4878 results for "*oma"

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• Analysis of ATL progression by CD30 signaling and its biomarkers (2)

  Adult T-cell leukemia/lymphoma (ATL) develops via stepwise accumulation of gene mutations and chromosome aberrations. However, the molecular mechanisms underlying this tumorigenic process are poorly understood. We aim to elucidate the mechanism of the tumorigenic process involving genomic aberrations by CD30 signaling in HTLV-1���infected T-cells.

  Study JGAS000537

• Genetic alterations that deregulate RB and PDGFRA signaling pathways drive tumor progression in IDH2-mutant astrocytoma

  In IDH-mutant astrocytomas, IDH2 mutation is quite rare and biological mechanisms underlying tumor progression in IDH2-mutant astrocytoma remain elusive. Here, we report a unique case of IDH2 mutant astrocytoma, CNS WHO grade 3 that developed tumor progression. We performed a comprehensive genomic and epigenomic analysis for primary and recurrent tumors and found that both tumors harbored recurrent IDH2R172K and TP53R248W mutation with CDKN2A/B hemizygous deletion. We also found amplifications of CDK4 and MDM2 with PDGFRA gain in the recurrent tumor and upregulated protein expressions of these genes. We further developed, for the first time, a xenograft mouse model of IDH2R172K mutant astrocytoma from the recurrent tumor, but not from the primary tumor. Consistent with parent recurrent tumor cells, amplifications of CDK4 and MDM2 with PDGFRA gain was found, while CDKN2A/B was identified as homozygous deletion in the xenografts, qualifying for integrated diagnosis of astrocytoma, IDH2-mutant, CNS WHO grade 4. Cell viability assay found that CDK4/6 inhibitor and PDGFR inhibitor potently decreased cell viability in recurrent tumor cells, as compared to primary tumor cells. These findings suggest that gene alterations that activate retinoblastoma (RB) signaling pathways and PDGFR may drive tumor progression and xenograft formation in IDH2-mutant astrocytoma, which is equivalent to progressive IDH1-mutant astrocytoma. Also, our findings suggest that these genomic alterations may represent therapeutic targets in IDH2-mutant astrocytoma.

  Study JGAS000646

• Whole exome sequencing of uterine adenomyosis

  Uterine adenomyosis, defined by proliferation of the ectopic endometrial glands in myometrium, is a common benign uterine disorder that significantly impairs the quality of life of the women it affects. Adenomyosis lesions have chronic inflammatory reactions as well as cancer-like features such as invasive capacity into the normal myometrium. In contrast to endometriosis and leiomyoma, the genomic characterization of adenomyosis has yet to be reported. We conducted high-coverage whole exome sequencing analyses of freshly frozen adenomyosis samples, as well as co-occurring leiomyoma. Our WES analyses showed that adenomyosis is a clonal disorder with somatic mutations.

  Study JGAS000169

• Genomics characterization of primary central nervous system lymphoma

  Primary central nervous system lymphoma (PCNSL) is a rare malignancy confined to the central nervous system (CNS). Despite low tendency of systemic dissemination, its prognosis is poor with median overall survival of 2?4 years. Due to its rarity, knowledge of genomic alterations underling PCNSL pathogenesis is severely limited. Here we performed whole-exome sequencing on 44 PCNSL and paired normal specimens, revealing high penetrance of nonsynonymous somatic mutations in PIM1 (95.5%), BTG2 (88.6%) and MYD88 (81.8%). Interestingly we found oncogenic mutations in GRB2, and this effect was cancelled when transformed cells are treated with inhibitors to downstream kinases MAP2K1/2. Further, when tumor cells carries MYD88 mutations, the same mutations were also found at low frequency in peripheral blood mononuclear cells (PBMNC), implying that MYD88 mutation?positive precancerous cells originate outside CNS and develop to lymphoma with additional genetic hits that fit the CNS environment.

  Study JGAS000021

• Durable clinical impacts and mechanisms of action and resistance in histone K27 methylation-targeting epigenetic therapy

  Epigenomes allow the rectification of disordered cancer gene expressions, thereby providing new targets for pharmacological interventions in cancer therapy. The clinical utility of targeting histone H3 lysine tri-methylation (H3K27me3) as an epigenetic hallmark has been demonstrated. However, in actual therapeutic settings, the mechanism by which H3K27me3-targeting therapies exert their effects and the response of tumor cells remain unclear. Here we show the potency and mechanisms of action and resistance of a newly developed EZH1/2 dual inhibitor, valemetostat, in the clinical trials of patients with adult T-cell leukemia/lymphoma (ATL). Valemetostat administration reduced the tumor size and demonstrated durable clinical benefits. Integrative single-cell analyses of patients before and after the administration of valemetostat showed that valemetostat abolishes the highly condensed chromatin structure formed by the plastic H3K27me3 and neutralizes multiple gene loci, such as tumor suppressor genes. Nevertheless, subsequent long-term treatment encounters the emergence of resistant clones with reconstructed aggregate chromatin that closely resemble the pre-dose state. The acquired mutations at the EZH2???compound interface result in the propagation of the clones with re-increased H3K27me3. In patients free of this mutation, TET2 mutation or elevated DNMT3A expression causes similar chromatin recondensation through de novo DNA methylation at the H3K27me3-associated regions. We identified subpopulations with distinct metabolic and gene translation characteristics implicated in primary susceptibility until the acquisition of the heritable (epi)mutations. Targeting chromatin homeostasis might provide opportunities for further sustained epigenetic cancer therapies.

  Study JGAS000553

• Comprehensive biomarker analysis from phase II study of nivolumab in patients with thymic carcinoma

  In a phase II trial of nivolumab in advanced thymic carcinoma (UMIN000022007), long SD (SD for more than 24 weeks) was seen in three patients and irAE (Gr2 or higher) was seen in four patients among 15 patients. We conducted preplanned comprehensive biomarker analyses. We obtained whole blood for Immuno Pharmacogenomic analysis using PBMC DNA. Immuno-PGx analysis showed non-synonymous SNVs in ITGAX and PDCD1 had some correlation with PFS.

  Study JGAS000588

• Whole-genome sequencing analysis for understanding of the stepwise progression of lung adenocarcinoma

  In this study, we performed long and short read whole-genome sequencing analysis of lung adenocarcinoma from early to advanced stages to identify molecular events associated with the stepwise progression of lung adenocarcinoma. We particularly focused on very early stage of lung adenocarcinoma, such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA). In addition to the whole-genome sequencing analysis, we conducted transcriptome and epigenome analysis, multiplex fluorescence immunostaining. This study would enable us to understand important molecular events of pathogenesis in detail during lung adenocarcinoma progression.

  Study JGAS000570

• Targeted exome sequencing identify compound heterozygous TYK2 mutations in patients with primary immunodeficiency who developed EBV-associated lymphoma

  In this study, we evaluated 2 siblings with primary immunodeficiency who developed EBV-associated lymphoma. Immunophenotyping of PBMCs revealed that both patients had significant T cell lymphopenia characterized by low na?ve CD4+ T cell counts. To identify the causative genetic mutations in the patients, we performed targeted exome sequencing using the Illumina MiSeq on the patients and their parents. The results showed a novel compound heterozygous mutations in the gene encoding tyrosine kinase 2 (TYK2) in the patients.

  Study JGAS000098

• High-coverage whole exome sequence in non-TRU-type lung adenocarcinomas

  In order to elucidate the key genetic events in non-TRU-type lung cancer, we selected 43 non-TRU-type lung adenocarcinomas and performed a whole exome sequence and RNA-seq analysis using a next-generation sequencer. The results of the analysis identified mutations in TP53, KRAS and NKX2-1 as the top three significantly mutated genes, while the EGFR mutation was rare in this cohort. Eight NKX2-1 mutations (5 frameshift, 2 nonsense, and one missense) were identified, with one case harboring two distinct NKX2-1 mutations (missense and frameshift). All NKX2-1 mutants were transcriptionally inactive in reporter assays. Histologically, invasive mucinous adenocarcinomas accounted for most of the NKX2-1 mutations (5 cases), while 1 enteric and 1 acinar adenocarcinoma harbored the NKX2-1 mutation.

  Study JGAS000105

• Development of cell lines and mouse models of bone and soft tissue sarcoma to establish novel treatment

  Malignant giant-cell tumors are extremely rare bone sarcomas that transform from conventional giant-cell tumors during long periods of treatment. We have applied the culture methods and succeeded in establishing patient-derived organoids (PDO) of rare sarcomas. This study aimed to investigate the genomic characteristics of our established novel organoids from human malignant giant-cell tumors. The developed tumors with xenograft were genomically analyzed to compare their characteristics with those of the original tumors. Genetic changes over time throughout treatment were analyzed, and the genomic status of the established organoid was confirmed. Next generation sequencing revealed that the established organoids lacked the H3-3A G34W mutation. The xenografted organoids of the malignant giant-cell tumor had phenotypes genetically similar to those of the original tumor. The established organoids were confirmed to be derived from human malignant giant-cell tumors. In summary, the present study demonstrated a novel organoid model of a malignant giant-cell tumor that was genetically confirmed to be a malignant transformed tumor. Our organoid model could be used to elucidate the molecular pathogenesis of a malignant giant-cell tumor and develop novel treatment modalities.

  Study JGAS000618