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Systemic inflammatory response syndrome and sepsis are considered to contribute to hypercytokinemia in both patients with severe infection and immunocompromised condition. Past research has demonstrated that antibiotics and antifungals not only have antimicrobial efficacy but also affect the immune system. We previously examined whether immune cells were modulated by antibiotics such as tetracyclines or macrolides. The modulation of lipopolysaccharide-stimulated cells by those agents was elucidated. However, few reports about the modulation of the immune system by antifungal agents were found. In this study, the production of pro-inflammatory cytokines and chemokines and signaling pathways involved were investigated in zymosan-activated THP-1 cells. The effects were examined using antifungal agents such as echinocandin including caspofungin (CAS) and micafungin. Pro-inflammatory cytokine and chemokine levels were determined using enzyme-linked immunosorbent assay. Protein phosphorylation was evaluated by western blot analysis. CAS significantly decreased zymosan-induced pro-inflammatory cytokine and chemokine release in THP-1 cells. CAS (30 µg/mL) also downregulated tumor necrosis factor alpha levels, as shown by enzyme-linked immunosorbent assay. In western blot analysis, inhibitor of nuclear factor-kappa-B alpha, p38, c-Jun N-terminal kinase, extracellular signal-regulated kinase, and nuclear factor of activated T-cells phosphorylation and activation of caspase-1 and spleen tyrosine kinase (Syk) were downregulated. The major underlying mechanism of pro-inflammatory cytokine and chemokine suppression by CAS is to inhibit activation of Syk and its downstream signaling molecules. Based on the results, it can be concluded that CAS activity possibly involves Syk signaling pathways and has potential to prevent hypercytokinemia in fungal sepsis.

Introduction Invasive fungal infections have been attracting attention as significant fatal complications in patients with febrile neutropenia (FN) who undergo intensive chemotherapy or hematopoietic stem cell transplantation to treat hematological malignancies. Although clinical trials are already underway in other countries, evidence supporting the use of caspofungin (CAS) in FN patients in Japan is still insufficient. Methods A retrospective study of patients treated with CAS for FN associated with hematological diseases between April 2015 and March 2018 was conducted to determine the treatment efficacy and safety. The study was conducted as a multicenter collaboration, and the data of 52 patients who met all of the inclusion criteria were analyzed. A five-composite-endpoint method was used, and the treatment was judged to be effective when all five endpoints (defervescence during neutropenia; no breakthrough fungal infections; resolution of baseline fungal infections; a survival for seven days or more after the completion of therapy; and no discontinuation of therapy due to side effects or invalidity) were met. Results The efficacy rate was 53.8% (28/52), which is close to the average reported efficacy rate. Adverse events included liver dysfunction and electrolyte abnormalities, but no renal dysfunction or serious events were seen. Conclusion These results suggest that the use of CAS in FN patients with hematological diseases is effective and well-tolerated, and we believe that the use of CAS could become a significant treatment in Japan.

Although hematological toxicities (HT) are the leading adverse events of systemic chemotherapy, the estimation of severe HT is challenging. Recently, 3′-deoxy-3′-[18F]-fluorothymidine (18F-FLT) accumulation with PET has been considered a biomarker of the cell proliferation. This study aims to elucidate whether the vertebral accumulation of 18F-FLT could estimate severe HT during platinum-doublet chemotherapy. In this Institutional Review Board–approved retrospective study, 50 patients with primary lung cancer underwent 18F-FLT PET scan before platinum-doublet chemotherapy. We evaluated the standardized uptake value, total vertebral proliferation (TVP), and TVP/body surface area (TVP/BSA) of the vertebral body (Th4, Th8, Th12, and L4), and then the associations between those parameters and frequency of severe HT during platinum-doublet chemotherapy were assessed. Severe HT (grade 3/4) was observed in 40.0% of patients during the first cycle. The ROC curve analyses revealed that the TVP/BSA of L4 was the most discriminative parameter among PET parameters for the prediction of severe HT. The multivariate logistic regression analysis revealed the TVP/BSA of L4 (odds ratio [OR], 0.94; p = 0.0036) and the frequency of the grade 3/4 hematological toxicity in previous clinical trials (OR, 1.03; p = 0.023) were independent predictors. Furthermore, the sensitivity, specificity, and accuracy of the TVP/BSA of L4 cut-off of 68.7 to predict grade 3/4 HT were 80.0%, 86.7%, and 84.0%, respectively. A low TVP/BSA of L4 (

Critically ill patients in the intensive care unit (ICU) develop muscle atrophy and decreased physical function. Though neuromuscular electrical stimulation (NMES) therapy has been shown to be effective in preventing this, but its effect on older patients is unknown. To examine the course of critically ill older patients treated with NMES in the ICU and to define the impact of its use. A retrospective cohort study was conducted using older ICU patients (≥65 years) categorized into a control group (n = 20) and an NMES group (n = 22). For subgroup analysis, each group was further classified into pre-old age (65-74 years) and old age (≥75 years). The control group showed significant decrease in muscle thickness during ICU and hospital stay. The NMES group showed lower reduction in muscle thickness and showed decrease in muscle echo intensity during hospital stay, compared to the control group. NMES inhibited decrease in muscle thickness in the pre-old age group versus the old age group. The decreasing effect of NMES on echo intensity during hospital stay manifested only in the pre-old age group. We did not find much difference in physical functioning between the NMES and control groups. Lower limb muscle atrophy reduces in critically ill older patients (≥65 years) with NMES and is pronounced in patients aged 75 years. The impact of NMES on the physical functioning of older patients in ICU needs to be further investigated.

Invasive trichosporonosis is a rare and lethal fungal infection that occurs in immunocompromised patients. Breakthrough trichosporonosis can occur in patients treated with echinocandins since Trichosporon spp. are resistant to these antifungal agents. We report a case of breakthrough Trichosporon asahii fungemia. A 62-year-old Japanese woman with relapsed follicular lymphoma was treated empirically with broad-spectrum antibiotics and micafungin due to an intermittent fever during reinduction chemotherapy. After four cycles of anti-cancer chemotherapy, she experienced a high neutropenic fever and T. asahii was subsequently detected from a blood culture. The patient was not given voriconazole due to the contraindication for use with carbamazepine, and she was successfully treated with fluconazole plus liposomal amphotericin B without any serious complications. The combined therapy of fluconazole and liposomal amphotericin B may therefore be useful in treating T. asahii fungemia, especially in patients receiving antiepileptic agents.

Although spiral bacteria are uncommon, they cause bacteremia. We evaluated their characteristics, in particular, the time from the start of blood culture to the first report of a positive result to physicians, using the BACTEC blood culture system. In cases of spiral bacteremia, an extended treatment period should be considered.

Background Cytarabine (ara-C) is the major drug for the treatment of acute myeloid leukemia (AML), but cellular resistance to ara-C is a major obstacle to therapeutic success. The present study examined enhanced anti-apoptosis identified in 3 newly established nucleoside analogue-resistant leukemic cell line variants and approaches to overcoming this resistance. Methods HL-60 human AML cells were used to develop the ara-C– or clofarabine (CAFdA)-resistant variants. The Bcl-2 inhibitor venetoclax and the Mcl-1 inhibitor alvocidib were tested to determine whether they could reverse these cells’ resistance. Results A 10-fold ara-C-resistant HL-60 variant, a 4-fold CAFdA-resistant HL-60 variant, and a 30-fold CAFdA-resistant HL-60 variant were newly established. The variants demonstrated reduced deoxycytidine kinase and deoxyguanosine kinase expression, but intact expression of surface transporters (hENT1, hENT2, hCNT3). The variants exhibited lower expression of intracellular nucleoside analogue triphosphates compared with non-variant HL-60 cells. The variants also overexpressed Bcl-2 and Mcl-1. Venetoclax as a single agent was not cytotoxic to the resistant variants. Nevertheless, venetoclax with nucleoside analogs demonstrated synergistic cytotoxicity against the variants. Alvocidib as a single agent was cytotoxic to the cells. However, alvocidib induced G1 arrest and suppressed the cytotoxicity of the co-administered nucleoside analogs. Conclusions Three new nucleoside analogue-resistant HL-60 cell variants exhibited reduced production of intracellular analogue triphosphates and enhanced Bcl-2 and Mcl-1 expressions. Venetoclax combined with nucleoside analogs showed synergistic anti-leukemic effects and overcame the drug resistance.

Enterococci is one of a major cause of bloodstream infection (BSI). Because of its intrinsic drug-resistant nature, empiric antibiotic treatment tends to be inappropriate. We conducted a single-center retrospective cohort study to evaluate the impact of Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOFMS) on the improvement of early antibiotic treatment for enterococcal infection. We also investigated the 28-day mortality, length of hospitalization and duration of antibiotic treatment for enterococcal bacteremia. A total of 173 BSI episodes (172 patients) between June 2012 and June 2019 were enrolled. Patients were divided into 2 groups before (n = 82) and after (n = 91) the implementation of MALDI-TOFMS (Control group and MALDI-TOF group, respectively). Almost an equal number of Enterococcus faecalis and Enterococcus faecium cases were identified in each group (51.2% and 48.8%, and 47.3% and 52.7% in each group). By implementing MALDI-TOFMS, the time to definitive antibiotic treatment was significantly improved (median 3 vs 1 days, p 0.001). The 28-day mortality (29.3% vs 26.4%, p = 0.63) and length of hospitalization (median 16 vs 19 days, p = 0.58) were not significantly different. The duration of antibiotic treatment did not significantly differ between the two groups (median 11 vs 11 days, p = 0.78), but the duration was often shorter in older patients (74 years old) in MALDI-TOF group, excluding those in the terminal phase of malignancy. By implementing MALDI-TOFMS, the time to definitive antibiotic treatment was significantly shortened. Although associated outcomes did not significantly differ, the duration of antibiotic treatment may be shortened.

Background The early response to treatment with immune-checkpoint inhibitors is difficult to evaluate. We determined whether changes in integrated [18F]-fluoro-2-deoxy-D-glucose positron emission tomography/MRI (18F-FDG PET/MRI) parameters after the first 2 weeks of antiprogrammed death-1 antibody nivolumab therapy could predict the response of patients with non-small cell lung cancer (NSCLC). Methods Twenty-five patients with previously treated NSCLC were enrolled prospectively and underwent 18F-FDG PET/MRI before and at 2 weeks after nivolumab therapy. Changes in maximal standardized uptake value, total lesion glycolysis (ΔTLG) and apparent diffusion coefficient (ΔADC) between the two scans were calculated and evaluated for their associations with the clinical response to therapy. Results The disease control rate was 64%. Patients with non-progressive disease (non-PD) had significantly decreased TLG, increased ADCmean (ie, negative ΔADCmean) and lower ΔTLG+ΔADCmean than patients with PD. Among the parameters tested, receiver operating characteristic curve analysis revealed that a cut-off value of 16.5 for ΔTLG+ΔADCmean had the highest accuracy (92%) for distinguishing between patients with non-PD and PD. A ΔTLG+ΔADCmean value

Cladophialophora bantiana (C. bantiana) is a life-threatening melanized mycelial fungus causing brain abscess. C. bantiana is usually observed in tropical countries, including India. We report a Japanese case of C. bantiana presenting with myelitis mimicking neuromyelitis optica (NMO) and brain abscess. A 73-year-old man was administered prednisolone (30 mg/day) for antineutrophil cytoplasmic antibody (ANCA)-related vasculitis 100 days before admission. He had right side-dominant paraplegia and sensory loss in the right leg. T2-weighted spinal cord MRI revealed longitudinal high-intensity signals at the T7 to T12 levels. A ring-enhancing lesion at the T10 level was detected on gadolinium (Gd)-enhanced MRI. He was tentatively diagnosed with NMO, and steroid pulse therapy was performed. One month later, an abscess at the right cerebropontine angle was noted on Gd-enhanced brain MRI. Two months later, several subcutaneous intramuscular tumors were detected. Based on the morphological study of the cultured organelle obtained by tumor enucleation and the internal transcribed spacer sequence of ribosomal RNA, the pathogen was identified as C. bantiana. Although he received liposomal amphotericin B treatment, the patient died of respiratory insufficiency. C. bantiana infection should be considered in patients with myelitis presenting with longitudinal lesions and CNS abscess in an immunocompromised state.

YM155, a novel small molecule inhibitor of survivin, shows broad anticancer activity. Here, we have focused on the cytotoxic activity of YM155 against multiple myeloma (MM) including cytokinetically quiescent (G0/G1) cells and bortezomib resistant cells. YM155 strongly inhibited the growth of MM cell lines with the IC50 value of below 10 nM. YM155 also showed potent anti-myeloma activity in mouse xenograft model. YM155 suppressed the expression of survivin and rapidly directed Mcl-1 protein for proteasome degradation. YM155 abrogated the interleukin-6-induced STAT3 phosphorylation, subsequently blocked Mcl-1 expression and induced apoptosis in MM cells. Triple-color flow cytometric analysis revealed that YM155 potently induced cell death of MM cells in G0 phase. Quiescent primary MM cells were also sensitive to YM155. We established bortezomib-resistant MM cell line, U266/BTZR1, which possess a point mutation G322A. YM155 exhibited similar cytotoxic potency against U266/BTZR1 compared with parental cells. Interestingly, survivin expression was markedly elevated in U266/BTZR1 cells. Treatment with YM155 significantly down-regulated this increased survivin and Mcl-1 expression in U266/BTZR1 cells. In conclusion, our data indicate that YM155 exhibits potent cytotoxicity against quiescent (G0/G1) MM cells and bortezomib-resistant cells. These unique features of YM155 may be beneficial for the development of new therapeutic strategies to eliminate quiescent MM cells and overcome bortezomib resistance.

As one of the countermeasures against infection at medical institutions, thorough hand hygiene is extremely important. In Japan, these controls are not sufficient. management, it is necessary to track the hand washing situation. Therefore, we decided to monitor the condition of hand washing by utilizing IoT. use IoT in our hospital, we decided to follow up using these environments. As a result, it is possible to collect data continuously for 24 hours, 365 days, and evaluate infection risk based on data. location information on smartphone, so we can also track work. We are considering support for medical staff by utilizing smart devices.

BackgroundThe early response to treatment with immune-checkpoint inhibitors is difficult to evaluate. We determined whether changes in integrated [18F]-fluoro-2-deoxy-D-glucose positron emission tomography/MRI (18F-FDG PET/MRI) parameters after the first 2 weeks of antiprogrammed death-1 antibody nivolumab therapy could predict the response of patients with non-small cell lung cancer (NSCLC).MethodsTwenty-five patients with previously treated NSCLC were enrolled prospectively and underwent18F-FDG PET/MRI before and at 2 weeks after nivolumab therapy. Changes in maximal standardized uptake value, total lesion glycolysis (ΔTLG) and apparent diffusion coefficient (ΔADC) between the two scans were calculated and evaluated for their associations with the clinical response to therapy.ResultsThe disease control rate was 64%. Patients with non-progressive disease (non-PD) had significantly decreased TLG, increased ADCmean(ie, negative ΔADCmean) and lower ΔTLG+ΔADCmeanthan patients with PD. Among the parameters tested, receiver operating characteristic curve analysis revealed that a cut-off value of 16.5 for ΔTLG+ΔADCmeanhad the highest accuracy (92%) for distinguishing between patients with non-PD and PD. A ΔTLG+ΔADCmeanvalue meanvalue ≥16.5. A multivariate Cox model revealed that ≥16.5 ΔTLG+ΔADCmeanwas an independent predictor of shorter progression-free survival (HR 37.7) and overall survival (HR 9.29).ConclusionsA combination of ΔTLG and ΔADCmeanmeasured by integrated18F-FDG PET/MRI may have value as a predictor of the response and survival of patients with NSCLC following nivolumab therapy.Trial registration numberUMIN 000020707.

Although hematological toxicities (HT) are the leading adverse events of systemic chemotherapy, the estimation of severe HT is challenging. Recently, 3'-deoxy-3'-[In this Institutional Review Board-approved retrospective study, 50 patients with primary lung cancer underwentSevere HT (grade 3/4) was observed in 40.0% of patients during the first cycle. The ROC curve analyses revealed that the TVP/BSA of L4 was the most discriminative parameter among PET parameters for the prediction of severe HT. The multivariate logistic regression analysis revealed the TVP/BSA of L4 (odds ratio [OR], 0.94; p = 0.0036) and the frequency of the grade 3/4 hematological toxicity in previous clinical trials (OR, 1.03; p = 0.023) were independent predictors. Furthermore, the sensitivity, specificity, and accuracy of the TVP/BSA of L4 cut-off of 68.7 to predict grade 3/4 HT were 80.0%, 86.7%, and 84.0%, respectively. A low TVP/BSA of L4 ( 68.7) as a binary variable was a significant indicator of severe HT (OR, 26.0; p = 0.000026).The lowTrial registration: UMIN000027540 KEY POINTS: • The vertebral

Bacillus cereus can spread easily in various environments and can contaminate medical environments, such as ventilator equipment, intravascular catheters, and linen. B. cereus is known to infect immunocompromised patients. Although nosocomial B. cereus outbreaks are often reported, effective preventive measures are not clarified. We report an outbreak of B. cereus catheter-related bloodstream infection (CRBSI) in the pediatric ward and aim at identifying risk factors and effective infection control measures for the outbreak. The nurse station at the pediatric ward and blood cultures were assessed. Sterilization of devices has been ensured thereafter. We identified common risk factors including catheter placement for liquid nutrition, use of high-caloric amino-acid-containing infusion fluid, immunocompromised patients, and contact of the catheter route with the floor. Intervention by the Infection Control Team and educating the medical staff regarding methods of disinfection, including scrubbing the facility, helped terminate the outbreak. We discuss a pre-emptive intervention to terminate the outbreak of CRBSI.

Gemtuzumab ozogamicin (GO) consists of the cluster of differentiation 33 (CD33) antibody linked to calicheamicin. The binding of GO to the CD33 antigen on leukemic cells results in internalization and subsequent release of calicheamicin, thereby inducing DNA strand breaks. We hypothesized that the poly (ADP-ribose) polymerase inhibitor olaparib might inhibit DNA repair initiated by GO-induced DNA strand breaks, thereby increasing cytotoxicity.The human myeloid leukemia cell line HL-60 and a GO-resistant variant (HL/GO20) were used.The 50% growth-inhibitory concentrations (IC50) were 24 ng/ml for HL-60 cells and 550 ng/ml for GO-resistant variant HL/GO20 cells. HL/GO20 cells were also refractory to GO-induced apoptosis. CD33 positivity was reduced in HL/GO20 cells. Olaparib-alone did not inhibit the cell growth and did not induce apoptosis in either HL-60 cells or HL/GO20 cells at concentrations of up to 10 μM. When cells were treated with different concentrations of GO in the presence of 10 μM olaparib, the IC50 of GO for HL-60 cells was 13 ng/ml. The combination index was 0.86, indicating synergistic cytotoxicity of GO and olaparib in combination. Such a combination was ineffective for HL/GO20 cells.GO and olaparib exerted synergistic cytotoxicity in CD33-positive myeloid leukemia cells in vitro.

Clofarabine is transported into leukemic cells via the equilibrative nucleoside transporters (hENT) 1 and 2 and the concentrative nucleoside transporter (hCNT) 3, then phosphorylated by deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK) to an active triphosphate metabolite. Cytarabine uses hENT1 and dCK for its activation. We hypothesized that cytarabine-resistant leukemia cells retain sensitivity to clofarabine.Human myeloid leukemia HL-60 cells and cytarabine-resistant variant HL/ara-C20 cells were used in the present study.Despite 20-fold cytarabine resistance, the HL/ara-C20 cells exhibited only a 6-fold resistance to clofarabine compared to HL-60 cells. The intracellular concentration of the triphosphate metabolite of cytarabine was reduced to 1/10, and that of clofarabine was halved in the HL/ara-C20 cells. hENT1 and dCK were reduced, but hCNT3 and dGK were not altered in the HL/ara-C20 cells, which might contribute to their retained capability to produce intracellular triphosphate metabolite of clofarabine.Clofarabine was cytotoxic to leukemia cells that were resistant to cytarabine.

s Background Arsenic trioxide (ATO) is reported to be an effective therapeutic agent in acute promyelocytic leukemia (APL) through inducing apoptotic cell death. Buthionine sulfoximine (BSO), an oxidative stress pathway modulator, is suggested as a potential combination therapy for ATO-insensitive leukemia. However, the precise mechanism of BSO-mediated augmentation of ATO-induced apoptosis is not fully understood. In this study we compared the difference in cell death of HL60 leukemia cells treated with ATO/BSO and ATO alone, and investigated the detailed molecular mechanism of BSO-mediated augmentation of ATO-induced cell death. Methods HL60 APL cells were used for the study. The activation and expression of a series of signal molecules were analyzed with immunoprecipitation and immunoblotting. Apoptotic cell death was detected with caspases and poly (ADP-ribose) polymerase activation. Generation of intracellular reactive oxygen species (ROS) was determined using a redox-sensitive dye. Mitochondrial outer membrane permeabilization was observed with a confocal microscopy using NIR dye and cytochrome c release was determined with immunoblotting. Small interfering (si) RNA was used for inhibition of gene expression. Results HL60 cells became more susceptible to ATO in the presence of BSO. ATO/BSO-induced mitochondrial injury was accompanied by reduced mitochondrial outer membrane permeabilization, cytochrome c release and caspase activation. ATO/BSO-induced mitochondrial injury was inhibited by antioxidants. Addition of BSO induced phosphorylation of the pro-apoptotic BCL2 protein, BIMEL, and anti-apoptotic BCL2 protein, MCL1, in treated cells. Phosphorylated BIMEL was dissociated from MCL1 and interacted with BAX, followed by conformational change of BAX. Furthermore, the knockdown of BIMEL with small interfering RNA inhibited the augmentation of ATO-induced apoptosis by BSO. Conclusions The enhancing effect of BSO on ATO-induced cell death was characterized at the molecular level for clinical use. Addition of BSO induced mitochondrial injury-mediated apoptosis via the phosphorylation of BIMEL and MCL1, resulting in their dissociation and increased the interaction between BIMEL and BAX.

Clofarabine (CAFdA) is incorporated into leukemic cells by human equilibrative nucleoside transporters (hENT) 1 and 2 and human concentrative nucleoside transporter (hCNT) 3. CAFdA is then phosphorylated to the active metabolite CAFdA triphosphate (CAFdATP) by deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK). Two novel CAFdA-resistant variants were established and their mechanism of resistance was elucidated. The two variants (HL/CAFdA20, HL/CAFdA80) were 20-fold and 80-fold more CAFdA-resistant than HL-60, respectively. mRNA levels of hENT1, hENT2 and hCNT3 were 53.9, 41.8 and 17.7% in HL/CAFdA20, and 30.8, 13.9 and 7.9% in HL/CAFdA80, respectively, compared with HL-60. Thus, the total nucleoside transport capacity of CAFdA was reduced in both variants. dCK protein levels were 1/2 in HL/CAFdA20 and 1/8 in HL/CAFdA80 of that of HL-60. dGK protein levels were 1/2 and 1/3, respectively. CAFdATP production after 4-h incubation with 10 μM CAFdA was 20 pmol/10(7) cells in HL/CAFdA20 and 3 pmol/10(7) cells in HL/CAFdA80 compared with 63 pmol/10(7) cells in HL-60. The decreased CAFdATP production attenuated drug incorporation into both mitochondrial and nuclear DNA. In addition, the two variants were resistant to CAFdA-induced apoptosis due to Bcl2 overexpression and decreased Bim. A Bcl2 inhibitor, ABT737, acted synergistically with CAFdA to inhibit the growth with combination index values of 0.27 in HL/CAFdA20 and 0.23 in HL/CAFdA80, compared with 0.65 in HL-60. Thus, the mechanism of resistance primarily included not only reduced CAFdATP production, but also increased antiapoptosis. The combination of CAFdA and ABT737 may be effective against CAFdA resistance.

Multiple myeloma (MM) is a molecularly heterogeneous hematologic malignancy and remains mostly incurable despite the recent improvement of treatment strategies by several novel agents. Therefore, it is important to develop more efficacious drug against MM. YM155, a novel small molecule suppressant of survivin, shows anti-proliferative activities against various human cancer cells. YM155 was identified in a survivin gene promoter assay by high throughput screening of chemical libraries. In the present study, we investigated the cytotoxic mechanism of YM155 against human myeloma cells including bortezomib (BTZ) resistant cells (U266/BTZ). Three myeloma cell lines, U266, KMS-11 and KMS-12, were employed. YM155 inhibited the cell growth of these cell lines with the IC50 value of below 5 nM. YM155 suppressed the expression of mRNA and protein of survivin. We also found that YM155 inhibited the protein expression of Mcl-1, as an essential anti-apoptotic protein for survival of myeloma cells. In addition, we observed that YM155 markedly suppressed the phosphorylation of STAT3, which is known as transcription factor of Mcl-1. When KMS-12 cells were incubated with IL-6, phosphorylation of STAT3 and upregulation of Mcl-1 protein were observed. Treatment of KMS-12 with YM155 inhibited these events and eventually induced apoptosis in KMS-12 cells. Interestingly, inhibitory effect of YM155 on Mcl-1 protein expression was much stronger than that on survivin. RQ-PCR analysis indicated that the level of Mcl-1 mRNA was not affected after YM155 treatment. Immunoblot analysis showed that proteasome inhibitor MG-132 blocked the inhibition of Mcl-1 expression by YM155, suggesting that proteasome-mediated degradation is involved in YM155-induced Mcl-1 downregulation. MM is a low-growth-fraction disease and low proliferation of MM seems to contribute to resistance to various anticancer drugs. To determine whether YM155 shows cytotoxic effect against quiescent (G0/G1) MM cells, U266 were cultured in low-serum medium to enrich the G0/G1 population. Dual-parametric flow cytometric analysis using Hoechest33342 and the RNA specific dye pyronin Y revealed that YM155 potently induced cell death of quiescent (G0/G1) MM cells. In quiescent MM cells, inhibitory effect of YM155 on Mcl-1 protein expression was much stronger than that on survivin. We also examined whether similar effect of YM155 could be observed in primary MM cells. The majority of primary MM cells from patients was found to be in quiescent phase by cell-cycle analysis. YM155 showed similar cytotoxic activity against primary MM cells. In contrast, Ara-C, the S-phase specific anticancer drug, never killed quiescent primary MM cells. We established BTZ-resistant MM cell line (U266/BTZ). The IC50 value was 45-fold higher than its parental cell line. DNA sequencing data indicated that U266/BTZ cells possess a point mutation, G322A, in the gene encoding the proteasome beta-5 subunit. YM155 almost equally exhibited cytotoxic activity against U266/BTZ compared with parental cells. U266/BTZ displayed significantly lowered amounts of bcl-2, survivin and aurora-B kinase proteins. Interestingly, U266/BTZ overexpressed the Mcl-1 protein. Treatment with YM155 rapidly suppressed Mcl-1 protein expression and induced apoptosis. These data suggest that overexpression of Mcl-1 may contribute to bortezomib resistance and downregulation of Mcl-1 by YM155 could overcome it. In conclusion, our data indicate that YM155 may exert robust cytotoxic activity against quiescent (G0/G1) MM and bortezomib resistant cells via inhibition of Mcl-1 and survivin. Disclosures No relevant conflicts of interest to declare.

Accumulating evidence suggests the possible association between the concentrations of serum brain-derived neurotrophic factor (BDNF) and psychiatric disease with impaired brain development. Yet the reasons remain unclear. We therefore investigated the characteristics of serum BDNF as well as its age-related changes in healthy controls in comparison to autism cases. BDNF was gradually released from platelets at 4 degrees C, reached a maximal concentration after around 24 h, and remained stable until 42 h. At room temperature, BDNF was found to be immediately degraded. Circadian changes, but not seasonal changes, were found in serum levels of BDNF existing as the mature form with a molecular mass of 14 kDa. In healthy controls, the serum BDNF concentration increased over the first several years, then slightly decreased after reaching the adult level. There were no sex differences between males and females. In the autism cases, mean levels were significantly lower in children 0-9 years old compared to teenagers or adults, or to age-matched healthy controls, indicating a delayed BDNF increase with development. In a separate study of adult rats, a circadian change in serum BDNF was found to be similar to that in the cortex, indicating a possible association with cortical functions.

A 77-year-old man treated with prednisolone for pemphigus developed severe sepsis by Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Several antibiotics were administered. A peripheral blood smear showed growth of a large number of yeast extending pseudohyphae which could be seen both inside and outside of leucocytes. Antifungal agents were added immediately; however, he did not recover. Several days later, blood culture showed Candida albicans septicemia. The autopsy revealed microabscesses in the lung, heart, liver and kidney. A large amount of neutrophil invasion and yeast with pseudohyphae were also detected.

Current first-line treatment options for chronic myeloid leukemia (CML) include imatinib (IM) and the second-generation agents nilotinib and dasatinib. Despite the effectiveness of these tyrosine kinase inhibitors, a small percentage of chronic-phase CML patients are primarily refractory or acquire secondary resistance to these agents. Moreover, the prognosis of patients in blast crisis is still poor despite the use of the current treatment modalities because of drug resistance. The major mechanism of drug resistance is the re-activation of ABL kinase either through mutations in the BCR-ABL gene or by BCR-ABLgene amplification. A novel pan-histone deacetylase inhibitor, panobinostat (formerly LBH589), induces the acetylation of heat shock protein 90, thereby inhibiting its chaperone function in association with its client proteins BCR-ABL, leading to the degradation of BCR-ABL. A new pan–ABL tyrosine kinase inhibitor, ponatinib, is a promising therapeutic option in patients with all kinds of BCR-ABLmutation including T315I. It was thus hypothesized that the combination of panobinostat and ponatinib exerts synergistic cytotoxicity against IM-resistant cells through a mechanism of action different from that of each agent. To test this hypothesis, K562/IM-R1 and Ba/F3/T315I cell lines were evaluated for the cytotoxicity of panobinostat and ponatinib in vitro. K562/IM-R1 cells, established in our previous study, showed BCR-ABL overexpression due to BCR-ABL gene amplification. The Ba/F3/T315I cell line showed BCR-ABL with a T315I mutation. The XTT proliferation assay revealed that K562/IM-R1 cells were 12-fold more IM-resistant (50%-inhibitory concentration (IC50), 7.6 µM) than K562 cells (IC50, 0.6 µM). Ba/F3/T315I cells were refractory to IM treatment (IC50, 34.1 µM) compared with Ba/F3 cells (IC50, 3.4 µM). Panobinostat overcame IM-resistance and inhibited similarly the growth of K562, K562/IM-R1, Ba/F3, and Ba/F3/T315I cells, with IC50 values of around 50 nM (40.0 - 51.0 nM). Ponatinib inhibited the growth of both K562/IM-R1 cells (IC50, 4 nM) and Ba/F3/T315I cells (25 nM) as potently as parental K562 cells (IC50, 2 nM) and Ba/F3 cells (IC50, 5 nM). Importantly, the combination of panobinostat and ponatinib exhibited enhanced growth inhibition effects on all cell lines. The IC50 values for this combination were 0.7 nM for K562 cells, 1.3 nM for K562/IM-R1 cells, 3.7 nM for Ba/F3 cells, and 10 nM for Ba/F3/T315I cells. The combination index clearly showed synergism, with values of 0.5 for K562 cells, 0.28 for K562/IM-R1 cells, 0.9 for Ba/F3 cells, and 0.4 for Ba/F3/T315I cells. When the cells were treated with 10 nM panobinostat or 10 nM ponatinib for 48 h alone or in combination, the combination of the 2 agents led to greater-than-additive apoptotic cell death than each agent alone in all cell lines, evaluated by annexin V-positivity. Western blotting was used to evaluate the protein expression levels of BCR-ABL and phospho-BCR-ABL in cells after treatment with panobinostat or ponatinib or both in combination. BCR-ABL expression was greater in K562/IM-R1 than K562 cells. Phospho-BCR-ABL expression was not inhibited by IM in K562/IM-R1 or Ba/F3/T315I cells. However, ponatinib inhibited the autophosphorylation of BCR-ABL in these cell lines. Treatment with panobinostat reduced the BCR-ABL and phospho-BCR-ABL expression levels in K562/IM-R1 and Ba/F3/T315I cells. The combination of the 2 agents augmented inhibition of the autophosphorylation of BCR-ABL in these IM-resistant cell lines. The activity of histone deacetylase, determined using the HDAC assay Kit (Active Motif, Carlsbad, CA, USA), was inhibited by panobinostat in all cell lines regardless of IM sensitivity. In comparison, IM did not alter cellular histone deacetylase activity. Upon treatment of K562 cells with panobinostat, the protein expression levels of acetylated histone H3 and H4 were increased, suggesting the consequence of the inhibition of histone deacetylase. In conclusion, we firstly reported that panobinostat and ponatinib demonstrated synergistic cytotoxicity against IM-resistant cell lines not only due to BCR-ABL gene amplification but also BCR-ABL T315I mutation. The synergism is attributable to the greater inhibition of ABL kinase activity through a mechanism of action different from that of each agent. Disclosures: No relevant conflicts of interest to declare.

Abstract 1356 Clofarabine(2-Chloro-9-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)adenine,2-chloro-2'-arabino-fluoro-2'-deoxyadenosine, CAFdA) is a relatively new purine nucleoside analog. Upon administration, CAFdA is incorporated into leukemic cells by human Equilibrative Nucleoside Transporters (hENT) 1 and 2, and human Concentrative Nucleoside Transporter (hCNT) 3. Inside the cell, the agent is phosphorylated to CAFdA monophosphate by cytosolic deoxycytidine kinase (dCK) and mitochondrial deoxyguanosine kinase (dGK), and then to an intracellular active metabolite CAFdA triphosphate (CAFdATP). CAFdATP inhibits ribonucleotide reductase and is incorporated into DNA, thereby terminating DNA synthesis as an antimetabolite. Moreover, CAFdA induces apoptosis via direct mitochondrial damage. Clinical studies suggest that CAFdA is effective against both acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). CAFdA therapy should be optimized based on the mechanistic understanding, because pharmacological determinants that correlate to the drug sensitivity may predict clinical efficacy of CAFdA as biological surrogate markers. Here, we have established two novel leukemic cell line variants that were resistant to CAFdA, and elucidated the mechanism of the drug resistance. The study focused on factors that were involved in the intracellular CAFdATP production and in the induction of apoptosis. To develop resistant variants, HL-60 cells were treated with escalating concentrations of CAFdA with the initial concentration at 1/100 of the concentration that inhibited 50% cell growth. After 7 months of the repeated passage, one cell line resistant to CAFdA (HL/CAFdA20) was cloned by the limiting dilution method. A part of this clone was further maintained with the drug for the subsequent 4 months to develop another variant (HL/CAFdA80). The 2 variants were 20- and 80-fold more CAFdA-resistant than HL-60 cells, respectively. They were cross-resistant to similar nucleoside analogs such as cladribine, gemcitabine, and cytarabine. Compared with HL-60 cell line, mRNA levels of the transporters (hENT1, hENT2, hCNT3) and protein levels of kinases (dCK, dGK), and the subsequent production of intracellular CAFdATP were all reduced in both CAFdA-resistant variants. Real time RT-PCR demonstrated that mRNA levels of hENT1, hENT2, and hCNT3 were 53.9%, 41.8%, 18.3% in HL/CAFdA20 cells, and 30.8%, 41.6%, 31.5% in HL/CAFdA80 cells, respectively, compared to the parental cells. The values of the initial uptake of CAFdA into the cell at 40 seconds after administration of tritiated CAFdA are 0.2 pmol/107cells in HL/CAFdA20 cells, and 0.1 pmol/107cells in HL/CAFdA80 cells, compared with 0.6 pmol/107 cells in parental HL60 cells. Western blotting revealed that protein levels of kinases were also reduced in these resistant variants with the greater reduction in HL/CAFdA80 cells. The subsequent production of CAFdATP after 4-h incubation with 10 μM CAFdA was 20 pmpl/107 cells in HL/CAFdA20 cells, 3 pmol/107cells in HL/CAFdA80 cells, and 63 pmol/107cells in HL-60 cells. The decreased CAFdATP production led to the attenuated incorporation of the drug into both mitochondrial and nuclear DNA. Concerning apoptosis, antiapoptotic Bcl2 protein overexpressed in the 2 resistant variants. The two variants were resistant to mitochondria-related apoptosis induced by CAFdA, in part due to the enhanced Bcl2 expression. A Bcl2 inhibitor ABT737 synergized the cytotoxic effect and the growth inhibition effect of CAFdA in both variants and HL-60, but the synergism was more profound in the resistant cell lines. The Combination Index values were 0.27 in HL/CAFdA20 cells, and 0.21 in HL/CAFdA80 cells, compared with 0.63 in HL-60 cells. This suggested the contribution of the enhanced Bcl2 protein to the mechanism of drug resistance. In conclusion, the mechanism of cellular resistance to CAFdA in the 2 variants was multifactorial, but primarily includes the reduced CAFdATP production and the increased antiapoptotic factor. It is noted that the decreased dGK level and Bcl2 overexpression were not reported previously in the context of CAFdA resistance. We suggest combination of CAFdA and ABT737 might be effective to CAFdA resistant and refractory leukemia. (This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan. No.23501307) Disclosures: No relevant conflicts of interest to declare.