Project description:MYCN amplification in neuroblastoma leads to aberrant expression of MYCN oncoprotein, which binds active genes promoting transcriptional amplification. Yet how MYCN coordinates transcription elongation to meet productive transcriptional amplification and which elongation machinery represents MYCN-driven vulnerability remain to be identified. We conducted a targeted screen of transcription elongation factors and identified the super elongation complex (SEC) as a unique vulnerability in MYCN-amplified neuroblastomas. MYCN directly binds EAF1 and recruits SEC to enhance processive transcription elongation. Depletion of EAF1 or AFF1/AFF4, another core subunit of SEC, leads to a global reduction in transcription elongation and elicits selective apoptosis of MYCN-amplified neuroblastoma cells. A combination screen reveals SEC inhibition synergistically potentiates the therapeutic efficacies of FDA-approved BCL2 antagonist ABT-199, in part due to suppression of MCL1 expression, both in MYCN-amplified neuroblastoma cells and in patient-derived xenografts. These findings identify disruption of the MYCN-SEC regulatory axis as a promising therapeutic strategy in neuroblastoma.
Project description:To evaluate the expression of genes associated with MYCN in NB, 10 tumors with MYCN amplification and 10 with normal MYCN copy number were subjected to oligonucleotide microarray using Agilent oligo microarray chips. Two-condition experiment, MYCN normal vs. MYCN amplified 10 NB patient tissues for each group.
Project description:The aims of this study are to compare transcripts that are differentially expressed in the MYCN amplified compare to the MYCN non-amplified neuroblastoma cell lines, in particular, long non-coding RNAs. Methods: Ribosomal depleted RNAs from six human neuroblastoma cell lines were subjected to deep sequencing, using Illumina Hiseq. Results: We identified 459 transcripts are differentially expressed betweeen the MYCN amplified and the MYCN non-amplified cell lines. Conclusions: We have identified a novel long noncoding RNA lncNB1 that is highly expressed in the MYCN amplified compared to the MYCN non-amplified cell lines.
Project description:The MYCN locus is amplified in about half of high-risk neuroblastoma tumors. To identify genomic loci occupied by MYCN protein in the MYCN-amplified neuroblastoma cell lines NGP, Kelly and NB-1643, we performed chromatin immunoprecipitation coupled with Next-Generation Sequencing (ChIP-seq) using an anti-MYCN antibody.
Project description:RNA-sequencing has been used to obtain and observe transcriptome-wide differences that occur in two parasspeckle-deficient, MYCN-amplified/model high-risk and one paraspeckle-abundant, non-MYCN-amplified/low-risk cell lines, to decipher the role of paraspeckles in this cancer type.
Project description:Purpose: Identify new targets in MYCN-amplified Neuroblastoma Methods: ChIP-Seq experiments were performed on Kelly and LAN-1 neuroblastoma cells by using the following antibodies: anti-EZH2 (Cell Signaling 5246S); anti-H3K27me3 (Millipore 07-449); anti-H3K4me3 (Abcam ab8580). We evaluated the global EZH2 PRC2-dependence by identifiying direct genome-wide target genes for EZH2, H3K27me3 and H3K4me3. Results: We found that EZH2 serves a PRC2-dependent function in neuroblastoma, repressing neuronal differentiation. Moreover, EZH2-regulated genes were strongly repressed in MYCN-amplified and high-risk primary tumors. Conclusion: Our study supports testing EZH2 inhibitors in patients with MYCN-amplified neuroblastoma.