4984 results for "*oma"

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• Preclinical Pediatric Molecular Analysis for Therapy Choice (MATCH)

  Purpose: Pediatric solid tumors arise from diverse tissues during development and exhibit a wide range of molecular, cellular and genetic features. This diversity, combined with the low incidence of pediatric cancer makes it increasingly difficult to personalize therapy for individual patients based on the unique features of their tumors. Therefore, well-credentialed preclinical models that capture the diversity and heterogeneity of pediatric solid tumors are essential for identifying molecular targeted therapeutics for precision medicine. Experimental Design: Here, we report 281 orthotopic patient derived xenografts (O-PDXs) from 224 patients representing 24 different types of pediatric solid tumors. We have performed genomic characterization of the O-PDXs and compared them to their corresponding patient tumors. To demonstrate the feasibility and utility of using such a diverse collection of O-PDXs in preclinical studies, we performed a preclinical pediatric precision medicine trial based on the NCI-COG Pediatric MATCH trial enrollment criteria. We also tested molecular targeted therapy for a novel oncogenic fusion recently reported in pediatric melanoma and precision drug delivery using nano-liposomal irinotecan. Results: In the preclinical match study, we identified one specific single agent response to LY3023414 in an osteosarcoma model with a TSC2 variant of unknown significance. Combinations of nano-liposomal irinotecan were effective in treating both Ewing sarcoma and rhabdomyosarcoma xenografts. Conclusion: Our studies demonstrate the value of large, well-credentialed preclinical models for future precision medicine in pediatric oncology using single agents, drug combinations and novel drug formulations.

  Study EGAS00001008011

• Ewing and Ewing-like-sarcoma tumoroid biobank reveals distinct drug sensitivities: translocation makes the difference

  Ewing sarcoma (ES) and Ewing-like sarcomas (ELS) are highly aggressive tumors found in soft tissues and bone of mostly children and young adults. Despite being different in many aspects, including genetics, possible cell-of-origin, and pathology, patients with any of these entities all receive the same therapeutic regimen. Currently, there is a lack of preclinical cell models that can predict drug response of these entities in vitro. Here, we describe a pediatric ES and ELS tumor organoid (tumoroid) biobank containing tumoroids with different translocations, including EWSR1::FLI1, EWSR1::ERG, CIC::DUX4, and BCOR-rearrangements. Using histology, whole genome sequencing and RNA sequencing, we demonstrate that these tumoroids retain key properties of their matching patient tumors. In addition, we traced tumor subclones in the tumoroids across patient-matched longitudinal samples, which showed that cellular heterogeneity was maintained. We subsequently performed drug screening on the tumoroid models, which unveiled entity-specific drug sensitivity to various cytotoxic compounds and targeted compounds, including MCL-1 inhibitors for CIC::DUX4 sarcomas. Taken together, this newly established ES and ELS patient-derived tumoroid biobank generates a unique source of material for future basic cancer research and drug-screening.

  Study EGAS00001007941

• Small molecule inhibitors of LOXL synergize with 5-AZA to restore erythropoiesis in myeloid neoplasms

  Objectives: Bone marrow (BM) stroma and microenvironmental factors in the BM milieu of myeloid neoplasms are increasingly being recognized as novel perspective therapeutic targets. Lysyl oxidases (LOX/LOXL) are crucial enzymes that cross-link collagen and contribute to the deposition of aberrant stiff extracellular matrix (ECM) in the BM of patients with myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). Here, we studied whether inhibition of LOX/LOXL enzymes produced by BM-derived MSCs favors the differentiation of MDS/MPN hematopoietic stem cell and progenitor cells (HPSCs) and enhances the effects of 5-azacytidine (5-AZA). Methods: Primary co-cultures of MSCs and HPSCs were established from n=31 MDS/MPN patients and treated with the pan-LOX/LOXL inhibitor PXS-5505, 5-AZA or the combination of both for 4 days. At the end of co-culture, HSPC differentiation was assessed by CFU assays and flow cytometry. In some of the experiments, MSCs monolayers were pre-treated or not with PXS-5505 for 6 days and decellularized using 20 mM ammonia. Subsequently, autologous HSPCs were cultured on ECM matrices in the presence of 5-AZA or PXS-5505 + 5-AZA combination with or without inhibitors of integrin signaling such as blebbistatin, Y-27632 and αvβ3-integrin blocking antibodies. Patient-derived xenografts (PDX) were established in NSG mice based on intrafemoral co-injection of HSPCs and autologous MSCs. PDX were treated with 3 cycles of 5-AZA (75 mg/m2), PXS-5505 (30 mg/kg on alternate days for the duration of 5-AZA treatment) or combination of both. Results: MSCs of MDS and MPN patients displayed significant overexpression of LOX/LOXL transcripts as compared to healthy age-matched controls. Remarkably, LOX/LOXL inhibition in MSCs/HSPCs co-cultures increased erythroid differentiation of patient HSPCs that had suboptimal or no response to 5-AZA alone. From a total of n=31 advanced stage MDS/MPN patients, n=11 (35.5%) responded to the combination treatment, which was evidenced by a significant increase of CD235a+CD45- erythroid cell production compared to 5-AZA/PXS/untreated arms (p<0.05). Of note, combination treatment with 5-AZA + PXS-5505 facilitated differentiation of CD235+ erythroid progenitors from HSPCs sub-clones with low mutational VAFs. The presence of MSCs was necessary for the effects of the combination treatment and required direct cell contacts between MSCs and HSPCs. Moreover, PXS-5505-mediated alterations of the ECM composition alone were sufficient to induce erythroid differentiation. Inhibition of integrin-mediated signaling using blebbistatin, Y-27632 and αvβ3-integrin antibodies completely abrogated the effects of PXS-5505 induced erythroid differentiation. In vivo, the combination of PXS-5505 + 5-AZA favored erythroid differentiation of HSPCs and confirmed the in-vitro results. The combination treatment of 5-AZA + PXS-5505 induced the greatest reduction of disease burden as assessed by decrease of spleen indexes, total engraftment rates, BM fibrosis and mutational VAF profiles. Conclusions: The combination of 5-AZA + LOX/LOXL inhibitor PXS-5505 in MDS and MPN synergistically restores erythropoietic differentiation of primary HSPCs. The effect is dependent of contact interaction between HSPCs and niche components, such as MSCs and MSCs-derived ECM. Our data propose a strong rationale for a BM niche targeted combination treatment with 5-AZA + PXS-5505 in transfusion dependent MDS and MPN, which will be assessed in forthcoming clinical trials.

  Study EGAS00001006174

• MPN_Tissue_WGS_NanoSeq

  An exploration of the somatic mutational landscape of a patient with myeloproliferative neoplasm (MPN) and squamous cell carcinoma (SCC). In particular this study aims to identify mutational signatures present in SCC lesion compared to a region of healthy skin, especially searching for the presence of signatures specific to hydroxycarbamide from previous chemotherapy treatment.

  Study EGAS00001007761

• Spatial transcriptomics analysis of HPV-dependent and HPV-independent vulval squamous cell carcinoma

  In this study we have used sequencing-based spatial transcriptomics (ST) optimised for FFPE tissue to investigate gene expression in a cohort of HPVi and HPVd VSCC, including assessment of pre-invasive LS, HSIL and DVIN and associated inflammation. Our data indicate significant differences in gene expression between VSCC of different aetiologies, with marked differences in immune-related gene expression both within the invasive disease and in peri-tumoural inflammatory areas.

  Study EGAS00001007981

• Dual targeting of polyamine synthesis and uptake in diffuse intrinsic pontine gliomas

  Diffuse intrinsic pontine glioma (DIPG) is an incurable malignant childhood brain tumour, with no active systemic therapies and a 5-year survival of less than 1%. Polyamines are small organic polycations that are essential for DNA replication, translation and cell proliferation. Ornithine decarboxylase 1 (ODC1), the rate limiting enzyme in polyamine synthesis, is irreversibly inhibited by difluoromethylornithine (DFMO). Herein we show that polyamine synthesis is upregulated in DIPG, leading to sensitivity to DFMO. DIPG cells compensate for ODC1 inhibition by upregulation of the polyamine transporter SLC3A2. Treatment with the polyamine transporter inhibitor AMXT 1501 reduced uptake of polyamines in DIPG cells, and co-administration of AMXT 1501 and DFMO led to potent in vitro activity, and significant extension of survival in three aggressive DIPG orthotopic animal models. Collectively, these results demonstrate the potential of dual targeting of polyamine synthesis and uptake as a therapeutic strategy for incurable DIPG.

  Study EGAS00001004905

• Whole-genome landscape of adult T-cell leukemia/lymphoma

  Whole-genome sequencing (WGS) data of tumor-normal pairs from 139 ATL patients and RNA sequencing (RNA-seq) data of tumors from 28 ATL patients.

  Study EGAS00001005237

• Genomic Landscape of Malignant Peripheral Nerve Sheath Tumor-like Melanoma

  Malignant peripheral nerve sheath tumor (MPNST)-like melanoma is a rare malignancy with overlapping characteristics of both neural sarcoma and melanoma. The genomics of MPNST-like melanoma have not been previously described. This study provides the results of whole exome and transcriptome sequencing analysis of 8 samples from 6 patients with confirmed diagnosis of MPNST-like melanoma. This study demonstrates that MPNST-like melanoma shares oncogenic alterations common to both cutaneous melanoma and MPNST, and also suggests that MPNST-like melanoma harbors unique genomic and transcriptomic alterations.

  Study EGAS00001005065

• Sclerosing epithelioid fibrosarcoma case report

  Sclerosing epithelioid fibrosarcoma (SEF) is a rare and aggressive soft tissue sarcomathought to originate in fibroblasts of the tissues surrounding tendons, ligaments and muscles. Minimally responsive to conventional cytotoxic chemotherapies, greater than 50% of SEF patients experience relapse and/or metastatic disease. SEF is most commonly discovered in middle-aged and elderly adults, but also rarely in children. A common gene fusion occurring between the EWSR1 and CREB3L1 genes has been observed in 80-90% of SEF cases. We describe here the youngest SEF patient reported to date (a 3-year-old Caucasian male) who presented with numerous bony and lung metastases. Additionally, we perform a comprehensive literature review of all SEF-related articles published since the disease was first characterized. The patient described in this report experienced persistent disease progression despite being heavily treated with multiple surgeries, radiation, numerous chemotherapies and targeted therapeutics. Primary tumor, metastatic and relapse sites were sequenced by whole genome, whole exome, and deep transcriptome next generation sequencing with comparison to a patient-matched normal blood sample. Consistent across all sequencing analyses was the disease-defining EWSR1-CREB3L1 fusion as a single feature consensus. We provide an analysis of our genomic findings and a discussion as to potential therapeutic strategies for SEF.

  Study EGAS00001005214

• Targeted sequencing of follicular lymphoma tumour samples from the UK's Haematological Malignancy Research Network

  Follicular lymphoma displays morphological and clinical heterogeneity, underpinned by shared molecular pathogenesis. Mutations in epigenetic regulators alongside t(14;18) have been identified as disease initiating events. Additional mutational diversity suggests disease heterogeneity. Whether this resolves into mechanistically distinct subsets remains an open question. Targeted sequencing was applied to an unselected population-based FL cohort (n=548) diagnosed in a catchment population of ~4 million (14 centers), with full clinical follow-up (n=538) that included 96 DLBCL transformations. We investigated whether molecular subclusters of FL can be identified, and whether mutational data provide predictive information relating to transformation.

  Study EGAS00001005238