs. Microarray analyses revealed that Vav2 and Vav3 controlled a vast transcriptional program in breast cancer cells through mechanisms that were shared between the two proteins, isoform-specific or synergistic. Furthermore, the abundance of Vav regulated transcripts was modulated by Rac1-dependent and Rac1-independent pathways. This transcriptome encoded therapeutically targetable proteins that played non redundant roles in primary tumorigenesis and lung-specific metastasis, such as integrin-linked kinase (Ilk), the transforming growth factorM-bM-^@M-^Sb family ligand inhibin bA, cyclooxygenase-2, and the epithelial cell adhesion molecule Tacstd2. It also contained gene signatures that predicted disease outcome in breast cancer patients. These results identify possible targets for treating breast cancer and lung metastases and provide a potential diagnostic tool for clinical use. All microarray experiments were performed by the personnel of the Genomics and Proteomics Unit of our Institution. Transcriptomal changes were determined using the Mouse Gene 1.0 ST arrays (Affymetrix). Two independent experiments were performed to identify the Vav2/Vav3-dependent transcriptome. In the first one, we compared the transcriptomes of Control, KD2/3(A) and KD2/3(B) to identify Vav family-dependent genes. In the second one, we compared the transcriptomes of KD2/3(A) and KD2/3+V2/3 cells. In all cases, total cellular RNA was extracted from three independent exponential cultures of the appropriate cell lines using the RNAeasy kit (Qiagen), quantified using 6000 Nano Chips (Agilent Technologies, Santa Clara, CA), and used (2.3 M-NM-<g/sample) to generated labeled cRNA probes according to the manufacturerM-bM-^@M-^Ys instructions (Affymetrix). Upon microarray hybridization, the raw data was normalized, filtered and analyzed with the Bioconductor software (www.bioconductor.com) using the Affy and Siggenes applications. Generation of knockdown cell lines. The shRNA-mediated knockdown of transcripts for Vav2 and Vav3 was carried out using already packaged Mission TRC lentiviral particles (Sigma-Aldrich) according to the manufacturerM-bM-^@M-^Ys protocol. The catalogue numbers and shRNA sequences yielding the greatest knockdown were clone number TRC0000097094 (5M-bM-^@M-^Y-CCGGGCCTGCATCTCTGGTTTAGATCTCGAGATCTAA ACCAGAGATGCAGGCTTTTTG-3M-bM-^@M-^Y) for the mouse Vav2 mRNA; TRC0000097124 (5M-bM-^@M-^Y-CCGGCCAGCATTTCTCGTCTTAAATCTCGAGATTTAA GACGAGAAATGCTGGTTTTTG-3M-bM-^@M-^Y) for the mouse Vav3 mRNA. Lentiviral particles containing the empty pLOK.1puro vector (Sigma-Aldrich) were used to generate the M-bM-^@M-^\ControlM-bM-^@M-^] 4T1 cells used in these experiments. Cells were incubated with lentiviral particles in the presence of 8 M-NM-<g/ml polybrene (Sigma), selected with puromycin (1 M-NM-<g/ml; Sigma), and used as either pools or isolated clones. Two clones of double Vav2;Vav3 knockdown cells (designated KD2/A(A) and KD2/3 (B)) were used in these experiments. Generation of rescued 4T1 cell lines. To generate the rescued KD2/3(A) cell line expressing both Vav2 and Vav3, cells were first infected with lentiviral particles produced from the pCCM33 vector (encoding wild type, HA-tagged Vav2) and then with lentiviral particles containing the pCQS1 vector (encoding wild type, Myc-tagged Vav3). Cells were then selected with hygromycin (present in the Vav2-encoding pCCM33 vector) and susbsequently sorted by flow cytometry to isolate GFP positive cells (which was expressed bicistronically from the same Vav3-encoding pCQS1 vector). A clone of double reconstituted cells was used in the microarray experiments and designated as KD2/3+V2/V3.
2012-10-03 | E-GEOD-33348 | biostudies-arrayexpress
Project description:ERBB4 is a member of the epidermal growth factor receptor (EGFR)/ERBB subfamily of receptor tyrosine kinases that regulates cellular processes including proliferation, migration and survival. ERBB4 signaling is involved in embryogenesis and homeostasis of adult tissues, but also in human pathologies such as cancer, neurological disorders and cardiovascular diseases. A mass spectrometry screen revealed guanine nucleotide exchange factor (GEF) VAV3, an activator of Rho family GTPases, as a novel ERBB4-interacting protein in breast cancer cells. The ERBB4-VAV3-interaction was confirmed by targeted mass-spectrometry, coimmunoprecipitation experiments, and further defined by demonstrating that kinase activity and tyrosine residues 1022 and 1162 of ERBB4, as well as the intact phosphotyrosine-interacting SH2 domain of VAV3 were necessary for the interaction. ERBB4 was also shown to stimulate tyrosine phosphorylation of the VAV3 activation domain, which is required for GEF activity of VAV proteins. In addition to VAV3, also the other members of the VAV family, VAV1 and VAV2 were shown to coprecipitate with ERBB4. Analyses of the effects of overexpression of dominant-negative VAV3 constructs or downregulation of VAV3 expression by shRNAs in breast cancer cells demonstrated that active VAV3 was involved in ERBB4-stimulated migration. These findings define the VAV GTPases as novel effectors of ERBB4 activity in a signaling pathway relevant for cancer cell migration.
2020-06-24 | PXD019430 | Pride
Project description:Cutaneous squamous tumors rely on autocrine/paracrine loops for proper fitness. Targeting this Achilles’ heel is therefore considered a potential avenue for patient treatment. However, the mechanisms that engage and sustain such programs during tumor ontogeny are poorly understood. Here, we show that two Rho/Rac activators, the exchange factors Vav2 and Vav3, control the expression of an epithelial autocrine/paracrine program that regulates keratinocyte survival and proliferation as well as the creation of an inflammatory microenvironment. Vav proteins are also critically involved in some of the subsequent autocrine signaling loops activated in keratinocytes. The genetic inactivation of both Vav proteins reduces tumor multiplicity without hampering skin homeostasis, thus suggesting that pan-specific Vav therapies may be useful in skin tumor prevention and treatment.
2013-07-30 | GSE40849 | GEO
Project description:The Rho guanosine exchange factors Vav2 and Vav3 modulate epidermal stem cell function
| PRJNA750092 | ENA
Project description:Here, we report that the Rho GTPase activators Vav2 and Vav3 utilize a new, miR-200c-dependent mechanism that maintains the epithelial state by limiting the abundance of the Zeb2 transcriptional repressor in breast cancer cells. In parallel, Vav proteins engage an expression program that maintains epithelial cell traits in 3D culture. Depletion of Vav proteins triggers EMT in epithelioid breast cancer cells and, conversely, expression of constitutively active Vav2 restores both miR-200c expression and epithelial traits in mesenchymal breast cancer cells. In silico analyses suggest that the negative Vav-Zeb2 axis is operative in human luminal breast tumors.
2018-09-21 | GSE97385 | GEO