Project description:Neuroblastoma (NB), the most common extracranial solid tumor in children, often metastasizes at a high rate. Here, we demonstrate that loss of function of the growth arrest-specific 7 gene (GAS7), located on Chr17p13.1, a deleted region in a subset of high-risk NB, accelerates dissemination of MYCN-overexpressing tumor cells in both zebrafish and xenografted mice models. Transcriptomic analysis of neuroblasotma tumors isolated from transgenic zebrafish overexpressing MYCN oncogene alone or MYCN with knockout of gas7 gene revealed that gene signitures affecting tumor cell-cell or cell-extracellular matrix interactions are significantly downregulated in tumors with gas7 loss of function. Our results provide the first genetic evidence that loss of function of a gene located in the Chr17p region contributes significantly to NB metastasis.
Project description:Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow. Advances in therapy and understanding of the metastatic process have been limited due in part, to the lack of animal models harboring bone marrow disease. The widely employed transgenic model, the TH-MYCN mouse, exhibits limited metastasis to this site. Here we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the bone marrow. This model recapitulates two frequent alterations in metastatic neuroblasoma, over-expression of MYCN and loss of caspase-8 expression. In this model, the mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a TH-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone TH-MYCN mouse. While over-expression of MYCN by itself rarely caused bone marrow metastasis (5% average incidence), combining MYCN overexpression and caspase-8 deletion significantly increased bone marrow metastasis (37% average incidence). Loss of caspase-8 expression did not alter the site, incidence, or latency of the primary tumors. However, secondary tumors were detected in the bone marrow of these mice as early as week 9-10. The mouse model described in this work is a valuable tool to enhance our understanding of metastatic neuroblastoma and treatment options and underscores the role of caspase-8 in neuroblastoma progression. Survey of spontateous 24 NB tumors and 5 bone marrow samples in wt and transgenic mice.
Project description:Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow. Advances in therapy and understanding of the metastatic process have been limited due in part, to the lack of animal models harboring bone marrow disease. The widely employed transgenic model, the TH-MYCN mouse, exhibits limited metastasis to this site. Here we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the bone marrow. This model recapitulates two frequent alterations in metastatic neuroblasoma, over-expression of MYCN and loss of caspase-8 expression. In this model, the mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a TH-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone TH-MYCN mouse. While over-expression of MYCN by itself rarely caused bone marrow metastasis (5% average incidence), combining MYCN overexpression and caspase-8 deletion significantly increased bone marrow metastasis (37% average incidence). Loss of caspase-8 expression did not alter the site, incidence, or latency of the primary tumors. However, secondary tumors were detected in the bone marrow of these mice as early as week 9-10. The mouse model described in this work is a valuable tool to enhance our understanding of metastatic neuroblastoma and treatment options and underscores the role of caspase-8 in neuroblastoma progression. Survey of spontateous 13 NB tumors in wt and transgenic mice
Project description:Here we sought metabolic alterations specifically associated with amplified MYCN as nodes to indirectly target the MYCN oncogene. Liquid chromatography-mass spectrometry-based proteomics identified 7 proteins consistently correlated with MYCN in proteomes from 49 neuroblastoma biopsies and 13 cell lines. Among these were phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme in de novo serine synthesis. MYCN associated with two regions in the PHGDH promoter, supporting transcriptional PHGDH regulation by MYCN. Pulsed stable isotope-resolved metabolomics utilizing 13C-glucose labeling demonstrated higher de novo serine synthesis in MYCN-amplified cells compared to cells with diploid MYCN. An independence of MYCN-amplified cells from exogenous serine and glycine was demonstrated by serine and glycine starvation, which attenuated nucleotide pools and proliferation only in cells with diploid MYCN but did not diminish these endpoints in MYCN-amplified cells. Proliferation was attenuated in MYCN-amplified cells by CRISPR/Cas9-mediated PHGDH knockout or treatment with PHGDH small molecule inhibitors without affecting cell viability. PHGDH inhibitors administered as single-agent therapy to NMRI-Foxn1nu/nu mice harboring patient-derived MYCN-amplified neuroblastoma xenografts slowed tumor growth. However, combining a PHGDH inhibitor with the standard-of-care chemotherapy drug, cisplatin, revealed antagonism of chemotherapy efficacy in vivo. Emergence of chemotherapy resistance was confirmed in the genetic PHGDH knockout model in vitro. Altogether, PHDGH knockout and inhibition by small molecules consistently slows proliferation, but stops short of killing the cells, which then establish resistance to classical chemotherapy. Although PHGDH inhibition with small molecules has produced encouraging results in other preclinical cancer models, this approach must be considered with caution in patients with neuroblastoma.
Project description:Neuroblastoma is an embryonic tumor arising from immature sympathetic nervous system progenitor cells. MYCN and ALK are driver oncogenes both of which are specifically expressed during early neurogenesis. This is in line with the assumption that neuroblastoma arises through disruption of normal developmental processes. MYCN has a broad impact on the tumor phenotype; however, the details of the MYCN driven oncogenic program are far from clear. In order to gain further insight into the role of gene expression during neuroblastoma initiation and progression, we evaluated gene expression profiles of hyperplastic ganglia and tumors isolated from MYCN transgenic mice.
Project description:High levels of LMO1 expression synergizes with MYCN to accelerate neuroblastomagenesis, enhance disease penetrance and promote widespread metastasis in zebrafish. Transcriptomic analysis of human neuroblasotma cells with programed expression of LMO1 vs vector control or neuroblastoma cells with differential endogenous LMO1 expression revealed that gene signitures affecting tumor cell-extracellular matrix interaction are significantly associated with high levels of LMO1 expression. Our findings provide compelling evidence for a major pathogenic role of LMO1 in MYCN-driven neuroblastoma.
Project description:Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow. Advances in therapy and understanding of the metastatic process have been limited due in part, to the lack of animal models harboring bone marrow disease. The widely employed transgenic model, the TH-MYCN mouse, exhibits limited metastasis to this site. Here we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the bone marrow. This model recapitulates two frequent alterations in metastatic neuroblasoma, over-expression of MYCN and loss of caspase-8 expression. In this model, the mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a TH-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone TH-MYCN mouse. While over-expression of MYCN by itself rarely caused bone marrow metastasis (5% average incidence), combining MYCN overexpression and caspase-8 deletion significantly increased bone marrow metastasis (37% average incidence). Loss of caspase-8 expression did not alter the site, incidence, or latency of the primary tumors. However, secondary tumors were detected in the bone marrow of these mice as early as week 9-10. The mouse model described in this work is a valuable tool to enhance our understanding of metastatic neuroblastoma and treatment options and underscores the role of caspase-8 in neuroblastoma progression.
Project description:Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow. Advances in therapy and understanding of the metastatic process have been limited due in part, to the lack of animal models harboring bone marrow disease. The widely employed transgenic model, the TH-MYCN mouse, exhibits limited metastasis to this site. Here we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the bone marrow. This model recapitulates two frequent alterations in metastatic neuroblasoma, over-expression of MYCN and loss of caspase-8 expression. In this model, the mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a TH-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone TH-MYCN mouse. While over-expression of MYCN by itself rarely caused bone marrow metastasis (5% average incidence), combining MYCN overexpression and caspase-8 deletion significantly increased bone marrow metastasis (37% average incidence). Loss of caspase-8 expression did not alter the site, incidence, or latency of the primary tumors. However, secondary tumors were detected in the bone marrow of these mice as early as week 9-10. The mouse model described in this work is a valuable tool to enhance our understanding of metastatic neuroblastoma and treatment options and underscores the role of caspase-8 in neuroblastoma progression.
Project description:MYCN amplification (MNA) is a defining feature of high-risk neuroblastoma (NB) that predicts poor prognosis. However, whether genes within or in close proximity to the MYCN amplicon also contribute to aggressiveness in MNA+ NB remains poorly understood. Here we identify that GREB1, a transcription factor encoding gene neighboring the MYCN locus, is frequently co-expressed with MYCN, and promotes cell survival in MNA+ NB. GREB1 controls gene expression independently of MYCN in MNA+ NB, among which we uncover Myosin 1B (MYO1B) as being highly expressed in MNA+ NB. MYO1B promotes aggressive features, including invasive capacity in vitro, as well as extravasation and distant metastasis in vivo. Global secretome and proteome profiling further delineate MYO1B as a major regulator of secretome reprogramming in MNA+ NB cells. Moreover, we identify the cytokine MIF as an important pro-invasive and pro-metastatic mediator of MYO1B activity. Together, we have identified a putative GREB1-MYO1B-MIF axis as an unconventional mechanism that promotes the aggressiveness of MNA+ NB, and independently of MYCN. Furthermore, we find that MYO1B is upregulated in association with other oncoproteins during cellular transformation, and is dramatically increased in multiple human cancer types, suggesting a crucial role of MYO1B in cancers in addition to MNA+ NB.
Project description:The undruggable nature of oncogenic Myc transcription factors poses a therapeutic challenge in neuroblastoma, a paediatric cancer in which MYCN amplification is strongly associated with unfavourable outcome. Here, we show that CYC065, a clinical inhibitor of CDK2 and CDK9, selectively targets MYCN-amplified neuroblastoma via blockade of CDK9-dependent, MYCN-driven transcriptional elongation and CDK2-dependent proliferation. CYC065 also targets nascent transcription of short half-life genes including MYCN and MCL-1 leading to downregulation of MYCN-driven ‘adrenergic’ gene expression programs, growth inhibition, and apoptosis in vitro and in vivo. These data highlight the clinical potential of CDK2/9 inhibition in the treatment of MYCN-amplified neuroblastoma.