5500 results for "*oma"

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• Molecular evolution of metastatic clear cell renal cell carcinoma progressing under tyrosine kinase inhibitor therapy (HIPO-045)

  Background:Acquired resistance to targeted drugs is largely due to intra-tumor molecular heterogeneity and clonal selection. Objective:The objective of this study was to determine molecular alterations and mediating resistant mechanisms and to suggest additional treatment options.Design, Setting, and Participants:Four patients were enrolled into the MORE (Molecular Renal Cancer Evolution) trial. We investigated the mutational spectra of metastatic clear cell renal cell carcinoma (ccRCC) at baseline and compared them to those upon clonal evolution at progression on systemic therapy with tyrosine kinase inhibitors.Outcome Measurements:DNA was isolated from tumor tissues after surgery, metastasis biopsies after progression on sunitinib or axitinib, and subjected to whole-exome sequencing (WES). In addition, the exomes of circulating tumor DNA (ctDNA) from two patients were sequenced at baseline and at progression.Results and Limitations:Our data provide evidence for clonal evolution and various acquired resistance mechanisms of ccRCC with subclonal mutations in FLT4, MTOR, ITGA3/5, SETD2, and VHL on metastatic progression. The limited number of shared mutations in tissue and plasma biopsies indicates that both sources provide complementary information, possibly due to mutations present in metastatic lesions which were not amenable to tissue sampling but are represented in the ctDNA. Conclusion:Acquired resistance to targeted therapies in metastatic ccRCC is due to intra-tumor heterogeneity and clonal evolution. Larger patient cohorts have to be studied to estimate the benefit of WES from biopsies and ctDNA for therapy decision in metastatic ccRCC.Patient Summary:We analyzed the molecular profiles of ccRCC patients in primary tissues and metastatic tissues upon progression on tyrosine kinase inhibitor therapy. Clinically relevant mutations upon progression were detected in the metastatic sites of all of four patients, suggesting that it might be possible to derive therapies based on sequencing the metastases.?HIPO-045

  Study EGAS00001001861

• Subtype specific progression from DCIS to invasive breast cancer

  Breast cancer consists of at least five main molecular “intrinsic” subtypes, which are reflected in both pre-invasive and invasive disease. Although previous studies have suggested that many of the molecular features of invasive breast cancer are established early, it is unclear what mechanisms drive progression, and whether the mechanisms of progression are dependent or independent of subtype. We have generated mRNA, miRNA and DNA copy number profiles from a total of 59 in situ lesions and 85 invasive tumors, in order to comprehensively identify those genes, signaling pathways, processes, and cell types that are involved in breast cancer progression. Our work provides evidence that there are molecular features associated with disease progression that are unique to the intrinsic subtypes. We additionally establish subtype-specific signatures that are able to identify a small proportion of pre-invasive tumors with expression profiles that resemble invasive carcinoma, indicating a higher likelihood of future disease progression.

  Study EGAS00001001866

• Multi-omics analysis of primary glioblastoma cell-lines shows recapitulation of pivotal molecular features of parental tumors

  Glioblastoma (GBM) is the deadliest primary brain cancer in adults. Emerging innovative therapies hold promise for personalized cancer treatment. Improving therapeutic options depends on research relying on relevant preclinical models. In this line we have established in the setting of the GlioTeX project (GBM and experimental therapeutics), a GBM-patient derived cell line library (GBM-PDCL). Multi-OMIC approach was used to determine the molecular landscape of PDCL and the extent to which they represent GBM tumors.

  Study EGAS00001001871

• Whole genome shotgun sequencing and somatic mutations data in Hepatocellular carcinoma

  Hepatocellular carcinoma (HCC) is the most common malignancy of the liver. Genomic analysis is conducted to identify genetic alterations in driver genes which are all druggable targets for cancer therapy.

  Study EGAS00001002578

• Non-Mendalian inheritance of extrachromosal DNA elements can drive disease evolution in glioblastoma

  Genomic heterogeneity of glioblastoma (GBM) is suspected to contribute to the poor response to therapy of this disease. We compared molecular characteristics between primary GBM, neurospheres and orthotopic xenograft models derived from the same parental tumor. Driver alterations were in majority propagated from tumor to model systems. Extrachromosomal amplifications of MET, a proto-oncogene coding for a receptor tyrosine kinase, were detected in three primary GBM, largely discarded in neurospheres cultures, but resurfaced in xenografts. The clonal dynamics inferred by somatic single nucleotide variants (sSNVs) in MET-amplified samples diverged from the pattern delineated by the MET amplification event suggesting that the MET event and sSNVs were inherited in different manners. Our analysis shows that extrachromosomal elements are able to drive tumor progression.

  Study EGAS00001001878

• EATL-II STUDY

  Enteropathy-associated T-cell lymphoma (EATL), a rare and aggressive intestinal malignancy of intraepithelial T lymphocytes, comprises two disease variants (EATL-I and EATL-II) differing in clinical characteristics and pathological features. Here we report findings derived from whole exome sequencing of 15 EATL-II tumor-normal tissue pairs. The tumor suppressor gene SETD2 encoding a non-redundant H3K36-specific trimethyltransferase is altered in 14/15 cases (93%), mainly by loss-of-function mutations and/or loss of the corresponding locus (3p21.31). These alterations consistently correlate with defective H3K36 trimethylation. The JAK/STAT pathway comprises recurrent STAT5B (60%), JAK3 (46%) and SH2B3 (20%) mutations, including a STAT5B V712E activating variant. Additionally, frequent mutations in TP53, BRAF and KRAS are observed. Conversely, in EATL-I, no SETD2, STAT5B or JAK3 mutations are found, and H3K36 trimethylation is preserved. This study describes SETD2 inactivation as EATL-II molecular hallmark, supports EATL-I and -II being two distinct entities, and defines potential new targets for therapeutic intervention.

  Study EGAS00001001879

• Spatiotemporal genomic architecture informs precision oncology in glioblsatoma

  We characterized genomic and expression profiles across 127 multi-sector or longitudinal specimens from 52 glioma patients. We showed that, while samples from nearby geographical location shared similar genomic alterations (clonal or subclonal) and expression signatures, multifocal tumors were seeded from individual clones.

  Study EGAS00001001880

• Inactivation of TGFβ receptors in stem cells drives cutaneous squamous cell carcinoma - 30 whole exomes

  Melanoma patients treated with oncogenic BRAF inhibitors can develop cutaneous squamous cell carcinoma (cSCC) within weeks of treatment, driven by paradoxical RAS/RAF/MAPK pathway activation. Here, we identify frequent TGFBR1 and TGFBR2 mutations in human vemurafenib-induced skin lesions and in sporadic cSCC. Functional analysis reveals these mutations ablate canonical TGFβ Smad signaling which is localised to bulge stem cells in both normal human and murine skin. MAPK pathway hyperactivation (through BrafV600E or KrasG12D knockin) and TGFβ signaling ablation (through Tgfbr1 deletion) in LGR5+ve stem cells enables rapid cSCC development in the mouse. Mutation of Tp53 (which is commonly mutated in sporadic cSCC) coupled with Tgfbr1 deletion in LGR5+ve cells also results in cSCC development. These findings indicate that LGR5+ve stem cells can act as cells of origin for cSCC and that RAS/RAF/MAPK pathway hyperactivation or Tp53 mutation, coupled with loss of TGFβ signaling, are driving events of skin tumorigenesis.

  Study EGAS00001001892

• Integrated Molecular Profilting in Advanced Cancers Trial

  The present protocol seeks to provide molecular profiling data to the treating physician for patients with advanced breast, non-small cell lung, colorectal, genitourinary, pancreatobiliary gastrointestinal, upper aerodigestive tract, gynecological, melanoma, unknown primary, and rare carcinomas, as well as patients who are phase I trial candidates, in order to help identify which standard regimens or clinical trials of molecularly targeted therapies may be most appropriate for the individual patient.

  Study EGAS00001001897

• Comparison of EGF and PDGF driven glioblastomas.

  Glioblastoma multiforme (GBM) is the most common and aggressive type of primary brain tumor. Epidermal growth-factor (EGF) and platelet-derived growth-factor (PDGF) receptors are frequently amplified and/or possess gain-of-function mutations in these tumors. Despite years of research into tyrosine-kinase inhibitors, clinical trials have shown disappointing efficacy. One of the underlying reasons is intra-tumor heterogeneity. To assess the effect of intra-tumor heterogeneity on gene expression, we derived a general approach to map single-cell expression profiles to sequentially-acquired mutations identified from exome sequencing. Using 288 single cells, we constructed high-resolution phylogenies of EGF-driven and PDGF-driven GBMs, modeling transcriptional kinetics during tumor evolution. A deletion in a PDGF-receptor domain involved in dimerization correlated to an up-regulation of the PI3K/AKT pathway in a proneural GBM, and ectopic expression of this mutant PDGFRA in vitro enhanced proliferation and invasiveness. Descending the phylogenetic tree of the PDGFR-driven tumor corresponded to a progressive induction of an oligodendrocyte progenitor-like cell type that expresses growth and angiogenic factors. In contrast, phylogenetic analysis of an EGFR-amplified tumor showed a gradual up-regulation of pro-invasive genes.

  Study EGAS00001001900