Lentzwood9276

To achieve a cure of multiple myeloma (MM), we have been developing novel therapies targeting epigenetic aberrations. EZH2 and its homolog EZH1 are the histone lysine methyltransferases inducing the repressive mark of H3K27me3. UNC1999 is a dual inhibitor of EZH2 and EZH1, showing significant anti-MM activities. It also synergizes with proteasome inhibitors, associated with derepression of NR4A1 and downregulation of MYC. Moreover, UNC1999 and a selective Akt inhibitor TAS-117 synergistically inhibit the growth of MM cells through epigenetic mechanisms. TAS-117 induces downregulation of EZH2 and compensatory upregulation of EZH1, which is inhibited by UNC1999. Interestingly, a microtubule polymerization inhibitor PTC596 cooperatively downregulates BMI1 protein with proteasome inhibitors, exhibiting in-vitro and in-vivo cytotoxicity in MM cells. Finally, our mouse model with concurrent loss of the histone demethylase Utx and the activating mutation of Braf V600E in post germinal center B cells demonstrates mature B-cell malignancies including plasma cell neoplasms. Our ongoing analyses will reveal the pathogenesis of MM induced by somatic mutations, and this model is a useful tool for the development of novel molecular-targeted therapies for MM patients.The bone marrow microenvironment is low in oxygen, promoting a hypoxic response which causes myeloma cells to acquire stem cell properties and enhanced therapy resistance. We performed comprehensive gene and microRNA expression analyses of samples from myeloma patients and cell lines cultured under hypoxia. Through this, we identified the histone demethylase KDM3A, the glycolytic enzyme HK2, and microRNA-210 as factors playing important roles in the behavior of cells under hypoxic conditions. These genes were regulated by the hypoxia-inducible factor HIF. However, we also found that the expression of IRF4 and MYC, factors required for maintenance of differentiation and proliferation was suppressed by hypoxia. This suggests that the regulatory factors that induce drug resistance and the anti-apoptotic capacity of myeloma cells fluctuate with the partial pressure of oxygen in their environment. Based on this premise, a dual treatment strategy in which a dominant clone and a dormant clone adapted to the hypoxic microenvironment are treated simultaneously with orthogonal drugs is a potentially viable strategy to achieve a cure for multiple myeloma.Regulatory T cells (Tregs) are a subset of CD4+ T lymphocytes that suppress the functions of antigen-presenting cells and effector T cells, characterized by the expression of transcription factor forkhead box P3 (FOXP3). Recent studies have reported an increase in the number of Tregs in the bone marrow (BM) of multiple myeloma (MM) patients. However, the role and mechanisms of Treg accumulation in the BM of MM patients remain debatable. Here, we present our data demonstrating the significance of Tregs in the context of MM disease progression. Using the transplantable MM mouse model, we observed a significant increase in Tregs in the BM of MM-injected mice from the early disease stage. We observed extended survival in MM-injected mice with Treg depletion than in mice without Treg depletion, demonstrating direct in vivo evidence that Tregs enhance disease progression in MM. It is noteworthy that type 1 interferon (IFN) signaling is activated in MM-associated Tregs. By using type 1 IFN receptor blocking antibody treatment and type 1 IFN receptor knockout Tregs, we demonstrated a significant decrease in MM-associated Treg proliferation, which was associated with longer survival in MM-injected mice. Thus, we have demonstrated that Tregs play a significant role in MM progression; the function and homeostasis of Tregs are regulated by type 1 IFN secreted in the BM microenvironment.Myelodysplastic syndrome (MDS) is characterized by its frequent appearance in elderly patients, and allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for MDS. However, the availability of HSCT depends on various factors, and it is possible that the HSCT outcomes may differ when compared on a country-by-country basis. Comparison of nationwide registry data from the US and Japan revealed that the two countries share a common trend of increasing the number of HSCT procedures from HLA-haploidentical relatives. However, the number of cord blood transplantation (CBT) procedures in the US is decreasing, whereas the number of those in Japan appears to be increasing. The results from the studies conducted by the adult MDS Working Group of the Japan Society for Hematopoietic Cell Transplantation revealed that the HSCT outcomes for elderly patients and for patients with intermediate cytogenetic risk and CBT in Japan were slightly superior to those in the United States and Europe. Because such differences in outcomes may be attributed to differences in patient backgrounds, it is preferable to establish "evidence" in one's own country. Although it is difficult to conduct a prospective study on rare diseases such as MDS, the use of a large-scale registry can provide an answer, even for such detailed clinical questions.Recent advances in sequencing technologies have increased the detection rate for identifying germline mutations that predispose an individual to various myeloid neoplasms and somatic mutations acquired during progression from myelodysplastic syndromes (MDS) to acute myeloid leukemia (AML). In addition to pediatric subjects, adult patients were analyzed in order to obtain a complete spectrum of driver mutations in germline cells and/or somatic tumor samples. As shown in several recent studies, such driver mutations are acquired in a gene-specific fashion. DDX41 mutations are observed in germline cells long before MDS presentation. SAMD9/SAMD9L germline mutations associated with defective hematopoiesis account for recurrent and familial -7/del (7q) lesions, which result in the removal of the disadvantageous allele. Additionally, MDS cases in younger population display compound heterozygous germline mutations in the Shwachman-Diamond syndrome-associated SBDS gene. In peripheral blood samples from healthy elderly individuals, DNMT3A, TET2, and ASXL1 somatic mutations are usually detected due to age-related clonal hematopoiesis and are considered to be a risk factor for hematological neoplasms. In MDS, mutations of genes, such as NRAS and FLT3, designated as type-1 genes, are significantly associated with leukemic evolution. On the other hand, mutations in type-2 genes, including RUNX1 and GATA2, are related to progression from low risk MDS to high risk MDS.Leukocytes that lack HLA allelic expression (HLA-LLs) caused by a copy-number-neutral loss of heterozygosity in the short arm of chromosome 6 (6pLOH) and somatic mutations in HLA class I genes are commonly identified in patients with acquired aplastic anemia (AA), although the exact mechanisms underlying the HLA loss and HLA class I allele repertoire likely to acquire loss-of-function mutations remain unknown due to the limited number of AA patients that have been studied for loss-of-function mutations in HLA class I genes. We identified a common nonsense mutation at codon19 (c.19C>T, p.R7X) in exon1 (Exon1mut) of different HLA-A and HLA -B alleles in HLA-LLs from AA patients. Screening of 353 Japanese patients with AA using a novel droplet digital PCR assay revealed Exon1mut in 101 (29%) of the patients. Exon1mut occurred in only 12 different HLA-A (n=4) and HLA-B (n=8) alleles that corresponded to 4 HLA supertypes (A02, A03, B07, and B44), suggesting that limited autoantigens presented by these HLA class I alleles to T cells are involved in AA development. These findings provide insight into the immune pathophysiology of BM failure and contribute to identify candidate autoantigens in AA.We report the case of a patient with lead poisoning caused by a dietary supplement. A 40-year-old man was referred to us due to intermittent upper abdominal pain and normocytic anemia. His hemoglobin level was 9.3 g/dl, with basophilic stippling in 2.8% of red blood cells. PF-4708671 datasheet Bone marrow aspirate smear showed ringed sideroblasts that represented 19% of the erythroblasts. The patient reported the use of an unauthorized, Indian-manufactured dietary supplement and was diagnosed with lead poisoning based on a significantly high blood lead level. The dietary supplement was discontinued, and he was successfully treated with lead chelation therapy, and his hemoglobin level normalized within 2 months.A 71-year-old woman presented to a clinic with the chief complaint of facial edema and dyspnea; chest radiography showed mediastinal mass shadow and right pleural effusion. Computed tomography guided biopsy of the mediastinal mass had been performed by her previous doctor, and she was diagnosed with diffuse large B-cell lymphoma. She was referred to our hospital for chemotherapy. Electrocardiography performed before initiating chemotherapy showed sinus arrest for about 4 s, and Holter electrocardiography showed sinus arrest for up to about 7.4 s, which was repeatedly observed 6 times, indicating sick sinus syndrome (SSS). The mediastinal mass completely excluded the superior vena cava, and considering the risk of infection, an extracorporeal pacemaker was not inserted. We believed that the tumor effect was the cause of sinus arrest; hence, chemotherapy initiation was prioritized. R-CHOP therapy preceding vincristine and prednisolone was started, and sinus arrest was not observed after initial treatment. SSS may have been caused by carotid hypersensitivity syndrome that involved the exclusion of carotid artery pressure receptors by the tumor or the direct stimulation of the vagus nerve by microtumor infiltration.Herein, we describe a 13-year-old male adolescent who had chronic thrombocytopenia since infancy. In this case, X-linked thrombocytopenia (XLT) was suspected owing to a family history of chronic thrombocytopenia and small-sized platelets. Moreover, the patient was refractory to immunoglobulin therapy. The Wiskott-Aldrich syndrome protein (WASP) expression analysis revealed a decreased expression. Results showed a missense mutation [c.296A>G (p.Gln99Arg)] in exon 3 of the WASP-interacting protein region. Therefore, a diagnosis of XLT was made. To lift exercise restrictions, we initiated treatment with eltrombopag at a dose of 12.5 µg/day. The platelet count of the patient increased to approximately 50×103/µl after the treatment dose was escalated to 25 µg/day, and bleeding symptoms decreased after the patient resumed exercise. Ultrastructural platelet abnormalities and abnormal platelet aggregation were observed on transmission electron microscopy after the administration of eltrombopag. Therefore, eltrombopag treatment can increase platelet count and reduce bleeding symptoms in patients with XLT.A 65-year-old woman received bone marrow transplantation from an HLA-DRB1 one locus mismatched donor for high-risk myelodysplastic syndrome. On day 237 after transplantation, she developed recurrent acute gastrointestinal graft-versus-host disease and adenoviral hemorrhagic cystitis. Hence, the methylprednisolone (mPSL) dose was increased to 2 mg/kg, and mesenchymal stem cells were administered. After the dose was tapered, she developed high fever, gross hematuria, and progressive pancytopenia. Then, the serum LDH, ferritin, and hepatobiliary enzyme levels of the patient increased, and hemophagocytosis was observed based on bone marrow examination. The adenovirus DNA level in the plasma was 6.3×106 copies/ml on day 278, and the volume of cerebrospinal fluid increased. Hence, the patient was diagnosed with meningitis and disseminated adenovirus infection. On day 288, cidofovir was administered at a dose of 1 mg/kg three times a week for 8 doses. The mPSL dose was again increased to 2 mg/kg for the treatment of hemophagocytic syndrome.