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DOI： 10.1186/s40170-024-00352-4

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Language：English  

DOI： 10.1124/jpet.123.001856

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Language：English   Publisher：Leukemia  

Aggressive natural killer cell leukemia (ANKL) is a rare hematological malignancy with a fulminant clinical course. Our previous study revealed that ANKL cells proliferate predominantly in the liver sinusoids and strongly depend on transferrin supplementation. In addition, we demonstrated that liver-resident ANKL cells are sensitive to PPMX-T003, an anti-human transferrin receptor 1 inhibitory antibody, whereas spleen-resident ANKL cells are resistant to transferrin receptor 1 inhibition. However, the microenvironmental factors that regulate the iron dependency of ANKL cells remain unclear. In this study, we first revealed that the anti-neoplastic effect of PPMX-T003 was characterized by DNA double-strand breaks in a DNA replication-dependent manner, similar to conventional cytotoxic agents. We also found that the influx of extracellular amino acids via LAT1 stimulated sensitivity to PPMX-T003. Taken together, we discovered that the amount of extracellular amino acid influx through LAT1 was the key environmental factor determining the iron dependency of ANKL cells via adjustment of their mTOR/Myc activity, which provides a good explanation for the different sensitivity to PPMX-T003 between liver- and spleen-resident ANKL cells, as the liver sinusoid contains abundant amino acids absorbed from the gut. (Figure presented.).

DOI： 10.1038/s41375-024-02296-6

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Language：English   Publisher：(一社)日本血液学会  

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DOI： 10.1007/s12185-024-03738-8

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Language：English  

DOI： 10.31547/bct-2023-032

PubMed

Language：English  

DOI： 10.31547/bct-2023-033

PubMed

Publisher：International Journal of Hematology  

Objectives: NS-87/CPX-351 is a dual-drug liposomal encapsulation of cytarabine and daunorubicin. NS-87/CPX-351 exerts antileukemic action by maintaining a synergistic molar ratio of cytarabine to daunorubicin of 5:1 within the liposome while in circulation. Patients with high-risk acute myeloid leukemia (AML), which includes therapy-related AML and AML with myelodysplasia-related changes (AML-MRC), have poorer outcomes than those with other AML. Methodology: This open-label phase 1/2 (P1/2) study was conducted in 47 Japanese patients aged 60–75 years with newly diagnosed high-risk AML to evaluate the pharmacokinetics, safety, and efficacy of NS-87/CPX-351. Results: In the 6 patients enrolled in the P1 portion, no dose-limiting toxicities (DLTs) were reported, and 100 units/m2 during the induction cycle was found to be acceptable. Cytarabine and daunorubicin had a long half-life in the terminal phase (32.8 and 28.7 h, respectively). In the 35 patients enrolled in the P2 portion, composite complete remission (CRc; defined as complete remission [CR] or CR with incomplete hematologic recovery [CRi]) was achieved in 60.0% (90% CI: 44.7–74.0) of the patients. Adverse events due to NS-87/CPX-351 were well tolerated. Outcomes: NS-87/CPX-351 can be considered as a frontline treatment option for Japanese patients with high-risk AML.

DOI： 10.1007/s12185-024-03733-z

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DOI： 10.1038/s41598-024-57361-y

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Language：English   Publisher：Annals of Hematology  

There are few prospective studies on patients with post-essential thrombocythemia myelofibrosis (PET-MF) and post-polycythemia vera myelofibrosis (PPV-MF). Therefore, we conducted a nationwide longitudinal prospective survey to clarify the clinical characteristics of these diseases. A total of 197 PET-MF and 117 PPV-MF patients diagnosed between 2012 and 2021 were analyzed. The median age at diagnosis was 70.0 years for both diseases. The time from diagnosis of ET or PV to that of MF was 9.6 and 10.4 years, respectively, with no significant difference. Patients with PPV-MF had higher hemoglobin levels and white blood cell counts than those with PET-MF, whereas those with PET-MF had higher platelet counts than those with PPV-MF. Although splenomegaly was more frequent in patients with PPV-MF at diagnosis, there was no difference in the frequency of constitutional symptoms. Ruxolitinib was the most common treatment administered to 74.6% and 83.8% of patients with PET-MF and PPV-MF, respectively. Patients with PET-MF and PPV-MF had similar prognoses, with 3-year overall survival (OS) of 0.742 in PET-MF and 0.768 in PPV-MF patients. In both diseases, leukemic transformation was the leading cause of death, followed by infection. The 3-year OS for patients with PET/PPV-MF and primary MF diagnosed during the same period was 0.754 and 0.626, respectively, with no significant difference. This survey provides real-world clinical features and prognostic data on secondary myelofibrosis in the ruxolitinib era.

DOI： 10.1007/s00277-023-05528-4

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DOI： 10.1109/icSmartGrid61824.2024.10576742

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Language：English   Publisher：The Japanese Society of Internal Medicine  

<p>Nodal T-follicular helper cell lymphoma (nTFHL), a hematologic neoplasm originating from T-follicular helper (TFH) cells, occasionally presents with pulmonary radiographic abnormalities, without neoplastic cellular infiltration. However, the precise mechanisms underlying non-neoplastic pulmonary opacities in patients with nTFHL remain unclear. Previous reports have shown that TFH cell abnormalities are associated with collagen disease and interstitial pneumonia with autoimmune features (IPAF). We herein report a patient with nTFHL accompanied by interstitial pneumonia diagnosed via lung and lymph node biopsies. These findings suggest the need to rule out nTFHL before diagnosing IPAF. </p>

DOI： 10.2169/internalmedicine.3601-24

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CiNii Research

Language：English  

DOI： 10.1507/endocrj.EJ23-0593

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PubMed

DOI： 10.1182/blood-2023-182620

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DOI： 10.1182/blood-2023-188986

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DOI： 10.3897/zookeys.1180.108418

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Language：English  

DOI： 10.1186/s40337-023-00864-2

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Language：English   Publisher：Blood Cancer Journal  

DOI： 10.1038/s41408-023-00869-9

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Language：English   Publisher：Cancer Science  

The cancer stem cell (CSC) theory features typically rare self-renewing subpopulations that reconstitute the heterogeneous tumor. Identification of molecules that characterize the features of CSCs is a key imperative for further understanding tumor heterogeneity and for the development of novel therapeutic strategies. However, the use of conventional markers of CSCs is still insufficient for the isolation of bona fide CSCs. We investigated organoids that are miniature forms of tumor tissues by reconstructing cellular diversity to identify specific markers to characterize CSCs in heterogeneous tumors. Here, we report that the receptor for hyaluronan-mediated motility (RHAMM) expresses in a subpopulation of CD44+ conventional human colorectal CSC fraction. Single-cell transcriptomics of organoids highlighted RHAMM-positive proliferative cells that revealed distinct characteristics among the various cell types. Prospectively isolated RHAMM+CD44+ cells from the human colorectal cancer tissues showed highly proliferative characteristics with a self-renewal ability in comparison with the other cancer cells. Furthermore, inhibition of RHAMM strongly suppressed organoid formation in vitro and inhibited tumor growth in vivo. Our findings suggest that RHAMM is a potential therapeutic target because it is a specific marker of the proliferative subpopulation within the conventional CSC fraction.

DOI： 10.1111/cas.15795

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Language：English   Publisher：John Wiley & Sons Australia, Ltd  

大腸癌幹細胞の中で増殖状態にあるものの特徴を決定するため、オルガノイドと大腸癌組織を材料に、それらのトランスクリプトミクスを解析した。その結果、CD44陽性を示す通常のヒト大腸癌幹細胞の分画の中に、ヒアルロン酸媒介運動性受容体(RHAMM)を発現している亜集団があることを発見した。細胞種の多様性を再構成することで腫瘍組織のミニチュア版としたオルガノイドを材料に、単一細胞トランスクリプトミクス解析を施行したところ、増殖性を示し、様々な細胞種の中にあって独特の特徴を示すRHAMM陽性細胞があることに注目された。ヒト大腸癌組織からRHAMM陽性CD44陽性の細胞を予期的に分離した結果、分離された同細胞は他の癌細胞と比較して高い増殖特性と自己新生能を現した。RHAMMを阻害するとin vitroでのオルガノイド形成は強く抑制され、in vivoでは腫瘍成長が阻害された。RHAMMは、通常の癌幹細胞分画内に含まれる増殖性の亜集団への特異的マーカーになりうると考えられた。

Language：English   Publisher：International Journal of Clinical Oncology  

Background: Tisagenlecleucel, an autologous CD19-directed T-cell immunotherapy, can induce a durable response in adult patients with relapsed/refractory (r/r) B-cell lymphoma. Methods: To elucidate the outcome of chimeric antigen receptor (CAR) T-cell therapy in Japanese, we retrospectively analyzed the outcomes of 89 patients who received tisagenlecleucel for r/r diffuse large B-cell lymphoma (n = 71) or transformed follicular lymphoma (n = 18). Results: With a median follow-up of 6.6-months, 65 (73.0%) patients achieved a clinical response. The overall survival (OS) and event-free survival (EFS) rates at 12 months were 67.0% and 46.3%, respectively. Overall, 80 patients (89.9%) had cytokine release syndrome (CRS), and 6 patients (6.7%) had a grade ≥ 3 event. ICANS occurred in 5 patients (5.6%); only 1 patient had grade 4 ICANS. Representative infectious events of any grade were cytomegalovirus viremia, bacteremia and sepsis. The most common other adverse events were ALT elevation, AST elevation, diarrhea, edema, and creatinine elevation. No treatment-related mortality was observed. A Sub-analysis showed that a high metabolic tumor volume (MTV; ≥ 80 ml) and stable disease /progressive disease before tisagenlecleucel infusion were both significantly associated with a poor EFS and OS in a multivariate analysis (P < 0.05). Notably, the combination of these 2 factors efficiently stratified the prognosis of these patients (HR 6.87 [95% CI 2.4–19.65; P < 0.05] into a high-risk group). Conclusion: We report the first real-world data on tisagenlecleucel for r/r B-cell lymphoma in Japan. Tisagenlecleucel is feasible and effective, even in late line treatment. In addition, our results support a new algorithm for predicting the outcomes of tisagenlecleucel.

DOI： 10.1007/s10147-023-02334-w

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Language：English   Publisher：シュプリンガー・ジャパン(株)  

CD19特異的キメラ抗原受容体T細胞療法であるチサゲンレクロイセルを受けた再発・難治性B細胞リンパ腫患者の転帰を後ろ向きに検討した。2019年10月から2021年10月までに5施設でチサゲンレクロイセルを処方された89例(年齢20～72歳)を対象とした(び漫性大細胞型B細胞リンパ腫患者71例、形質転換濾胞性リンパ腫患者18例)。その結果、追跡期間中央値6.6ヵ月で、65例が臨床的奏効を得た。12ヵ月時点の全生存率(OS)は67.0%、無イベント生存率(EFS)は46.3%であった。患者80例にサイトカイン放出症候群が認められ、6例はグレード3以上であった。免疫エフェクター細胞関連神経毒性症候群は5例に発生した。代表的な感染症イベントは、サイトメガロウイルスウイルス血症、菌血症、敗血症であった。その他の有害事象では、ALT上昇、AST上昇、下痢、浮腫、クレアチニン上昇が多かった。多変量解析により、高い代謝腫瘍体積(≧80mL)、およびチサゲンレキュセル注入前のSD(安定)/PD(進行)はEFSおよびOSの不良と有意に関連していた。さらに、それら二つの因子の組み合わせは患者の予後を効率的に層別化した(ハザード比6.87、95%CI 2.4～19.65、P<0.05)。以上より、チサゲンレクロイセルは後期治療においても実行可能であり、有効であった。

Language：English   Publisher：Leukemia  

To identify molecules/pathways governing Venetoclax (VEN) sensitivity, we performed genome-wide CRISPR/Cas9 screens using a mouse AML line insensitive to VEN-induced mitochondrial apoptosis. Levels of sgRNAs targeting March5, Ube2j2 or Ube2k significantly decreased upon VEN treatment, suggesting synthetic lethal interaction. Depletion of either Ube2j2 or Ube2k sensitized AML cells to VEN only in the presence of March5, suggesting coordinate function of the E2s Ube2j2 and Ube2k with the E3 ligase March5. We next performed CRISPR screens using March5 knockout cells and identified Noxa as a key March5 substrate. Mechanistically, Bax released from Bcl2 upon VEN treatment was entrapped by Mcl1 and Bcl-XL and failed to induce apoptosis in March5 intact AML cells. By contrast, in March5 knockout cells, liberated Bax did not bind to Mcl1, as Noxa likely occupied Mcl1 BH3-binding grooves and efficiently induced mitochondrial apoptosis. We reveal molecular mechanisms underlying AML cell-intrinsic VEN resistance and suggest a novel means to sensitize AML cells to VEN.

DOI： 10.1038/s41375-023-01879-z

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DOI： 10.1182/blood-2022-164647

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DOI： 10.1182/blood-2022-168650

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DOI： 10.1088/1361-6463/ac893d

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Language：English   Publisher：Gastric Cancer  

Background: Loss of E-cadherin expression is frequently observed in signet ring carcinoma (SRCC). People with germline mutations in CDH1, which encodes E-cadherin, develop diffuse gastric cancer at a higher rate. Loss of E-cadherin expression is thus assumed to trigger oncogenic development. Methods: To investigate novel therapeutic targets for gastric SRCC, we engineered an E-cadherin-deficient SRCC model in vitro using a human gastric organoid (hGO) with CDH1 knockout (KO). Results: CDH1 KO hGO cells demonstrated distinctive morphological changes similar to SRCC and high cell motility. RNA-sequencing revealed up-regulation of matrix metalloproteinase (MMP) genes in CDH1 KO hGO cells compared to wild type. MMP inhibitors suppressed cell motility of CDH1 KO hGO cells and SRCC cell lines in vitro. Immunofluorescent analysis with 95 clinical gastric cancer tissues revealed that MMP-3 was specifically abundant in E-cadherin-aberrant SRCC. In addition, CXCR4 molecules translocated onto the cell membrane after CDH1 KO. Addition of CXCL12, a ligand of CXCR4, to the culture medium prolonged cell survival of CDH1 KO hGO cells and was abolished by the inhibitor, AMD3100. In clinical SRCC samples, CXCL12-secreting fibroblasts showed marked infiltration into the cancer area. Conclusions: E-cadherin deficient SRCCs might gain cell motility through upregulation of MMPs. CXCL12-positive cancer-associated fibroblasts could serve to maintain cancer-cell survival as a niche. MMPs and the CXCL12/CXCR4 axis represent promising candidates as novel therapeutic targets for E-cadherin-deficient SRCC.

DOI： 10.1007/s10120-022-01307-8

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Language：English   Publisher：シュプリンガー・ジャパン(株)  

E-カドヘリン欠損胃印環細胞癌(SRCC)における新規治療標的を同定することを目的とした。E-カドヘリンをコードするCDH1遺伝子をノックアウト(KO)したヒト胃オルガノイド(hGO)を用いて、in vitroのE-カドヘリン欠損胃癌モデルを作製し、新規治療標的を探索した。CDH1 KO hGO細胞は、SRCCに類似した特徴的な形態変化と高い細胞運動性を示した。RNA配列解析の結果、CDH1 KO hGO細胞では、野生型と比較して、マトリックスメタロプロテアーゼ(MMP)遺伝子の発現が増加していた。MMP阻害剤は、in vitroでCDH1 KO hGO細胞およびSRCC細胞株の細胞運動を抑制した。95例の臨床胃癌組織を用いた免疫蛍光分析により、MMP-3はE-カドヘリン異常のSRCCに特異的に多く存在することが示された。また、CDH1 KO後、CXCR4分子が細胞膜上に移行した。CXCR4のリガンドであるCXCL12を培養液に添加すると、CDH1 KO hGO細胞の細胞生存率が延長し、CXCR4アンタゴニストであるAMD3100によってその効果が消失した。SRCCの臨床サンプルでは、CXCL12を分泌する線維芽細胞が癌領域に著しく浸潤していることを確認した。以上より、MMPとCXCL12/CXCR4軸は、E-カドヘリン欠損SRCCの新規治療標的として有望な候補であると考えられた。

Language：English   Publisher：Therapeutic Drug Monitoring  

Background:Gilteritinib, a novel oral tyrosine kinase inhibitor, is used to treat acute myeloid leukemia (AML) with FMS-like tyrosine kinase-3 (FLT3) mutations. Therapeutic drug monitoring (TDM) of gilteritinib is important for improving clinical outcomes and ensuring safety. Therefore, this study aimed to develop a simplified method for quantifying gilteritinib in human plasma using liquid chromatography-tandem mass spectrometry.Methods:Liquid chromatography was performed by using an Acquity BEH C18 column (50 mm × 2.1 mm, 1.7 m) and a gradient elution with 0.1% formic acid in water (A) and acetonitrile (B). Detection was performed by using a Shimadzu tandem mass spectrometer through multiple reaction monitoring in the positive-ion mode.Results:The developed method enabled quantification of gilteritinib in 4 minutes and was validated by evaluating selectivity, calibration curve (10-1000 ng/mL, r2> 0.99), a lower limit of quantification (LLOQ), accuracy (overall bias -4.2% to 1.9%), precision (intraday CV ≤ 7.9%; interday CV ≤ 13.6%), carryover, recovery, matrix effect, dilution integrity, and stability according to the US Food and Drug Administration (FDA) guidelines. This method was successfully applied to the TDM of gilteritinib trough concentrations in 3 patients with AML.Conclusions:The developed method fulfilled the FDA guideline criteria and can easily be implemented to facilitate TDM in patients receiving gilteritinib in a clinical setting.

DOI： 10.1097/FTD.0000000000000971

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Language：English   Publisher：(一社)日本血液学会  

早期に臨床的に意義のあるサイトメガロウイルス(csCMV)感染がなく、レテルモビル(LMV)予防投与を完了した同種造血細胞移植(allo-HCT)レシピエントにおいて、晩期csCMV感染に関連する危険因子を後方視的に検討した。2018年6月から2021年2月までに当院でallo-HCTを受け、csCMV感染予防のための予防的LMVを受けた患者81例(年齢18～70歳)を対象とした。そのうち23例(28.4%)はCMV再活性化を起こし、抗CMV薬による初回介入までの期間の中央値はallo-HCT後で131日(範囲103～166日)、LMV中止後で30日(範囲5～67日)であった。晩期csCMV初回感染の治療期間中央値は21日(範囲12～43日)であった。晩期csCMVは免疫再構成の遅れと明らかに相関していた。HLA不一致ドナー(HR 13.0、p=0.011)またはCMVに対するIgG陰性ドナー(HR 2.39、p=0.043)からのallo-HCTはリスクが有意に高かった。また、晩期CMV感染の有無による移植成績に差は認められなかった。以上より、より多くのallo-HCTレシピエント、特に「高リスク」ドナーから移植を受けるレシピエントにおいて、LMV長期投与の晩期csCMV感染予防に対する効果を明らかにする必要性が示唆された。

Language：English   Publisher：International Journal of Hematology  

Prophylactic use of letermovir (LMV) markedly reduces the incidence of early clinically significant cytomegalovirus (csCMV) infection within the first 100 days after allogeneic hematopoietic cell transplantation (allo-HCT), which improves transplant outcomes. However, some patients eventually develop late-csCMV infection (beyond day 100) after completing LMV prophylaxis. To assess the incidence of late-csCMV infection as well as its risk factors and impacts on transplant outcome, a total of 81 allo-HCT recipients who had not developed early csCMV infection during LMV prophylaxis were retrospectively analyzed. Among them, 23 (28.4%) patients developed late-csCMV infection (until day 180) at a median time of 131 days after transplantation and 30 days after LMV discontinuation, respectively. Late-csCMV infection was correlated with apparent delayed immune reconstitution: patients transplanted from HLA-mismatched donors (hazard ratio [HR] = 13.0, p = 0.011) or CMV-IgG-negative donors (HR = 2.39, p = 0.043) had a significantly higher risk. In this study, transplant outcomes did not differ between patients with and without late-csCMV infection. This suggests a need to clarify the efficacy of extended administration of LMV for preventing late-csCMV infection in a larger number of allo-HCT recipients, especially those with “high-risk” donors.

DOI： 10.1007/s12185-022-03348-2

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DOI： 10.1038/s41598-022-16451-5

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DOI： 10.35848/1347-4065/ac3ef1

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DOI： 10.1038/s41588-022-01058-3

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Language：English  

DOI： 10.1038/s41598-022-06055-4

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Language：English   Publisher：Blood  

Acute lymphoblastic leukemia (ALL) harboring the IgH-CRLF2 rearrangement (IgH-CRLF2-r) exhibits poor clinical outcomes and is the most common subtype of Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL). While multiple chemotherapeutic regimens, including ruxolitinib monotherapy and/or its combination with chemotherapy, are being tested, their efficacy is reportedly limited. To identify molecules/pathways relevant for IgH-CRLF2-r ALL pathogenesis, we performed genome-wide CRISPR-Cas9 dropout screens in the presence or absence of ruxolitinib using 2 IgH-CRLF2-r ALL lines that differ in RAS mutational status. To do so, we employed a baboon envelope pseudotyped lentiviral vector system, which enabled, for the first time, highly efficient transduction of human B cells. While single-guide RNAs (sgRNAs) targeting CRLF2, IL7RA, or JAK1/2 significantly affected cell fitness in both lines, those targeting STAT5A, STAT5B, or STAT3 did not, suggesting that STAT signaling is largely dispensable for IgH-CRLF2-r ALL cell survival. We show that regulators of RAS signaling are critical for cell fitness and ruxolitinib sensitivity and that CRKL depletion enhances ruxolitinib sensitivity in RAS wild-type (WT) cells. Gilteritinib, a pan-tyrosine kinase inhibitor that blocks CRKL phosphorylation, effectively killed RAS WT IgH-CRLF2-r ALL cells in vitro and in vivo, either alone or combined with ruxolitinib. We further show that combining gilteritinib with trametinib, a MEK1/2 inhibitor, is an effective means to target IgH-CRLF2-r ALL cells regardless of RAS mutational status. Our study delineates molecules/pathways relevant for CRLF2-r ALL pathogenesis and could suggest rationally designed combination therapies appropriate for disease subtypes.

DOI： 10.1182/blood.2021012976

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Language：English   Publisher：International Journal of Hematology  

Introduction: Primary myelofibrosis (PMF) is a clonal stem cell disorder characterized by myeloid dominant hematopoiesis and dysregulated proliferation of fibroblasts in the bone marrow. However, how these aberrant myeloid cells and fibroblasts are produced remains unclear. Aim and methods: In this study, we examined in vivo engraftment kinetics of PMF patient-derived CD34+ cells in immunecompromised NOD/SCID/IL2rgKO (NSG) mice. Engrafted human cells were analyzed with flow cytometry, and proliferation of fibroblastic cells and bone marrow fibrosis were assessed with the histo-pathological examination. Results: Transplantation of PMF patient-derived circulating CD34+ fractions into NSG newborns recapitulates clinical features of human PMF. Engraftment of human CD45+ leukocytes resulted in anemia and myeloid hyperplasia accompanied by bone marrow fibrosis by six months post-transplantation. Fibrotic bone marrow contained CD45-vimentin+ cells of both human and mouse origin, suggesting that circulating malignant CD34+ subsets contribute to myelofibrotic changes in PMF through direct and indirect mechanisms. Conclusion: A patient-derived xenotransplantation (PDX) model of PMF allows in vivo examination of disease onset and propagation originating from immature CD34+ cells and will support the investigation of pathogenesis and development of therapeutic modalities for the disorder.

DOI： 10.1007/s12185-021-03239-y

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Language：English   Publisher：(一社)日本血液学会  

原発性骨髄線維症(PMF)患者の末梢血から調製したCD34+細胞を免疫不全の新生仔マウスに移植する患者由来異種移植モデルを検討した。PMF患者のCD34+細胞画分を、生後48時間以内に亜致死線量の放射線を照射した免疫不全NOD/SCID/IL2rgKO(NSG)新生仔マウスの顔面静脈から注入した。移植後4週間の時点で、マウス末梢血中のヒトCD45+キメリズムは20%以下であり、主にCD33+骨髄系細胞から構成されていた。移植後4～14ヵ月目では、PMF患者由来CD34+細胞画分を移植したマウスは、正常のヒト造血幹細胞を移植したマウスと比較して有意に高い頻度でCD33+骨髄系が優勢な再構成を示した。さらに、PMF患者由来CD34+細胞画分を移植したマウスでは、ヒトPMFの臨床的特徴が再現され、PMFの遺伝子変異の種類に関係なく、CD34+細胞画分が骨髄線維化の開始と進行に関与していた。線維化した骨髄には、ヒトおよびマウス由来のCD45-ビメンチン+細胞が存在しており、PMF患者の悪性CD34+サブセットが直接および間接的なメカニズムでPMFの骨髄線維性変化に寄与していることが示唆された。本研究で開発したヒトPMF患者由来異種移植モデルを用いて、PMFの病態解明やPMF治療薬のin vivoでの検証が可能になると考えられた。

Language：English   Publisher：Leukemia  

Acute myeloid leukemia (AML) is a devastating disease, and clinical outcomes are still far from satisfactory. Here, to identify novel targets for AML therapy, we performed a genome-wide CRISPR/Cas9 screen using AML cell lines, followed by a second screen in vivo. We show that PAICS, an enzyme involved in de novo purine biosynthesis, is a potential target for AML therapy. AML cells expressing shRNA-PAICS exhibited a proliferative disadvantage, indicating a toxic effect of shRNA-PAICS. Treatment of human AML cells with a PAICS inhibitor suppressed their proliferation by inhibiting DNA synthesis and promoting apoptosis and had anti-leukemic effects in AML PDX models. Furthermore, CRISPR/Cas9 screens using AML cells in the presence of the inhibitor revealed genes mediating resistance or synthetic lethal to PAICS inhibition. Our findings identify PAICS as a novel therapeutic target for AML and further define components of de novo purine synthesis pathway and its downstream effectors essential for AML cell survival.

DOI： 10.1038/s41375-021-01369-0

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PubMed

Language：English   Publisher：International Journal of Hematology  

Post-transplant cytomegalovirus (CMV) disease can be almost completely avoided by current infection control procedures. However, CMV reactivation occurs in more than half of patients, and some patients can develop clinically resistant CMV infections. Whether resistance is due to the host’s immune status or a viral resistance mutation is challenging to confirm. Therefore, a prospective observational analysis of refractory CMV infection was conducted in 199 consecutive patients who received allogeneic hematopoietic stem cell transplantation at a single institution. Among them, 143 (72%) patients received anti-CMV drugs due to CMV reactivation, and only 17 (8.5%) exhibited refractory CMV infection. These patients had clinically refractory infection. However, viral genome analysis revealed that only one patient exhibited a mutation associated with the anti-CMV drug resistance. Clinical resistance was mainly correlated with host immune factors, and the incidence of resistance caused by gene mutations was low at the early stage after a transplantation.

DOI： 10.1007/s12185-021-03218-3

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Scopus

PubMed

Language：English   Publisher：(一社)日本血液学会  

同種造血幹細胞移植を受けた患者199例を対象に、サイトメガロウイルス(CMV)pp65抗原陽性細胞数や抗CMV薬への反応性を前向きに検討した。早期死亡(好中球生着前の死亡と定義)は8例に認められた。患者36例は、臨床経過中および移植後1年までCMV抗原血症(pp65抗原陽性細胞を染色して検査)を発症しなかった。患者155例は、移植後の中央値34日(範囲9～97)で少なくとも1回、CMV抗原血症の検査結果が陽性であった。追跡期間中の白血球5万個あたりのCMV pp65抗原陽性細胞の最大数の中央値は5個(範囲1～332)であった。患者143例(72%)はCMV再活性化により抗CMV薬を投与され、17例(8.5%)は臨床的に難治性CMV感染症であった。ウイルスゲノム解析の結果、抗CMV薬耐性に関連する変異を有する患者は1例のみであった。以上より、CMV感染症の臨床抵抗性は主に宿主の免疫因子と相関しており、遺伝子変異による抗CMV薬抵抗性の発生は移植後早期には少ないことが示された。

Language：English  

DOI： 10.1093/jjco/hyab170

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PubMed

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1093/intimm/dxaa022.

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Leukemic relapse is frequently accompanied by progressively aggressive clinical course. To understand the molecular mechanism of leukemic relapse, MLL/AF9-transformed mouse leukemia cells were serially transplanted in C57BL/6 mice (N = 96) by mimicking repeated recurrences, where mutations were monitored by exome sequencing (N = 42). The onset of leukemia was progressively promoted with advanced transplants, during which increasing numbers of somatic mutations were acquired (P < 0.005). Among these, mutations in Ptpn11 (p.G60R) and Braf (p.V637E) corresponded to those identified in human MLL-AML, while recurrent mutations affecting Msn (p.R295C) were observed only in mouse but not in human MLL-AML. Another mutated gene of interest was Gnb2 which was reported to be recurrently mutated in various hematological neoplasms. Gnb2 mutations (p.G77R) were significantly increased in clone size (P = 0.007) and associated with earlier leukemia onset (P = 0.011). GNB2 transcripts were significantly upregulated in human MLL-AML compared to MLL-negative AML (P < 0.05), which was supported by significantly increased Gnb2 transcript induced by MLL/AF9 overexpression (P < 0.001). In in vivo model, both mutation and overexpression of GNB2 caused leukemogenesis, and downregulation of GNB2 expression reduced proliferative potential and survival benefit, suggesting a driver role of GNB2. In conclusion, alterations of driver genes over time may play an important role in the progression of MLL-AML.

DOI： 10.1038/s41375-018-0253-3

Language：English   Publishing type：Research paper (scientific journal)  

To identify novel targets for acute myeloid leukemia (AML) therapy, we performed genome-wide CRISPR-Cas9 screening using AML cell lines, followed by a second screen in vivo. Here, we show that the mRNA decapping enzyme scavenger (DCPS) gene is essential for AML cell survival. The DCPS enzyme interacted with components of pre-mRNA metabolic pathways, including spliceosomes, as revealed by mass spectrometry. RG3039, a DCPS inhibitor originally developed to treat spinal muscular atrophy, exhibited anti-leukemic activity via inducing pre-mRNA mis-splicing. Humans harboring germline biallelic DCPS loss-of-function mutations do not exhibit aberrant hematologic phenotypes, indicating that DCPS is dispensable for human hematopoiesis. Our findings shed light on a pre-mRNA metabolic pathway and identify DCPS as a target for AML therapy. Yamauchi et al. perform in vitro and in vivo CRISPR-Cas9 genetic screening of p53 WT AML to identify potential therapeutic targets. They find that AML relies on the DCPS decapping enzyme, and a DCPS inhibitor shows anti-leukemia activity in tumor models without impacting normal hematopoiesis.

DOI： 10.1016/j.ccell.2018.01.012

Language：English   Publishing type：Research paper (scientific journal)  

Acute myelogenous leukemia (AML) is a clinically heterogeneous disease that is frequently associated with relapse and a poor prognosis. Among the various subtypes, AML with the monosomal karyotype (AML-MK) has an extremely unfavorable prognosis. We performed screening to identify antitumor compounds that are capable of inducing apoptosis in primary leukemia cells harboring the AML-MK karyotype and identified a naturally occurring stilbene, Gnetin-C, with potent anti-tumor activities against AML cells from patients with various cytogenetic abnormalities, including patients with the AML-MK karyotype. Gnetin-C simultaneously inhibits the ERK1/2 and the AKT/mTOR pathways, two signals that are essential for the survival of leukemia cells. A combination of Gnetin-C with low doses of chemotherapeutic drugs led to synergistic anti-tumor effects against AML cells. In an immunodeficient mouse model of human leukemia, Gnetin-C attenuated the formation of leukemia, depleted leukemia cells and improved survival. These findings suggest that Gnetin-C has antitumor activities in AML and supports the therapeutic potential of blocking two different pathways in AML.

DOI： 10.1016/j.canlet.2017.04.027

Language：English   Publishing type：Research paper (scientific journal)  

Composite lymphomas (CLs) are defined as two unrelated lymphomas occurring at the same time within the same tissue. The incidence of these tumors is low. Of all possible combinations between lymphomas, the least frequent are the ones combining peripheral T-cell lymphoma (PTCL) and Hodgkin lymphoma (HL). We recently identified five cases of CL composed of PTCL and classical HL, mixed cellularity type. We investigated histological and clinical features of these cases. Immunostaining was performed on paraffin sections. PTCL cells were positive for CD8 and TIA-1 in four of the five cases. Hodgkin and Reed-Sternberg (HRS) cells were positive for CD30 and weakly positive for PAX5 in all cases, positive for CD15 in three of five cases, positive for CD20 in one of five cases, and negative for EBER. Monoclonal rearrangement of the T-cell receptor (TCR) and immunoglobulin heavy chain (IGH) genes was confirmed by polymerase chain reaction (PCR) using whole paraffin sections. We concluded more precisely the monoclonality of the IGH rearrangement of HRS cells based on single-cell PCR for IGH and DNA sequencing analysis after laser microdissection of single cells in one case. HL can occur in CD8-positive and TIA-1-positive PTCL. Clinicians should recognize the possibility of these CL.

DOI： 10.1111/pin.12515

Language：English   Publishing type：Research paper (scientific journal)  

Combination use of the proteasome inhibitor bortezomib and the immunomodulatory drugs lenalidomide or thalidomide has provided superior outcomes in multiple myeloma over their single use; however, these combinations can produce significant toxicities. Unexpectedly, we found a small but significant increase in the population of immature granulocytes and erythrocytes/megakaryocytes in peripheral blood in 16 of 22 patients (73%) treated with dexamethasone in combination with bortezomib and immunomodulatory drugs (triplet), but not in any of 25 patients treated with either bortezomib or immunomodulatory drugs with dexamethasone (doublet). These immature cells gradually increased to a peak level (mean 2.6% per white blood cells) with triplet therapy, and disappeared immediately after therapy cessation. The numbers of circulating CD34⁺ cells and colony-forming cells derived from peripheral blood mononuclear cells increased after triplet therapy compared with those in patients treated by either bortezomib or immunomodulatory drugs plus dexamethasone. Furthermore, triplet regimen downregulated the expression of CXCR4, a chemokine receptor essential for bone marrow retention, on CD34⁺ cells, suggesting an unexpected effect on normal hematopoietic stem/progenitor cells through the reduced interaction with the bone marrow microenvironment. Our observations suggest that combination use should be carefully evaluated to exert synergistic anti-myeloma effects while avoiding unexpected adverse events.

DOI： 10.1007/s12185-016-2148-2

Language：English   Publishing type：Research paper (scientific journal)  

Somatic mutations of calreticulin (CALR) have been observed in many cases of essential thrombocythemia (ET) or primary myelofibrosis that harbor non-mutated Janus kinase 2 (JAK2). CALR mainly localizes within the endoplasmic reticulum lumen, but a small fraction of the total CALR pool is distributed over the cell surface. Cell surface CALR is known to transduce prophagocytic “eat me” signals to macrophages and acts as one of the important regulators for macrophage engulfment. In this study, we attempted to clarify whether mutant CALR may affect the threshold for macrophage engulfment and play an integral role in the pathogenesis of CALR-mutated ET. First, we compared the surface expression levels of CALR on hematopoietic stem and progenitor cells (HSPCs) and mature blood cells in patients with myeloproliferative neoplasms and found that the surface expression of mutant CALR did not change. Next, we compared the threshold for macrophage phagocytosis of each HSPC fraction and mature blood cells and found no significant change in the efficiency of macrophage engulfment. Our data suggest that CALR mutation does not affect sensitivity to phagocytosis by macrophages. Finally, we analyzed the phosphorylation statuses of molecules downstream of JAK2 at each HSPC level in patients with ET and found that CALR mutations activated the JAK-STAT pathway in a manner similar to that associated with JAK2 mutations. These results indicate that mutant CALR causes myeloproliferation because of the activation of JAK-STAT pathway and not by the inhibition of phagocytosis, which is similar to the myeloproliferation caused by JAK2 V617F mutation.

DOI： 10.1016/j.exphem.2016.05.001

Language：English   Publishing type：Research paper (scientific journal)  

Mogamulizumab (MOG), a humanized anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, has recently played an important role in the treatment of adult T cell leukemia/lymphoma (ATLL). Because CCR4 is expressed on normal regulatory T cells as well as on ATLL cells, MOG may accelerate graft-versus-host disease (GVHD) by eradicating regulatory T cells in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, there is limited information about its safety and efficacy in patients treated with MOG before allo-HSCT. In the present study, 25 patients with ATLL were treated with MOG before allo-HSCT, after which 18 patients (72%) achieved remission. The overall survival and progression-free survival at 1 year post-transplantation were 20.2% (95% CI, 6.0% to 40.3%) and 15.0% (95% CI, 4.3% to 32.0%), respectively. The cumulative incidence of acute GVHD was 64.0% (95% CI, 40.7% to 80.1%) for grade II-IV and 34.7% (95% CI, 15.8% to 54.4%) for grade III-IV. The cumulative incidence of transplantation-related mortality (TRM) was 49.0% (95% CI, 27.0% to 67.8%). Six of 7 patients with acute GVHD grade III-IV died from GVHD, which was the leading cause of death. In particular, a shorter interval from the last administration of MOG to allo-HSCT was associated with more severe GVHD. MOG use before allo-HSCT may decrease the ATLL burden; however, it is associated with an increase in TRM due to severe GVHD. Because MOG is a potent anti-ATLL agent, new treatment protocols should be developed to integrate MOG at suitable doses and timing of administration to minimize unwanted GVHD development.

DOI： 10.1016/j.bbmt.2016.05.017

Language：English   Publishing type：Research paper (scientific journal)  

In human-to-mouse xenograft models, reconstitution of human hematopoiesis is usually B-lymphoid dominant. Here we show that the introduction of homozygous Kit^Wv mutations into C57BL/6.Rag2^nullIl2rg^null mice with NOD-Sirpa (BRGS) strongly promoted human multi-lineage reconstitution. After xenotransplantation of human CD34⁺CD38⁻ cord blood cells, these newly generated C57BL/6.Rag2^nullIl2rg^nullNOD-Sirpa Kit^Wv/Wv (BRGSK^Wv/Wv) mice showed significantly higher levels of human cell chimerism and long-term multi-lineage reconstitution compared with BRGS mice. Strikingly, this mouse displayed a robust reconstitution of human erythropoiesis and thrombopoiesis with terminal maturation in the bone marrow. Furthermore, depletion of host macrophages by clodronate administration resulted in the presence of human erythrocytes and platelets in the circulation. Thus, attenuation of mouse KIT signaling greatly enhances the multi-lineage differentiation of human hematopoietic stem and progenitor cells (HSPCs) in mouse bone marrow, presumably by outcompeting mouse HSPCs to occupy suitable microenvironments. The BRGSK^Wv/Wv mouse model is a useful tool to study human multi-lineage hematopoiesis.

DOI： 10.1016/j.stemcr.2016.07.002

Language：English   Publishing type：Research paper (scientific journal)  

PBSC products for auto- and allografting can be cryopreserved in liquid nitrogen with controlled-rate freezing until their use. Alternatively, they can be stored at -80 °C in a mechanical chest freezer, but it remains to be clarified whether PBSCs can be stored for the long term. We evaluated viability and functions of PBSCs cryopreserved for more than 10 years with this simplified method. Although recovery rate and viability of CD34 + cells were significantly decreased, myeloid differentiation potential and in vivo reconstitution and self-renewal potential of CD34 + cells in a xenogeneic engraftment assay were maintained for more than 10 years. These results indicate that PBSCs can be stored at -80 °C for years. Although accumulation of clinical engraftment data is required to confirm our results, this simplified cryopreservation will thus meet the increasing worldwide demand for PBSC transplantation in a region with limited resources.

DOI： 10.1038/bmt.2015.147

Language：English   Publishing type：Research paper (scientific journal)  

It has been shown that in xenotransplantation of human cells into immunodeficient mice, the mouse strain background is critical. For example, the nonobese diabetic (NOD) strain is most efficient, the BALB/c is moderate, and the C57BL/6 is inefficient for human cell engraftment. We have shown that the NOD-specific polymorphism of the signal regulatory protein-alpha (Sirpa) allows NOD SIRPA to bind human CD47, and the resultant "don't eat me" signaling by this binding prevents host macrophages to engulf human grafts, thereby inhibiting rejection. Here we tested whether the efficient xenotransplantation capability of the BALB/c strain is also mediated by the SIRPA-CD47 self-recognition system. BALB/c SIRPA was capable of binding to human CD47 at an intermediate level between those of C57BL/6 SIRPA and NOD SIRPA. Consistent with its binding activity, BALB/c-derived macrophages exhibited a moderate inhibitory effect on human long-term culture-initiating cells in in vitro cultures, and showed moderate phagocytic activity against human hematopoietic stem cells. The increased affinity of BALB/c SIRPA for human CD47 was mounted at least through the BALB/c-specific L29V SNP within the IgV domain. Thus, the mouse strain effect on xenogeneic engraftment might be ascribed mainly to the binding affinity of strain-specific polymorphic SIRPA with human CD47. This information should be useful for developing a novel immunodeficient strain with superior efficiency for xenogeneic transplantation of human cells.

DOI： 10.1016/j.exphem.2013.11.005

Language：English   Publishing type：Research paper (scientific journal)  

Introduction: Cord blood (CB) is being increasingly used as a source of hematopoietic stem cells for transplantation to treat diseases of the blood and immune systems, and there is an urgent need to expand CB banking worldwide. CB processing requires costly machinery or a clean room that hampers wider application of CBT particularly in the developing countries. Methods: We developed a novel filtration system using a nonchemical-coated and nonwoven polyester fabric filter, which traps cells through affinity and does not require centrifugation or potentially toxic chemicals. Results: Cell processing with the device resulted in minimum cell loss of total cells and CD34⁺ cells, without impairing the ability of CD34⁺ cells to engraft and differentiate both in vivo and in vitro. Conclusion: CB processing with this device is simple, cost-effective, and nontoxic without requiring costly equipment will thus facilitate international CB banking, which helps in meeting the increasing worldwide demand for CB for allogeneic hematopoietic stem cell transplantation.

DOI： 10.1111/ijlh.12039

Language：English   Publishing type：Research paper (scientific journal)  

Background:Definite identification of the cell types and the mechanism relevant to cardiomyogenesis is essential for effective cardiac regenerative medicine. We aimed to identify the cell populations that can generate cardiomyocytes and to clarify whether generation of donor-marker⁺ cardiomyocytes requires cell fusion between BM-derived cells and recipient cardiomyocytes.Methodology/Principal Findings:Purified BM stem/progenitor cells from green fluorescence protein (GFP) mice were transplanted into C57BL/6 mice or cyan fluorescence protein (CFP)-transgenic mice. Purified human hematopoietic stem cells (HSCs) from cord blood were transplanted into immune-compromised NOD/SCID/IL2rγ^null mice. GFP⁺ cells in the cardiac tissue were analyzed for the antigenecity of a cardiomyocyte by confocal microscopy following immunofluorescence staining. GFP⁺ donor-derived cells, GFP⁺CFP⁺ fused cells, and CFP⁺ recipient-derived cells were distinguished by linear unmixing analysis. Hearts of xenogeneic recipients were evaluated for the expression of human cardiomyocyte genes by real-time quantitative polymerase chain reaction. In C57BL/6 recipients, Lin^-/lowCD45⁺ hematopoietic cells generated greater number of GFP⁺ cardiomyocytes than Lin^-/lowCD45^- mesenchymal cells (37.0+/-23.9 vs 0.00+/-0.00 GFP⁺ cardiomyocytes per a recipient, P = 0.0095). The number of transplanted purified HSCs (Lin^-/lowSca-1⁺ or Lin^-Sca-1⁺c-Kit⁺ or CD34^-Lin^-Sca-1⁺c-Kit⁺) showed correlation to the number of GFP⁺ cardiomyocytes (P<0.05 in each cell fraction), and the incidence of GFP⁺ cardiomyocytes per injected cell dose was greatest in CD34^-Lin^-Sca-1⁺c-Kit⁺ recipients. Of the hematopoietic progenitors, total myeloid progenitors generated greater number of GFP⁺ cardiomyocytes than common lymphoid progenitors (12.8+/-10.7 vs 0.67+/-1.00 GFP⁺ cardiomyocytes per a recipient, P = 0.0021). In CFP recipients, all GFP⁺ cardiomyocytes examined coexpressed CFP. Human troponin C and myosin heavy chain 6 transcripts were detected in the cardiac tissue of some of the xenogeneic recipients.Conclusions/Significance:Our results indicate that HSCs resulted in the generation of cardiomyocytes via myeloid intermediates by fusion-dependent mechanism. The use of myeloid derivatives as donor cells could potentially allow more effective cell-based therapy for cardiac repair.

DOI： 10.1371/journal.pone.0062506

Language：English   Publishing type：Research paper (scientific journal)  

Current mouse lines efficient for human cell xenotransplantation are backcrossed into NOD mice to introduce its multiple immunodeficient phenotypes. Our positional genetic study has located the NOD-specific polymorphic Sirpa as a molecule responsible for its high xenograft efficiency: it recognizes human CD47 and the resultant signaling may cause NOD macrophages not to engulf human grafts. In the present study, we established C57BL/6.Rag2 ^{null//2rgnull} mice harboring NOD-Sirpa (BRGS). BRGS mice engrafted human hematopoiesis with an efficiency that was equal to or even better than that of the NOD.Rag1^{null//2rgnull} strain, one of the best xenograft models. Consequently, BRGS mice are free from other NOD-related abnormalities; for example, they have normalized C5 function that enables the evaluation of complement-dependent cytotoxicity of antibodies against human grafts in the humanized mouse model. Our data show that efficient human cell engraftment found in NOD-based models is mounted solely by their polymorphic Sirpa. The simplified BRGS line should be very useful in future studies of human stem cell biology.

DOI： 10.1182/blood-2012-06-440354

Language：English   Publishing type：Research paper (scientific journal)  

Hemophagocytic lymphohistiocytosis (HLH) is characterized by deregulated engulfment of hematopoietic stem cells (HSCs) by BM macrophages, which are activated presumably by systemic inflammatory hypercytokinemia. In the present study, we show that the pathogenesis of HLH involves impairment of the antiphagocytic system operated by an interaction between surface CD47 and signal regulatory protein α (SIRPA). In HLH patients, changes in expression levels and HLH-specific polymorphism of SIRPA were not found. In contrast, the expression of surface CD47 was down-regulated specifically in HSCs in association with exacerbation of HLH, but not in healthy subjects. The number of BM HSCs in HLH patients was reduced to approximately 20% of that of healthy controls and macrophages from normal donors aggressively engulfed HSCs purified from HLH patients, but not those from healthy controls in vitro. Furthermore, in response to inflammatory cytokines, normal HSCs, but not progenitors or mature blood cells, down-regulated CD47 sufficiently to be engulfed by macrophages. The expression of prophagocytic calreticulin was kept suppressed at the HSC stage in both HLH patients and healthy controls, even in the presence of inflammatory cytokines. These data suggest that the CD47-SIRPA antiphagocytic system plays a key role in the maintenance of HSCs and that its disruption by HSC-specific CD47 down-regulation might be critical for HLH development.

DOI： 10.1182/blood-2012-02-408864

Language：English   Publishing type：Research paper (scientific journal)  

We report here that in chronic lymphocytic leukemia (CLL), the propensity to generate clonal B cells has been acquired already at the hematopoietic stem cell (HSC) stage. HSCs purified from patients with CLL displayed lymphoid-lineage gene priming and produced a high number of polyclonal B cell progenitors. Strikingly, their maturation into B cells was restricted always to mono- or oligo-clones with CLL-like phenotype in xenogeneic recipients. These B cell clones were independent of the original CLL clones because they had their own immunoglobulin VDJ genes. Furthermore, they used preferentially VH genes frequently used in human CLL, presumably reflecting the role of B cell receptor signaling in clonal selection. These data suggest that HSCs can be involved in leukemogenesis even in mature lymphoid tumors.

DOI： 10.1016/j.ccr.2011.06.029

Language：English   Publishing type：Research paper (scientific journal)  

Invasive aspergillosis (IA) is an important cause of infectious morbidity and mortality in patients who undergo haematopoietic stem cell transplantation (HSCT). History of IA before allogeneic HSCT is still challenging because of the high risk of recurrence after HSCT. Recent advances in early-stage diagnosis and new, more effective classes of antifungal agents have improved the management of IA in the HSCT recipients. We report two cases with acute myelogenous leukaemia after primary failure of induction chemotherapy with the patients developing pulmonary IA. They responded well to a combination of voriconazole (VCZ) and micafungin, resulting in a remarkable reduction of pulmonary IA lesions at short intervals. Thereafter, antifungal therapy was switched to liposomal amphotericin B (L-AmB), followed by conditioning regimen for allogeneic HSCT, because of the possibility of VCZ altering the metabolism of chemotherapeutic agents and calcineurin inhibitors. Successful engraftment was achieved without severe adverse side-effects or aggravation of IA after HSCT. Combining VCZ with micafungin followed by L-AmB throughout HSCT could be advantageous in stabilising IA in HSCT patients.

DOI： 10.1111/j.1439-0507.2010.01858.x

Language：English   Publishing type：Research paper (scientific journal)  

Summary The acquired JAK2 V617F mutation is observed in the majority of patients with BCR-ABL1 negative chronic myeloproliferative neoplasms (MPN). BCR-ABL1 negative MPN displays myeloproliferation with an elevated leucocyte alkaline phosphatase (LAP) activity, a neutrophil activation marker. We tried to separate the downstream signalling of JAK2 V617F to stimulate myeloproliferation and LAP activity. NB4, a myeloid lineage cell line, was transduced with Jak2 V617F mutation or wild-type Jak2. We found that Jak2 V617F mutation, but not wild-type Jak2 enhanced LAP expression in NB4-derived neutrophils and proliferation of NB4 cells. JAK2 V617F induces constitutive phosphorylation of STAT3 and STAT5, and uses signalling targets such as Ras/MEK/ERK and PI3K/Akt pathways. By using MEK1/2 inhibitor U0126, PI3K inhibitor LY294002, and STAT3 or STAT5 siRNAs, JAK2 V617F was found to specifically use the STAT3 pathway to enhance LAP expression, while STAT5, Ras/MEK/ERK and PI3K/Akt, but not STAT3 pathways, were able to stimulate cell proliferation. These data strongly suggest that JAK2 V617F uses distinct signalling pathways to induce typical pathological features of MPN, such as high LAP activity and enhanced cell proliferation.

DOI： 10.1111/j.1365-2141.2010.08249.x

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1399-3062.2010.00496.x

Language：English   Publishing type：Research paper (scientific journal)  

Nasal natural killer (NK)/T cell lymphoma is a rare disease with a poor prognosis. We report the case of a 52-year-old woman with progressive advanced nasal NK/T cell lymphoma, with local invasiveness and bone marrow involvement, who was successfully treated with unrelated cord blood transplantation (UCBT). The patient was initially refractory to conventional chemotherapy. She was therefore treated with local irradiation, which induced a partial response. The patient then underwent UCBT using a conditioning regimen consisting of cyclophosphamide and total body irradiation. Acute graft-versus-host disease involving the skin was observed, but it was well controlled without systemic administration of corticosteroids. The patient remained in complete remission for 18 months after UCBT. Although the observation period has been relatively short and longer follow-up is needed, our observations suggest that incorporating focal irradiation to conditioning regimen for local control might be an effective treatment option for advanced nasal NK/T cell lymphoma in the setting of UCBT.

DOI： 10.1007/s12185-009-0453-8

Language：English   Publishing type：Research paper (scientific journal)  

A 27-year-old man was admitted to our hospital complaining of a persistent high fever since August 2007. Chest radiography showed infiltration shadows in the right lower lung field. Chest CT revealed scattered small nodular shadows and patchy consolidations in the right lower lobe. He was diagnosed as secondary pulmonary alveolar proteinosis (sPAP) associated with myelodysplastic syndrome (MDS), confirmed by video-assisted thoracic surgery (VATS) and bone marrow aspiration. Sera were negative for anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibody. He developed a subcutaneous abscess and meningitis caused by M. absessus after VATS. After a long-course of antibiotic therapy, an allogenic peripheral blood stem cell transplantation was performed. But he died of graft versus host disease and M. abscessus sepsis 87 days after transplantation.

Language：English   Publishing type：Research paper (scientific journal)  

We report a 29-year-old Japanese male with acute myelogenous leukemia (AML)-M4 with a cryptic t(7;11)(p15;p15), in which a chimeric NUP98-HOXA9 fusion was detected by polymerase chain reaction analysis and a chromosomal analysis showed 46,XY. The patient received intensive chemotherapy and underwent autologous stem cell transplantation, and remission was confirmed by the disappearance of NUP98-HOXA9. However, 6 months after transplantation, the patient relapsed; NUP98-HOXA9 was detected again and karyotypic analysis revealed 46,XY, t(1;21)(p32;q22). Fluorescent in situ hybridization (FISH) analysis using an AML1-ETO translocation dual probe, showed that the 21q22 breakpoint involved AML1 locus. A retrospective FISH analysis showed that t(1;21) was absent at onset. This is the first reported case with AML who had a cryptic t(7;11)(p15;p15), and additionally acquired t(1;21)(p32;q22) at relapse.

DOI： 10.1007/s12185-008-0198-9

Language：English   Publishing type：Research paper (scientific journal)  

Gemtuzumab ozogamicin (GO) is an effective molecular-targeted agent for CD33-positive acute myelogenous leukemia (AML) patients who are resistant to conventional chemotherapy. Recent prospective trials have revealed the safety and efficacy of GO as part of conditioning following allogeneic bone marrow or peripheral blood stem cell transplantation (SCT). We report here for the first time three AML cases that relapsed after allogeneic SCT and underwent unrelated cord blood transplantation (UCBT) following reduced-intensity conditioning (RIC) comprising fludarabine, melphalan, and low-dose total body irradiation combined with GO. Primary neutrophil engraftment occurred in all cases, while recovery of platelet count was delayed. Only one case of reversible hepatic sinusoidal obstruction syndrome was documented. Non-relapse mortality at day 100 was not documented. Notably, one patient who responded to GO survived for 6 months after UCBT in remission with excellent performance status, while the remaining cases relapsed early. These data suggest that GO may be safely combined with RIC for UCBT after previous allogeneic SCT.

DOI： 10.1007/s12185-009-0405-3

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