Neural Precursor Cell-Derived Pleiotrophin Mediates Glioma Invasion of the Subventricular Zone
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ABSTRACT: The lateral ventricle subventricular zone (SVZ) is a frequent and consequential site of pediatric and adult glioma spread, but the cellular and molecular mechanisms mediating this are poorly understood. We demonstrate that neural precursor cell (NPC):glioma cell communication underpins this propensity of glioma to colonize the SVZ through secretion of chemoattractant signals toward which glioma cells home. Biochemical, proteomic, and functional analyses of SVZ NPC-secreted factors revealed the neurite outgrowth-promoting factor pleiotrophin, along with required binding partners SPARC/SPARCL1 and HSP90B, as key mediators of this chemoattractant effect. Pleiotrophin expression is strongly enriched in the SVZ, and pleiotrophin knockdown starkly reduced glioma invasion of the SVZ in the murine brain. Pleiotrophin, in complex with the binding partners and signaling through the receptor PTPRZ1, activated glioma Rho/ROCK signaling, and ROCK inhibition decreased invasion toward SVZ NPC-secreted factors. These findings demonstrate a pathogenic role for NPC:glioma interactions and potential therapeutic targets to limit glioma invasion.
Project description:The lateral ventricle subventricular zone (SVZ) is a frequent site of high-grade glioma (HGG) spread and tumor invasion of the SVZ is a predictor of a worse clinical prognosis. A range of HGG types invade the stem cell niche of the SVZ, including both adult glioblastoma and pediatric high-grade gliomas such as diffuse intrinsic pontine glioma (DIPG). The cellular and molecular mechanisms mediating this frequent invasion of the SVZ are poorly understood. Here we demonstrate that neural precursor cell (NPC):glioma cell communication underpins the propensity of glioma to colonize the SVZ. SVZ NPCs secrete chemoattractant signals toward which glioma cells home. Biochemical and proteomic analyses of factors secreted by SVZ NPCs revealed a discrete list of candidate proteins. Necessity and sufficiency testing implicated the neurite outgrowth-promoting factor pleiotrophin, along with three required binding partners (secreted protein acidic and rich in cysteine (SPARC), SPARC-like protein 1, and heat shock protein 90B), as key mediators of this chemoattractant effect. Pleiotrophin protein expression is strongly enriched in the SVZ, and knockdown of pleiotrophin expression starkly reduced glioma invasion of the SVZ in the adult murine brain. Pleiotrophin, in complex with the three binding partners, activated the Rho/ROCK pathway in DIPG cells, and inhibition of ROCK resulted in decreased DIPG invasion toward SVZ neural precursor cell-secreted factors. These findings demonstrate a pathogenic role for neural precursor cell – glioma interactions and potential therapeutic targets to limit glioma invasion.
Project description:Several novel potential oncogenic and tumor suppressor miRNAs were identified by using the appropriate controls for stem cells. Expression profiles for human miRNAs in six samples were generated. The Agilent platform GPL7731 was used to analyze six RNA samples: CD133- human NPC, CD133+ human NPC, CD133- B4 glioma, CD133+ B4 Glioma, CD133+ NCH441 glioma, CD133+ NCH644 glioma
Project description:The mammalian adult brain contains two neural stem and precursor (NPC) niches: subventricular zone [SVZ] lining the lateral ventricles and subgranular zone [SGZ] in the hippocampus. From these SVZ NPCs represent the largest NPC pool. Notably, while SGZ NPCs typically only produce neurons and astrocytes, SVZ NPCs produce neurons, astrocytes and oligodendrocytes throughout life. Of particular importance is the generation and replacement of oligodendrocytes, the only myelinating cells of the central nervous system (CNS). SVZ NPCs contribute to myelination by regenerating oligodendrocyte precursor cell (OPC) pool and by differentiating into oligodendrocytes in the developing and demyelinated brain. The neurosphere assay has been widely adopted by the scientific community to facilitate the study of NPCs in vitro. Here, we present a streamlined protocol for culturing postnatal and adult SVZ NPCs and OPCs from primary neurosphere cells. We characterize the purity and differentiation potential as well as provide RNA-sequencing profiles of postnatal SVZ NPCs, postnatal SVZ OPCs and adult SVZ NPCs. We show that primary neurospheres cells generated from postnatal and adult SVZ differentiate into neurons, astrocytes and oligodendrocytes concurrently and at comparable levels. SVZ OPCs are generated by subjecting primary neurosphere cells to OPC growth factors fibroblast growth factor (FGF) and platelet-derived growth factor-AA (PDGF-AA). We further show SVZ OPCs can differentiate into oligodendrocytes in the absence and presence of thyroid hormone T3. Transcriptomic analysis confirmed the identities of each cell population and revealed novel immune and signalling pathways expressed in an age and cell type specific manner.
Project description:miRNA expression analysis of mouse glioma and PNET. Glioma was developed from SVZ cells through conditional codeletion of Pten/p53 or Rb/p53; while PNET was developed by codeletion of Rb/p53.
Project description:To analyze OTX2 function in adult choroid plexus, we performed several OTX2 co-immunoprecipitation (co-IP) experiments with mass spectrometry analysis to identify potential protein partners. We previously discovered that OTX2 protein also accumulates non-cell autonomously in subventricular zone (SVZ) and rostral migratory stream (RMS) astrocytes and in visual cortex (VCx) parvalbumin cells. The identification of alternate protein partners in cell-autonomous and non-cell-autonomous contexts would suggest OTX2 takes on specific roles after transferring between cells. In order to test this hypothesis, and to reinforce choroid plexus analysis, we also performed OTX2 co-IP on lysates from adult mouse SVZ, RMS and VCx.
Project description:Thiostrepton, a natural antibiotic, has recently been shown to be a potential anticancer drug for certain cancers, but its study in nasopharyngeal carcinoma (NPC) is still limited. The aims of this study were to investigate the anticancer effect of thiostrepton on NPC cells and to explore its underlying mechanism. Our results showed that thiostrepton reduced NPC cell viability in a dose-dependent manner. Thiostrepton inhibited the migration and invasion of NPC cells in wound healing and cell invasion assays. Thiostrepton effectively suppressed NPC cell proliferation, migration, and invasion, likely by several mechanisms. Thiostrepton may be a potential therapeutic agent for treating NPC in the future.
Project description:Cen3tel cells, obtained by telomerase immortalization of human fibroblasts, gradually underwent neoplastic transformation and became metastatic in immunocompromised mice. Neoplastic transformation was associated with a change in cell morphology (from fibroblastic to polygonal). Tumorigenic cells acquired a clear-cut membrane localization of adhesion molecules, a reorganization of the actin cytoskeleton, increased cell motility and invasiveness. In a 3-dimensional environment, tumorigenic cells showed a spherical morphology with cortical actin rings, suggesting a switch from a mesenchymal to an amoeboid ROCK-dependent movement. Accordingly, cell invasion decreased upon treatment with the ROCK inhibitor Y27632, but not with the matrix protease inhibitor Ro28-2653. The increased invasiveness of tumorigenic cen3tel cells was associated with a reduced expression of RhoE, a cellular inhibitor of ROCK. Ectopic RhoE expression decreased cen3tel invasion capability. These results point to RhoE and ROCK as regulators of invasiveness of mesenchymal tumor cells and indicate ROCK as a possible therapeutic target.
Project description:Nasopharyngeal carcinoma (NPC) is known for its high metastatic potential. From genomic expression profiles comparing clones derived from the NPC cell line CNE-2, serglycin (SRGN) was identified as one of the most up-regulated genes in the high-metastasis clone. Serglycin protein was secreted by the high-metastasis clone, but not by any of the low-metastasis clones. Suppression of serglycin by shRNA diminished serglycin secretion and subsequently inhibited the migration and invasion of high-metastasis clone, and also reduced its metastasis rate in vivo. Overexpression of serglycin in low-metastasis cells resulted in an increased metastasis rate in vivo. Moreover, secreted serglycin promoted cellular motility in the wild-type low-metastasis cells. Interestingly, suppression of serglycin reduced the protein level of vimentin but did not influence the level of E-cadherin in high-metastasis clone. Proliferation was not influenced by serglycin in both high-and low-metastasis clones. Clinically, serglycin expression was significantly elevated in liver metastases from NPC relative to its expression in primary tumors. The prognostic value of serglycin was evaluated by immunohistochemical staining of tissue microarrays of NPC tissues from 263 patients, followed by multivariate analyses. A high level of serglycin expression in primary NPC was found to be an independent unfavorable indicator for distant-metastasis-free survival and disease-free survival. In summary, serglycin regulates NPC metastasis via autocrine and paracrine means without influencing proliferation, and it serves as a prognostic indicator of metastasis-free survival and disease-free survival for NPC patients. Keywords: Gene Expression experiment
Project description:Nasopharyngeal carcinoma (NPC) is known for its high metastatic potential. From genomic expression profiles comparing clones derived from the NPC cell line CNE-2, serglycin (SRGN) was identified as one of the most up-regulated genes in the high-metastasis clone. Serglycin protein was secreted by the high-metastasis clone, but not by any of the low-metastasis clones. Suppression of serglycin by shRNA diminished serglycin secretion and subsequently inhibited the migration and invasion of high-metastasis clone, and also reduced its metastasis rate in vivo. Overexpression of serglycin in low-metastasis cells resulted in an increased metastasis rate in vivo. Moreover, secreted serglycin promoted cellular motility in the wild-type low-metastasis cells. Interestingly, suppression of serglycin reduced the protein level of vimentin but did not influence the level of E-cadherin in high-metastasis clone. Proliferation was not influenced by serglycin in both high-and low-metastasis clones. Clinically, serglycin expression was significantly elevated in liver metastases from NPC relative to its expression in primary tumors. The prognostic value of serglycin was evaluated by immunohistochemical staining of tissue microarrays of NPC tissues from 263 patients, followed by multivariate analyses. A high level of serglycin expression in primary NPC was found to be an independent unfavorable indicator for distant-metastasis-free survival and disease-free survival. In summary, serglycin regulates NPC metastasis via autocrine and paracrine means without influencing proliferation, and it serves as a prognostic indicator of metastasis-free survival and disease-free survival for NPC patients. Keywords: Gene Expression experiment High-metastasis clone (S18) and low-metastasis clones (S22 and S26) together with their parental line CNE-2 were subjected for gene expression profiling to identify the genes highly expressed in high-metastasis clone. To explore the molecular mechanism(s) underlying this important biological behavior, we performed genomic expression profiling of these four cell lines from in vitro cultured cells, as well as in vivo xenograft tumors generated in nude mice by subcutaneous injection of the cells into the BALB/c (nu/nu) female mice. Briefly, 1 × 10^5 cells were subcutaneously injected into the left flank of a nude mouse, and the tumors were collected when their volume was 150-250 mm^3.