EWI-2 regulates melanoma growth and lung metastasis in a TGF-β1-dependent manner
ABSTRACT: EWI-2 (IgSF8) plays a novel, bifunctional role in melanoma cells. EWI-2 inhibits migration, metastasis, EMT-like changes, and CD271-dependent invasion in multiple melanoma cell lines. On the other hand, EWI-2 supports melanoma cell proliferation, survival, and xenograft growth. Consistent with these results, EWI-2 levels were elevated in human malignant melanoma, but not in metastatic melanoma samples. Altered melanoma cell functions, caused by EWI-2 ablation, are almost entirely dependent on enhanced TRF-β1 signaling, and also require contributions from tetraspanin proteins CD9 and CD81. In melanoma cells lacking EWI-2, tetraspanins CD9 and CD81 enhance TRF-β1 signaling by facilitating TβR-2−TβR-1 receptor complex formation. When EWI-2 is present, CD9 and CD81 are diverted into EWI-2 complexes, and thus TRF-β1 signaling is inhibited. 4 samples = 2 Control + 2 EWI-2 KD.
Project description:Clinical and genomic evidence support the view that the metastatic potential of a primary tumor may be dictated by transforming events acquired early in the tumorigenic process. It has been proposed that the presence of such pro-metastatic events in early-stage tumors reflects their additional capability to function as oncogenes. Here, to test this ‘deterministic’ hypothesis and identify potential pro-metastasis oncogenes, we adopted a comparative oncogenomics-guided functional genetic screening strategy involving (i) global transcriptomic data from two genetically engineered mouse models of melanoma with contrasting metastatic potential, (ii) genomic and transcriptomic profiles of human primary and metastatic melanoma and (iii) an invasion screen in TERT-immortalized human melanocytes and melanoma cells in vitro as well as (iv) evidence of expression selection in human melanoma tissues. This integrated effort led to the identification of 6 genes that are both potently pro-invasive and oncogenic. Further, we show that one such pro-invasion oncogene, ACP5, can confer spontaneous metastasis in vivo, engages a key pathway governing metastasis and is prognostic in human primary melanomas. The tetracycline-inducible MET-driven mouse (iMet) model (Tyr-rtTA;Tet-Met;Ink4a/Arf-/-) was constructed similar to the previously described iHRAS* model (Tyr-rtTA;Tet-HRASV12G;Ink4a/Arf-/-). RNA from cutaneous melanomas derived from iMet (n=6) or iHRAS* (n=6) models were profiled on Affymetrix M430A_2 chips and resultant transcriptomes were compared to generate a phenotype-based (metastatic capable or not) differentially expressed gene list. Cross-species triangulation to human gene expression and copy number aberrations was based on ortholog mapping.
Project description:This SuperSeries is composed of the following subset Series: GSE37698: Reactivation of ERK signaling causes resistance to EGFR kinase inhibitors (SNP array) GSE37699: Aberrant ERK signaling causes resistance to EGFR kinase inhibitors Refer to individual Series
Project description:This SuperSeries is composed of the following subset Series: GSE16676: Rescue of murine Gata1s mutant M7 leukemic cells by full-length Gata1 GSE16677: Gene expression profiling of Down Syndrome (DS)-AMKL and non-DS AMKL samples GSE16679: Plag1 overexpression cooperates with Evi1 overexpression and Gata1s mutation in leading to M7 leukemia GSE16682: Murine M7 leukemia derived from retroviral insertional mutagenesis of Gata1s fetal progenitors GSE16684: Murine M7 leukemia derived from retroviral insertional mutagenesis of Gata1s fetal progenitors depends on IGF signaling Refer to individual Series
Project description:Activated phosphoinositide 3-kinase (PI3K)-AKT signaling appears to be an obligate event in the development of cancer. The highly related members of the mammalian FoxO transcription factor family, FoxO1, FoxO3, and FoxO4, represent one of several effector arms of PI3K-AKT signaling, prompting genetic analysis of the role of FoxOs in the neoplastic phenotypes linked to PI3K-AKT activation. While germline or somatic deletion of up to five FoxO alleles produced remarkably modest neoplastic phenotypes, broad somatic deletion of all FoxOs engendered a progressive cancer-prone condition characterized by thymic lymphomas and hemangiomas, demonstrating that the mammalian FoxOs are indeed bona fide tumor suppressors. Transcriptome and promoter analyses of differentially affected endothelium identified direct FoxO targets and revealed that FoxO regulation of these targets in vivo is highly context-specific, even in the same cell type. Functional studies validated Sprouty2 and PBX1, among others, as FoxO-regulated mediators of endothelial cell morphogenesis and vascular homeostasis. Mice were engineered with negative control (MxCre- Fk1 L/L Fk2 L/L Afx L/L) and experimental (MxCre+ Fk1 L/L Fk2 L/L Afx L/L) genotypes. RNAs were isolated from Lung endothelial cells (2 negative controls, 2 experimental), liver sinusoidal endothelial cells (3 negative controls, 3 experimental) and thymus cells (2 negative controls, 2 experimental), and profiled on Affymetrix Mouse Genome 430 2.0 Array.
Project description:The goal of this study is to develop a Plag1 signature and determine how its overexpression contributes to leukemogenesis. To study this, we transduced an immortalized (but not transformed) cell line (derived from Gata1s mutant fetal liver progenitor through insertional mutagenesis) by Plag1-expressing retrovirus. This turned a non-transformed cell line to a leukemogenic cell line. To study whether Plag1 overexpression led to deregulation of signaling pathways that may contribute to leukemic transformation, we generated microarray gene expression profiles of this cell line transduced with either Plag1 or the empty vector. We generated gene expression profiles by microarray from stable cell lines transduced with either the empty vector or the Plag1-expressing vector.
Project description:Activation of b-catenin has been causatively linked to the etiology of colon cancer. Conditional stabilization of this molecule in pro-T-cells promotes thymocyte development without the requirement for preTCR signaling. We show here that activated b-catenin stalls the developmental transition from the double-positive (DP) to the single-positive (SP) thymocyte stage and predisposes DP thymocytes to transformation. b-Catenin induced thymic lymphomas have a leukemic arrest at the early DP stage. Lymphomagenesis requires Rag activity, which peaks at this developmental stage, as well as additional secondary genetic events. A consistent secondary event is the transcriptional upregulation of c-Myc, whose activity is required for transformation since its conditional ablation abrogates lymphomagenesis. In contrast, the expression of Notch receptors as well as targets is reduced in DP thymocytes with stabilized b-catenin and remains low in the lymphomas indicating that Notch activation is not required or selected for in b-catenin induced lymphomas. Thus, b-catenin activation may provide a mechanism for the induction of T-ALL that does not depend on Notch activation. Experiment Overall Design: This study was used to compare gene expression patterns of LckCre mice, CD4Cre-Ctnnbex3 mice before and after T-cell transformation. 5 independent Lckcre (control), 5 independent CD4Cre-Ctnnbex3 mice and 8 independent mice with lymphomas were used. Thymocytes or tumor masses were collected from Lckcre, CD4Cre-Ctnnbex3 mice. Total RNA isolation and purification followed by synthesis of dscDNA, Biotinylated cRNA and purification of Biotinylated cRNA. Then the hybridization to Affymetrix “Mouse Expression Array 430 Genechips” was done. Data was analysed by dchip.
Project description:The clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show that in multiple complementary models harboring EGFR T790M, resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002, and the combination of WZ4002 and a MEK inhibitor prevents the emergence of drug resistance. The WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy compared to the parental counterparts. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials. Our study identifies ERK signaling as a mediator of resistance to irreversible pyrimidine EGFR inhibitors in EGFR T790M-bearing cancers. We further provide a therapeutic strategy to both treat and prevent the emergence of this resistance mechanism. To generate drug-resistant NCI-H1975 cell lines, non-small cell lung cancer (NSCLC) cells were exposed to increasing concentrations of WZ4002 similar to previously described methods. Individual clones from WZ4002-resistant (WZR) cells were isolated and confirmed to be drug resistant. Clone #6, designated as WZR6, was used in this study. For expression analysis, samples were prepared in triplicate from parental NCI-H1975 and NCI-H1975 WZR6 cells.
Project description:Background: Clinical trial and epidemiological data support that the cardiovascular effects of estrogen are complex, including a mixture of both potentially beneficial and harmful effects. In animal models, estrogen protects females from vascular injury and inhibits atherosclerosis. These effects are mediated by estrogen receptors (ERs), which when bound to estrogen can bind to DNA to directly regulate transcription. ERs can also activate several cellular kinases by inducing a “rapid” non-nuclear signaling cascade. However, the biologic significance of this rapid signaling pathway has been unclear. Methods and Results: Here, we develop a novel transgenic mouse in which rapid signaling is blocked by over-expression of a peptide that prevents ERs from interacting with the scaffold protein, striatin (the Disrupting Peptide Mouse, DPM). Microarray analysis of ex vivo-treated mouse aortas demonstrates that rapid ER signaling plays an important role in E2-mediated gene regulatory responses. Disruption of ER-striatin interactions also eliminates the ability of E2 to stimulate cultured endothelial cell migration and to inhibit cultured vascular smooth muscle cell growth. The importance of these findings is underscored by in vivo experiments demonstrating loss of estrogen-mediated protection against vascular injury in the DPM mouse following carotid artery wire injury. Conclusions: Taken together, these results support that rapid, non-nuclear ER signaling contributes to the transcriptional regulatory functions of ER, and is essential for many of the vasoprotective effects of estrogen. These findings also identify the rapid ER signaling pathway as a potential target for the development of novel therapeutic agents. Transgenic disrupting peptide mice (DPM) express the Estrogen Receptor (ER) alpha amino acids 176-253 peptide under CMV promoter control. This peptide blocks interactions between ER and striatin, which inhibits rapid non-genomic signaling by ER to cellular kinases. Female WT and DPM mice (4 mice per sample) were overiectomized, and 1 week later aortas were harvested and treated + 10 nM beta-estradiol (E2) or + EtOH vehicle (Veh) for 4 hrs ex vivo. Total RNA was collected, reverse transcribed to cDNA and used to probe Affymetrix mouse 430.A 2.0 arrays.
Project description:We developed a computational framework that integrates chromosomal copy number and gene expression data for detecting aberrations that promote cancer progression. We demonstrate the utility of this framework using a melanoma dataset. Our analysis correctly identified known drivers of melanoma and predicted multiple novel tumor dependencies. Two dependencies, TBC1D16 and RAB27A, confirmed empirically, suggest that abnormal regulation of protein trafficking contributes to proliferation in melanoma. Together, these results demonstrate the ability of integrative Bayesian approaches to identify novel candidate drivers with biological, and possibly therapeutic, importance in cancer. Effects of knockdown of two genes -TBC1D16 and RAB27A - were tested on four cell lines each, each of them with two different hairpins. As a control, we used a hairping targeting GFP. shGFP experiments were done in biological duplicates or more. The second WM1976-shGFP sample was identified as an outlier by a PCA analysis and was excluded from our analysis.
Project description:Extracellular membrane vesicles (EVs) function as vehicles of intercellular communication in autocrine or paracrine manner. We report that cancer-derived EV biomaterials reach nuclei of human melanoma and breast carcinoma cells and multipotent mesenchymal stromal cells (MSCs) through Rab7+ late endosome subdomains that penetrate into nuclear envelope invaginations. MSCs were exposed to cancer Evs in the presence or absence of drugs that block nucler import or export through the nuclear pores. Depletion of CD9 or inhibition of importin β1, two EV-associated molecules, abrogated the nuclear localization of EV-derived biomaterials and EV-induced early changes in MSC transcriptome notably in genes involved in inflammation. Also inhibition of nuclear export by leptomycin B inhibited early changes in MSC transcriptome. This novel cellular pathway may become a cancer therapeutic target. Overall design: mRNA-Seq Human mesenchymal stromal cells alone or exposed to cancer Evs in the presence or absence of uptake modulators