Project description:It is widely believed that the molecular and cellular features of a tumor reflect its cell-of-origin and can thus provide clues about treatment targets. The retinoblastoma cell-of-origin has been debated for over a century. Here we report that human and mouse retinoblastomas have molecular, cellular, and neurochemical features of multiple cell classes, principally amacrine/horizontal interneurons, retinal progenitor cells, and photoreceptors. Importantly, single-cell gene expression array analysis showed that these multiple cell type–specific developmental programs are coexpressed in individual retinoblastoma cells, which creates a progenitor/neuronal hybrid cell. Importantly, neurotransmitter receptors, transporters, and biosynthetic enzymes are expressed in human retinoblastoma, and targeted disruption of these pathways reduces retinoblastoma growth in vivo and in vitro. Our finding that retinoblastoma tumor cells express multiple neuronal differentiation programs that are normally incompatible in development suggests that the pathways that control retinal development and establish distinct cell types are perturbed during tumorigenesis. Therefore, the cell-of-origin for retinoblastoma cannot be inferred from the features of the tumor cells themselves. However, we now have a detailed understanding of the neuronal pathways that are deregulated in retinoblastoma and targeting the catecholamine and indolamine receptors or downstream components could provide useful therapeutic approaches in future studies. This example highlights the importance of comprehensive molecular, cellular and physiological characterization of human cancers with single cell resolution as we incorporate molecular targeted therapy into treatment regimens. 55 primary pediatric retinoblastoma tumors were collected and assayed and compared to with 3 passaged xenografts and 4 RB cell lines
Project description:It is widely believed that the molecular and cellular features of a tumor reflect its cell-of-origin and can thus provide clues about treatment targets. The retinoblastoma cell-of-origin has been debated for over a century. Here we report that human and mouse retinoblastomas have molecular, cellular, and neurochemical features of multiple cell classes, principally amacrine/horizontal interneurons, retinal progenitor cells, and photoreceptors. Importantly, single-cell gene expression array analysis showed that these multiple cell type–specific developmental programs are coexpressed in individual retinoblastoma cells, which creates a progenitor/neuronal hybrid cell. Importantly, neurotransmitter receptors, transporters, and biosynthetic enzymes are expressed in human retinoblastoma, and targeted disruption of these pathways reduces retinoblastoma growth in vivo and in vitro. Our finding that retinoblastoma tumor cells express multiple neuronal differentiation programs that are normally incompatible in development suggests that the pathways that control retinal development and establish distinct cell types are perturbed during tumorigenesis. Therefore, the cell-of-origin for retinoblastoma cannot be inferred from the features of the tumor cells themselves. However, we now have a detailed understanding of the neuronal pathways that are deregulated in retinoblastoma and targeting the catecholamine and indolamine receptors or downstream components could provide useful therapeutic approaches in future studies. This example highlights the importance of comprehensive molecular, cellular and physiological characterization of human cancers with single cell resolution as we incorporate molecular targeted therapy into treatment regimens. 20 single cells isolated from primary pediatric retinoblastoma tumors were assayed to asses the within tumor consistency of expression signals
Project description:It is widely believed that the molecular and cellular features of a tumor reflect its cell-of-origin and can thus provide clues about treatment targets. The retinoblastoma cell-of-origin has been debated for over a century. Here we report that human and mouse retinoblastomas have molecular, cellular, and neurochemical features of multiple cell classes, principally amacrine/horizontal interneurons, retinal progenitor cells, and photoreceptors. Importantly, single-cell gene expression array analysis showed that these multiple cell type–specific developmental programs are coexpressed in individual retinoblastoma cells, which creates a progenitor/neuronal hybrid cell. Importantly, neurotransmitter receptors, transporters, and biosynthetic enzymes are expressed in human retinoblastoma, and targeted disruption of these pathways reduces retinoblastoma growth in vivo and in vitro. Our finding that retinoblastoma tumor cells express multiple neuronal differentiation programs that are normally incompatible in development suggests that the pathways that control retinal development and establish distinct cell types are perturbed during tumorigenesis. Therefore, the cell-of-origin for retinoblastoma cannot be inferred from the features of the tumor cells themselves. However, we now have a detailed understanding of the neuronal pathways that are deregulated in retinoblastoma and targeting the catecholamine and indolamine receptors or downstream components could provide useful therapeutic approaches in future studies. This example highlights the importance of comprehensive molecular, cellular and physiological characterization of human cancers with single cell resolution as we incorporate molecular targeted therapy into treatment regimens.
Project description:It is widely believed that the molecular and cellular features of a tumor reflect its cell-of-origin and can thus provide clues about treatment targets. The retinoblastoma cell-of-origin has been debated for over a century. Here we report that human and mouse retinoblastomas have molecular, cellular, and neurochemical features of multiple cell classes, principally amacrine/horizontal interneurons, retinal progenitor cells, and photoreceptors. Importantly, single-cell gene expression array analysis showed that these multiple cell type–specific developmental programs are coexpressed in individual retinoblastoma cells, which creates a progenitor/neuronal hybrid cell. Importantly, neurotransmitter receptors, transporters, and biosynthetic enzymes are expressed in human retinoblastoma, and targeted disruption of these pathways reduces retinoblastoma growth in vivo and in vitro. Our finding that retinoblastoma tumor cells express multiple neuronal differentiation programs that are normally incompatible in development suggests that the pathways that control retinal development and establish distinct cell types are perturbed during tumorigenesis. Therefore, the cell-of-origin for retinoblastoma cannot be inferred from the features of the tumor cells themselves. However, we now have a detailed understanding of the neuronal pathways that are deregulated in retinoblastoma and targeting the catecholamine and indolamine receptors or downstream components could provide useful therapeutic approaches in future studies. This example highlights the importance of comprehensive molecular, cellular and physiological characterization of human cancers with single cell resolution as we incorporate molecular targeted therapy into treatment regimens.
Project description:It is widely believed that the molecular and cellular features of a tumor reflect its cell-of-origin and can thus provide clues about treatment targets. The retinoblastoma cell-of-origin has been debated for over a century. Here we report that human and mouse retinoblastomas have molecular, cellular, and neurochemical features of multiple cell classes, principally amacrine/horizontal interneurons, retinal progenitor cells, and photoreceptors. Importantly, single-cell gene expression array analysis showed that these multiple cell type–specific developmental programs are coexpressed in individual retinoblastoma cells, which creates a progenitor/neuronal hybrid cell. Importantly, neurotransmitter receptors, transporters, and biosynthetic enzymes are expressed in human retinoblastoma, and targeted disruption of these pathways reduces retinoblastoma growth in vivo and in vitro. Our finding that retinoblastoma tumor cells express multiple neuronal differentiation programs that are normally incompatible in development suggests that the pathways that control retinal development and establish distinct cell types are perturbed during tumorigenesis. Therefore, the cell-of-origin for retinoblastoma cannot be inferred from the features of the tumor cells themselves. However, we now have a detailed understanding of the neuronal pathways that are deregulated in retinoblastoma and targeting the catecholamine and indolamine receptors or downstream components could provide useful therapeutic approaches in future studies. This example highlights the importance of comprehensive molecular, cellular and physiological characterization of human cancers with single cell resolution as we incorporate molecular targeted therapy into treatment regimens.
Project description:The Dobzhansky-Muller model provides a widely accepted mechanism for the evolution of reproductive isolation: incompatible substitutions disrupt interactions between genes. To date, few candidate incompatibility genes have been identified, leaving the genes driving speciation mostly uncharacterized. The importance of interactions in the Dobzhansky-Muller model suggests that gene coexpression networks provide a powerful framework to understand disrupted pathways associated with postzygotic isolation. Here, we perform Weighted Gene Coexpression Network Analysis (WGCNA) to infer gene interactions in hybrids of two recently diverged European house mouse subspecies, Mus mus domesticus and M. m. musculus, which commonly show hybrid male sterility or subfertility. We use genome-wide testis expression data from 467 hybrid mice from two mapping populations: F2s from a laboratory cross between wild-derived pure subspecies strains and offspring of natural hybrids captured in the Central Europe hybrid zone. This large data set enabled us to build a robust consensus network using hybrid males with fertile phenotypes. We identify several expression modules, or groups of coexpressed genes, that are disrupted in subfertile hybrids, including modules functionally enriched for spermatogenesis, cilium and sperm flagellum organization, chromosome organization and DNA repair, and including genes expressed in spermatogonia, spermatocytes and spermatids. Our network-based approach enabled us to hone in on specific hub genes likely to be influencing module-wide gene expression and hence potentially driving Dobzhansky-Muller incompatibilities. A total of 67 (24.4%) of these genes lie in sterility loci identified previously in these mapping populations, and represent promising candidate barrier genes and targets for future functional analysis.
Project description:Retinoblastoma is the most common intraocular cancer of infancy and childhood, with an incidence of one case per 15,000 - 20,000 live births. An early event in retinoblastoma genesis is a functional loss of both alleles of the RB1 gene. However, other genes are likely to be involved in the development of this cancer. In this study we sought to build a comprehensive molecular portrait of this cancer by performing transcriptomic, methylomic, genomic profiling of primary retinoblastoma samples. Most of the patients whose tumors were studied had received no treatment prior to surgical enucleation.