Antibiotic-resistant infections remain to be a major issue for all over the world. Although appropriate diagnosis and rapid treatment initiation are crucially important particularly in ...immunocompromised patients, selection of antibiotics without identification of causative bacteria is often challenging. A 44-year-old woman with acute myeloid leukemia (AML) under myelosuppression suffered from teicoplanin-resistant gram-positive cocci bacteremia. Taking severe neutropenia due to chemotherapy and glycopeptide-resistance into account, teicoplanin was empirically substituted with daptomycin, which led to prompt defervescence. This microorganism later turned out to be Leuconostoc lactis (L. Lactis), and daptmycin was continued to use based on antimicrobial susceptibility tests. As a result, empiric use of daptomycin successfully controlled glycopeptide-resistant gram-positive cocci bacteremia under neutropenia. This is the first report of daptomycin treatment for L. lactis bacteremia in a patient with AML under neutropenia. Our findings suggest that daptomycin would be a suitable treatment option for glycopeptide-resistant gram-positive cocci bloodstream infections, especially in myelosuppressive patients.
Adult T-cell leukemia/lymphoma (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1). In addition to HTLV-1 bZIP factor (HBZ), a leukemogenic antisense transcript of HTLV-1, abnormalities of ...genes involved in TCR-NF-κB signaling, such as CARD11, are detected in about 90% of patients. Utilizing mice expressing CD4
T cell-specific CARD11(E626K) and/or CD4
T cell-specific HBZ, namely CARD11(E626K)
mice, HBZ transgenic (Tg) mice, and CARD11(E626K)
;HBZ Tg double transgenic mice, we clarify these genes' pathogenetic effects. CARD11(E626K)
and HBZ Tg mice exhibit lymphocytic invasion to many organs, including the lungs, and double transgenic mice develop lymphoproliferative disease and increase CD4
T cells in vivo. CARD11(E626K) and HBZ cooperatively activate the non-canonical NF-κB pathway, IRF4 targets, BATF3/IRF4/HBZ transcriptional network, MYC targets, and E2F targets. Most KEGG and HALLMARK gene sets enriched in acute-type ATL are also enriched in double transgenic mice, indicating that these genes cooperatively contribute to ATL development.
Premalignant clonal expansion of human T-cell leukemia virus type-1 (HTLV-1)-infected cells occurs before viral carcinogenesis. Here we characterize premalignant cells and the multicellular ecosystem ...in HTLV-1 infection with and without adult T-cell leukemia/lymphoma (ATL) by genome sequencing and single-cell simultaneous transcriptome and T/B-cell receptor sequencing with surface protein analysis. We distinguish malignant phenotypes caused by HTLV-1 infection and leukemogenesis and dissect clonal evolution of malignant cells with different clinical behavior. Within HTLV-1-infected cells, a regulatory T-cell phenotype associates with premalignant clonal expansion. We also delineate differences between virus- and tumor-related changes in the nonmalignant hematopoietic pool, including tumor-specific myeloid propagation. In a newly generated conditional knockout mouse model recapitulating T-cell-restricted
(encoding PD-L1) gene lesions found in ATL, we demonstrate that PD-L1 overexpressed by T cells is transferred to surrounding cells, leading to their PD-L1 upregulation. Our findings provide insights into clonal evolution and immune landscape of multistep virus carcinogenesis.
Our multimodal single-cell analyses comprehensively dissect the cellular and molecular alterations of the peripheral blood in HTLV-1 infection, with and without progression to leukemia. This study not only sheds light on premalignant clonal expansion in viral carcinogenesis, but also helps to devise novel diagnostic and therapeutic strategies for HTLV-1-related disorders.
Abstract Rituximab, a monoclonal antibody directed against CD20, became widely used for the treatment of immunoglobulin M (IgM)-related neuropathy. However, response rate by rituximab monotherapy is ...no more than 30%. Previous studies revealed that fludarabine acts synergistically with rituximab in vitro and that fludarabine also ameliorates IgM-related neuropathy in a subset of patients. Here we present two cases of IgM-related neuropathy in the background of Waldenström macroglobulinaemia, including one with rituximab resistance. They showed marginal to high titres of both anti-myelin associated glycoprotein and anti-sulphate-3-glucuronyl paragloboside antibodies, and their symptoms were featured by prominent motor deterioration. The combination therapy with rituximab and fludarabine stabilised or improved neuropathic symptoms with tolerable adverse events. Fludarabine may have a potential to overcome rituximab resistance. In conclusion, combination therapy with rituximab and fludarabine should be considered for IgM-related neuropathy, especially when efficacy of rituximab monotherapy is insufficient.
Abstract
We present our novel software, nanomonsv, for detecting somatic structural variations (SVs) using tumor and matched control long-read sequencing data with a single-base resolution. The ...current version of nanomonsv includes two detection modules, Canonical SV module, and Single breakend SV module. Using tumor/control paired long-read sequencing data from three cancer and their matched lymphoblastoid lines, we demonstrate that Canonical SV module can identify somatic SVs that can be captured by short-read technologies with higher precision and recall than existing methods. In addition, we have developed a workflow to classify mobile element insertions while elucidating their in-depth properties, such as 5′ truncations, internal inversions, as well as source sites for 3′ transductions. Furthermore, Single breakend SV module enables the detection of complex SVs that can only be identified by long-reads, such as SVs involving highly-repetitive centromeric sequences, and LINE1- and virus-mediated rearrangements. In summary, our approaches applied to cancer long-read sequencing data can reveal various features of somatic SVs and will lead to a better understanding of mutational processes and functional consequences of somatic SVs.
Graphical Abstract
Graphical Abstract
Adult T-cell leukemia/lymphoma (ATL) is an aggressive peripheral T-cell malignancy with a markedly poor prognosis. The low prevalence of ATL among human T-cell leukemia virus type-1 (HTLV-1) carriers ...and the long latency period before ATL onset suggest that additional genetic lesions are required for ATL leukemogenesis. Recently, a large-scale genetic analysis clarified the entire picture of genetic alterations, identified a number of novel driver genes, and delineated their characteristics. Frequent alterations are observed in the molecules belonging to T-cell receptor/NF-κB signaling and other T-cell-related pathways. A notable feature of the ATL genome is the predominance of gain-of-function alterations, including activating mutations in PLCG1, PRKCB, and CARD11. As many as one-fourth of all ATL cases harbor structural variations disrupting the 3′-untranslated region of the PD-L1 gene, leading to immune evasion of tumor cells. The frequency and pattern of these somatic alterations differ among clinical subtypes. Aggressive subtypes are associated with an increased burden of genetic alterations, and higher frequencies of TP53 and IRF4 mutations, PD-L1 amplifications, and CDKN2A deletions than indolent subtypes. In contrast, STAT3 mutations are more characteristic of indolent ATL. Furthermore, these subtypes are further classified into molecularly distinct subsets with a different prognosis by genetic alterations. We present an overview of the current understanding of somatic alterations in ATL, with specific focus on their utility in clinical settings. Furthermore, we highlight their genetic features by exploring their similarities and differences among peripheral T-cell lymphomas.
Using 48,627 samples from the Center for Cancer Genomics and Advanced Therapeutics (C-CAT), we present a pan-cancer landscape of driver alterations and their clinical actionability in Japanese ...patients. Comparison with White patients in Genomics Evidence Neoplasia Information Exchange (GENIE) demonstrates high TP53 mutation frequencies in Asian patients across multiple cancer types. Integration of C-CAT, GENIE, and The Cancer Genome Atlas data reveals many cooccurring and mutually exclusive relationships between driver mutations. At pathway level, mutations in epigenetic regulators frequently cooccur with PI3K pathway molecules. Furthermore, we found significant cooccurring mutations within the epigenetic pathway. Accumulation of mutations in epigenetic regulators causes increased proliferation-related transcriptomic signatures. Loss-of-function of many epigenetic drivers inhibits cell proliferation in their wild-type cell lines, but this effect is attenuated in those harboring mutations of not only the same but also different epigenetic drivers. Our analyses dissect various genetic properties and provide valuable resources for precision medicine in cancer.
We present a genetic landscape of 26 principal cancer types/subtypes, including Asian-prevalent ones, in Japanese patients. Multicohort data integration unveils numerous cooccurring and exclusive relationships between driver mutations, identifying cooccurrence of multiple mutations in epigenetic regulators, which coordinately cause transcriptional and phenotypic changes. These findings provide insights into epigenetic regulator-driven oncogenesis. This article is featured in Selected Articles from This Issue, p. 695.
EVI-1 (ecotropic viral integration site 1) is a transcription factor essential for the development as well as progression of acute myeloid leukemia (AML). Since high expression of EVI-1, seen in ...approximately 10% of patients with AML (EVI-1high AML), is associated with chemoresistance and poor clinical outcome, development of a novel therapeutic strategy is definitely required. Recent studies suggest that high EVI-1 expression alters metabolic profiles of leukemia cells including glycolysis, oxidative phosphorylation and amino acid and nucleotide synthesis. However, it has yet to be elucidated how these metabolic properties are induced and affect the clinical features of EVI-1high AML cells.
In this study, we investigated key molecules that are induced by aberrant EVI-1 expression and modulate the metabolomics of leukemia cells. We conducted whole transcriptome analysis by RNA-sequencing in murine leukemia cells induced by retroviral transduction of bone marrow cells with EVI-1 followed by transplantation into irradiated mice. We identified 45 genes with more than 10-fold expression in EVI-1-transduced bone marrow leukemia cells compared to those with the mock vector at both early (4 weeks) and late (6 months) time points after transplantation. Intriguingly, the fructose bisphosphatase 1 gene (Fbp1), which encodes a key enzyme of gluconeogenesis was highly upregulated in EVI-1-induced leukemic bone marrow cells. We confirmed that FBP1 expression is quickly upregulated at both mRNA and protein levels by ectopic expression of EVI-1 in mouse bone marrow cells as well as human leukemia cell lines. Moreover, we observed a significant enrichment of EVI-1 in the promoter region of Fbp1 by chromatin immunoprecipitation followed by qPCR analysis in murine hematopoietic cells, suggesting that Fbp1 expression is directly regulated by EVI-1. Although high FBP-1 expression suppresses glycolytic metabolism by catalyzing the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and negatively affects cellular proliferation in various types of solid tumor cells, its role in leukemia cells has not been investigated. In contrast to the results previously reported in other types of cancers, pharmacologic inhibition or short hairpin RNA (shRNA)-mediated knockdown of FBP-1 significantly decreased colony-forming cell (CFC) capacity in EVI-1-transduced murine LSK (Linneg, c-Kitpos, Sca-1pos) cells but not in normal LSK cells. Moreover, treatment with an FBP-1 inhibitor of the mice secondarily transplanted with EVI-1-overexpressing AML cells significantly delayed progression of leukemia without compromising normal hematopoiesis in vivo. These results suggest that aberrant expression of FBP-1 is important for progression of EVI-1high AML.
Since high FBP-1 enzymatic activity negatively affects the glycolytic pathway, it in turn enhances the pentose phosphate pathway (PPP), one of the main bypassing pathways from the glycolytic process. PPP generates pentoses and then ribose-5-phosphates, resulting in enhanced nucleotide synthesis essential for rapidly dividing cells. In addition to FBP-1, we found that multiple PPP-related enzymes such as glucose-6-phosphate dehydrogenase, 6-phosphogluconolactonase and ribose-5-phosphate isomerase were transcriptionally upregulated in EVI-1-transduced leukemia cells compared with the normal bone marrow cells. Importantly, knockdown of these PPP enzymes by shRNA transduction significantly decreased the CFC capacity of EVI-1 transduced murine LSK cells, further confirming that PPP has an important role in driving proliferation of EVI-1high leukemia cells. Collectively, these results indicate that the activated PPP through transcriptional upregulation of FBP-1 as well as its catalyzing enzymes is crucial for progression of EVI-1-driven leukemia cells. Since inhibition of FBP-1 did not compromise normal hematopoiesis, targeting the enzyme can be a promising therapeutic approach for the EVI-1high AML.
Kurokawa:Kyowa Hakko Kirin: Honoraria, Research Funding; MSD: Honoraria, Research Funding; Nippon Sinyaku: Honoraria, Research Funding; Astellas Pharma: Research Funding; Takeda Pharmaceutical: Research Funding; Eizai: Research Funding; Pfizer: Research Funding; Chugai Pharmaceutical: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Sumitomo Dainippon Pharma: Research Funding; Otsuka Pharmaceutical: Research Funding; Teijin Pharma: Research Funding.
Neutrophils play an essential role in innate immune responses to bacterial and fungal infections, and loss of neutrophil function can increase the risk of acquiring lethal infections in clinical ...settings. Here, we show that engineered neutrophil-primed progenitors derived from human induced pluripotent stem cells can produce functional neutrophil-like cells at a clinically applicable scale that can act rapidly in vivo against lethal bacterial infections. Using 5 different mouse models, we systematically demonstrated that these neutrophil-like cells migrate to sites of inflammation and infection and increase survival against bacterial infection. In addition, we found that these human neutrophil-like cells can recruit murine immune cells. This system potentially provides a straight-forward solution for patients with neutrophil deficiency: an off-the-shelf neutrophil transfusion. This platform should facilitate the administration of human neutrophils for a broad spectrum of physiological and pathological conditions.
A current broad spectrum of genomic studies on acute myeloid leukemia (AML) has demonstrated that a gene encoding for DNA methyltransferase, specifically DNA methyltransferase 3 alpha (DNMT3A) is ...frequently mutated. However, DNMT3A variants are present in elderly healthy individuals and patients with AML in complete remission, which suggests that DNMT3A mutations may contribute to pre-leukemic clonal hematopoiesis. Although DNMT3A mutation has been thought to play a pivotal role in AML pathogenesis through the loss of DNA methylation functionality, other potential disease-related mechanisms are poorly understood. We identified that DNMT3A Arg882 mutation has two distinct mechanisms for developing clonal hematopoiesis and leukemia: (1) DNA methylation-dependent effect, which caused up-regulation of the anterior Hoxb cluster and many hematopoietic stem cell (HSC) -related genes, with hypo-methylation of the promoter-associated CpG island; and (2) DNA methylation-independent effect with enhanced recruitment of polycomb repressive complex 1 (PRC1) that subsequently suppressed the expression of an array of differentiation-associated genes. Through these mechanisms, DNMT3A mutations were shown to inhibit the differentiation of HSCs and leukemic cells. These results identified PRC1 as a promising candidate for the development of therapeutic strategies in mutant DNMT3A-associated AML. Here, we review recent studies on AML with a focus on the clinical features and functional roles of DNMT3A mutations, and discuss future challenges to effectively cure DNMT3A mutation-associated hematopoietic disorders.
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