Yusuke Kamihara

Stromal cells expressing hedgehog-interacting protein regulate the proliferation of myeloid neoplasms

Aberrant reactivation of hedgehog (Hh) signaling has been described in a wide variety of human cancers including cancer stem cells. However, involvement of the Hh-signaling system in the bone marrow (BM) microenvironment during the development of myeloid neoplasms is unknown. In this study, we assessed the expression of Hh-related genes in primary human CD34+ cells, CD34+ blastic cells and BM stromal cells. Both Indian Hh (Ihh) and its signal transducer, smoothened (SMO), were expressed in CD34+ acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)-derived cells. However, Ihh expression was relatively low in BM stromal cells. Remarkably, expression of the intrinsic Hh-signaling inhibitor, human Hh-interacting protein (HHIP) in AML/MDS-derived stromal cells was markedly lower than in healthy donor-derived stromal cells. Moreover, HHIP expression levels in BM stromal cells highly correlated with their supporting activity for SMO+ leukemic cells. Knockdown of HHIP gene in stromal cells increased their supporting activity although control cells marginally supported SMO+ leukemic cell proliferation. The demethylating agent, 5-aza-2′-deoxycytidine rescued HHIP expression via demethylation of HHIP gene and reduced the leukemic cell-supporting activity of AML/MDS-derived stromal cells. This indicates that suppression of stromal HHIP could be associated with the proliferation of AML/MDS cells.

Novel missense mutation in the TMPRSS6 gene in a Japanese female with iron-refractory iron deficiency anemia

Iron-refractory iron deficiency anemia (IRIDA) is a rare autosomal-recessive disorder hallmarked by hypochromic microcytic anemia, low transferrin saturation, and unresponsiveness to oral iron with partial recovery after parenteral iron administration. The disease is caused by mutations in TMPRSS6 (transmembrane protease serine 6) that prevent inactivation of membrane-bound hemojuvelin, an activator of hepcidin transcription. To date, 38 cases have been characterized and reported in European countries and the United States. In this paper, we describe the first case of a Japanese female with IRIDA, who carried a novel mutation (K253E) in the CUB (complement factor C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domain of the TMPRSS6 gene.

Synergistic Immunostimulatory Effects and Therapeutic Benefit of Combined Histone Deacetylase and Bromodomain Inhibition in Non–Small Cell Lung Cancer

Effective therapies for non-small cell lung cancer (NSCLC) remain challenging despite an increasingly comprehensive understanding of somatically altered oncogenic pathways. It is now clear that therapeutic agents with potential to impact the tumor immune microenvironment potentiate immune-orchestrated therapeutic benefit. Herein, we evaluated the immunoregulatory properties of histone deacetylase (HDAC) and bromodomain inhibitors, two classes of drugs that modulate the epigenome, with a focus on key cell subsets that are engaged in an immune response. By evaluating human peripheral blood and NSCLC tumors, we show that the selective HDAC6 inhibitor ricolinostat promotes phenotypic changes that support enhanced T-cell activation and improved function of antigen-presenting cells. The bromodomain inhibitor JQ1 attenuated CD4+FOXP3+ T regulatory cell suppressive function and synergized with ricolinostat to facilitate immune-mediated tumor growth arrest, leading to prolonged survival of mice with lung adenocarcinomas. Collectively, our findings highlight the immunomodulatory effects of two epigenetic modifiers that, together, promote T cell-mediated antitumor immunity and demonstrate their therapeutic potential for treatment of NSCLC.Significance: Selective inhibition of HDACs and bromodomain proteins modulates tumor-associated immune cells in a manner that favors improved T-cell function and reduced inhibitory cellular mechanisms. These effects facilitated robust antitumor responses in tumor-bearing mice, demonstrating the therapeutic potential of combining these epigenetic modulators for the treatment of NSCLC. Cancer Discov; 7(8); 852-67. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 783.

Rituximab Administration and Reactivation of HBV

Rituximab is a drug used for the treatment of B-cell non-Hodgkins lymphoma, and its range of use has expanded to the treatment of collagen diseases such as idiopathic thrombocytopenic purpura and rheumatoid arthritis. One serious complication of rituximab use is the reactivation of dormant hepatitis B virus, and prevention of this phenomenon has become an urgent issue. This paper provides a general outline of the problem through an analysis of patient cases that we and other groups have experienced to date.

Efficacy of Enteral Supplementation Enriched with Glutamine, Fiber, and Oligosaccharide on Mucosal Injury following Hematopoietic Stem Cell Transplantation

The combination of glutamine, fiber and oligosaccharides (GFO) is thought to be beneficial for alleviating gastrointestinal mucosal damage caused by chemotherapy. A commercial enteral supplementation product (GFO) enriched with these 3 components is available in Japan. We performed a retrospective study to test whether oral GFO decreased the severity of mucosal injury following hematopoietic stem cell transplantation (HSCT). Of 44 HSCT patients, 22 received GFO and 22 did not. Severity of diarrhea/mucositis, overall survival, weight loss, febrile illness/documented infection, intravenous hyperalimentation days/hospital days, engraftment, acute and chronic GVHD, and cumulative incidence of relapse were studied. Sex, age, performance status, diagnosis, disease status, and treatment variables were similar in both groups. There were fewer days of diarrhea grade 3-4 in patients receiving GFO than in those who did not (0.86 vs. 3.27 days); the same was true for days of mucositis grade 3-4 (3.86 vs. 6.00 days). Survival at day 100 was 100% in the GFO group, but only 77.3% for the patients not receiving GFO (p = 0.0091, log-rank test). Weight loss and the number of days of intravenous hyperalimentation were better in the GFO group (p < 0.001 and p = 0.0014, respectively). Although not significant, less gut bacterial translocation with Enterococcus species developed in the GFO group (p = 0.0728) than in the non-GFO group. Other outcomes were not affected. To the best of our knowledge, this is the first comparative clinical study of GFO supplementation to alleviate mucosal injury after allo-HSCT. We conclude that glutamine, fiber and oligosaccharide supplementation is an effective supportive therapy to decrease the severity of mucosal damage in HSCT.

Extracellular vesicle miR-7977 is involved in hematopoietic dysfunction of mesenchymal stromal cells via poly(rC) binding protein 1 reduction in myeloid neoplasms

The failure of normal hematopoiesis is observed in myeloid neoplasms. However, the precise mechanisms governing the replacement of normal hematopoietic stem cells in their niche by myeloid neoplasm stem cells have not yet been clarified. Primary acute myeloid leukemia and myelodysplastic syndrome cells induced aberrant expression of multiple hematopoietic factors including Jagged-1, stem cell factor and angiopoietin-1 in mesenchymal stem cells even in non-contact conditions, and this abnormality was reverted by extracellular vesicle inhibition. Importantly, the transfer of myeloid neoplasm-derived extracellular vesicles reduced the hematopoietic supportive capacity of mesenchymal stem cells. Analysis of extracellular vesicle microRNA indicated that several species, including miR-7977 from acute myeloid leukemia cells, were higher than those from normal CD34+ cells. Remarkably, the copy number of miR-7977 in bone marrow interstitial fluid was elevated not only in acute myeloid leukemia, but also in myelodysplastic syndrome, as compared with lymphoma without bone marrow localization. The transfection of the miR-7977 mimic reduced the expression of the posttranscriptional regulator, poly(rC) binding protein 1, in mesenchymal stem cells. Moreover, the miR-7977 mimic induced aberrant reduction of hematopoietic growth factors in mesenchymal stem cells, resulting in decreased hematopoietic-supporting capacity of bone marrow CD34+ cells. Furthermore, the reduction of hematopoietic growth factors including Jagged-1, stem cell factor and angiopoietin-1 were reverted by target protection of poly(rC) binding protein 1, suggesting that poly(rC) binding protein 1 could be involved in the stabilization of several growth factors. Thus, miR-7977 in extracellular vesicles may be a critical factor that induces failure of normal hematopoiesis via poly(rC) binding protein 1 suppression.

Intermittent administration of recombinant human soluble thrombomodulin successfully controlled chronic disseminated intravascular coagulation in a patient with dissecting aortic aneurysm on an outpatient basis.

Chronic disseminated intravascular coagulation (DIC) is a rare but life-threatening complication of dissecting aortic aneurysm. Although anticoagulant therapy may often proves effective for controlling DIC itself, patients would have to be hospitalized for a long period due to continuous infusion therapy. Subcutaneous injection of a highly concentrated preparation of heparin calcium may offer one alternative treatment for DIC; however, daily subcutaneous use of heparin for the treatment of DIC has impaired quality of life (QOL). The other alternative therapy is intravenous administration of recombinant human soluble thrombomodulin (rTM), which includes the active extracellular domain of thrombomodulin. Reportedly, rTM effectively resolves DIC by only 6 consecutive days of administration; however, how frequently rTM should be administered after the resolution of chronic DIC to have good control of it has been unclear. We report herein a case of chronic DIC complicated with dissecting aortic aneurysm, whose resolution of chronic DIC achieved by 6 consecutive days of rTM has been maintained by once a week administration of rTM on an outpatient basis.

Narrow-Band Ultraviolet B Phototherapy Ameliorates Acute Graft-Versus-Host Disease of the Intestine by Expansion of Regulatory T Cells.

Narrowband ultraviolet B (NB-UVB) has been widely used in dermatological phototherapy. As for the application of NB-UVB phototherapy to graft-versus-host disease (GVHD), we previously reported that it was highly efficacious for cutaneous lesions of acute GVHD (aGVHD) and that expansion of regulatory T (Treg) cells induced by NB-UVB might be one of the mechanisms. In order to examine whether NB-UVB irradiation through expansion of Treg cells is effective for the treatment of not only cutaneous aGVHD but also aGVHD of inner organs such as the intestine or liver, we conducted experiments in which a murine lethal aGVHD model, characterized by severe involvement of the intestine, was irradiated with NB-UVB. We found that NB-UVB irradiation improved the clinical score and survival rate. The pathological score of aGVHD was improved in all affected organs: intestine, liver, and skin. In the serum of mice irradiated with NB-UVB, the levels of Treg cells-associated cytokines such as transforming growth factor beta (TGFβ) and interleukin-10 (IL-10) were elevated. The numbers of infiltrating Treg cells in inflamed tissue of the intestine and those in spleen were increased in mice treated with NB-UVB. This is the first report demonstrating that NB-UVB phototherapy has the ability to ameliorate intestinal aGVHD through the expansion of Treg cells.

Activated p53 with Histone Deacetylase Inhibitor Enhances L-Fucose-Mediated Drug Delivery through Induction of Fucosyltransferase 8 Expression in Hepatocellular Carcinoma Cells.

Background The prognosis of advanced hepatocellular carcinoma (HCC) is dismal, underscoring the need for novel effective treatments. The α1,6-fucosyltransferase (fucosyltransferase 8, FUT8) has been reported to accelerate malignant potential in HCC. Our study aimed to investigate the regulation of FUT8 expression by p53 and develop a novel therapeutic strategy for targeting HCC cells using L-fucose-mediated drug delivery. Methods Binding sites for p53 were searched for within the FUT8 promoter region. FUT8 expression was assessed by immunoblotting. Chromatin immunoprecipitation (ChIP) assays were performed to analyze p53 binding to the FUT8 promoter. The delivery of Cy5.5-encapsulated L-fucose-liposomes (Fuc-Lip-Cy5.5) to a Lens Culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3)-expressing HCC cells was analyzed by flow cytometry. The induction of FUT8 by histone deacetylase inhibitor (HDACi) -inducing acetylated -p53 was evaluated by immunoblotting. Flow cytometric analysis was performed to assess whether the activation of p53 by HDACi affected the uptake of Fuc-Lip-Cy5.5 by HCC cells. The cytotoxicity of an L-fucose-bound liposome carrying sorafenib (Fuc-Lip-sorafenib) with HDACi was assessed in vivo and in vitro. Results The knock down of p53 with siRNA led to decreased FUT8 expression. ChIP assays revealed p53 binds to the FUT8 promoter region. Flow cytometric analyses demonstrated the specific uptake of Fuc-Lip-Cy5.5 into AFP-L3-expressing HCC cells in a p53- and FUT8-dependent manner. HDACi upregulated the uptake of Fuc-Lip-Cy5.5 by HCC cells by increasing FUT8 via acetylated -p53. The addition of a HDACi increased apoptosis induced by Fuc-Lip-sorafenib in HCC cells. Conclusions Our findings reveal that FUT8 is a p53 target gene and suggest that p53 activated by HDACi induces Fuc-Lip-sorafenib uptake by HCC cells, highlighting this pathway as a promising therapeutic intervention for HCC.

Focal 18F-FDG uptake in bone marrow on PET/CT in a patient with JAK2 mutation without overt myeloproliferative neoplasm.

A 58-year-old female diagnosed with early stage esophageal carcinoma in our hospital underwent endoscopic resection by endoscopic submucosal dissection (ESD) in April 2013. F-FDG PET/CT performed immediately prior to the ESD showed focal F-FDG accumulations in the vertebral body of Th8, and vertebral body and arch of L4 with SUV max of 3.98–4.42 (Fig. 1a–c). No masses or osteoclastic lesions were observed. MRI findings of the lesions showed low intensity on T1WI and high intensity on STIR image (Fig. 2a–d). To clarify the cause of the FFDG accumulation in the bone, we performed bone biopsy from the vertebral arch of L4. Histopathological findings revealed hypercellular marrow (80 % cellularity) and increases in number and size of megakaryocytes, most of which were in maturated form with hyperlobulated nuclei, which are usually found in cases with myeloproliferative neoplasm (MPN) (Fig. 3a, b). Reticulin fibrosis of marrow was observed minimally by Gitter staining (Fig. 3c), and collagen fibrosis was not observed. In contrast, laboratory workup for peripheral blood showed no abnormality: WBC 6,920/lL (stab 0.0 %, seg 61.0 %, lymph 30.0 %, mono 6.0 %, eosino 1.5 %, and baso 1.5 %), RBC 452 9 10/ lL, Hb 14.1 g/dL, Ht 40.6 %, PLT 33.3 9 10/lL, reticulocytes 1.2 %, LDH 229 U/L, VB12 351 mg/dL, and NAP score 223. Bone marrow biopsy subsequently performed from the left iliac bone showed normocellular marrow, but the number of megakaryocytes was also increased (Fig. 3d). Furthermore, JAK2 V617F mutation was detected in the bone marrow sample by real-time qualitative PCR with a sensitivity of more than 2 % of all alleles. G-banding showed normal diploid karyotype, and BCR–ABL translocation was not detected by FISH analysis. 5 months after the first visit, her laboratory data of peripheral blood was within the normal range, and FFDG PET/CT also showed similar F-FDG accumulation in the bone, without new lesions. We will continue to follow her progress carefully. The JAK2 V617F mutation is present in patients with Philadelphia-negative MPN, including over 90 % of polycythemia vera cases and about half of essential thrombocythemia and primary myelofibrosis cases [1]. The JAK2 V617F mutation may also be detected in healthy individuals without overt MPN [2]. Nielsen et al. [2] reported that the JAK2 V617F mutation was detected in 18 of 10,507 participants (0.2 %) in the general population, and three of these 18 individuals with the JAK2 V617F mutation developed overt myeloproliferative disorder during up to 17.6 years of follow-up. In the present case, focal F-FDG accumulation in bone marrow and histopathological findings, other than the finding of the left iliac bone marrow as positive for JAK2 V617F mutation, suggest that the patient is more likely to develop some form of overt MPN in the A. Fujimi (&) Y. Kanisawa Department of Hematology and Oncology, Oji General Hospital, 3-4-8 Wakakusa-cho, Tomakomai 053-8506, Japan e-mail: Akihito.fujimi@ojihosp.or.jp