11789 results for "cancer rna-seq"

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• Metastatic Prostate Follow Up 2

  Validation/deeper sequencing for metastatic prostate cancer samples

  Dataset EGAD00001000989

• CPC-GENE Prostate Cancer Heterogeneity Study

  Aligned Sequence (bam format), Duplicates removed

  Dataset EGAD00001001329

• The INFORM Precision Medicine Study for High-Risk Pediatric Malignancies

  Study EGAS00001005112

• ACT-Discover: identifying karyotype heterogeneity in pancreatic cancer evolution using ctDNA

  Background Liquid biopsies, and the dynamic tracking of somatic mutations within circulating tumour DNA (ctDNA) can provide insight into the dynamics of cancer evolution and the intra-tumour heterogeneity that fuels treatment resistance. However, identifying and tracking dynamic changes in somatic copy-number alterations (SCNAs), which have been associated with poor outcome and metastasis, using ctDNA is challenging. Pancreatic adenocarcinoma is a disease which has been considered to harbour early punctuated events in its evolution, leading to an early fitness peak, with minimal further subclonal evolution. Methods To interrogate the role of SCNAs in pancreatic adenocarcinoma cancer evolution, we applied whole-exome sequencing of 55 longitudinal cell-free DNA (cfDNA) samples taken from 24 patients (including 8 from whom a patient-derived xenograft (PDX) was derived) with metastatic disease prospectively recruited into a clinical trial. We developed a method, Aneuploidy in Circulating Tumour DNA (ACT-Discover), that leverages haplotype phasing of paired tumour biopsies or PDXs to identify SCNAs in cfDNA with greater sensitivity. Results SCNAs were observed within 28 of 47 evaluable cfDNA samples. Of these events, 30% could only be identified by harnessing the haplotype-aware approach leveraged in ACT-Discover. The exceptional purity of PDX tumours enabled near-complete phasing of genomic regions in allelic imbalance, highlighting an important auxiliary function of PDXs. Finally, although the classical model of pancreatic cancer evolution emphasises the importance of early, homogenous somatic events as a key requirement for cancer development, ACT-Discover identified substantial heterogeneity of SCNAs, including parallel focal and arm-level events, affecting different parental alleles within individual tumours. Indeed, ongoing acquisition of SCNAs was identified within tumours throughout the disease course, including within an untreated metastatic tumour. Conclusions This work demonstrates the power of haplotype phasing to study genomic variation in cfDNA samples and reveals undiscovered intra-tumour heterogeneity with important scientific and clinical implications. Implementation of ACT-Discover could lead to important insights from existing cohorts, or underpin future prospective studies seeking to characterise the landscape of tumour evolution through liquid biopsy.

  Study EGAS00001007077

• Genetics of Prostate Cancer in Africa

  African Americans (AA) suffer from the highest rates of Prostate Cancer (CaP) in the world, but while men of African descent around the world suffer disproportionately from CaP compared to men of other races or ethnicities, our understanding of the reasons for these disparities remains incomplete. To date, few exposure, lifestyle, or environmental influences have been identified in CaP etiology. In contrast, CaP is among the most heritable of common cancers, and over 290 susceptibility loci have been identified. However, many of these loci have not been replicated in AA, in part because of limited African descent sample sizes, incomplete capture of African alleles, and a limited understanding of African genomic architecture. To better understand the etiology of CaP in African descent men, we established a large, multicenter consortium known as “Men of African Descent and Carcinoma of the Prostate” (MADCaP). Using resources of this consortium, we have undertaken a multicenter study of CaP in Sub-Saharan Africa, enrolling CaP cases from 7 institutions in 4 countries in Africa (Nigeria, Senegal, Ghana, and South Africa) and age matched controls from the same institutions. We designed a novel genotyping array, in partnership with Thermo Fisher Scientific, leveraging its Applied BiosystemTM AxiomTM Genotyping solution, to provide good coverage of African genomic variation, as well as incorporating cancer loci, with the goal of being able to fine-map existing prostate cancer loci, as well as mapping novel loci. The data available encompasses genotyping our Africa cohort on this array.

  Study phs002718

• Genomic consequences of aberrant DNA repair mechanisms stratify ovarian cancer histotypes

  Aberrant DNA repair processes are a hallmark of human tumours. How these deficiencies variously impact the genomes of ovarian cancer between and within histotypes remains unknown. We studied the whole genome pointmutation and structural variation patterns of 133 tumours (59 high grade serous (HGSC), 35 clear cell (CCOC), 29 endometrioid (ENOC), and 10 adult granulosa cell tumours (GCT)) as a substrate for class discovery in ovarian cancer. Ab-initio clustering of integrated point mutation and structural variation signatures revealed seven novel subgroups, comprising between and within histotype stratification. Prevalence of fold-back inversions (FBI) co-localised with high level amplification events divided HGSC into two prognostically significant subgroups. This finding was recapitulated in two additional independent cohorts (total n=576 cases), and transcended gene based mutation status and gene expression as prognostically relevant features of HGSC. CCOC were divided into one group harbouring a signature reflective of active genome editing via APOBEC enzymes (26%) and a complementary group with an age-relatedmutational signature. ENOC were divided intomicrosatellite instable (MSI) cases (28%) with a distinctmismatch repairmutation signature and an outlying mutation rate, with the remainder of cases distributed amongst the remaining six groups. We suggest the FBI, MSI, and APOBEC groups represent biologic strata that could direct treatment strategies. Taken together, our work establishes the efficacy of the somatic genome as a biomarker to stratify ovarian cancers, simultaneously identifying patients that may benefit from emerging therapeutics and distinct subgroups within classic ovarian cancer histotypes.

  Study EGAS00001002390

• Neoantigen responses to Immunotherapy in Prostate Cancer

  To determine whether antigen-specific T cell responses can be elicited following treatment with ICT in cancers that have a low TMB, a clinical trial with ipilimumab (anti-CTLA-4) was conducted in 30 patients with metastatic castration-resistant prostate cancer (CRPC). We identified 2 distinct groups of patients divided by clinical outcomes, which consisted of a cohort with Favorable and Unfavorable outcomes. Compared to the Unfavorable cohort, the patients in the Favorable cohort were more likely to have higher intratumoral CD8 T cell density and/or IFN-γ response gene signature, including five patients who had antigen-specific T cell responses that were only detectable after ipilimumab therapy. Three patients had T cell responses against tumor-associated antigens (PSMA and PAP). Importantly, two patients with a relatively low TMB had T cell responses against unique neoantigens. Collectively, our data indicate that a subset of patients with metastatic prostate cancer benefit from ICTs, particularly those who have immunological biomarkers associated with effector T cell responses. Publication: Sumit K. Subudhi, Luis Vence, Hao Zhao, Jorge Blando, Shalini S. Yadav, Qing Xiong, Alexandre Reuben, Ana Aparicio, Paul G. Corn, Brian F. Chapin, Louis L. Pisters, Patricia Troncoso, Rebecca Slack Tidwell, Peter Thall, Chang-Jiun Wu, Jianhua Zhang, Christopher L. Logothetis, Andrew Futreal, James P. Allison and Padmanee Sharma, 2020, Neoantigen responses, immune correlates, and favorable outcomes after ipilimumab treatment of patients with prostate cancer. Science Translational Medicine, 01 Apr 2020:Vol. 12, Issue 537, eaaz3577DOI: 10.1126/scitranslmed.aaz3577. https://pubmed.ncbi.nlm.nih.gov/32238575/

  Study EGAS00001004050

• Neoadjuvant Trastuzumab Response in Breast Cancer

  HER2 (ERBB2) gene amplification and overexpression are present in 15-30% of invasive breast cancers. While HER2-targeted agents such as trastuzumab are effective treatments, therapeutic resistance remains a concern in HER2-positive breast cancer with 40-50% of patients having residual disease after neoadjuvant treatment with chemotherapy and trastuzumab. To investigate features that may make it possible to predict at diagnosis which cancers will be responsive to trastuzumab and chemotherapy, 48 tumor/normal DNA pairs extracted from pretreatment tumor biopsies and blood of HER2-positive breast cancer cases treated with neoadjuvant chemotherapy and trastuzumab were sequenced. Whole genome and exome sequence from tumor (average depth 49x and 71x) and normal (average depth 33x and 69x) DNA are included here as well as RNAseq data for 42 of the tumors. The study cohort was equally divided between patients who experienced pathological complete response and those with residual disease. Samples were obtained from the American College of Surgeons Oncology Group Z1041 trial (NCT00513292) and a local single-institution study (NCT00353483).

  Study phs001291

• Analysis of Epigenomes and Genome Topology in Colorectal Cancer

  When diagnosing cancer, pathologists use nuclear morphology as a hallmark of tumor cells, but the topological changes linked to alterations in the shape of the nucleus were poorly understood. To uncover the molecular changes that occur in the 3D structure of cancer genomes, we integrated topological maps for colon tumors and normal colon tissues with epigenetic, transcriptional, and imaging data. We characterized tumor-associated changes in chromatin loops, topologically associated domains (TADs), and large-scale compartments. We found that chromatin loop rewiring contributes to oncogenic gene expression programs. Whereas TAD structures are largely stable, the spatial partitioning of the open and closed genome compartments is compromised in tumors and is accompanied by hypomethylation and histone mark rearrangements. We also identified a compartment that is reorganized in tumors and is at the interface between the canonical A and B compartments. Similar changes were evident in non-malignant cells that had accumulated excessive cellular divisions. Our analyses suggest that these compartment changes repress stemness and invasion programs while inducing immunity genes, and they may therefore restrain malignant progression.

  Study phs002288

• CALGB 40601: Randomized Phase III Trial of Paclitaxel Combined With Trastuzumab, Lapatinib, or Both As Neoadjuvant Treatment of HER2-Positive Primary Breast Cancer

  This randomized phase III trial studies paclitaxel and trastuzumab with or without lapatinib to see how well they work in treating patients with stage II or stage III breast cancer that can be removed by surgery. Drugs used in chemotherapy, such as paclitaxel, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Monoclonal antibodies, such as trastuzumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Lapatinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving paclitaxel with trastuzumab and/or lapatinib before surgery may make the tumor smaller and reduce the amount of normal tissue that needs to be removed. It is not yet known which regimen is more effective in treating patients with breast cancer.

  Study phs001570