3288 results for "ovarian cancer"

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• Whole Exome Sequencing of Pancreatic Neuroendocrine Tumors at The Human Genome Sequencing Center, Baylor College of Medicine (HGSC-BCM)

  Pancreatic neuroendocrine tumors (PNETs), often referred to as "islet cell tumors", are neuroendocrine neoplasms that arise from cells of the endocrine and nervous system within the pancreas. These rare tumors which originate from the pancreatic islet are divided into many categories and are often classified by the hormone most strongly secreted. With the collaboration of the Elkins Pancreatic Center, the Human Genome Sequencing Center (HGSC) at Baylor College of Medicine had access to approximately 30 untreated tumor specimens and matched normal blood samples. Since the onset and progression of cancer is driven by extensive mutation of the genome, we are combining enrichment of exonic DNA with next generation sequencing to detect and characterize the somatic mutation profile of patients with pancreatic neuroendocrine cancer. This work was done at the Human Genome Sequencing Center (HGSC) in collaboration with the Elkins Pancreatic Center at Baylor College of Medicine in Houston, TX and was supported by grant number 5U54HG003273 from National Human Genome Research Institute (NHGRI).

  Study phs000871

• International Cancer Proteogenomics Consortium (ICPC): Proteogenomics of East-Asian Breast Cancer

  The incidence of invasive breast cancer is rapidly increasing in East Asia, enriching in younger patients and luminal disease. We presented a deep proteogenomic landscape of a prospectively enrolled early-stage cohort in Taiwan to uncover the etiology, age-related subtype and oncogenic vulnerabilities underlying the heterogeneous disease. Multilayer proteogenomic architecture revealed distinct endogenous and environmental carcinogen-associated mutagenesis, linking APOBEC (apolipoprotein-B mRNA editing enzyme, catalytic polypeptide-like) cytidine deaminase and DBAC (dibenz[a,j] acridine) signatures to significantly elevated hormone biosynthesis and chemical carcinogenesis in younger patients, and identifying a novel subset of high mutation burden and immune escape potentially beneficial from combined epigenetic therapy and immunotherapy. A proteomics-informed classification resolves luminal heterogeneity, defines high-risk recurrent luminal disease and nominates biomarkers and actionable druggable pathways. Furthermore, proteogenomics profile distinguished a young luminal population susceptible to exogenous carcinogen and having DNA repair deficiency. This study illuminates the age-related molecular subtypes and oncogenic vulnerabilities, providing a proteogenomics-transformative guide for patient stratification and precision therapeutics beyond clinical staging.

  Study phs003150

• A Multi-Gene Mutation Classification of 468 Colorectal Cancers Reveals a Prognostic Role for APC

  Colorectal cancer (CRC) is a highly heterogeneous disease, for which prognosis has been relegated to clinic-pathologic staging for decades. There is a need to molecularly stratify subpopulations of CRC to better predict outcome and assign therapies. Here we report targeted exome sequencing of 1,321 cancer-related genes on 468 tumor specimens, which identified a subset of 17 genes that best classify CRC, with APC (Gene ID: 324) playing a central role in predicting overall survival. APC may assume 0, 1, or 2 truncating mutations, each with a striking differential impact on survival. Tumors lacking any APC mutation carry a worse prognosis than single APC mutation tumors, but tumors with two APC mutations and KRAS (Gene ID: 3845) and TP53 (Gene ID: 7157) mutations confer the poorest survival among all the subgroups examined. Our study demonstrates a substantial prognostic role for APC and suggests that sequencing of APC may have clinical utility in the routine staging and potential therapeutic assignment for CRC.

  Study phs001111

• Genomic Analysis of Fibrolamellar Hepatocellular Carcinoma

  Fibrolamellar hepatocellular carcinoma (FL-HCC) is a very rare and distinct subtype of hepatocellular carcinoma that occurs in the previously healthy livers of adolescents and young adults. The low incidence rate has kept FL-HCC an understudied cancer, thus the list of FL-HCC markers is limited and the genetic alterations driving its growth have remained unknown. In order to gain a better understanding of the molecular mechanisms underlying FL-HCC initiation and progression, we performed an in-depth genomic analyses of one tumor followed by immunohistochemistry validation on seven other tumors. We showed the expression of neuroendocrine markers in FL-HCC. In addition, DNA/RNA sequencing revealed that common cancer pathways are not visibly altered in FL-HCC but identified two novel structural variants, both resulting in fusion transcripts. Through in vitro studies, we demonstrated the oncogenic properties of these fusion transcripts. These experiments further highlight the tumorigenic role of gene fusions in the etiology of pediatric solid tumors and identify both candidate biomarkers and possible therapeutic targets for this lethal pediatric disease.

  Study phs000828

• Retinoblastoma Aqueous Humor Liquid Biopsy Repository

  This study involves the use of the aqueous humor (AH, the clear fluid in the front of the eye) as an organ specific liquid biopsy for retinoblastoma. This relatively new liquid biopsy platform was started at CHLA/USC and was developed to overcome the lack of tumor tissue -- due to contraindication to biopsy -- for this cancer. We have demonstrated that the aqueous humor is an enriched source of tumor DNA. Previously tumoral information was only available after the eye was removed for treatment failure. Due to the AH liquid biopsy, we are now able to assay tumor derived molecular information from these eyes at diagnosis and longitudinally during treatment -- as opposed to only eyes that have failed therapy. We have demonstrated that using the platform we can identify the specific mutations in the RB1 gene that initiate tumorigenesis in this cancer as well as the secondary chromosomal alterations the drive further tumor growth. This database will provide sequencing information as well as associated clinical information and globe salvage outcomes.

  Study phs003077

• HiDEF-seq Single-Molecule Sequencing of Single-Strand Mismatches and Damage

  Our study sought to resolve, with single-molecule resolution, the mismatches and damage events that precede DNA mutations. Using a novel single-molecule, long-read sequencing method (HiDEF-seq) we detected base substitutions when present in either one or both DNA strands. We compared the fidelity for dsDNA mutations to that of the same samples profiled by NanoSeq duplex sequencing. We also detected cytosine deamination, a common type of DNA damage, with single-molecule resolution. We profiled 134 samples from diverse tissues, including from individuals with cancer predisposition syndromes. These samples revealed single-strand mismatch and damage signatures. Since double-strand DNA mutations are only the endpoint of the mutation process, our approach enables new studies of how mutations arise in a variety of contexts, especially in cancer and aging.The data available via dbGaP includes raw HiDEF-seq sequencing files (Pacific Biosciences subreads in BAM format), raw NanoSeq sequencing files (Illumina FASTQ format), and raw germline sequencing files (Illumina FASTQ format).The HiDEF-seq main publication contains a supplementary table with a list of accession IDs for each sample's files.

  Study phs003604

• Long-read-transcriptome-sequencing of CLL and MDS patients uncovers common molecular effects of SF3B1 mutations

  Mutations in SF3B1 occur frequently in patients with chronic lymphocytic leukemia (CLL) and myelodysplastic syndromes (MDS), and a full-length transcriptome approach can expand our current knowledge on SF3B1 mutation effects on RNA splicing. We applied long-read-transcriptome-sequencing (LRTS) to 44 MDS and CLL patients with and without SF3B1 mutations and found a large fraction (>60%) of novel isoforms. Furthermore, we revealed that mutation effects on alternative splicing were largely common in both cancer types and specifically altered the usage of introns as well as 3’-splice-sites. We combined the LRTS with genome-wide SF3B1-RNA binding maps and show multimodal binding at 3’-splice-sites highlighting a window of 12-21nt upstream of the canonical 3’-splice-site in which a dynamic switch in splice site usage is observable in patients carrying SF3B1 mutations. Our work presents the hitherto most complete LRTS study in CLL and MDS and provides a resource for further research on aberrant splicing in cancer.

  Study EGAS50000000053

• Genome-wide mutational consequences of nucleotide excision repair-deficiency through XPC deletion in a human adult stem cell culture

  Nucleotide excision repair (NER) is one of the main DNA repair pathways that protect cells against genomic damage. Deficiency in this pathway can contribute to the development of cancer and accelerate aging. NER-deficiency is an important determinant for cancer treatment outcome, as NER-deficient tumors are selectively sensitive to cisplatin treatment. While NER-deficiency has been linked to mutational Signature 5, not all NER-deficient tumors are characterized by a high Signature 5 contribution, illustrating the importance to further characterize the mutational consequences of NER-deficiency. Here, we analyzed the mutational profile of a human adult stem cell (organoid) culture that is deficient in NER through XPC deletion by CRISPR-Cas9 gene-editing, and subsequent whole-genome sequencing analysis of a clonally derived organoid. We found that XPC deletion results in an increase in base substitution load and specifically induces Signature 8 mutations, a mutational signature with previously unknown etiology. Presence of Signature 8 may, therefore, serve as a novel biomarker for NER-deficient tumors and could improve personalized treatment strategies.

  Study EGAS00001002681

• Primary prostate Hi-C

  Prostate cancer is a heterogeneous disease whose progression is linked to genome instability. Despite large-scale tumour sequencing efforts, the impact of mutations on the genetic architecture in cancer remains ill-defined due to limited integration of genomics data across dimensions. We addressed this limitation by assessing the impact of structural variants on the chromatin states and the three-dimensional organization across benign and malignant primary prostate genomes. We find high concordance in the three-dimensional genome organization between malignant and benign prostate tissues, arguing for constraints to the three-dimensional genome of prostate tumours. Moreover, we identify structural variants as effectors of changes to focal chromatin interactions, guiding cis-regulatory element hijacking that imposes opposing expression changes on genes found at antipodes of a rearrangement. This leads to the repression of tumour suppressor gene expression and up-regulation of oncogenes, such as at the TMPRSS2-ERG and PMEPA1-ZNF156 loci. Collectively, our results argue that cis-regulatory element hijacking by structural variants overshadows large-scale topological changes to alter gene regulation and promote oncogenesis.

  Study EGAS00001005014

• Spatio-temporal analysis of prostate tumors in situ suggests pre-existence of treatment-resistant clones

  The molecular mechanisms underlying lethal castration-resistant prostate cancer remain poorly understood, with intratumoral heterogeneity a likely contributing factor. To examine the temporal aspects of resistance, we analyzed tumor heterogeneity in needle biopsies collected before and after treatment with androgen deprivation therapy. By doing so, we were able to couple clinical responsiveness and morphological information such as Gleason score to transcriptome-wide data. Our data-driven analysis of transcriptomes identified several distinct intratumoral cell populations, characterized by their unique gene expression profiles. Strikingly, certain cell populations present before treatment exhibited gene expression profiles that matched those of resistant tumor cell clusters, present after treatment. We confirmed that these clusters were resistant by the localization of active androgen receptors to the nuclei in cancer cells post-treatment. Our data also demonstrated that most stromal cells adjacent to resistant clusters do not express the androgen receptor, and we identified differentially expressed genes for these cells. Altogether, this study shows the potential to increase the power in predicting resistant tumors.

  Study EGAS00001006113