Project description:It has been already reported that there are undifferentiated/proliferating neuroblasts in the postnatal sympathetic ganglia in TH-MYCN mice. We established suitable spheroid culture condition that selectively isolates undifferentiated neuroblasts from superior mesenteric ganligon (SMG) of TH-MYCN mice. In the present study, in order to investigate the transcriptomic differences between embryonic day 13.5 (E13.5) WT derived primary spheres and E13.5 TH-MYCN derived passageable spheres, we carried out microarray gene expression analysis. We investigated critical molecular events in MYCN-transformed neuroblastoma cells in TH-MYCN mice.
Project description:It has been already reported that there are undifferentiated/proliferating neuroblasts in the postnatal sympathetic ganglia in TH-MYCN mice. We established suitable spheroid culture condition that selectively isolates undifferentiated neuroblasts from superior mesenteric ganligon (SMG) of TH-MYCN mice. In the present study, in order to investigate the transcriptomic differences among 3-week-old WT SMG, TH-MYCN (hemizygote) SMG, and TH-MYCN (hemizygote) spheres, we carried out microarray gene expression analysis. We investigated whether or not undifferentiated cells observed in TH-MYCN SMG were selectively isolated and maintaned as spheres.
Project description:It has been already reported that there are undifferentiated/proliferating neuroblasts in the postnatal sympathetic ganglia in TH-MYCN mice, a neuroblastoma model. We established suitable spheroid culture condition that selectively isolates undifferentiated neuroblasts from superior mesenteric ganligon (SMG) of TH-MYCN mice. In order to investigate the chromosomal alterations (gains or losses) of spheres derived from TH-MYCN mice, we carried out array comparative genomic hybridization. We investigated whether chromosomal alterations occured during early neuroblastoma tumorigenesis in TH-MYCN mice.
Project description:It has been already reported that there are undifferentiated/proliferating neuroblasts in the postnatal sympathetic ganglia in TH-MYCN mice. Given the fact that neuroblastoma is derived from sympathoadrenal progenitors which are originated from neural crest stem cells, we attempted to use the well-established culture condition that has been utilized to maintain derivatives of neural crest stem cells. However, the medium contained retinoic acid (RA) which is known to induce neuroblastoma differentiation and is used in clinical treatment against high-risk patients. In the present study, the medium with RA (RA (+) medium) and without RA (RA (-) medium) were compared. Since undifferentiated neuroblasts are observable at one of the sympathetic ganglia, superior mesenteric ganglion (SMG), in 3-week-old TH-MYCN hemizygote (TH-MYCN+/-) mice with 129+Ter/SvJcl mice background, we dissected and dissociated the SMG to prepare single cells. These cells were cultured in either RA (+) or RA (-) media. Spheres formed in either RA (+) or RA (-) medium were subjected to microarray analysis.
Project description:Adrenal chromaffin cells and sympathetic neuron are derived from neural crest precursors and both cell types can give rise to childhood cancer, neuroblastoma. However only limited is known about the mechanism of their development. Better understanding of their transcriptomic profiles during development could gives an insight into the cell fates acquisition as well as the origin of neuroblastoma. Yellow fluorescent protein expressing sympathetic neuroblasts and adrenal chromaffin cells were isolated from E12.5 TH-IRES-Cre;ROSA26-EYFP mouse embryos by fluorescence-activated cell sorting. Transcriptomic profiles of sympathetic neuroblasts and adrenal chromaffin cells from embryonic age (E)12.5 TH-IRES-Cre;ROSA26-EYFP mice were generated by RNA sequencing, in four paired biological replicates.
Project description:Changes in epigenetic regulation are believed to be a major contributing factor to neuroblastoma development. Using a large-scale in vivo mutagenesis screen in Th-MYCN transgenic mice, we identified a single point mutation in the transcriptional corepressor Runx1t1, that can block N-myc-driven neuroblastoma tumorigenesis. The loss of function mutation disrupts a highly conserved zinc finger domain (NHR4) within Runx1t1. Crossing an independent Runx1t1 knockout model with Th-MYCN mice, demonstrated that Runx1t1 haploinsufficiency is enough to prevent neuroblastoma development and reverse ganglia hyperplasia. Silencing RUNX1T1 in human neuroblastoma cells resulted in decreased colony formation in vitro, and significant inhibition of tumor growth in vivo. Our results show that RUNX1T1 forms part of a transcriptional LSD1-CoREST3-HDAC repressive complex that regulates the epigenomic landscape and chromatin accessibility, to control neuron-specific pathway genes and maintain an undifferentiated state. Runx1t1 thus represents an entirely novel and highly promising target not previously described in neuroblastoma.
Project description:In order to investigate the chromosomal alterations (gains or losses) of tumor tissuees developed in TH-MYCN mice, a neuroblastoma model, we carried out array comparative genomic hybridization. We investigated whether chromosomal alterations occured in the tumor tissues developed in the abdomen of TH-MYCN hemizygote mice.
Project description:Neuroblastoma is a pediatric cancer of the sympathetic nervous system. MYCN amplification is a key indicator of poor prognosis for the disease, however, mechanisms by which MYCN promotes neuroblastoma tumorigenesis are not fully understood. In this study, we analyzed global miRNA and mRNA expression profiles of tissues at different stages of tumorigenesis from TH-MYCN transgenic mice, a model of MYCN-driven neuroblastoma. Based on a Bayesian learning network model in which we compared pre-tumor ganglia from TH-MYCN+/+ mice to age-matched wild-type controls, we devised a predicted miRNA-mRNA interaction network. Among the miRNA-mRNA interactions operating during human neuroblastoma tumorigenesis, we identified that miR-204 is a tumor suppressor miRNA that inhibits a subnetwork of oncogenes strongly associated with MYCN-amplified neuroblastoma and poor patient outcome. Accordingly, we found that MYCN was bound to the miR-204 promoter and repressed miR-204 transcription, while in contrast, miR-204 directly bound MYCN mRNA and repressed MYCN expression. In support of a tumor suppressor role, miR-204 overexpression significantly inhibited neuroblastoma cell proliferation in vitro and tumorigenesis in vivo. Together these findings identify novel tumorigenic miRNA gene networks and miR-204 as a tumor suppressor that regulates MYCN expression in neuroblastoma tumorigenesis.