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P16.08 Inhibition of melanoma brain metastasis by targeting miR-146a. Neuro Oncol 2021. [DOI: 10.1093/neuonc/noab180.199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released from the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression.
MATERIAL AND METHODS
miRNAs in exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development.
RESULTS
miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146 in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo.
CONCLUSION
miR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.
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P11.57 A 3D brain organoid coculture system delineates the invasive cell components in glioblastoma. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Glioblastoma (GBM) cell infiltration into the surrounding normal brain tissue where the blood brain barrier is intact, represents a major problem for clinical management and therapy. There is a vital need to understand the molecular mechanism that drives tumor cell invasion into the surrounding brain. We have previously developed a 3D coculture model where mature brain organoids are confronted with patient-derived glioblastoma stem-like cells (GSCs). In such a coculture system, single cell invasion into the normal brain tissue can be studied in detail. Here, we first describe in detail, by RNA-seq and proteomics, the differentiation of various neural cell lineages into mature brain organoids as well as their cellular organization. By real-time confocal microscopy and imaging analyses we also determine the speed of tumor cell invasion into the brain. Finally, we used this coculture system to delineate in detail the cellular heterogeneity within the invasive compartment and their gene expression.
MATERIAL AND METHODS
Immunohistochemistry and immunofluorescence were used to determine the expression and distribution of mature neurons, astrocytes, oligodendrocytes, and microglia within the brain organoids. Proteomics and RNA-seq were used to determine brain development ex-vivo. To assess the clonal composition of the GBM-invasive compartment, we used cellular (RGB) barcoding technology. By advanced imaging, we tracked in real time the invasion of barcoded cells into the brain organoids. Finally, we isolated invasive cells and non-invasive cells from our coculture system and used single cell sequencing to analyze their gene expression profiles and molecular phenotypes.
RESULTS
Immunohistochemistry and immunofluorescence showed that brain organoids, after 21 days of differentiation, display a highly cellular and structural organization. RNA-seq and proteomics, performed at different time points of organoid differentiation, revealed that the brain organoids develop into mature brain structures after 21 days as verified by a comparative analysis to normal rat brain development in vivo. Imaging analyses showed that multiple clones within the GBMs have the capacity to invade into the brain tissue with an average speed of ~ 20 μm/h. RNA-sec analysis of the invasive compartment revealed a strong up-regulation of genes and pathways associated with anaerobic respiration (glycolysis).
CONCLUSION
We describe a highly standardized brain organoid coculture system that can be used to delineate GBM invasion ex-vivo. We demonstrate that this platform can be used to unravel the mechanisms that drive GBM invasion into the normal brain.
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P04.87 Delineating the invasive component of human brain tumors using brain organoids. Neuro Oncol 2018. [DOI: 10.1093/neuonc/noy139.321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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