Project description:Cancers are characterized by non-random, chromosome copy number variations that presumably contain oncogenes and tumor suppressor genes (TSGs). The affected loci are often large, making it difficult to pinpoint which genes are driving the cancer. Here, we report a cross-species, in vivo screen of 84 candidate oncogenes and 39 candidate TSGs, located within 28 recurrent chromosomal alterations in ependymoma. Through a series of mouse models we validate eight new ependymoma oncogenes and 11 TSGs that dysregulate a small number of cell functions including vesicle trafficking and cholesterol biosynthesis; pinpointing these as potential points for therapeutic intervention. Mouse cortical tumors were excised. These tumors derived from cells expressing one of 3 genes: RAB3A, BC74C, or ZNF668
Project description:Cancers are characterized by non-random, chromosome copy number variations that presumably contain oncogenes and tumor suppressor genes (TSGs). The affected loci are often large, making it difficult to pinpoint which genes are driving the cancer. Here, we report a cross-species, in vivo screen of 84 candidate oncogenes and 39 candidate TSGs, located within 28 recurrent chromosomal alterations in ependymoma. Through a series of mouse models we validate eight new ependymoma oncogenes and 11 TSGs that dysregulate a small number of cell functions including vesicle trafficking and cholesterol biosynthesis; pinpointing these as potential points for therapeutic intervention.
Project description:Ependymomas exist within distinct genetic subgroups, but the molecular diversity within individual ependymomas is unknown. We performed multiplatform molecular profiling of 6 spatially-distinct samples from an ependymoma with C11orf95-RELA fusion. DNA methylation and RNA sequencing distinguished clusters of samples according to neuronal development gene expression programs that could also be delineated by differences in magnetic resonance blood perfusion. Exome sequencing and phylogenetic analysis revealed epigenomic intratumor heterogeneity, and suggested that chromosomal structural alterations may precede accumulation of single nucleotide variants during ependymoma tumorigenesis. In sum, these findings shed new light on the oncogenesis and intratumor heterogeneity of ependymoma.
Project description:In this work the objective is identify chromosomal alterations in ependymoma in pediatric patients, we used CGH microarray were performed through the Agilent platform.
Project description:Cancers harbouring loss-of-function (LOF) alterations in tumour suppressor genes lack targeted therapies, thus alternative means to characterise gene function and identify vulnerabilities in these cancer cells are required. Here, we map the in silico genetic networks of KMT2D, a frequently mutated tumour suppressor gene, to demonstrate its utility in uncovering novel functional associations and vulnerabilities in cancer cells with tumour suppressor gene LOF alterations. In silico KMT2D networks revealed associated with histone modification, DNA replication, metabolism, and immune response. We identified synthetic lethal (SL) candidates encoding exising therapeutic targets. Analysing patient data from The Cancer Genome Atlas (TCGA) and the Personalized OncoGenomics Project (NCT021556210), we showed dysregulated pathways associated with SL candidates and elevated immune checkpoint response markers in KMT2DLOF cases, bringing forth evidence supporting KMT2D as a biomarker for immune checkpoint inhibitors. Our study presents a framework for identifying targetable vulnerabilities in cancers with tumour suppressor gene alterations.
Project description:Genome sequencing studies have uncovered the most frequent mutations in cancer and novel targets for therapy. While successful in many tumors, this approach has failed in others. Lethal infant ependymomas (Group A) lies at the far end of this spectrum with no recurrent focal genomic alterations, no recurrent somatic mutations, and no clear driver for targeted therapy. Despite a paucity of genetic aberrations, Group A ependymomas demonstrate widespread epigenetic alterations. We therefore sought to interrogate the oncogenic drivers of ependymoma by characterizing the enhancer landscapes of 30 primary tumors. Super enhancer (SE) mapping revealed novel ependymoma oncogenes such as PAX6, SKI, and FGFRL1 and uncovered subgroup specific SE lesions across ependymoma, specifically, in Group A such as PAX3, MEIS1, and IGF2BP1. Finally, we identified SE associated gene dependencies that maintain FGFR1 and WEE1 expression in ependymoma, demonstrating the utility of SE lesions to predict novel targets for cancer therapy.
Project description:Mycosis fungoides (MF), the most common cutaneous T-cell lymphoma (CTCL), is a malignancy of mature, skin-homing T cells. Sézary syndrome (Sz) is often considered to represent a leukemic phase of MF. In this study the pattern of numerical chromosomal alterations in MF tumor samples was defined using array-based CGH; simultaneously gene expression was analyzed using microarrays. Highly recurrent chromosomal alterations in MF include copy number gain of 7q36, 7q21-7q22 and loss of 5q13 and 9p21. This pattern characteristic of MF differs markedly from chromosomal alterations observed in Sz. Integration of data from array-based CGH and gene expression analysis yielded several candidate genes with potential relevance in the pathogenesis of MF. We confirmed that the FASTK and SKAP1 genes, residing in loci with recurrent gain, demonstrated increased expression. The RB1 and DLEU1 tumor suppressor genes showed diminished expression associated with loss. In addition, it was found that presence of chromosomal alterations on 9p21, 8q24 and 1q21-1q22 was associated with poor prognosis in patients with MF. This study provides novel insight into genetic alterations underlying MF. Furthermore, our analysis uncovered genomic differences between MF and Sz, which suggest that the molecular pathogenesis and therefore therapeutic requirements of these CTCLs may be distinct. To identify candidate oncogenes and tumor suppressor genes residing in chromosomal regions with recurrent copy number alteration in MF. To this end chromosomal alteration and gene expression patterns of 22 MF tumor samples were integrated to determine which genes located in minimal common regions (MCRs) with CNA demonstrated dysregulated expression associated with chromosomal alteration Keywords: aCGH and gene expression integration
Project description:Genomic technologies have unmasked molecularly distinct subgroups among tumors of the same histological type; but understanding the biologic basis of these subgroups has proved difficult since their defining alterations are often numerous, and the cellular origins of most cancers remain unknown. We sought to decipher complex genomic data sets by matching the genetic alterations contained within these, with candidate cells of origin, to generate accurate disease models. Using an integrated genomic analysis we first identified subgroups of human ependymoma: a form of neural tumor that arises throughout the central nervous system (CNS). Validated alterations included amplifications and homozygous deletions of genes not yet implicated in ependymoma. Matching the transcriptomes of human ependymoma subgroups to those of distinct types of mouse radial glia (RG)—neural stem cells (NSCs) that we identified previously to be a candidate cell of origin of ependymoma - allowed us to select RG types most likely to represent cells of origin of disease subgroups. The transcriptome of human cerebral ependymomas that amplify EPHB2 and delete INK4A/ARF matched most closely that of embryonic cerebral Ink4a/Arf-/- RG: remarkably, activation of EphB2 signaling in this RG type, but not others, generated highly penetrant ependymomas that modeled accurately the histology and transcriptome of one human cerebral tumor subgroup (subgroup ‘D’). Further comparative genomic analysis revealed selective alterations in the copy number and expression of genes that regulate neural differentiation, particularly synaptogenesis, in both mouse and human subgroup ‘D’ ependymomas; pinpointing this pathway as a previously unknown target of ependymoma tumorigenesis. Our data demonstrate the power of comparative genomics to sift complex genetic data sets to identify key molecular alterations in cancer subgroups. [human mRNA] samples: 83 human ependynoma primary tumors were collected and clustered into distinct classes by unsupervised methods and then compared to mouse model data. [mouse mRNA] samples: 192 mouse tumors and cell lines were collected and clustered into distinct classes by unsupervised methods and then compared to human tumors. [human miRNA] samples: 64 human ependynoma primary tumors were collected and miRNA expression was assesed and compared to genomic expression
Project description:Clinical and genomic evidence support the view that the metastatic potential of a primary tumor may be dictated by transforming events acquired early in the tumorigenic process. It has been proposed that the presence of such pro-metastatic events in early-stage tumors reflects their additional capability to function as oncogenes. Here, to test this ‘deterministic’ hypothesis and identify potential pro-metastasis oncogenes, we adopted a comparative oncogenomics-guided functional genetic screening strategy involving (i) global transcriptomic data from two genetically engineered mouse models of melanoma with contrasting metastatic potential, (ii) genomic and transcriptomic profiles of human primary and metastatic melanoma and (iii) an invasion screen in TERT-immortalized human melanocytes and melanoma cells in vitro as well as (iv) evidence of expression selection in human melanoma tissues. This integrated effort led to the identification of 6 genes that are both potently pro-invasive and oncogenic. Further, we show that one such pro-invasion oncogene, ACP5, can confer spontaneous metastasis in vivo, engages a key pathway governing metastasis and is prognostic in human primary melanomas.