ABSTRACT: Loss of the tumor suppressor CHD5 frequently occurs during neuroblastoma progression. We used microarray analyses to identify genes that change expression following transient transfection of human CHD5 into KELLY cells
Project description:Loss of the tumor suppressor CHD5 frequently occurs during neuroblastoma progression. We used microarray analyses to identify genes that change expression following transient transfection of human CHD5 into KELLY cells KELLY cells were transiently transfected with the human CHD5 cDNA or the empty vector. RNA was extracted and hybridized on Affymetrix microarrays
Project description:CHD5, a tumor suppressor at 1p36, is frequently lost or silenced in poor prognosis neuroblastoma (NB) and many adult cancers. The role of CHD5 in metastasis is unknown. We confirm that low expression of CHD5 is associated with stage 4 NB. Forced expression of CHD5 in NB cell lines with 1p loss inhibited key aspects of the metastatic cascade in vitro: anchorage-independent growth, migration and invasion. In vivo, formation of bone marrow and liver metastases developing from intravenously injected NB cells was delayed and decreased by forced CHD5 expression. Genome-wide mRNA sequencing revealed reduction of genes and gene sets associated with metastasis when CHD5 was overexpressed. Known metastasis-suppressing genes preferentially up-regulated in CHD5-overexpressing NB cells included PLCL1. In patient NB, low expression of PLCL1 was associated with metastatic disease and poor survival. Knock-down of PLCL1 and of p53 in IMR5 NB cells overexpressing CHD5 reversed CHD5-induced inhibition of invasion and migration in vitro. In summary, CHD5 is a metastasis suppressor in NB.
Project description:The chromatin remodeler CHD5 is expressed in neural tissue and is frequently deleted in aggressive neuroblastoma. Very little is known about the function of CHD5 in the nervous system or its mechanism of action. Here we report that depletion of Chd5 in the developing murine neocortex blocks neuronal differentiation and leads to an accumulation of undifferentiated progenitors. CHD5 binds a large cohort of genes and is required for facilitating the activation of neuronal genes. It also binds a cohort of Polycomb targets and is required for the maintenance of H3K27me3 on these genes. Interestingly, the chromodomains of CHD5 directly bind H3K27me3 and are required for neuronal differentiation. In the absence of CHD5, a subgroup of Polycomb-repressed genes becomes aberrantly expressed. These findings provide new insights into the regulatory role of CHD5 during neurogenesis and suggest how inactivation of this candidate tumor suppressor might contribute to neuroblastoma. Examination of genome-wide binding/occupancy of CHD5 in the SH-SY5Y cell line
Project description:The chromatin remodeler CHD5 is expressed in neural tissue and is frequently deleted in aggressive neuroblastoma. Very little is known about the function of CHD5 in the nervous system or its mechanism of action. Here we report that depletion of Chd5 in the developing murine neocortex blocks neuronal differentiation and leads to an accumulation of undifferentiated progenitors. CHD5 binds a large cohort of genes and is required for facilitating the activation of neuronal genes. It also binds a cohort of Polycomb targets and is required for the maintenance of H3K27me3 on these genes. Interestingly, the chromodomains of CHD5 directly bind H3K27me3 and are required for neuronal differentiation. In the absence of CHD5, a subgroup of Polycomb-repressed genes becomes aberrantly expressed. These findings provide new insights into the regulatory role of CHD5 during neurogenesis and suggest how inactivation of this candidate tumor suppressor might contribute to neuroblastoma.
Project description:CHD5 is frequently deleted in neuroblastoma, and appears to be a tumor suppressor gene; however, little is known about the role of CHD5. We found CHD5 mRNA was restricted to brain; by contrast most other remodeling ATPases were broadly expressed. CHD5 protein isolated from mouse brain was associated with HDAC2, p66, MTA3 and RbAp46 in a megadalton complex. CHD5 protein was detected in several rat brain regions and appeared to be enriched in neurons. CHD5 protein was predominantly nuclear in primary rat neurons and brain sections. Microarray analysis revealed genes that were upregulated and downregulated when CHD5 was depleted from primary neurons. CHD5 depletion altered expression of neuronal genes, transcription factors, and brain-specific subunits of the SWI/SNF remodeling enzyme. Aging and Alzheimers gene sets were strongly affected by CHD5 depletion from primary neurons. Chromatin immunoprecipitation revealed CHD5 bound to these genes, suggesting the regulation was direct. Together, these results indicate that CHD5 is found in a NuRD-like multi-protein complex. CHD5 is restricted to the brain, unlike the closely related family members CHD3 and CHD4. CHD5 regulates expression of neuronal genes, cell cycle genes and remodeling genes. CHD5 is linked to regulation of aging and Alzheimer’s genes.
Project description:CHD5 is frequently deleted in neuroblastoma, and appears to be a tumor suppressor gene; however, little is known about the role of CHD5. We found CHD5 mRNA was restricted to brain; by contrast most other remodeling ATPases were broadly expressed. CHD5 protein isolated from mouse brain was associated with HDAC2, p66, MTA3 and RbAp46 in a megadalton complex. CHD5 protein was detected in several rat brain regions and appeared to be enriched in neurons. CHD5 protein was predominantly nuclear in primary rat neurons and brain sections. Microarray analysis revealed genes that were upregulated and downregulated when CHD5 was depleted from primary neurons. CHD5 depletion altered expression of neuronal genes, transcription factors, and brain-specific subunits of the SWI/SNF remodeling enzyme. Aging and Alzheimers gene sets were strongly affected by CHD5 depletion from primary neurons. Chromatin immunoprecipitation revealed CHD5 bound to these genes, suggesting the regulation was direct. Together, these results indicate that CHD5 is found in a NuRD-like multi-protein complex. CHD5 is restricted to the brain, unlike the closely related family members CHD3 and CHD4. CHD5 regulates expression of neuronal genes, cell cycle genes and remodeling genes. CHD5 is linked to regulation of aging and Alzheimer’s genes. CHD5 KD shRNA sequences were designed according to the instructions for the pLKO.1 system (Addgene). Control was as described (Sci307-1098,2005) Scramble, clone 1864 from Addgene). Virus was packaged using HEK-293T cells, pLKO.1 vector with shRNA inserts for CHD5, and the control. 48 hours after transfection of 293 cells, medium containing virus was filtered (0.45 micron), then applied for 6 hours to primary cortical neurons one day after the neurons were plated (Day 1). Medium was removed, and replaced with Neural Basal Medium, and the cells were cultured until Day 5, 9 or 12. RNA was harvested from 3 replicates of the treated primary cortical neurons at each time point. RNA was isolated using RNAeasy Kit (Qiagen), Quality and quantity of the total RNA was checked with the Agilent 2100 bioanalyzer using RNA 6000 Nano chips. RNA was labeled using the standard Illumina protocol and Illumina TotalPrep RNA Amplification Kit (Ambion; Austin, TX, cat # IL1791) Biotin labeled cRNA was hybridized to Illumina's Sentrix Rat Ref-12 v1 Expression BeadChips.
Project description:Transcription profiling of the neuroblastoma cell line Kelly following transient transfection with Pre-miR-335 and negative controls to identify potential miR-335 target genes.