Project description:Metastatic spread in Ewing Tumors (ET) is hematogenous and malignant features have been shown to correlate with hypoxia and angiogenesis. We identified several Ewing tumor specific genes (Staege MS et al. Cancer Res. 2004;64:8213-21). Microarray analysis confirmed an endothelial signature of this tumor and revealed the G-protein coupled receptor-64 (GPR64), an orphan receptor with normal expression restricted to human epididymis, to be highly induced in ET. Down-regulation of GPR64 in ET lines by RNA interference did not reduce their proliferative capacity in vitro as measured by plastic adherence dependent proliferation or contact independent growth in colony forming assays. Of interest inhibition of GPR64 expression in ET cell lines resulted in impaired endothelial differentiation in tube formation assays. Furthermore, GPR64 suppression substantially inhibited tumor growth and metastatic spread in immunodeficient Rag2-/-gammaC-/- mice. Microarray analysis of ET after GPR64 knock down revealed a GPR64-mediated induction of VEGF receptor 1 ligand placental growth factor (PGF) in ET. PGF itself was induced by EWS-FLI1 in mesenchymal stem cells. Repression of PGF expression in ET cell lines resulted in a similar phenotype as observed after GPR64 knockdown. GPR64 as well as PGF knock down correlated with a reduced proteolytic activity of Matrix Metalloproteinase MMP1 and invasiveness in vitro. MMP1 specific knock down resulted in the abrogation of metastasis of ET in Rag2-/-gammaC-/- mice. We conclude, that GPR64 and subsequent PGF up-regulation in ET orchestrate and promote endothelial invasiveness and metastatic spread and play a pivotal role in the pathogenesis and aggressiveness of this tumor. Established Ewing tumor cell lines were transfected with siRNA with specificity for CHM1 (control) or GPR64. RNA was extracted and hybridized with Affymetrix HG_U133A microarrays.
Project description:Metastatic spread in Ewing Tumors (ET) is hematogenous and malignant features have been shown to correlate with hypoxia and angiogenesis. We identified several Ewing tumor specific genes (Staege MS et al. Cancer Res. 2004;64:8213-21). Microarray analysis confirmed an endothelial signature of this tumor and revealed the G-protein coupled receptor-64 (GPR64), an orphan receptor with normal expression restricted to human epididymis, to be highly induced in ET. Down-regulation of GPR64 in ET lines by RNA interference did not reduce their proliferative capacity in vitro as measured by plastic adherence dependent proliferation or contact independent growth in colony forming assays. Of interest inhibition of GPR64 expression in ET cell lines resulted in impaired endothelial differentiation in tube formation assays. Furthermore, GPR64 suppression substantially inhibited tumor growth and metastatic spread in immunodeficient Rag2-/-gammaC-/- mice. Microarray analysis of ET after GPR64 knock down revealed a GPR64-mediated induction of VEGF receptor 1 ligand placental growth factor (PGF) in ET. PGF itself was induced by EWS-FLI1 in mesenchymal stem cells. Repression of PGF expression in ET cell lines resulted in a similar phenotype as observed after GPR64 knockdown. GPR64 as well as PGF knock down correlated with a reduced proteolytic activity of Matrix Metalloproteinase MMP1 and invasiveness in vitro. MMP1 specific knock down resulted in the abrogation of metastasis of ET in Rag2-/-gammaC-/- mice. We conclude, that GPR64 and subsequent PGF up-regulation in ET orchestrate and promote endothelial invasiveness and metastatic spread and play a pivotal role in the pathogenesis and aggressiveness of this tumor.
Project description:Tumors have the capacity to trigger the formation of blood vessels allowing them to spread to other body parts. We examined here the stem cells that form arteries and veins within tumors and propose that their inhibition reduces metastatic spread.
Project description:During pancreatic cancer progression, heterogeneous subclonal populations evolve in the primary tumor that possess differing capacities to metastasize and cause patient death. However, the genetics of metastasis reflects that of the primary tumor, and PDAC driver mutations arise early. This raises the possibility than an epigenetic process could be operative late. Using an exceptional resource of paired patient samples, we found that different metastatic subclones from the same patient possessed remarkably divergent malignant properties and global epigenetic programs. Global reprogramming was targeted to thousands of large chromatin domains across the genome that collectively specified malignant divergence. This was maintained by a metabolic shift within the pentose phosphate pathway, independent of KRAS driver mutations. Analysis of paired primary and metastatic tumors from multiple patients uncovered substantial epigenetic heterogeneity in primary tumors, which resolved into a terminally reprogrammed state in metastatic lesions. This supports a model whereby driver mutations accumulate early to initiate pancreatic tumorigenesis, followed by a period of subclonal evolution that generates sufficient intra-tumor heterogeneity for selection of epigenetic programs that may increase fitness during malignant progression and metastatic spread. To map the epigenomic landscape of pancreatic cancer progression as it evolves within patients. BS-Seq of 4 patients (A13, A38, A124 and A125). Patient A38 included local peritoneal metastasis and 2 distant metastsis (liver and lung mets). Patient A13 included 2 primary tumors and 1 distant lung metastasis. Each sample has been done with replicates. Patient A124 included 2 primary tumors and 1 normal pancreas.
Project description:Tumor: tumor microenvironment (TME) interactions are critical for tumor progression and the composition and structure of the local extracellular matrix (ECM) are key determinants of tumor metastasis. We recently reported that activation of Wnt/beta- catenin signaling in Ewing sarcoma cells induces widespread transcriptional changes that are associated with acquisition of a metastatic tumor phenotype. Significantly, ECM protein-encoding genes were found to be enriched among Wnt/beta-catenin induced transcripts, leading us to hypothesize that activation of canonical Wnt signaling might induce changes in the Ewing sarcoma secretome. To address this hypothesis, conditioned media from Ewing sarcoma cell lines cultured in the presence or absence of Wnt3a was collected for proteomic analysis. Label-free mass spectrometry was used to identify and quantify differentially secreted proteins. We then used in silico databases to identify only proteins annotated as secreted. Comparison of the secretomes of two Ewing sarcoma cell lines revealed numerous shared proteins, as well as a degree of heterogeneity, in both basal and Wnt-stimulated conditions. Gene set enrichment analysis of secreted proteins revealed that Wnt stimulation reproducibly resulted in increased secretion of proteins involved in ECM organization, ECM receptor interactions, and collagen formation. In particular, Wnt-stimulated Ewing sarcoma cells upregulated secretion of structural collagens, as well as matricellular proteins, such as the metastasis-associated protein, tenascin C (TNC). Interrogation of published databases confirmed reproducible correlations between Wnt/beta-catenin activation and TNC and COL1A1 expression in patient tumors. In summary, this first study of the Ewing sarcoma secretome reveals that Wnt/beta-catenin activated tumor cells upregulate secretion of ECM proteins. Such Wnt/beta-catenin mediated changes are likely to impact on tumor: TME interactions that contribute to metastatic progression.
Project description:Developmental tumors in children and young adults carry few genetic alterations, yet they have diverse clinical presentation. Focusing on Ewing sarcoma, we sought to establish the prevalence and characteristics of epigenetic heterogeneity in genetically homogeneous cancers. We performed genome-scale DNA methylation sequencing for a large cohort of Ewing sarcoma tumors and analyzed epigenetic heterogeneity on three levels: between cancers, between tumors, and within tumors. We observed consistent DNA hypomethylation at enhancers regulated by the disease-defining EWS-FLI1 fusion protein, thus establishing epigenomic enhancer reprogramming as a ubiquitous and characteristic feature of Ewing sarcoma. DNA methylation differences between tumors identified a continuous disease spectrum underlying Ewing sarcoma, which reflected the strength of an EWS-FLI1 regulatory signature and a continuum between mesenchymal and stem cell signatures. There was substantial epigenetic heterogeneity within tumors, particularly in patients with metastatic disease. In summary, our study provides a comprehensive assessment of epigenetic heterogeneity in Ewing sarcoma and thereby highlights the importance of considering nongenetic aspects of tumor heterogeneity in the context of cancer biology and personalized medicine.
Project description:Melanoma tumors are highly metastatic partly due to the ability of melanoma cells to transition between invasive and proliferative states, however, the mechanisms underlying this plasticity are still not fully understood. To identify new epigenetic regulators of melanoma plasticity, we combined data mining, tumor models, proximity proteomics, and CUT&RUN-sequencing. We focused on the druggable family of bromodomain epigenetic readers, and identified TRIM28 as a new regulator of melanoma plasticity. We found that TRIM28 promotes the expression of pro-invasive genes, and that TRIM28 controls the balance between invasiveness and growth of melanoma cells. We demonstrate that TRIM28 acts via the transcription factor JUNB, that directly regulates the expression of pro-invasive and pro-growth genes. Mechanistically, TRIM28 controls the expression of JUNB by negatively regulating its transcriptional elongation by RNA polymerase II. In conclusion, our results demonstrate that a TRIM28-JUNB axis controls the balance between invasiveness and growth in melanoma tumors and suggests that the bromodomain protein TRIM28 could be targeted to reduce tumor spread.
Project description:During pancreatic cancer progression, heterogeneous subclonal populations evolve in the primary tumor that possess differing capacities to metastasize and cause patient death. However, the genetics of metastasis reflects that of the primary tumor, and PDAC driver mutations arise early. This raises the possibility than an epigenetic process could be operative late. Using an exceptional resource of paired patient samples, we found that different metastatic subclones from the same patient possessed remarkably divergent malignant properties and global epigenetic programs. Global reprogramming was targeted to thousands of large chromatin domains across the genome that collectively specified malignant divergence. This was maintained by a metabolic shift within the pentose phosphate pathway, independent of KRAS driver mutations. Analysis of paired primary and metastatic tumors from multiple patients uncovered substantial epigenetic heterogeneity in primary tumors, which resolved into a terminally reprogrammed state in metastatic lesions. This supports a model whereby driver mutations accumulate early to initiate pancreatic tumorigenesis, followed by a period of subclonal evolution that generates sufficient intra-tumor heterogeneity for selection of epigenetic programs that may increase fitness during malignant progression and metastatic spread. To map the epigenomic landscape of pancreatic cancer progression as it evolves within patients. RNA-Seq of 2 patients (A13 and A38). Patient A38 included local peritoneal metastasis and 2 distant metastsis (liver and lung mets), and 6AN treated and DMSO control samples. Patient A13 included 2 primary tumors and 1 distant lung metastasis. Each sample has been done with replicates.
Project description:During inflammation and tissue regeneration, the alarmin High Mobility Group Box 1 (HMGB1), in its reduced isoform, enhances the activity of the chemokine CXCL12, forming a heterocomplex that acts via the chemokine receptor CXCR4. Despite the established roles of both HMGB1 and CXCL12 in tumor progression and metastatic spread to distal sites, the role of the CXCL12/HMGB1 heterocomplex in cancer has never been investigated. By employing a newly established mass spectrometry protocol that allows an unambiguous distinction between reduced (red HMGB1) and oxidized (ox HMGB1) HMGB1 isoforms in cell lysates, we demonstrate that human epithelial cells derived from breast (MCF-7 and MDA-MB-231) and prostate (PC-3) cancer predominantly express red-HMGB1, while primary CD3+ T lymphocytes from peripheral blood express both HMGB1 isoforms. All these cancer cells release HMGB1 in the extracellular microenvironment together with varying concentrations of thioredoxin and thioredoxin reductase. The CXCL12/HMGB1 heterocomplex enhances, via CXCR4, the directional migration and invasiveness of cancer cells characterized by high metastatic potential that possess a fully active thioredoxin system, contributing to maintain red-HMGB1. On the contrary, cancer cells with low metastatic potential, lack thioredoxin reductase, promptly uptake CXCL12 and fail to respond to the heterocomplex. Our study demonstrates that the responsiveness of cancer cells to the CXCL12/HMGB1 heterocomplex, resulting in enhanced cell migration and invasiveness, depends on the maintenance of HMGB1 in its reduced isoform, and suggests disruption of the heterocomplex as a potential therapeutic target to inhibit invasion and metastatic spread in cancer therapies.