Publications by authors named "Tatsutoshi NAKAHATA"

Human hematopoietic stem cell (HSC)-transferred humanized mice are valuable models for exploring human hematology and immunology. However, sufficient recapitulation of human hematopoiesis in mice requires large quantities of enriched human CD34 HSCs and total-body irradiation for adequate engraftment. Recently, we generated a NOG mouse strain with a point mutation in the c-kit tyrosine kinase domain (W41 mutant; NOGW mice).

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Article Synopsis
  • Acute myeloid leukemia (AML) involves the halted development of blood cell precursors, with limited differentiation therapies available outside acute promyelocytic leukemia.
  • A study evaluated seven benzimidazole anthelmintics, finding that most increased expression of monocyte markers in AML cells, with parbendazole (PBZ) being particularly effective at inducing differentiation, gene expression changes, and cell death.
  • In tests with a mouse model of AML, PBZ treatment significantly reduced disease progression and improved survival, suggesting potential for better differentiation therapies in AML patients.
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Due to their physiological relevance, cell-based assays using human-induced pluripotent stem cell (iPSC)-derived cells are a promising in vitro pharmacological evaluation system for drug candidates. However, cell-based assays involve complex processes such as long-term culture, real-time and continuous observation of living cells, and detection of many cellular events. Automating multi-sample processing through these assays will enhance reproducibility by limiting human error and reduce researchers' valuable time spent conducting these experiments.

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  • Osteosarcoma, the most prevalent malignant bone tumor, often has poor prognoses linked to alterations in TP53 and cell cycle pathways, with MYC serving as a key prognostic marker.
  • Researchers created an in vitro model of osteosarcoma using hiPSC-derived neural crest cells, incorporating a MYCN overexpression in a TP53 mutation background to study its effects.
  • The study found that inhibiting MYCN reduced tumor cell growth, highlighting MYCN as a potential treatment target and revealing unique molecular characteristics of osteosarcoma through comprehensive gene expression and sequencing analyses.
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Spinal muscular atrophy (SMA) is a congenital neuromuscular disease caused by the mutation or deletion of the gene. Although the primary cause of progressive muscle atrophy in SMA has classically been considered the degeneration of motor neurons, recent studies have indicated a skeletal muscle-specific pathological phenotype such as impaired mitochondrial function and enhanced cell death. Here, we found that the down-regulation of SMN causes mitochondrial dysfunction and subsequent cell death in in vitro models of skeletal myogenesis with both a murine C2C12 cell line and human induced pluripotent stem cells.

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Malignant rhabdoid tumor (MRT) is a highly aggressive pediatric malignancy with no effective therapy. Therefore, it is necessary to identify a target for the development of novel molecule-targeting therapeutic agents. In this study, we report the importance of the runt-related transcription factor 1 () and RUNX1-Baculoviral IAP (inhibitor of apoptosis) Repeat-Containing 5 (BIRC5/survivin) axis in the proliferation of MRT cells, as it can be used as an ideal target for anti-tumor strategies.

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Background: Chediak-Higashi syndrome (CHS) is a congenital disease characterized by immunodeficiency, hemophagocytic lymphohistiocytosis, oculocutaneous albinism, and neurological symptoms. The presence of giant granules in peripheral blood leukocytes is an important hallmark of CHS. Here we prepared induced pluripotent stem cells (iPSCs) from CHS patients (CHS-iPSCs) and differentiated them into hematopoietic cells to model the disease phenotypes.

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Glioblastoma is the most common adult brain tumour, representing a high degree of malignancy. Transcription factors such as RUNX1 are believed to be involved in the malignancy of glioblastoma. RUNX1 functions as an oncogene or tumour suppressor gene with diverse target genes.

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JAK2 rearrangements can occur in Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL). Here, we performed functional analysis of the SPAG9::JAK2 fusion, which was identified in a pediatric patient with Ph-like ALL, to establish molecular targeted therapy. Ba/F3 cells expressing SPAG9::JAK2 generated by retroviral transduction (Ba/F3-SPAG9-JAK2), proliferated in the absence of IL-3, and exhibited constitutive phosphorylation of the tyrosine residues in the JAK2 kinase domain of the fusion protein and STAT3/STAT5.

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A lack of practical resources in Japan has limited preclinical discovery and testing of therapies for pediatric relapsed and refractory acute lymphoblastic leukemia (ALL), which has poor outcomes. Here, we established 57 patient-derived xenografts (PDXs) in NOD.Cg-Prkdc ll2rg /ShiJic (NOG) mice and created a biobank by preserving PDX cells including three extramedullary relapsed ALL PDXs.

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Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. As overall cure rates of childhood ALL have improved, reduction of overall treatment intensity while still ensuring excellent outcomes is imperative for low-risk patients. We report the outcomes of patients treated following the standard-risk protocol from the prospective Japan Association of Childhood Leukemia Study (JACLS) ALL-02 study, which was conducted between 2002 and 2008 for patients with newly diagnosed ALL aged 1-18 years.

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The aryl hydrocarbon receptor (AHR) plays an important role during mammalian embryo development. Inhibition of AHR signaling promotes the development of hematopoietic stem/progenitor cells. AHR also regulates the functional maturation of blood cells, such as T cells and megakaryocytes.

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Article Synopsis
  • Acute lymphoblastic leukemia with chromosomal rearrangements involving the MLL gene is currently incurable, highlighting the need for effective treatments.* -
  • Researchers have developed a multi-bromodomain inhibitor called CN470, which shows promise in inhibiting tumor growth by targeting BRD4, CBP, and p300 proteins.* -
  • In tests, CN470 demonstrated significant anti-tumor effects both in laboratory settings and in live models, leading to prolonged survival in mice with MLL-r ALL.*
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The emergence of tyrosine kinase inhibitors as part of a front-line treatment has greatly improved the clinical outcome of the patients with Ph acute lymphoblastic leukemia (ALL). However, a portion of them still become refractory to the therapy mainly through acquiring mutations in the BCR-ABL1 gene, necessitating a novel strategy to treat tyrosine kinase inhibitor (TKI)-resistant Ph ALL cases. In this report, we show evidence that RUNX1 transcription factor stringently controls the expression of BCR-ABL1, which can strategically be targeted by our novel RUNX inhibitor, Chb-M'.

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Neuroblastoma, the most common extracranial solid tumor of childhood, is thought to arise from neural crest-derived immature cells. The prognosis of patients with high-risk or recurrent/refractory neuroblastoma remains quite poor despite intensive multimodality therapy; therefore, novel therapeutic interventions are required. We examined the expression of a cell adhesion molecule CD146 (melanoma cell adhesion molecule [MCAM]) by neuroblastoma cell lines and in clinical samples and investigated the anti-tumor effects of CD146-targeting treatment for neuroblastoma cells both in vitro and in vivo.

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Down syndrome (DS) is caused by the trisomy of chromosome 21. Among the many disabilities found in individuals with DS is an increased risk of early-onset Alzheimer's disease (AD). Although higher oxidative stress and an upregulation of amyloid β (Aβ) peptides from an extra copy of the APP gene are attributed to the AD susceptibility, the relationship between the two factors is unclear.

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One of the most frequent cytogenetic abnormalities in acute myeloid leukemia (AML) is t(8;21). Although patients with t(8;21) AML have a more favorable prognosis than other cytogenetic subgroups, relapse is still common and novel therapeutic approaches are needed. A recent study showed that t(8;21) AML is characterized by deregulation and that co-inhibition of CDK4/6 and autophagy induces apoptosis in t(8;21) AML cells.

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Patients with refractory graft-versus-host disease (GVHD) have a dismal prognosis. Therefore, novel therapeutic targets are still needed to be identified. Runt-related transcriptional factor (RUNX) family transcription factors are essential transcription factors that mediate the essential roles in effector T cells.

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Children with Down syndrome (DS) are susceptible to two blood disorders, transient abnormal myelopoiesis (TAM) and Down syndrome-associated acute megakaryocytic leukemia (DS-AMKL). Mutations in GATA binding protein 1 (GATA1) have been identified as the cause of these diseases, and the expression levels of the resulting protein, short-form GATA1 (GATA1s), are known to correlate with the severity of TAM. On the other hand, despite the presence of GATA1 mutations in almost all cases of DS-AMKL, the incidence of DS-AMKL in TAM patients is inversely correlated with the expression of GATA1s.

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Induced pluripotent stem cells (iPSCs) are attractive for use in early drug discovery because they can differentiate into any cell type. Maintenance cultures and differentiation processes for iPSCs, however, require a high level of technical expertise. To overcome this problem, technological developments such as enhanced automation are necessary to replace manual operation.

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We have recently discovered Japanese children with a novel Fanconi anemia-like inherited bone marrow failure syndrome (IBMFS). This disorder is likely caused by the loss of a catabolic system directed toward endogenous formaldehyde due to biallelic variants in ADH5 combined with a heterozygous ALDH2*2 dominant-negative allele (rs671), which is associated with alcohol-induced Asian flushing. Phytohemagglutinin-stimulated lymphocytes from these patients displayed highly increased numbers of spontaneous sister chromatid exchanges (SCEs), reflecting homologous recombination repair of formaldehyde damage.

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Article Synopsis
  • - Nakajo-Nishimura syndrome (NNS) is an autoinflammatory disorder linked to mutations in the PSMB8 gene, which is partially managed with corticosteroids but can cause severe side effects.
  • - Researchers developed a pluripotent stem cell (PSC)-derived model of NNS to replicate inflammatory symptoms, leading to a high-throughput screening for potential treatments.
  • - The study identified CUDC-907 as a promising drug that effectively reduces the inflammatory proteins MCP-1 and IP-10 without harming cells, suggesting that using PSC-derived models can help discover new therapies for autoinflammatory diseases.
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