Project description:Alveolar soft part sarcoma (ASPS) is a rare soft part malignancy affecting adolescents and young adult. ASPS is characterized by its alveolar structure consisting of tumor cells and highly integrated vascular network, and its high metastatic potential indicates the importance of the prominent angiogenic activity of ASPS. Here we find that the expression of ASPSCR1-TFE3, the fusion transcription factor causatively associated with ASPS, is dispensable for in vitro tumor maintenance but required for in vivo tumor development via angiogenesis. ASPSCR1-TFE3 frequently associates with active enhancers including super-enhancers (SE) upon its DNA binding, and the loss of its expression induces dynamic modification of SE distribution related to genes belonging to the angiogenesis pathway. Using epigenomic CRISPR/dCas9 screening, we identify Pdgfb, Rab27a, Sytl2, and Vwf as critical target genes associated with reduced enhancer activities due to the ASPSCR1-TFE3 loss. ASPSCR1-TFE3 thus orchestrates higher ordered angiogenesis via enhanced intracellular trafficking of angiogenic factors.
Project description:Alveolar soft part sarcoma (ASPS) is a rare soft part malignancy affecting adolescents and young adult. ASPS is characterized by its alveolar structure consisting of tumor cells and highly integrated vascular network, and its high metastatic potential indicates the importance of the prominent angiogenic activity of ASPS. Here we find that the expression of ASPSCR1-TFE3, the fusion transcription factor causatively associated with ASPS, is dispensable for in vitro tumor maintenance but required for in vivo tumor development via angiogenesis. ASPSCR1-TFE3 frequently associates with active enhancers including super-enhancers (SE) upon its DNA binding, and the loss of its expression induces dynamic modification of SE distribution related to genes belonging to the angiogenesis pathway. Using epigenomic CRISPR/dCas9 screening, we identify Pdgfb, Rab27a, Sytl2, and Vwf as critical target genes associated with reduced enhancer activities due to the ASPSCR1-TFE3 loss. ASPSCR1-TFE3 thus orchestrates higher ordered angiogenesis via enhanced intracellular trafficking of angiogenic factors. We used microarrays to detail the global program of gene expression in mouse and human ASPS cells.
Project description:Alveolar soft part sarcoma (ASPS) is a rare soft part malignancy affecting adolescents and young adult. ASPS is characterized by its alveolar structure consisting of tumor cells and highly integrated vascular network, and its high metastatic potential indicates the importance of the prominent angiogenic activity of ASPS. Here we find that the expression of ASPSCR1-TFE3, the fusion transcription factor causatively associated with ASPS, is dispensable for in vitro tumor maintenance but required for in vivo tumor development via angiogenesis. ASPSCR1-TFE3 frequently associates with active enhancers including super-enhancers (SE) upon its DNA binding, and the loss of its expression induces dynamic modification of SE distribution related to genes belonging to the angiogenesis pathway. Using epigenomic CRISPR/dCas9 screening, we identify Pdgfb, Rab27a, Sytl2, and Vwf as critical target genes associated with reduced enhancer activities due to the ASPSCR1-TFE3 loss. ASPSCR1-TFE3 thus orchestrates higher ordered angiogenesis via enhanced intracellular trafficking of angiogenic factors. We used microarrays to detail the global program of gene expression in mouse and human ASPS cells.
Project description:Alveolar soft part sarcoma (ASPS) is a rare soft part malignancy affecting adolescents and young adult. ASPS is characterized by its alveolar structure consisting of tumor cells and highly integrated vascular network, and its high metastatic potential indicates the importance of the prominent angiogenic activity of ASPS. Here we find that the expression of ASPSCR1-TFE3, the fusion transcription factor causatively associated with ASPS, is dispensable for in vitro tumor maintenance but required for in vivo tumor development via angiogenesis. ASPSCR1-TFE3 frequently associates with active enhancers including super-enhancers (SE) upon its DNA binding, and the loss of its expression induces dynamic modification of SE distribution related to genes belonging to the angiogenesis pathway. Using epigenomic CRISPR/dCas9 screening, we identify Pdgfb, Rab27a, Sytl2, and Vwf as critical target genes associated with reduced enhancer activities due to the ASPSCR1-TFE3 loss. ASPSCR1-TFE3 thus orchestrates higher ordered angiogenesis via enhanced intracellular trafficking of angiogenic factors.
Project description:This SuperSeries is composed of the SubSeries listed below. Alveolar soft part sarcoma (ASPS) is a rare mesenchymal malignancy driven by the ASPSCR1::TFE3 fusion. A better understanding of the mechanisms by which this oncogenic transcriptional regulator drives cancer growth is needed to help identify potential therapeutic targets. Here, we characterized the transcriptional and chromatin landscapes of ASPS tumors and preclinical models, identifying the essential role of ASPSCR1::TFE3 in tumor cell viability by regulating core transcriptional programs involved in cell proliferation, angiogenesis, and mitochondrial biology. ASPSCR1::TFE3 directly interacted with key epigenetic regulators at enhancers and promoters to support ASPS-associated transcription. Among the effector programs driven by ASPSCR1::TFE3, cell proliferation was driven by high levels of cyclin D1 expression. Disruption of cyclin D1/CDK4 signaling led to loss of ASPS proliferative capacity, and combined inhibition of CDK4/6 and angiogenesis halted tumor growth in xenografts. These results define the ASPS oncogenic program, reveal mechanisms by which ASPSCR1::TFE3 controls tumor biology, and identify a strategy for therapeutically targeting tumor cell-intrinsic vulnerabilities.
Project description:Alveolar soft part sarcoma (ASPS) is a rare mesenchymal malignancy driven by the ASPSCR1::TFE3 fusion, though the mechanisms by which this oncogenic transcriptional regulator drives cancer growth are poorly understood. Here, we characterize the transcriptional and chromatin landscapes of ASPS tumors and preclinical models, identifying the essential role of ASPSCR1::TFE3 in tumor cell viability by regulating core transcriptional programs including cell proliferation, angiogenesis, and mitochondrial biology. ASPSCR1::TFE3 directly interacts with key epigenetic regulators at enhancers and promoters to support ASPS-associated transcription. Among the effector programs driven by ASPSCR1::TFE3, cell proliferation was driven by high levels of Cyclin D1 expression, and disruption of Cyclin D1/CDK4 signaling led to loss of ASPS proliferative capacity, which when combined with angiogenesis inhibition halted tumor growth in xenografts. These results define the ASPS oncogenic program, mechanisms by which ASPSCR1::TFE3 controls tumor biology, and identify a strategy for therapeutically targeting tumor cell-intrinsic vulnerabilities.