Diffuse intrinsic pontine glioma (DIPG) is an incurable pediatric brain tumor, resulting in the death of 200-300 children each year in the United States. Recently it was discovered that approximately 25% of all DIPG cases harbor activating mutations in ACVR1, a gene that encodes Activin A receptor (ALK2), a receptor in the bone morphogenetic protein (BMP) pathway, and that DIPGs with ALK2 mutations commonly harbor an H3.1K27M mutation. Herein, we used the RCAS/TVA retroviral system to study the effects of ACVR1 mutations and H3.1K27M on DIPG pathogenesis. In vitro expression of R206H ACVR1 with and without H3.1K27M in nestin-expressing brainstem progenitors resulted in upregulation of mesenchymal markers and gene set enrichment analysis (GSEA) revealed Stat3 pathway activation. Neonatal expression of ACVR1 R206H or G328V in combination with H3.1K27M and p53 deletion in nestin-expressing brainstem progenitors induced glioma-like lesions expressing mesenchymal markers with Stat3 activation but was not sufficient for full gliomagenesis. In combination with platelet-derived growth factor A (PDGFA) signaling, ACVR1 R206H and H3.1K27M significantly decreased survival and increased tumor incidence. We demonstrate that targeting the BMP signaling pathway may be an effective therapeutic strategy to treat ACVR1 R206H mutant DIPGs. Exogenous Noggin expression at tumor initiation significantly increased tumor latency and treatment of ACVR1 R206H mutant murine DIPGs with LDN212854, an ACVR1 inhibitor, significantly prolonged their survival. We confirm relevance of our model to the human disease as human DIPG models with ACVR1 mutations were also sensitive to treatment with LDN212854 in vitro. Altogether, our studies demonstrate that ACVR1 R206H and H3.1K27M promote tumor initiation, accelerate gliomagenesis, promote a mesenchymal profile in part due to Stat3 activation, and identify LDN212854 as a promising compound to treat children with DIPG. Overall design: We use RNAseq to study the transcriptomal effects of ACVR1 WT or R206H ACVR1 mutation alone and in combination with H3.1K27M mutation on murine nestin-expressing brainstem progenitors at P3-5 (using RCAS/TVA). Key findings were validated by Real-Time PCR.
ACVR1 R206H cooperates with H3.1K27M in promoting diffuse intrinsic pontine glioma pathogenesis.
Specimen part, Subject
View SamplesCutaneous malignant melanoma is among the most deadly human cancers, broadly resistant to most clinical therapies. A majority of patients with BRAFV600E melanomas respond well to inhibitors such as vemurafenib, but all ultimately relapse. Moreover, there are no viable treatment options available for other non-BRAF melanoma subtypes in the clinic. A key to improving treatment options lies in a better understanding of mechanisms underlying melanoma progression, which are complex and heterogeneous. In this study we perform gene expression profilling of highly and poorly malignant melanocytic tumors from genetically engineered mouse models to discover important drivers of cancer progression.
Integrated Genomics Identifies miR-32/MCL-1 Pathway as a Critical Driver of Melanomagenesis: Implications for miR-Replacement and Combination Therapy.
Specimen part
View SamplesIn the present study, we demonstrate that hMSCs migrate toward human keratinocytes as well as toward conditioned medium from cultured human keratinocytes (KCM) indicating that the hMSCs can respond to signals from keratinocytes. Incubation of hMSCs with KCM induced dermal myofibroblast like differentiation characterized by expression of cytoskeletal markers vinculin and F-actin filaments with increased expression of alpha smooth muscle actin. We then examined the therapeutic efficacy of hMSCs in wound healing in two animal models representing normal and chronic wound healing. Accelerated wound healing, as determined by quantitative measurements of wound area, was observed when hMSCs and KCM exposed hMSCs (KCMSCs) were injected near the site of incisional/excisional wounds in nondiabetic athymic and NOD/SCID mice as compared with normal human fetal lung fibroblast WI38 cells or saline control induced wound healing.
Keratinocyte Induced Differentiation of Mesenchymal Stem Cells into Dermal Myofibroblasts: A Role in Effective Wound Healing.
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View SamplesRNA expression was measured by RNA-seq in Drosophila ML-DmBG3-c2 cells depleted for proteins involved in sister chromatid cohesion, and in developing third instar wing discs with or withough brca2 gene mutations Overall design: RNA expression in depleted cells was compared to mock treated cells and RNA expression in wing discs from brca2 mutant Drosophila was compared to expression in wing discs without brca2 mutations This series includes mock RNAi treated samples re-used from GSE100547.
Brca2, Pds5 and Wapl differentially control cohesin chromosome association and function.
Specimen part, Cell line, Subject
View SamplesRNA expression was measured using RNA-seq Overall design: RNA levels in Mock-treated control Drosophila cells were compared to RNA levels in cells RNAi depleted for Ph, Sce, and Pc
Polycomb repressive complex 1 modifies transcription of active genes.
Subject
View SamplesRNA nascent transcription was measured using NT-seq Overall design: RNA nascent transcript levels in Mock-treated control Drosophila cells were compared to those in cells RNAi depleted for Ph and Sce
Polycomb repressive complex 1 modifies transcription of active genes.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cohesin and polycomb proteins functionally interact to control transcription at silenced and active genes.
Sex, Specimen part
View SamplesCohesin is crucial for proper chromosome segregation, but also regulates gene transcription and organism development by poorly understood mechanisms. We find that in Drosophila, cohesin functionally interacts with Polycomb group (PcG) silencing proteins at both silenced and active genes. Cohesin unexpectedly facilitates binding of Polycomb Repressive Complex 1 (PRC1) to many active genes. In contrast, cohesin and PRC1 binding are mutually antagonistic at silenced genes. PRC1 depletion decreases phosphorylated RNA polymerase and mRNA at many active genes, but increases them at silenced genes. Cohesin also facilitates long-range interactions between Polycomb Response Elements in the invected-engrailed gene complex where it represses transcription. These multiple distinct cohesin-PcG interactions reveal a previously unrecognized role for PRC1 in facilitating productive gene transcription, and provide new insights into how cohesin and PRC1 control development.
Cohesin and polycomb proteins functionally interact to control transcription at silenced and active genes.
Sex
View SamplesLeaf samples were used. We exposed young seedlings to NaCl and drought.
Identification of cis-regulatory elements associated with salinity and drought stress tolerance in rice from co-expressed gene interaction networks.
Specimen part
View SamplesRad21 is a subunit of cohesin. The main function of cohesin is to hold replicated chromosomes together until cells divide, but it also plays a role in gene expression. To find out which genes might be regulated by cohesin, a study was conducted to look for global changes in gene expression in zebrafish embryos lacking cohesin component Rad21.
Positive regulation of c-Myc by cohesin is direct, and evolutionarily conserved.
Specimen part, Time
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