Project description:Circular RNAs (circRNAs), a noncoding RNA class originating from alternative splicing, are highly abundant in neural tissues and were shown to regulate gene expression e.g. by interacting with microRNAs and RNA-binding proteins. Neuroblastoma is an embryonal neoplasia, which arises from undifferentiated neural crest cells. Here, we aimed to explore, whether circRNAs influence the pathogenesis of high-risk neuroblastoma. We performed whole-transcriptome sequencing of 104 primary neuroblastoma samples of all risk-groups and identified 5,203 unique circRNAs involving 2,302 genes. Candidate circRNA expression did not correlate with host gene expression, indicating independent regulatory mechanisms. circRNAs were significantly downregulated in the MYCN-amplified high-risk tumors. These findings were independently reproduced in a tetracycline-inducible MYCN-overexpression system based on a non MYCN-amplified neuroblastoma cell line, suggesting that MYCN drives this global circRNA repression. We identified the RNA helicase DHX9 as a mediator of this global suppressive effect of MYCN on circRNAs. Comparing our RNA sequencing data with other cancers and controls revealed a circRNA subset specifically upregulated in neuroblastoma that included a circRNA derived from the ARID1A tumor suppressor gene. Specific circARID1A knockdown resulted in reduced proliferation, cell numbers and viability, prompted apoptosis and induced a differentiated phenotype. Neither knockdown, nor overexpression of circARID1A influenced ARID1A mRNA and protein levels significantly. To dissect the potential mode of function, we performed a pulldown assay with subsequent mass spectrometry. We identified the RNA-binding protein KHSRP as an interaction partner that participates in the mechanism of action of circARID1A. In summary, this study highlights an important role of circRNAs in neuroblastoma biology and may establish this RNA class as a future therapeutic target and biomarker.
Project description:RNA-sequencing was performed on the following human neuroblastoma cell lines: Kelly, NBL-S, CHP-212, SH-SY5Y, SH-SY5Y LDK-resistant and SH-EP.
Project description:This study was undertaken to assess transcriptional and epigenetic heterogeneity a the level of individual cells within neuroblastoma cell lines, and to compare cell lines with MYCN amplificaion to cell lines without MYCN amplification. Methods: We used 10X Genomics multiome sequencing technology to perform joint gene expression and ATAC profiling on thousands of nuclei isolated from the following human neuoblastoma cell lines: SHSY5Y, SK-N-AS, SK-N-SH, SK-N-DZ, Be-2c, and CHP134. Results: We found considerable gene expression and epigeneic heterogeneity both within and between neuroblastoma cell lines. Conclusion: Joint single-nucleus RNA sequencing and single-nucleus ATAC sequencing has demonsrated that neuroblastoma cell lines are heterogeneous, which may have implications for therapeutic strategies.
Project description:To elucidate potential role of piRNAs in Neuroblastoma (NB), we performed the genome wide profiling in two human NB cell lines, IMR-32 and SH-SY-5Y by adopting high-throughput RNA sequencing (RNA-Seq) and unveil their possible functions in neoplastic pathways. The RNA sequencing results revealed both known and novel piRNAs in both the cell lines. We observed a total 630 annotated mature piRNAs, distributed across chromosomes and mitochondria which were mapped to various genomic locations such as introns, protein coding regions, repeats, pseudogenes, ncRNAs etc. This is the first study reporting the extensive catalogue of human NB piRNAs which will provide a useful resource to dissect complex neoplastic events that are possibly mediated by piRNAs in neuroblastoma. Moreover, these piRNAs could be used as probable small RNA biomarkers for the Neuroblastoma.
Project description:Our current knowledge of the different immune cells in neuroblastoma is based on in vitro and in vivo studies mainly focusing on a single cell type. Importantly, different studies have conveyed conflicting results. Moreover, a comprehensive immune cell overview at the single-cell level is still missing and understanding the complete immune cell composition of neuroblastoma will be crucial for the development of novel immunotherapeutics against the disease. In this study, we performed single-cell RNA-sequencing on nineteen human neuroblastoma samples coupled with multiplex immunohistochemistry and survival analysis using additional datasets to provide a comprehensive cellular and molecular immune cell landscape of human neuroblastoma. Further, we contrasted our data with single-cell RNA-sequencing data from normal fetal adrenal gland to characterize cell-state changes from normal tissue to cancerous neuroblastoma. Our analysis revealed 27 immune cell subtypes including distinct subpopulations of myeloid, NK, B and T cells not identified in neuroblastoma before. Several immune cell subtypes demonstrated a survival benefit such as inflammatory monocytes, tumor associated macrophages, various T cell populations, and Active NK cells. Furthermore, in contrast to adult cancers and previous neuroblastoma studies, we demonstrated an increase in inflammatory monocyte cell-state when contrasting normal and tumor tissue, while we do not observe differences in cytotoxicity and exhaustion score for cytotoxic T cells, nor in Treg activity. Finally, we performed a systemic receptor-ligand interaction analysis between tumor, stroma and immune cells, where we showed the neuroblastoma tumor microenvironment is highly complex and strongly correlated to survival. In addition, we highlighted several interactions that we suggest to be tested in future studies as a therapeutic option in human neuroblastoma. Taken together, our study significantly adds to the in depth understanding of the immune cell landscape, the complexity of the tumor microenvironment and it provides a resource for the development of novel immunotherapeutics for neuroblastoma.
Project description:WGBS was performed on: 1) untreated SH-SY5Y human neuroblastoma cells (day 0) 2) vincristine-treated SH-SY5Y human neuroblastoma cells (7 days of treatment - day 7) 3) vincristine-treated SH-SY5Y human neuroblastoma cells (7 days of treatment followed by 7 days of recovery - day 14)
Project description:H3K27me3 ChIP-seq was performed on: 1) untreated SH-SY5Y human neuroblastoma cells (day 0) 2) vincristine-treated SH-SY5Y human neuroblastoma cells (7 days of treatment - day 7) 3) vincristine-treated SH-SY5Y human neuroblastoma cells (7 days of treatment + 7 days of recover - day 14)
Project description:Pediatric malignancies, including neuroblastoma, are best understood as disorders of development. Neuroblastoma explicitly represents a failure of sympathoadrenal development. Yet, its molecular pathogenesis remains elusive. The application of an in vitro model of human sympathoadrenal development would allow for studying the normal developmental trajectory. Such a model could also interrogate the early steps toward neuroblastoma transformation utilizing genetic manipulation. However, in vitro models have thus far been unable to generate the cells of interest reliably. We developed and characterized a human in vitro pluripotent stem cell-based model via sequential single-cell RNA sequencing throughout sympathoadrenal development. We demonstrate the power of our model to study early events of the development of human neuroblastoma. We do so by identifying the differences between normal and patient-specific induced pluripotent stem cells, derived from a child with familial neuroblastoma, harboring a germline mutation in the Anaplastic Lymphoma Kinase (ALK) gene.