3429 results for "ovarian cancer"

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• Establishment of xenogfafts and cultured cell lines from clinical samples

  The purpose of the present study was to clarify the presence or absence of alterations in the molecular properties of patient-derived xenografts (PDXs) with up to eight passages in endometrial carcinomas. Alterations in the proportion of immunohistochemically positive/negative cells for PAX8, estrogen receptor, PAX2, and PTEN were observed in established PDXs of endometrioid carcinomas and carcinosarcomas, whereas proportions of cells with AE1/AE3, TP53, ARID1A PMS2, and MSH6 were maintained. Variants of cancer-associated genes in PDX compared to those in the parental tumors were examined in two cases, a frameshift deletion in BRCA1 was observed in the parental tumor tissue, and additional genomic alterations were found in the PDXs of this case. Genomic and phenotypic alterations in endometrial carcinoma PDXs relative to the parental tumors were observed and were partly associated with endometrial cancer-specific characteristics in cellular differentiation and gene mutations.

  Study JGAS000585

• Genetic landscape of pediatric Retinoblastoma

  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.

  Study EGAS00001000346

• A Unifying Paradigm for Transcriptional Heterogeneity and Squamous Features in Pancreatic Ductal Adenocarcinoma

  Pancreatic cancer expression profiles largely reflect a classical or basal-like phenotype. The extent to which these profiles vary within a patient is unknown. We integrated evolutionary analysis and expression profiling in multiregion sampled metastatic pancreatic cancers, finding that squamous features are the histologic correlate of an RNA-seq defined basal-like subtype. In patients with coexisting basal/squamous and classical/glandular morphology, phylogenetic studies revealed that squamous morphology represented a subclonal population in an otherwise classical/glandular tumor. Cancers with squamous features were significantly more likely to have clonal mutations in chromatin modifiers, intercellular heterogeneity for MYC amplification, and entosis. These data provide a unifying paradigm for integrating basal-type expression profiles, squamous histology, and somatic mutations in chromatin modifier genes in the context of clonal evolution of pancreatic cancer.  

  Study EGAS00001003974

• The function of circular RMST in neuroendocrine tumours

  Circular RNA (circRNA) is a class of noncoding RNA with regulatory potentials. Its role in the transdifferentiation of prostate and lung adenocarcinoma into neuroendocrine prostate cancer (NEPC) and small cell lung cancer (SCLC) remains unexplored. Here we identified circRMST as an exceptionally abundant circRNA predominantly expressed in NEPC using total RNA-seq profiling of patient samples. In addition, circRMST is also abundantly expressed in SCLC. Functional studies using shRNA, siRNA, CRISPR-Cas13 and Cas9 consistently demonstrate that circRMST is essential for tumour growth and the expression of ASCL1, a master regulator of neuroendocrine fate. Mechanistically, circRMST physically interacts with lineage transcription factors NKX2-1 and SOX2. Loss of circRMST induces NKX2-1 protein degradation through autophagy-lysosomal pathway and alters the genomic binding of SOX2, collectively leading to the loss of ASCL1 transcription.

  Study EGAS50000000897

• Patient-derived organoids model treatment response of metastatic gastrointestinal cancers (targeted and whole-genome sequencing)

  Patient-derived organoids (PDOs) have recently emerged as robust pre-clinical models, however, their potential to predict patient clinical outcomes remain unclear. We report a living biobank of PDOs from metastatic, heavily-pretreated colorectal and gastroesophageal cancer patients recruited in phase I/II clinical trials. Phenotypic and genotypic profiling of PDOs showed a high-degree of similarity to the original patient tumor. Molecular profiling of tumor organoids was matched to drug screening results, suggesting PDOs could complement existing approaches in defining cancer vulnerabilities and improving treatment responses. We compared ex vivo organoid responses to anticancer agents, and PDO-based orthotopic mouse tumor xenograft models to the response of the patient in clinical trials. Our data suggest that PDOs can recapitulate patient responses in the clinic, and have the potential to be implemented in personalized medicine programs.

  Study EGAS00001002784

• Sequencing data from a highly cost-effective cell-free DNA methylome test

  Plasma cell-free DNA (cfDNA), originating from multiple organs, holds significant potential for non-invasive diagnostics and prognostics. Current cfDNA methylation assays primarily focus on single clinical indications by targeting specific genomic loci. In contrast, comprehensive profiling of cfDNA methylome can enable simultaneous detection of multiple diseases by capturing organ-specific methylation signatures, thereby offering a holistic view of health, when disease etiology is unclear or when conventional biochemical diagnostics are unavailable. However, deep sequencing required for sensitive detection of methylation abnormalities remains prohibitively expensive, limiting widespread clinical use. To overcome this barrier, we developed MethylScan, a highly cost-effective approach for cfDNA methylome sequencing. We demonstrated its broad clinical utility in a cohort of 1,061 individuals across diverse applications, including multi-cancer detection in general population, liver cancer surveillance in high-risk individuals, liver disease classification, identification of organ abnormalities, and race prediction from cfDNA.

  Study EGAS00001008125

• Screening_for_human_epigenetic_variation_at_CpG_islands

  Many human characteristics, including susceptibility to disease, are determined genetically. An unexplored alternative to such genetic determination concerns epigenetic mechanisms such as DNA methylation. CpG islands (CGIs) are generally constitutively hypomethylated, however there are circumstances in which they become heavily methylated and, when coincident with a gene promoter, this invariably causes transcriptional silencing. CGI methylation occurs in normal tissues during processes such as X-inactivation, but abnormal patterns of methylation have also been implicated in disease. The vast majority of evidence relates to cancer, where silencing of multiple genes in this way appears to be a causal contributor to the cancer state. To address the role and extent of CGI methylation in ‘normal’ and diseased cells we applied MBD-affinity purification in conjunction with next generation sequencing in a panel of human brain autopsy samples. These samples represent a panel of individuals as well as specific brain regions and neurological pathologies.

  Study EGAS00001000074

• Exome sequencing of early and late passage Patient Derived Xenogratf Tumoroids with matched Patient Derived Xenogratfs and matched normal liver

  The breadth and depth at which cancer models are interrogated contribute to successful translation of drug discovery efforts to the clinic. In colorectal cancer (CRC), model availability is limited by a dearth of large-scale collections of patient-derived xenografts (PDXs) and paired tumoroids from metastatic disease, the setting where experimental therapies are typically tested. XENTURION is a unique open-science resource that combines a platform of 129 PDX models and a sister platform of 129 matched PDX-derived tumoroids (PDXTs) from patients with metastatic CRC, with accompanying multidimensional molecular and therapeutic characterization. This specific dataset is focused on a comparison of early and late passage tumoroids transcriptomes. In this study we focused our attention on early (passage 3) and late (passage 8-12) PDXTs with their matched PDXs and normal liver

  Study EGAS50000000185

• Genetic makeup of agnospheres

  Agnospheres are cultures of cancer stem cells isolated from tissue biopsies from patients with Cancer of Unknown Primary (CUPs). The latter is a lethal malignancy (median survival <1 year), representing approximately the 3% of all cancers, and characterized by metastatic dissemination in the absence of a primary tumor recognizable by a standardized protocol including thorough body imaging and histopathological analysis. Agnospheres are long-term propagated in culture and, after subcutaneous injection into immunocompromised mice, they display high tumorigenicity and quickly reproduce the clinical presentation of the original tumor, featuring a multi-organ metastatic pattern and poorly differentiated histology. The goal of the project is to analyse the mutational profile of agnospheres in detail, as to verify its correspondance with that of the original tumors. Genetic information will be exploited to investigate the genetic drivers of the CUP phenotype, in particular the hypermetastatic ability and the differentiative block.

  Study EGAS00001004868

• Spatial atlas of clonal copy number alterations in co-existing benign and malignant tissue

  Defining the transition from benign to malignant tissue is fundamental to improve early diagnosis of cancer. Here, we use a systematic approach to study spatial genome integrity in situ and describe previously unidentified clonal relationships. We employed spatially resolved transcriptomics to infer spatial copy number variations in >120,000 regions across multiple organs, in benign and malignant tissues. We demonstrate that genome-wide copy number variation reveals distinct clonal patterns within tumours and in nearby benign tissue using an organ-wide approach focused on the prostate. Our results suggest a model for how genomic instability arises in histologically benign tissue that may represent early events in cancer evolution. We highlight the power of capturing the molecular and spatial continuums in a tissue context and challenge the rationale for treatment paradigms, including focal therapy.

  Study EGAS00001006124