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Leukemic stem cells in acute myeloid leukemia (AML) express high B cell lymphoma 2 (BCL2) levels, which contribute to leukemic cell survival and resistance to therapy. Venetoclax-a BCL-2 inhibitor-is indicated for the treatment of AML, which may also target leukemic stem cells; however, it is only available as a tablet. There are no reports of venetoclax use in patients who cannot take oral drugs; therefore, the efficacy, safety, and pharmacokinetics (PK) of venetoclax administered through a gastrostomy tube is unknown.We report, for the first time, a case of relapsed Japanese AML patient treated with crushed venetoclax tablets through a percutaneous endoscopic gastrostomy (PEG) tube because of esophageal stricture due to complications of stem cell transplantation. The patient was also taking posaconazole and clarithromycin concomitantly. We evaluated the plasma concentrations of venetoclax administered through a PEG tube. Time to maximum concentration, maximum plasma concentration, and the area under the plasma concentration-time curve were similar to the previously reported PK parameters after oral administration of intact venetoclax tablets in Japanese patients with AML. The clinical course passed safely without the occurrence of unexpected adverse events during the administration of crushed venetoclax tablets in combination with azacitidine.The PK parameters of the crushed administered venetoclax via PEG tube was similar to the previously reported PK parameters of the orally administered venetoclax. Therefore, administration of crushed venetoclax tablets through a PEG tube could be an alternate route for patients who have difficulty with oral administration.

The effects of polymorphisms of ABCB1 and ABCG2 on the dose-adjusted plasma trough concentrations and cerebrospinal fluid (CSF)-to-plasma ratios of ponatinib were evaluated. Blood (C4) and CSF (CSF4) concentrations at 4 h after administration were determined. The median (95% confidence interval (CI)) CSF4-to-C4 ratio of ponatinib in subjects homozygous for ABCB1 variants 1236T/T, 2677T/T+T/A, or 3435T/T were significantly higher than that in a group of subjects with other genotypes (P = 0.026, 0.012, and 0.015, respectively). The median (95% CI) CSF4-to-C4 ratio of ponatinib in four patients with the combination of ABCB1 variants 1236T/T-2677T/T+T/A-3435T/T was 2.62 (1.42 – 3.42)%; this ratio was significantly higher than that in subjects with other genotypes [1.08 (0.89 – 1.47)%; P = 0.006]. The brain distribution of ponatinib was affected by ABCB1 polymorphisms and therefore seems to be modulated by P-glycoprotein at the blood-brain and blood-CSF barriers.

Autologous hematopoietic cell transplantation (HCT) is an effective therapy for patients with relapsed acute promyelocytic leukemia (APL). However, it remains unclear whether this procedure is equally effective for certain groups of patients. To address this question, we analyzed 296 patients with APL who had undergone autologous HCT during second or subsequent complete remission (CR2+) between 2006 and 2019. Among them, 24 patients were ≥65 years old, and 17 underwent autologous HCT during third or subsequent CR. Of the 286 patients whose measurable residual disease (MRD) data were available, 21 showed detectable MRD. The 5-year probabilities of relapse-free survival (RFS), overall survival, relapse, and nonrelapse mortality for the entire cohort were 85%, 88%, 9%, and 6%, respectively. The multivariate analysis revealed that the duration of first CR (

Background Until recently, no effective targeted therapies for FLT3-mutated (FLT3mut+) relapsed/refractory (R/R) acute myeloid leukemia (AML) were available in Japan. The FLT3 inhibitor, gilteritinib, was approved in Japan for patients with FLT3mut+ R/R AML based on the phase 3 ADMIRAL trial, which demonstrated the superiority of gilteritinib over salvage chemotherapy (SC) with respect to overall survival (OS; median OS, 9.3 vs 5.6 months, respectively; hazard ratio, 0.64 [95% confidence interval 0.49, 0.83]; P Methods We evaluated the Japanese subgroup (n = 48) of the ADMIRAL trial, which included 33 patients randomized to 120-mg/day gilteritinib and 15 randomized to SC. Results Median OS was 14.3 months in the gilteritinib arm and 9.6 months in the SC arm. The complete remission/complete remission with partial hematologic recovery rate was higher in the gilteritinib arm (48.5%) than in the SC arm (13.3%). After adjustment for drug exposure, fewer adverse events (AEs) occurred in the gilteritinib arm than in the SC arm. Common grade ≥ 3 AEs related to gilteritinib were febrile neutropenia (36%), decreased platelet count (27%), and anemia (24%). Conclusion Findings in Japanese patients are consistent with those of the overall ADMIRAL study population.

We conducted a multicenter study on anti-programmed cell death-1 monoclonal antibodies (anti-PD-1 mAbs) before/after allogeneic hematopoietic cell transplantation (allo-HCT) for Hodgkin lymphoma. Anti-PD-1 mAbs were administered to 25 patients before allo-HCT and to 20 after allo-HCT. In pre-allo-HCT setting, the median interval from the last administration to allo-HCT was 59 days. After allo-HCT, 12 patients developed non-infectious febrile syndrome requiring high-dose corticosteroid. The cumulative incidences of grade II-IV acute graft-versus-host disease (aGvHD) were 47.1%. Eight patients who had GvHD prophylaxis with post-transplant cyclophosphamide (PTCy) had less frequent aGvHD (grade II-IV, 14.6% versus 58.8%; P = 0.086). The 1 year overall survival (OS), relapse/progression, and non-relapse mortality rates were 81.3%, 27.9%, and 8.4%. In post-allo-HCT setting, the median interval from allo-HCT to the first administration was 589 days. The overall and complete response rates were 75% and 40%. At 100 days after anti-PD-1 therapy, the cumulative incidences of grade II-IV aGvHD, moderate-to-severe chronic GvHD, and grade 3-4 immune-related toxicity were 15.0%, 30.0%, and 30.0%. While the 1 year relapse/progression rate was 47.4%, the 1 year OS probability was 89.7%. In conclusion, immune-related complications were frequent despite modifications of GvHD prophylaxis or anti-PD-1 mAb dosing. In anti-PD-1-mAb-pretreated patients, PTCy-based GvHD prophylaxis may be effective.

Fit patients with peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) and angioimmunoblastic T-cell lymphoma (AITL) in relapsed or refractory (R/R) disease status often receive salvage chemotherapy followed by autologous hematopoietic stem cell transplantation (autoHCT) or allogeneic HCT (alloHCT). However, there is no consensus on the type of HCT that should be applied for such patients. Herein, we retrospectively evaluated the survival outcome of 760 adult R/R PTCL-NOS or AITL patients who underwent the first HCT. Among them, 318 relapsed after first remission (REL) and 442 were refractory to the primary therapy (PIF). The 4-year overall survival (OS) of autoHCT and alloHCT was 50 and 50% for REL patients, and 52 and 49% for PIF patients, respectively. In the multivariable analysis, alloHCT tended to be associated with better progression-free survival (PFS) in REL (hazard ratio [HR] 0.74; 95% confidence interval [CI]: 0.53-1.03), and significantly better PFS in PIF (HR 0.64; 95% CI: 0.46-0.88) compared with autoHCT. The subgroup analysis with propensity-score matching showed that alloHCT was associated with better OS for REL-sensitive and PIF-nonremission disease. This study suggested that the advantage of alloHCT for R/R PTCL-NOS or AITL is different, depending on the disease status at HCT.

Autologous hematopoietic cell transplantation (HCT) is an effective therapy for patients with relapsed acute promyelocytic leukemia (APL). However, it remains unclear whether this procedure is equally effective for certain groups of patients. To address this question, we analyzed 296 patients with APL who had undergone autologous HCT during second or subsequent complete remission (CR2+) between 2006 and 2019. Among them, 24 patients were ≥65 years old, and 17 underwent autologous HCT during third or subsequent CR. Of the 286 patients whose measurable residual disease (MRD) data were available, 21 showed detectable MRD. The 5-year probabilities of relapse-free survival (RFS), overall survival, relapse, and nonrelapse mortality for the entire cohort were 85%, 88%, 9%, and 6%, respectively. The multivariate analysis revealed that the duration of first CR ( or ≥2 years) was the sole factor associated with RFS (P = 0.002), but even those with CR1 duration2 years showed a 5-year RFS of 76%. The other factors such as age, disease status, and MRD status were not predictive for the survival outcomes. Our findings demonstrate very favorable long-term results when autologous HCT is conducted during CR2 + across the various subgroups of patients with relapsed APL.

A 53-year-old woman presented at our hospital due to nasal bleeding and petechiae with profound thrombocytopenia (0.4×109/L). Her platelet count returned to the normal range immediately following a platelet transfusion. In this case, tea brewed from Taxus yunnanensis was the only suspected agent ingested prior to the onset of thrombocytopenia while all other etiologies for thrombocytopenia were excluded. A re-exposure test to Taxus yunnanensis resulted in the recurrence of acute thrombocytopenia. The association of thrombocytopenia with substances other than drugs has so far only been rarely described and to the best of our knowledge, this is the first reported case of thrombocytopenia caused by Taxus yunnanensis.

Severe hepatic failure is rarely a cause of death in patients with immunoglobulin light chain (AL) amyloidosis. We herein report a case of AL amyloidosis involving a bleeding tendency due to factor X deficiency and marked hepatic involvement of amyloidosis. The patient died due to severe liver dysfunction two weeks after admission. The diagnosis was confirmed histologically by AL-λ amyloidosis, with the liver and spleen as the main lesions, on an autopsy. As treatment-related toxicity is strong in advanced cases, appropriate treatments are required to improve the prognosis of AL amyloidosis with severe liver dysfunction.

Although programmed cell death (PD)-1 blockade induces immune-related adverse events (irAEs), little is known about the safety of PD-1 blockade after allogeneic hematopoietic stem cell transplantation (HSCT). Here, we describe immune system changes during nivolumab-related myositis in a patient with Hodgkin's lymphoma after allogeneic HSCT; to our knowledge, this is the first such report in the literature. At the onset of myositis, the patient lost lower limb mobility against gravity, and had an activated immune profile with increased cytotoxic CD107a and granzyme B expression, as well as pro-inflammatory cytokines, interferon-γ, tumor necrosis factor-α, interleukin-2 in T and NK cells compared to healthy donor. Pulse steroid therapy decreased creatine kinase levels and induced PD-1 expression and regulatory T cells, but did not improve myositis; previously activated markers remained high. Four-week corticosteroid therapy decreased previously activated markers and the myositis improved. These findings provide new insights into nivolumab-induced irAE pathogenesis and suggest possible optimal treatments for irAEs.

After primary graft failure following allogeneic hematopoietic stem cell transplantation, some patients experience autologous recovery of hematopoiesis without salvage transplantation. However, clinicians occasionally encounter unusual chromosomal abnormalities in recipient cells, not related to the original underlying diseases. In this study, through a survey based on data from the nationwide registry at the Japan Society for Hematopoietic Cell Transplantation, 42 patients were identified as having chromosomal abnormalities after autologous recovery. The complex chromosomal abnormalities were not consistent and randomly changed at each testing. Of the 42 patients, seven experienced disappearance of chromosome abnormalities without any treatment, and the probability was estimated as 17.4% (95% CI: 7.5-30.7%) at the 5-year observation. On the other hand, two patients developed hematologic malignancy at 1447 and 6202 days. Ten patients were alive without relapse or development of hematologic disorders, even though chromosomal abnormalities were continuously detected at a median of 3192 (103-4710) days. In conclusion, chromosomal abnormalities can persist for more than 10 years, and may eventually contribute to hematologic malignancy development in a small fraction of cases. Although oncogenic effects of the chromosomal abnormalities are still unclear, these findings may provide supporting evidence for late occurrence of secondary malignant neoplasms after cancer treatment.

Background Tacrolimus is metabolized by cytochrome P450 (CYP) 3A4 and 3A5. We investigated the influence of CYP3A5 polymorphism and concurrent use of azole antifungal agents (AZ) on the pharmacokinetics of a once-daily modified-release tacrolimus formulation (Tac-QD) in patients after hematopoietic stem cell transplantation (HSCT). Design and methods Twenty-four patients receiving allogeneic HSCT were enrolled. Genotyping for CYP3A5*3 was done by a PCR-restriction fragment length polymorphism method. Trough blood concentrations (C0) of tacrolimus were measured by chemiluminescence magnetic microparticle immunoassay. Continuous infusion of tacrolimus was administered from the day before transplantation and was switched to Tac-QD after adequate oral intake. Results Thirteen patients had a CYP3A5*3/*3 genotype, and 11 patients had a CYP3A5*1/*1 or *1/*3 genotype. No significant difference was observed in daily dosages and the C0 of tacrolimus between the two genotype groups without AZ. However, in patients who were co-administered AZ, the C0 values of tacrolimus were higher in patients with the CYP3A5*3/*3 allele than with the CYP3A5*1 allele (P = 0.034), although daily doses of Tac-QD in patients with CYP3A5*3/*3 were significantly lower than those with the CYP3A5*1 allele (P = 0.041). The cumulative incidence of acute kidney injury was higher in patients with the CYP3A5*3/*3 than with the CYP3A5*1 allele when AZ was co-administered. The decrement for daily dosage of Tac-QD was significantly greater in patients expressing the CYP3A5*3/*3 than the CYP3A5*1 allele. Conclusions CYP3A5 genotyping may be useful for safe and effective immunosuppressive therapy with Tac-QD in HSCT patients in whom the use of AZ is anticipated. Electronic supplementary material The online version of this article (doi:10.1007/s00280-016-3060-4) contains supplementary material, which is available to authorized users.

We recently demonstrated that upregulation of a chemokine receptor CCR6 and its ligand CCL20 led to metastasis of advanced cutaneous T-cell lymphoma (CTCL) cells, suggesting the involvement of CCL20-CCR6 interaction in initiating CTCL cell metastasis. In this study, we determined whether this interaction is functional in metastatic CTCL cells. We first demonstrated increased STAT3 expression during the progression of primary CTCL. STAT3 was spontaneously activated and mediated the transcription of CCL20 in CTCL cell lines. Next, to determine whether the transient knockdown of STAT3, CCL20, or CCR6 or treatment with neutralizing antibody against CCL20 (neutralizing CCL20 antibody) could reduce the migration ability of CTCL cells, we conducted an in vitro migration assay. All treatments reduced the nutrition-dependent migration activity of CTCL cells. Notably, treatment with neutralizing CCL20 antibody reduced the migration ability of the cells without decreasing the expression of CCL20 and CCR6. This demonstrated that the CCL20-CCR6 interaction is actually functional in metastatic CTCL cells. Finally, to examine the in vivo effect of neutralizing CCL20 antibody, we used NOD/Shi-scid IL-2γnul mice inoculated with CTCL cells. These mice were expected to die due to metastasis of CTCL cells into multiple organs. However, administration of neutralizing CCL20 antibody significantly prolonged the survival of the xenografted mice. These findings suggested that automatic activation of the STAT3/CCL20/CCR6 cascade was involved in CTCL lymphomagenesis and that disruption of CCL20-CCR6 interaction could be a key therapeutic strategy against advanced CTCL.

Hypereosinophilic syndrome, which is characterized by eosinophilia in the peripheral blood, often causes various organ disorders. Charcot-Leyden crystals are recognized features of various diseases, such as parasite infection and asthma, and are known to be classic hallmarks of eosinophilic inflammation. Our recent study revealed the mechanism of Charcot-Leyden crystal formation (i.e., galectin-10 crystallization), namely the involvement of eosinophil extracellular trap cell death, a nonapoptotic cell death. Here we report an autopsy case of a 57-year-old man who had died of hypereosinophilic syndrome. We found numerous eosinophil extracellular trap cell death-associated Charcot-Leyden crystals in the spleen and lymph nodes. Observation of abdominal lymph nodes by electron microscopy revealed eosinophil extracellular traps and free extracellular granules, which are characteristic of typical eosinophil extracellular trap cell death. In this case, we observed various sizes of Charcot-Leyden crystals that were stained with anti-galectin-10 immunofluorescent staining. Further studies are required to understand the pathophysiological roles of Charcot-Leyden crystals and these may lead to the development of novel therapeutic modalities for severe eosinophilic inflammation.

We conducted two parallel prospective, multicenter, phase II studies to evaluate the safety and efficacy of HLA-haploidentical peripheral blood stem cell transplantation using post-transplant cyclophosphamide (PTCy-haploPBSCT) following myeloablative conditioning (MAC, n = 50) and reduced-intensity conditioning (RIC, n = 77). Event-free survival (EFS) at 1-year as for primary endpoint was 64% and 43% in the MAC and RIC groups, respectively. Neutrophil engraftment was achieved in 98% and 94% in the MAC and RIC groups, respectively. The incidences of grades II–IV and III–IV acute graft-versus-host disease (GVHD) were 18% and 8% in the MAC group, and 14% and 5% in the RIC group, respectively. Those of all grade and moderate to severe chronic GVHD at 2-year were 36% and 20% in the MAC group, and 27% and 20% in the RIC group, respectively. Overall survival (OS), EFS, nonrelapse mortality, and relapse rate at 2-year were 68%, 54%, 10%, and 36% in the MAC group, and 44%, 35%, 20%, and 45% in the RIC group, respectively. Notably, 83% and 86% of patients who survived without relapse stopped immunosuppressant at 2-year in the MAC and RIC groups, respectively. Our results indicate that both MAC and RIC are valid options for PTCy-haploPBSCT for adults with hematological malignancies.

Although voriconazole (VRCZ) is metabolized to VRCZ N-oxide principally by CYP2C19, VRCZ clearance is affected by multiple factors. In this study, we investigated the relationship between the CYP2C19 phenotype using the VRCZ-to-VRCZ N-oxide plasma concentration ratio (VRCZ/N-oxide) and demographic and clinical characteristics of Japanese patients taking VRCZ.A total of 65 Japanese patients taking VRCZ for prophylaxis or treatment of fungal infection were enrolled in this study. Stepwise selection multiple linear regression analysis was performed to investigate the effect of factors on the VRCZ/N-oxide ratio.In patients not undergoing concurrent treatment with a drug influencing CYP2C19 activity (n = 54), the VRCZ/N-oxide ratio with definite thresholds for CYP2C19 genotypes, CYP2C19*1/*1, *1/*2 + *1/*3 + *2/*17, and *2/*2 + *2/*3, was specifically identified in patients taking VRCZ (0.48, ≥0.48and0.82 and ≥0.82). However, the VRCZ/N-oxide ratio could not be predicted based solely on the CYP2C19 genotype (R = 0.053). The route of VRCZ administration, C-reactive protein concentration determined on the same day as VRCZ plasma concentration measurement, CYP2C19 extensive metabolizer, and patient age were independent factors influencing the VRCZ/N-oxide ratio (R = 0.489, standardized regression coefficient = 0.385, 0.380, -0.231, and 0.231; P = 0.001, 0.001, 0.032, and 0.036, respectively).It is possible to comprehensively evaluate CYP2C19 activity using the actual measured value of the VRCZ/N-oxide ratio in patients taking VRCZ. The predictive performance of the VRCZ/N-oxide ratio was improved by including the route of administration, C-reactive protein level, and patient age in addition to the CYP2C19 genotype as predictive factors.

A 64-year-old woman was admitted to our hospital to undergo allogeneic stem cell transplantation. She was diagnosed with polycythemia vera with a JAK2 V617F mutation 7 years ago. She was administered ruxolitinib for splenomegaly two years prior to admission but this was discontinued because of progressive pancytopenia. One months after cessation of ruxolitinib, she developed acute myeloid leukemia transformed from post-polycythemia vera myelofibrosis. Although she achieved complete remission after induction therapy, 8-finger-breadth splenomegaly remained below the left costal margin. Ruxolitinib was re-administered following two courses of consolidation therapy. She underwent unrelated peripheral blood stem cell transplantation. Ruxolitinib was administered until the day before transplantation, and the spleen was palpated in 4-finger breadth below costal arc. Neutrophil engraftment was achieved 13 days after transplantation. In allogeneic stem cell transplantation, splenomegaly is one of the risk factors for engraftment failure and/or therapy-related mortality. Hence, a smaller spleen size can theoretically improve the outcome after transplantation. The administration of ruxolitinib prior to transplantation may have contributed to engraftment with a non-invasive reduction in the size of the spleen.

The purpose of this study was to investigate the interactions of itraconazole (ITCZ) with orally administered calcineurin inhibitors (CNIs) in Japanese allogeneic hematopoietic stem cell transplant (HSCT) recipients. Sixteen HSCT patients (8 patients each receiving tacrolimus or cyclosporine) were enrolled. An ITCZ oral solution was administered from day 30 after the initiation of ITCZ administration as a loading dose. Before the co-administration of ITCZ and CNI and 1 week daily thereafter, whole blood ITCZ and CNI (tacrolimus or cyclosporine) concentrations were measured in samples taken just before (C0h) and 2 h (C2h) after CNI administration. The median dose-adjusted C0h values of tacrolimus and cyclosporine on day 7 after the start of ITCZ co-administration were 5.6- and 2.7-fold higher, respectively, than the corresponding values obtained before the initiation of ITCZ treatment. On day 7 after ITCZ treatment, the mean single dosages of tacrolimus and cyclosporine were reduced to 33.7 and 66.5 % of the dosages before ITCZ co-administration, respectively, to adjust the CNI target concentration. Although ITCZ co-administration did not alter the dose-adjusted C0h values of tacrolimus in a patient with a CYP3A5*1/*1 allele, it did change this value of tacrolimus in patients with CYP3A5*3 alleles. However, in patients receiving cyclosporine, no such tendency was observed. The magnitude of the interaction between orally administered tacrolimus and ITCZ was significantly greater than that between cyclosporine and ITCZ. Prospective analysis of the CYP3A5 polymorphism may be important to ensure safe and reliable immunosuppressive therapy with tacrolimus in patients treated with ITCZ.

Prior history of HLA-mismatched stem cell transplantation is a risk factor for graft failure in HLA-haploidentical transplantation

Mammalian erythroblasts undergo enucleation, a process thought to be similar to cytokinesis. Although an assemblage of actin, non-muscle myosin II, and several other proteins is crucial for proper cytokinesis, the role of non-muscle myosin II in enucleation remains unclear. In this study, we investigated the effect of various cell-division inhibitors on cytokinesis and enucleation. For this purpose, we used human colony-forming unit-erythroid (CFU-E) and mature erythroblasts generated from purified CD34+ cells as target cells for cytokinesis and enucleation assay, respectively. Here we show that the inhibition of myosin by blebbistatin, an inhibitor of non-muscle myosin II ATPase, blocks both cell division and enucleation, which suggests that non-muscle myosin II plays an essential role not only in cytokinesis but also in enucleation. When the function of non-muscle myosin heavy chain (NMHC) IIA or IIB was inhibited by an exogenous expression of myosin rod fragment, myosin IIA or IIB, each rod fragment blocked the proliferation of CFU-E but only the rod fragment for IIB inhibited the enucleation of mature erythroblasts. These data indicate that NMHC IIB among the isoforms is involved in the enucleation of human erythroblasts.

Background Itraconazole is a potent inhibitor of CYP3A4 and P-glycoprotein, but not CYP2C9. Herein, we report a case study in which the plasma concentration of the CYP2C9 substrate ( S )-warfarin, and not the CYP3A4 substrate ( R )-warfarin, increased with itraconazole coadministration. Case A 67-y-old man received an allogenic bone marrow transplant for acute lymphoid leukemia. He was taking oral itraconazole (200 mg/day) and was started on a warfarin dose of 2.0 mg/day. The plasma concentrations of ( S )- and ( R )-warfarin 3 days after starting warfarin administration were 216 and 556 ng/mL, respectively (INR 0.98), and after 10 days, the concentrations were 763 and 545 ng/mL, respectively (INR 2.43). On day 11 after withdrawal of itraconazole, the concentrations of ( S )- and ( R )-warfarin were 341 and 605 ng/mL, respectively (INR 1.38). The concentration of ( R )-warfarin was not affected by itraconazole; however, the final ( S )-warfarin concentration had increased 7.3-fold. The ( S )-warfarin/( S )-7-hydroxywarfarin ratio decreased to 2.45 from 8.40 after discontinuation of itraconazole. The permeability of warfarin enantiomers across Caco-2 cells was not influenced by itraconazole and showed no difference between enantiomers. Conclusions Careful INR monitoring is necessary for warfarin co-administration with itraconazole. Further examination is necessary to elucidate mechanisms of the interaction between warfarin and itraconazole.

A 22-year-old woman, who often carried heavy books, was admitted for evaluation of hyperreninemic hypertension. Two months prior to admission, she noted leg edema. Radiological examinations revealed bilateral renal infarction with no other abnormal findings. An echocardiography showed a patent foramen ovale (PFO). Hypertension was considered secondary to renal infarction caused by paradoxical embolism through PFO. Antihypertensive and anticoagulant therapy led to improvement of hypertension. In previously reported cases of renal paradoxical embolism, multiorgan involvement was usually observed. Our case is unique in that embolism was confirmed only in the kidneys, and that clinical characteristics of renal embolism were not observed.

A 44-year-old woman was admitted with generalized lymphadenopathy, which was diagnosed as angioimmunoblastic T-cell lymphoma (AITL). The patient showed autoimmune hemolytic anemia (AIHA), polyclonal hypergammaglobulinemia and a high antinuclear antibody titer. Moreover, a human immunodeficiency virus (HIV)-1/2 screening test using the particle agglutination method was reactive. After chemotherapy for AITL, the AIHA was eliminated, and the false-positive HIV results were no longer detected. Autoimmunity associated with AITL is the likely cause of the cross-reaction with HIV and the AIHA. It is important to recognize that the cross-reaction with HIV can be a potential complication in AITL as well as AIHA.

Gemtuzumab ozogamicin (GO) is a humanized anti-CD33 monoclonal antibody conjugated to calicheamicin, that is rapidly internalized after binding to CD33. This is followed by intracellular release of calicheamicin, which induces double-stranded DNA breaks, cell cycle arrest, and apoptosis. So GO is a more selective agent for acute myeloid leukemia (AML), because the CD33 antigen is expressed on AML, while it is not expressed on normal hematopoietic stem cells and nonhematopoietic tissues. However, some studies indicated that this agent showed resistance to refractory AML cells via various mechanisms, and that there were no potent effects. In this study, we report a 76-year-old female with recurrent AML who responded to single therapy with GO, achieving complete remission for more than 1 year after the start of administration, although additional remission induction was impossible. The response to GO can be stratified with reference to the response to conventional chemotherapy.

MicroRNA (miRNA)s are a class of small regulatory RNA molecules that play important roles in tumor development by pairing with the 3' untranslated region (UTR) of target messenger RNAs to repress their productive translation. Thus although the genes responsible for T-cell lymphomas remain largely unknown, in some lymphoma subtypes, miRNA dysregulation may contribute to tumorigenesis. For example, altered expression of various oncRogenic or tumor suppressive miRNAs has been identified in lymphomas/leukemias and solid tumors We show here that a tumor suppressive miRNA, miR-150, is significantly downregulated in advanced cutaneous T-cell lymphoma (CTCL), and that the downregulation is strongly associated with tumor invasion and metastasis. Inoculation of cutaneous T-cell lymphoma cell lines into NOD/Shi-scid IL-2γnul mice led to CTCL cell migration to multiple organs, but this invasion/metastasis was substantially reduced in miR-150-transfected CTCL cells due to direct downregulation of CCR6, a specific receptor for the chemokine CCL20. MiR-150 thus appears to negatively regulate the interaction between CCL20 and CCR6 in CTCL cells, thereby inhibiting autocrine CTCL cell metastasis. CD4+ T helper cells are divided into TH1, TH2, TH17, and TH22 subsets. Among these, the TH22 subset produces only IL-22, while TH17 cells produce both IL-17 and IL-22. Normally, IL-22 activates CCL20 transcription by binding to the IL-22RA1/IL-10RB receptor, which is not expressed in lymphoid organs or lymphocytes. In the present study, we further found that both IL-22 and its receptor subunit, IL-22RA1, are aberrantly overexpressed in advanced CTCL, but IL-17 is not expressed, suggesting CTCL is derived from the TH22 subset. In the presence of continuous upregulation of CCR6 accompanied by downregulation of miR-150, IL-22 activation could lead to continuous CCL20-CCR6 interaction in CTCL cells and, in turn, autocrine metastasis to distal organs. This is the first report demonstrating an invasion/metastasis mechanism in advanced CTCL. Disclosures: No relevant conflicts of interest to declare.

Side population (SP) cells in cancers, including multiple myeloma, exhibit tumor-initiating characteristics. In the present study, we isolated SP cells from human myeloma cell lines and primary tumors to detect potential therapeutic targets specifically expressed in SP cells. We found that SP cells from myeloma cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11) express CD138 and that non-SP cells include a CD138-negative population. Serial transplantation of SP and non-SP cells into NOD/Shi-scid IL-2 gamma nul mice revealed that clonogenic myeloma SP cells are highly tumorigenic and possess a capacity for self-renewal. Gene expression analysis showed that SP cells from five MM cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11, JJN3) express genes involved in the cell cycle and mitosis (e. g., CCNB1, CDC25C, CDC2, BIRC5, CENPE, SKA1, AURKB, KIFs, TOP2A, ASPM), polycomb (e. g., EZH2, EPC1) and ubiquitin-proteasome (e. g., UBE2D3, UBE3C, PSMA5) more strongly than do non-SP cells. Moreover, CCNB1, AURKB, EZH2 and PSMA5 were also upregulated in the SPs from eight primary myeloma samples. On that basis, we used an aurora kinase inhibitor (VX-680) and a proteasome inhibitor (bortezomib) with RPMI 8226 and AMO1 cells to determine whether these agents could be used to selectively target the myeloma SP. We found that both these drugs reduced the SP fraction, though bortezomib did so more effectively than VX-680 due to its ability to reduce levels of both phospho-histone H3 (p-hist. H3) and EZH2; VX-680 reduced only p-hist. H3. This is the first report to show that certain oncogenes are specifically expressed in the myeloma SP, and that bortezomib effectively downregulates expression of their products. Our approach may be useful for screening new agents with which to target a cell population possessing strong tumor initiating potential in multiple myeloma.

Abstract 3939 Background: Multiple myeloma (MM) is characterized by the accumulation of a population of malignant plasma cells within the bone marrow. Cytotoxic chemotherapy-based treatment is not curative, and the disease eventually recurs. Although currently available anti-MM strategies are effective at targeting the bulk of tumor cells, it is not clear that these agents are targeting the tumor-initiating subpopulation, or cancer stem cells. Side Population (SP) cells are an enriched source of cancer-initiating cells with stem cell properties, which have been identified in solid tumors, as well as in hematopoietic malignancies. SP cells express high levels of various members of the ABC transporter family, which are responsible for their drug resistance. A recent our work demonstrated that SP cells in MM have shown to exhibit stem cell like characteristics as well as high tumorigenicity. Therefore, it is worthy to identify gene/proteins specifically expressed in MM SP cells, which could be essential therapeutic targets. Purpose: The aim of this study was to identify genes and transcripts that could serve as molecular markers for targeting the MM SP cells, and to identify candidate agents for the MM SP cells. Experimental design: We used Hoechst 33342 dye to detect the MM SP in five MM cell lines (RPMI 8226, AMO1, KMS-12BM, KMS-11 and JJN3) and eight primary samples. We then tested whether the MM SP cells have stem-like characteristics and performed gene expression analysis to detect genes specifically expressed in the MM SP. On that basis, we tested candidate agents such as an aurora kinase inhibitor (VX-680), a histone methyltransferase inhibitor (DZNep), lenalidomide, thalidomide and a proteasome inhibitor (bortezomib) for their ability to target MM SP cells. Results: We found that clonogenic MM SP cells exhibit “stem cell-like” properties, including self renewal, differentiation and repopulation. Gene expression analysis of MM cell lines and primary samples revealed that, in SP cells, expression of genes related to G2/M phase (e.g. CDC2, CCNB1)-, microtubule attachment (e.g. BIRC5, CENPE, SKA1)-, mitosis or centrosomes (e.g. AURKB, KIF2C, KIF11, KIF15)-, proliferation (e.g. TOP2A, ASPM)-, polycomb (e.g. EZH2, EPC1)- and proteasomes(e.g. UBE2D3, UBE3C, PSMA5)- was significantly stronger in SP than non-SP cells. On that basis, we used VX-680, DZNep, lenalidomide, thalidomide and bortezomib against MM cells. Of these, bortezomib reduced the SP fraction most effectively due to its ability to reduce levels of target gene transcripts including phospho-histone H3, aurora kinase B and EZH2. Finally we tried to examine effects of those candidate agents to “clonogenic ability of SP”, and found that bortezomib possessed the most powerful effects for reduction of SP colonies. These results suggest that bortezomib has a broader range of targets than other agents and could include cell cycle, centrosome, polycomb and proteasome genes/proteins. Conclusion: Our findings are i) the first to identify genes specifically expressed in the MM SP, ii) the first to provide a rationale for treating MM using agents against genes and encoded proteins that are specifically expressed in MM SP cells. Disclosures: Iida: Janssen Pharmaceutical K.K.: Honoraria.

Abstract 861 Background: Mantle cell lymphoma (MCL) is categorized as an indolent CD5+ B-cell lymphoma and is associated with numerous genomic copy number alterations, including 9p21 deletion (CDKN2A) and 10p12 amplification (BMI1). The target gene of the 10p12 amplification has been identified as BMI1, whose overexpression is frequently observed in the blastoid variant of MCL. CDKN2A is also well-known target of BMI1 in solid tumor. So, it has been hypothesized that BMI1 regulates CDKN2A in MCL. However there are the MCL cases with both 10p12 amplification and 9p21 homozygous deletion, suggesting that BMI1 might regulate the other target gene(s). The proto-oncogene, BMI1 is crucially involved in cancer stem cell maintenance and the upregulation has been demonstrated in aggressive or relapsed cases of solid tumors. Cancer stem cells are often identified in the side population (SP) of cancer cells, which is detected based on the cell's ability to export Hoechst 33342 dye via an ATP-binding cassette (ABC) membrane transporter, which gives the SP a distinct low-staining pattern. Aim of the study: The aim of this study is to determine the role of BMI1 in MCL initiating cells, especially in the relapsed cases. In this presentation, we show that the SP fraction has stem cell-like characteristics and high tumorigenic potential, and that BMI1 expression is upregulated in the SP in both relapsed MCL cases and MCL cell lines. Further we show that miR-16 is upstream regulator of the BMI1 in MCL. Results: To determine the role of BMI1 in the pathogenesis of MCL-initiating cells, we firstly examined BMI1 expression at primary MCL cases and found that its expression is stronger in cases of recurrent MCL than at initial diagnosis. We next characterized the MCL SP and found that the SP cells exhibit cancer stem cell-like features and upregulated BMI1 expression, which appears to enhance anti-apoptosis activity. Knocking down of BMI1 increases apoptosis and reduces tumorigenicity in CDKN2A−/− MCL cell lines (REC1 and Z138c). Subcutaneous inoculation of NOD/Shi-scid IL-2γnul (NOG) mice with CDKN2A−/− MCL cell lines, siBMI1-expressing cells were significantly smaller than those in mice receiving control siRNA in vivo. Chip assay showed that BMI1 interacts with BCL2L11/Bim and PMAIP3/Noxa, which were recently shown to be Bmi-1 target. These results suggest that BMI1/Bmi-1 may regulate Bim and/or Noxa to inhibit apoptosis in MCL cells. Furthermore, upon screening for upstream regulator of BMI1, we found that expression of a non-cording regulatory RNA, microRNA-16 (miR-16) is weaker in MCL SP cells than in non-SP cells. To investigate relationship between BMI1 and miR-16, we transfected miR-16 into MCL cell lines, and found that it directly downregulated BMI1, leading to reductions in tumor size following in vivo lymphoma xenograft (NOG mice). Finally, we find that bortezomib, which is known to be a proteasome inhibitor, led to dose-and time- dependent reductions in Bmi-1 expression with re-upregulation of miR-16 in both cell lines and a primary sample. Conclusion: We conclude that dysregulation of miR-16 and BMI1 plays a key role in lymphomagenesis by reducing MCL cell apoptosis, especially in refractory/recurrent cases via enhancement of anti apoptotic function. Disclosures: No relevant conflicts of interest to declare.