Project description:Following treatment with the de-methylating agent 5-aza-deoxycytidine (DAC), the gene expression profiles of neuroblastoma cell lines Kelly, SK-N-AS and NGP were analysed in order to examine the relationship between transcriptional re-activation and promoter region DNA methylation.<br>In addition, the neuroblastoma cell line SK-N-BE was treated with all-trans-retinoic acid (ATRA) in order to examine the impact this differentiation agent has on DNA methylation status.
Project description:We report here the DNA-binding profiles for all human and mouse ETS factors, which we generated using two different methods: a high-throughput microwell-based transcription factor DNA-binding specificity assay, and protein binding microarrays (PBMs). Both approaches reveal that the ETS binding profiles cluster into four distinct classes, and that all ETS factors linked to cancer, ERG, ETV1, ETV4 and FLI1, fall into just one of these classes. We identify amino acid residues that are critical for the differences in specificity between all the classes, and confirm the specificities in vivo using chromatin immunoprecipitation followed by sequencing (ChIP-seq) for a member of each class. To determine whether the ChIP-seq peaks were near genes regulated by the respective ETS-factors, we used RNAi to downregulate EWS-FLI1 in SK-N-MC Ewing's sarcoma cells. The results indicate that even relatively small differences in in vitro binding specificity of a TF contribute to site selectivity in vivo.
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.
Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive âtargetâ genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis. ChIP-Seq in SHEP21, BE2C, KELLY, and NGP neuroblastoma cell lines for H3K27ac, H3K4me3, RNA PolII, MYCN, BRD4, or TWIST1
Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates1,2. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models3. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness4,5 and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation6-9. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models10-12 and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo13-15. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive â??targetâ?? genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis. ATAC-Seq in SHEP21, BE2C, KELLY, NGP, and MM1S cell lines
Project description:The aim of the study was to describe the function of miR-146a in human skin keratinocytes in relation to chronic skin diseases. miR-146a precursor and the control were transfected into human primary keratinocytes treated with IFN-gamma, TNF-alpha or left untreated. mRNA expression profiles of each conditions were detected.
Project description:MicroRNA 21 (miR-21) has been implicated in various aspects of carcinogenesis. However, the function and molecular mechanism of miR-21 in cervical squamous carcinoma has not been studied. Using TaqMan quantitative real-time PCR and Northern blot, we confirmed that miR-21 is significantly overexpressed in human cervical squamous cancer tissues and cell lines. Remarkably, we showed that the level of miR-21 correlates with the nodal status and differentiation by ISH. Furthermore, we demonstrated that miR-21 regulates cervical squamous cells proliferation, apoptosis, and migration which are HPV16 positive. In order to identify the candidate target genes for miR-21, we used gene expression profiling. By luciferase reporter assay, we confirmed the CCL20 gene is one of its targets, which is relative to the HPV16 oncogenes E6 and E7. Our results suggest that miR-21 may be involved in the cervical squamous cell tumorigenesis. Total RNA of cells transfected with anti-miR-21 or scrambled RNA oligonucleotide was extracted using the TRIZOL Reagent according to the manufacturer's instructions. Gene-expression profiling was performed for each pooling RNA sample separately on the GeneChip_ Porcine Genome Array (Affymetrix) at CapitalBio Corporation (Beijing, China) in which GeneChip microarray service was certificated by Affymetrix.
Project description:miR-10a has been shown to regulate proliferation and invasiveness of cancer cells and inflammatory responses of endothelial cells. The function of miR-10a in the skin has not been studied before. Here we examined miR-10a expression, regulation and functions in keratinocytes (KCs) in association with atopic dermatitis (AD).
Project description:MicroRNA (miRNA) expression profiling identified miR-638 as one of the most significantly overexpressed miRNAs in metastatic lesions compared with primary melanomas. miR-638 enhanced the tumourigenic properties of melanoma cells in vitro and lung colonization in vivo. mRNA expression profiling of miR-638 and antagomir-transduced cells identified new candidate genes as miR-638 targets, the majority of which is involved in p53-mediated apoptosis regulation. miR-638 depletion stimulated expression of p53 and its downstream target genes and induced apoptosis and autophagy in melanoma cells. miR-638 promoter analysis revealed transcription factor associated protein 2-? (TFAP2A) as a direct negative regulator of miR-638. Further analyses provided strong evidence for a double negative regulatory feedback loop between miR-638 and TFAP2A. Taken together, miR-638 may support melanoma progression by suppressing p53-mediated apoptosis pathways and by targeting the transcriptional repressor TFAP2A. Whole genome cDNA microarray (Illumina Human HT-12 v4 Expression BeadChip Kit, San Diego, CA 92122 USA) analyses were performed in duplicates using RNA extracted from SK-Mel-147 cells transfected with a non-targeting control, miR-638 or antagomiR-638.