Genetic landscape of pediatric Retinoblastoma
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ABSTRACT:
PROVIDER: EGAS00001000346 | EGA |
REPOSITORIES: EGA
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Project description:<p>Retinoblastoma is a pediatric cancer of the developing retina. All retinoblastomas are believed to initiate with biallelic inactivation of the RB1 gene. To identify subsequent genetic lesions in retinoblastoma, we performed whole genome sequencing of tumor and normal DNA of 4 children with retinoblastoma and one matched orthotopic xenograft. Both alleles of RB1 were inactivated in the tumor samples. 3 of the patients had sporadic retinoblastoma and one patient had inherited retinoblastoma. Overall, there were few single nucleotide changes in coding regions of the genome and some of the tumors had few chromosomal lesions. There were very few new genetic lesions in the xenograft compared to the primary tumor. These data suggest that the genome in retinoblastoma is more stable than previously believed and there are relatively few recurrent genetic lesions in known cancer pathways other than the RB1 pathway.</p>
| phs000352 | dbGaP
Project description:<p>Retinoblastoma is a pediatric cancer of the developing retina. All retinoblastomas are believed to initiate with biallelic inactivation of the RB1 gene. To identify subsequent genetic lesions in retinoblastoma, we performed whole genome sequencing of tumor and normal DNA of 4 children with retinoblastoma and one matched orthotopic xenograft. Both alleles of RB1 were inactivated in the tumor samples. 3 of the patients had sporadic retinoblastoma and one patient had inherited retinoblastoma. Overall, there were few single nucleotide changes in coding regions of the genome and some of the tumors had few chromosomal lesions. There were very few new genetic lesions in the xenograft compared to the primary tumor. These data suggest that the genome in retinoblastoma is more stable than previously believed and there are relatively few recurrent genetic lesions in known cancer pathways other than the RB1 pathway.</p>
| phs000352.v1.p1 | EGA
Project description:Retinoblastoma is a childhood cancer of the developing retina that initiates with biallelic inactivation of the RB1 gene. To develop a laboratory model of human retinoblastoma formation, we made induced pluripotent stem cells (iPSCs) from 15 participants with germline RB1 mutations. After 45 days in culture, the retinal organoids were dissociated and injected into the vitreous of eyes of immunocompromised mice to support retinoblastoma tumor growth. Retinoblastomas formed from retinal organoids made from patient-derived iPSCs had molecular, cellular and genomic features indistinguishable from human retinoblastomas.
2021-05-11 | GSE174201 | GEO
Project description:Retinoblastoma is a childhood cancer of the developing retina that initiates with biallelic inactivation of the RB1 gene. To develop a laboratory model of human retinoblastoma formation, we made induced pluripotent stem cells (iPSCs) from 15 participants with germline RB1 mutations. After 45 days in culture, the retinal organoids were dissociated and injected into the vitreous of eyes of immunocompromised mice to support retinoblastoma tumor growth. Retinoblastomas formed from retinal organoids made from patient-derived iPSCs had molecular, cellular and genomic features indistinguishable from human retinoblastomas.
2021-05-11 | GSE174200 | GEO
Project description:Background Retinoblastoma is a pediatric eye cancer associated with RB1 loss or MYCN amplification (RB1+/+MYCNA). There are controversies concerning the existence of molecular subtypes within RB1-/- retinoblastoma. To test whether these molecular subtypes exist, we performed molecular profiling. Methods Genome-wide mRNA expression profiling was performed on 76 primary human retinoblastomas. Expression profiling was complemented by genome-wide DNA profiling and clinical, histopathological, and ex vivo drug sensitivity data. Findings RNA and DNA profiling identified major variability between retinoblastomas. While gene expression differences between RB1+/+MYCNA and RB1-/- tumors seemed more dichotomous, differences within the RB1-/- tumors were gradual. Tumors with high expression of a photoreceptor gene signature were highly differentiated, smaller in volume and diagnosed at younger age compared to tumors with low photoreceptor signature expression. Tumors with lower photoreceptor expression showed increased expression of genes involved in M-phase and mRNA and ribosome synthesis and increased frequencies of somatic copy number alterations. Interpretation Molecular, clinical and histopathological differences between RB1-/- tumors are best explained by tumor progression, reflected by a gradual loss of differentiation and photoreceptor expression signature. Since copy number alterations were more frequent in tumors with less photoreceptorness, genomic alterations might be drivers of tumor progression. Fresh frozen material from 76 primary human retinoblastoma samples were profiled with Affymetrix human genome u133 plus 2.0 PM microarray
2015-07-01 | E-GEOD-59983 | biostudies-arrayexpress
Project description:Background: Mutation of the RB1 gene is necessary but not sufficient for the development of retinoblastoma. The nature of events occurring subsequent to RB1 mutation is unclear, as is the retinal cell-of-origin of this tumour. Methods: Gene expression profiling of 21 retinoblastomas was carried out to identify genetic events that contribute to tumorigenesis and to obtain information about tumour histogenesis. Results: Expression analysis showed a clear separation of retinoblastomas into two groups. Group 1 retinoblastomas express genes associated with a range of different retinal cell types, suggesting derivation from a retinal progenitor cell type. Recurrent chromosomal alterations typical of retinoblastoma, for example, chromosome 1q and 6p gain and 16q loss were also a feature of this group, and clinically they were characterised by an invasive pattern of tumour growth. In contrast, group 2 retinoblastomas were found to retain many characteristics of cone photoreceptor cells and appear to exploit the high metabolic capacity of this cell type in order to promote tumour proliferation. Conclusion: Retinoblastoma is a heterogeneous tumour with variable biology and clinical characteristics. Kapatai, G et al. Br J Cancer (2013) 109, 512-525 doi: 10.1038/bjc.2013.283
2021-04-16 | GSE172170 | GEO
Project description:Background Retinoblastoma is a pediatric eye cancer associated with RB1 loss or MYCN amplification (RB1+/+MYCNA). There are controversies concerning the existence of molecular subtypes within RB1-/- retinoblastoma. To test whether these molecular subtypes exist, we performed molecular profiling. Methods Genome-wide mRNA expression profiling was performed on 76 primary human retinoblastomas. Expression profiling was complemented by genome-wide DNA profiling and clinical, histopathological, and ex vivo drug sensitivity data. Findings RNA and DNA profiling identified major variability between retinoblastomas. While gene expression differences between RB1+/+MYCNA and RB1-/- tumors seemed more dichotomous, differences within the RB1-/- tumors were gradual. Tumors with high expression of a photoreceptor gene signature were highly differentiated, smaller in volume and diagnosed at younger age compared to tumors with low photoreceptor signature expression. Tumors with lower photoreceptor expression showed increased expression of genes involved in M-phase and mRNA and ribosome synthesis and increased frequencies of somatic copy number alterations. Interpretation Molecular, clinical and histopathological differences between RB1-/- tumors are best explained by tumor progression, reflected by a gradual loss of differentiation and photoreceptor expression signature. Since copy number alterations were more frequent in tumors with less photoreceptorness, genomic alterations might be drivers of tumor progression.
2015-07-01 | GSE59983 | GEO
Project description:Human embryonic stem cells (hESCs) provide a platform for understanding mechanisms underlying diseases and finding ways to treat them. Trilateral retinoblastoma (TRb) is a condition in which retinoblastoma, the most common congenital intraocular malignancy, is associated with an intracranial neural tumor. This mostly fatal disease is caused by biallelic inactivation of the retinoblastoma-1 (RB1) gene, transcribing pRB. Using CRISPR-Cas9 we generated RB1-null hESCs, an embryonic lethal condition. These cells display distinct gene expression patterns with alterations in pRB targets, and mitochondrial phenotypes similar to those of poorly differentiated retinoblastomas. RB1–/– hESC produce extremely large teratomas, with neural expansions similar to those of TRb tumors. Analysis of these tumors revealed a potentially novel role of pRB in ectoderm differentiation, acting through ZEB1. Lastly, RB1–/– cells are significantly sensitive to carboplatin, a chemotherapy used to treat TRb, suggesting our model can be used to screen novel treatments for the disease.
2017-04-09 | GSE84504 | GEO
Project description:Retinoblastoma is a childhood retinal tumor that initiates in response to biallelic RB1 inactivation. We show that post-mitotic human cone precursors are uniquely sensitive to the oncogenic effects of Rb depletion. Rb knockdown induced cone precursor proliferation in prospectively isolated populations. SNP-array analysis of two Rb/p130-depleted cone precursor cell lines, revealing no megabase-size loss of heterozygosity (LOH) or copy number alterations (CNAs). SNP-array analysis of one Rb/p130-depleted (tumor 1) or one Rb-depleted (tumor 2) cone precursor-derived tumors, revealing no megabase-size LOH or CNAs, consistent with the lack of DNA copy number alterations in some retinoblastomas. Thus, the cone precursor tumors resembled human retinoblastomas at the molecular cytogenetic level. High resolution SNP-array DNA copy number analyses were performed using CytoScan® HD (Affymetrix, 901835) according to the manufacturer's directions. Data were analyzed using Chromosome Analysis Suite 2.0 (Affymetrix). DNA was extracted from two Rb/p130 depleted cone precursor cell lines and two cryopreserved mouse retinoblastoma samples from eyes xenograted with Rb/p130 or Rb depleted cone precursors. Affymetrix SNP analysis on retinoblastoma cell lines Y79, RB176, and WERI were used as control. Normal human genome 19 was used as reference.
2014-08-25 | E-GEOD-60720 | biostudies-arrayexpress
Project description:Retinoblastoma is a malignant tumor of the retina which most often occurs in children below 5 years of age with an incident rate of about 1 in 15,000 to 18,000 live births. Retinoblastoma is the first ever cancer that was reported to have a genetic basis. It occurs widely due to inactivating mutations in RB1 gene. Gene expression studies, copy number variation analysis, epigenetic profiling including miRNA and methylation of retinoblastoma has been carried to understand the disease mechanism and key players in the disease. Our group has earlier performed differential proteomics of retinoblastoma to identify proteins of therapeutic importance. However, there are no studies to understand the signalling mechanisms associated with retinoblastoma. Hence, global phosphoproteomics of retinoblastoma was carried out to identify signalling events associated with this cancer. Our study identified stress response proteins to be hyper phosphorylated which included H2AFX and sirtuin 1. In particular, Ser140 of H2AFX also known as gamma-H2AX was found to be hyperphosphorylated in retinoblastoma that indicated activation of DNA damage response pathways. We also observed activation of anti-apoptotic proteins in retinoblastoma compared to control. These observations showed activation of survival pathways and signalling networks activated in tumors.
2019-11-11 | PXD007228 | Pride