9295 results for "cancer rna-seq"

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• The interface of malignant and immunologic clonal dynamics in high-grade serous ovarian cancer

  High-grade serous ovarian cancer exhibits extensive intratumoral heterogeneity coupled with widespread intraperitoneal disease. Despite this, metastatic spread of tumor clones is non-random, implying the existence of local microenvironmental factors that shape tumor progression. We interrogated the molecular interface between tumorinfiltrating lymphocytes (TIL) and cancer cells in 143 samples from 21 patients using whole-genome sequencing, immunohistochemistry, histologic image analysis, gene expression profiling, and T- and B-cell receptor sequencing. We identify 3 immunologic response categories, which frequently co-exist within individual patients. Furthermore, epithelial CD8+ TIL were inversely associated with malignant cell diversity, evidenced by subclonal neoepitope elimination and spatial tracking between tumor and T-cell clones. Intersecting mutational signatures and immune analysis showed that foldback inversion genomic aberrations lead to worse outcomes even in the presence of cytotoxic TIL (n=433). Thus, regional variation in immune contexture mirrors the pattern of intraperitoneal malignant spread, provoking new perspectives for treatment of this challenging disease.

  Study EGAS00001002839

• Combined gene expression and digital pathology identifies molecular mediators of T cell exclusion and immune suppression in ovarian cancer

  Close proximity between cytotoxic T lymphocytes and tumour cells is required for effective immunotherapy. However, what determines the spatial distribution of T cells in the tumour microenvironment is not well understood. Coupling digital pathology and transcriptome analysis on a large ovarian tumour cohort, we develop a machine learning approach to molecularly classify and characterize tumour-immune phenotypes. Our study identifies two important hallmarks characterizing T cell excluded tumours: 1) loss of antigen presentation on tumour cells and 2) upregulation of TGFb and activated stroma. Furthermore, we identify TGFb as a key mediator of T cell exclusion. TGFb reduces MHC-I expression in ovarian cancer cells in vitro; TGFb also activates fibroblasts and induced extracellular matrix (ECM) production as a potential physical barrier to hinder T cell infiltration. Our findings indicate that targeting TGFb may represent a promising strategy to overcome T cell exclusion and improve clinical benefits of cancer immunotherapy.

  Study EGAS00001003487

• Genome-wide cell-free DNA mutational integration enables ultra-sensitive cancer monitoring

  In many areas of oncology, we lack sensitive tools to track low burden disease. While cell-free DNA (cfDNA) shows promise in detecting cancer mutations, we found that the combination of low tumor fraction (TF) and limited number of DNA fragments restricts low disease burden monitoring through the prevailing deep targeted sequencing paradigm. We reasoned that breadth may supplant depth of sequencing to overcome the barrier of cfDNA abundance. Whole genome sequencing (WGS) of cfDNA allowed ultra-sensitive detection, capitalizing on the cumulative signal of thousands of somatic mutations observed in solid malignancies, with TF detection sensitivity as low as 10-5. The WGS approach enabled dynamic tumor burden tracking and post-operative residual disease detection, associated with adverse outcome. Thus, we present an orthogonal framework for cfDNA cancer monitoring via genome wide mutational integration, enabling ultra-sensitive detection, overcoming the limitation of cfDNA abundance, and empowering treatment optimization in low-disease burden oncology care

  Study EGAS00001004406

• Genomic Analysis of Paired Endometrial Cancer Primaries and Metastases

  Formation of metastases is the major cause of cancer related deaths. Recent studies have sequenced primary endometrial carcinomas yielding data for a single entity in the progression from the birth of a progenitor tumor cell to metastatic disease. However, the progression of these tumors to metastases has not been characterized. We performed whole-exome sequencing of 98 tumor biopsies including complex atypical hyperplasias, primary tumors and paired abdominopelvic metastases to survey the evolutionary landscape of endometrial cancer. We expanded and reanalyzed TCGA-data, identifying novel recurrent alterations in primary tumors, including mutations in the estrogen receptor cofactor NRIP1 in 12% of patients. We found that likely driver events tended to be shared by primary and metastatic tissue-samples, with notable exceptions such as ARID1A mutations. Phylogenetic analyses in cases with multiple metastases indicated these metastases typically arose from one lineage of the primary tumor. These data indicate extensive genetic heterogeneity within endometrial cancers and relative homogeneity across metastatic sites.

  Study phs001127

• Analysis of AR Gene Rearrangements in Prostate Cancer

  Molecularly-targeted therapies for advanced prostate cancer include castration modalities that suppress ligand-dependent transcriptional activity of the androgen receptor (AR). However, persistent AR signaling undermines therapeutic efficacy and promotes progression to lethal castration-resistant prostate cancer (CRPC), even when patients are treated with potent second-generation AR-targeted therapies abiraterone and enzalutamide. Here we define diverse AR genomic structural rearrangements (AR-GSRs) as a class of molecular alterations occurring in one third of CRPC-stage tumors. AR-GSRs occur in the context of copy-neutral and amplified AR and display heterogeneity in breakpoint location, rearrangement class, and sub-clonal enrichment in tumors within and between patients. Despite this heterogeneity, one common outcome in tumors with high sub-clonal enrichment of AR-GSRs is outlier expression of diverse AR variant species lacking the ligand binding domain and possessing ligand-independent transcriptional activity. Collectively, these findings reveal AR-GSRs as important drivers of persistent AR signaling in CRPC.

  Study phs001223

• Prospective Analysis of Genotypes in Adults Undergoing Therapy for Lung Cancer (Paclitaxel Cohort)

  Lung cancer is frequently treated with paclitaxel in combination with several other agents; however, paclitaxel treatment is often ineffective or limited by treatment-related toxicities. Heritable variants in genes associated with absorption, distribution, metabolism, and elimination may predict paclitaxel clinical outcome and toxicity. We designed a prospective multi-institutional study that recruited 546 patients receiving therapy with a 5-year follow up. All patients were genotyped using the Drug Metabolizing Enzymes and Transporters (DMET) platform, which ascertains 1931 genotypes in 235 genes. Genotypes were compared to the progression-free survival of paclitaxel therapy and clinically-significant paclitaxel toxicities. Seven genetic variants were associated with paclitaxel PFS (in ABCB11, ABCC3, ABCG1, CYP8B1, NR3C1, FMO6P, and GSTM3), whereas four genetic variants (in VKORC1, SLC22A14, GSTA2, and DCK) were associated with paclitaxel toxicities. The present SNPs have limited clinical utility but suggest that certain genes are related to important paclitaxel pathways in lung cancer.

  Study phs001660

• Genomics and Methylation of Neuroendocrine Prostate Cancer from cfDNA (Cornell/Trento 2019)

  A subset of castration resistant prostate cancers develop small cell neuroendocrine prostate cancer (NEPC) as a mechanism of treatment resistance. Metastatic tissue biopsies to evaluate for NEPC transformation are invasive and challenging to perform serially. We performed whole exome and whole genome bisulfite sequencing of plasma cfDNA and matched tumor biopsy samples from 62 patients with metastatic prostate cancer along the disease spectrum to evaluate for NEPC associated genomic and epigenomic features. Multiple tissue biopsies and/or plasma time points were included for a subset of patients to characterize disease heterogeneity and dynamic changes. Computational analysis of clonality and allele specific quantification allowed for detailed comparison of matched tumor tissue and cfDNA data (CLONET v2). Methylation profiles detected from tissue and plasma data were compared and NEPC specific alterations were evaluated in cfDNA. The study supports the feasibility of a plasma based assay for the detection of NEPC.

  Study phs001752

• International Cancer Proteogenome Consortium (ICPC): proteogenomics of early stage lung adenocarcinoma in Taiwan

  Lung cancer in East Asia is characterized by high percentage of never-smokers, early-onset and predominant EGFR mutations. To provide an insight into the molecular phenotype of this demographically distinct disease, we have performed a proteogenomics study on a prospectively collected cohort representing early stage lung adenocarcinomas in Taiwan. The distinct mutational profile revealed high prevalence of the APOBEC mutational signature in early-onset females implicating differential regulation of APOBEC enzymes and DNA damage pathways, as well as enrichment of mutational signatures congruent with environmental carcinogens over-represented in the genomic location of EGFR. We delineate the proteogenomic hallmarks of tumor progression and propose a proteomics-informed classification that resolves the EGFR mutation heterogeneity associated with survival within the early stages. Functional annotation of the molecular subtypes by protein network analysis highlights candidate biomarkers for patient stratification. Our integrative analysis reveals the molecular architecture of lung cancer in East Asia and enables the path for precision medicine.

  Study phs001954

• Genetic Analysis of Latin American Cervical Cancer

  HPV16 is the most oncogenic type of human papillomaviruses (HPV). Integration of HPV into the human genome is an important mechanism of carcinogenesis but is absent in at least 30% of HPV16+ tumors. We applied long-read whole-genome sequencing (WGS) to cervical cancer cell lines and tumors to characterize HPV16 carcinogenesis in the absence of integration. WGS of HPV16+ cervical tumor samples from Latin America revealed that 11/20 tumors with only episomal HPV (EP) had intact monomer episomes. The remaining 9 EP tumors had multimer and rearranged HPV genomes. The majority (80%) of the HPV rearrangements and deletions disrupted the E1 and E2 genes, and EP tumors overexpressed the E6 and E7 viral oncogenes, a similar profile to tumors with HPV integration. Tumors with putative multimer HPV integrations display HPV multimers and concatemers of human and viral sequences. Our data uncovered a novel mechanism for HPV16 to cause cancer without integration through aberrant episomal replication, and forming rearranged, mutated, and multimer episomes.

  Study phs002810

• A Phase III Randomized Study of Nivolumab Plus Ipilimumab Versus Nivolumab in Stage IV Squamous Cell Lung Cancer

  Lung-MAP (S1400, NCT02785952) was a multicenter, open-label, phase III randomized clinical trial. The Lung-MAP-I substudy (S1400I) was conducted from December 2015 to April 2018, through the National Clinical Trials Network and led by the SWOG Cancer Research Network. The trial compared nivolumab plus ipilimumab (nivo+ipi) with nivolumab monotherapy (nivo) in patients with chemotherapy-pretreated, immunotherapy-naïve, advanced squamous non-small cell lung carcinoma (sqNSCLC). Two hundred fifty-two patients were randomly assigned to receive nivo+ipi (n = 125) or nivo (n = 127). The clinical efficacy endpoints were overall survival, progression free survival, duration of response, and best objective response by RECIST 1.1. Multi-omic translational analysis was performed in collaboration with the the CIMAC–Cancer Immunologic Data Commons (CIDC) Network using available tumor tissue samples and blood samples (n = 160) submitted for Lung-MAP screening and provided by the SWOG tissue bank.

  Study phs003412