Kazunori Miyake

MDM2 Antagonist Nutlin-3 Displays Antiproliferative and Proapoptotic Activity in Mantle Cell Lymphoma

Purpose: Mantle cell lymphoma (MCL) has one of the poorest prognoses of the non-Hodgkins lymphomas, and novel therapeutic approaches are needed. We wished to determine whether Nutlin-3, a novel small-molecule murine double minute 2 (MDM2) antagonist that efficiently activates TP53, might be effective in inducing cell death in MCL. Experimental Design: MCL cell lines with known TP53 status were treated with Nutlin-3, and biological and biochemical consequences were studied. Synergies with the prototypic genotoxic agent doxorubicin and the novel proteasome inhibitor bortezomib were assessed. Results: Nutlin-3 resulted in a reduction in cell proliferation/viability (IC50 < 10 μmol/L), an increase in the apoptotic fraction, and cell cycle arrest in wild-type (wt) TP53 Z-138 and Granta 519 cells. These effects were accompanied by TP53 accumulation and induction of TP53-dependent proteins p21, MDM2, Puma, and Noxa. Cell cycle arrest was characterized by suppression of S phase and an increase in the G0-G1 and G2-M fractions and accompanied by suppression of total and phosphorylated retinoblastoma protein and a decrease in G2-M-associated proteins cyclin B and CDC2. The combination of Nutlin-3 with doxorubicin or bortezomib was synergistic in wt-TP53 MCL cells. Nutlin-3 also induced cell cycle arrest and reduced cell viability in the mutant TP53 MINO cells but at a significantly higher IC50 (22.5 μmol/L). These effects were associated with induction of the TP53 homologue p73, slight increases in p21 and Noxa, and caspase activation. Nutlin-3 and bortezomib synergistically inhibited cell growth of MINO. Conclusion: These findings suggest that the MDM2 antagonist Nutlin-3 may be an effective agent in the treatment of MCL with or without wt-TP53.

Novel role of HDAC inhibitors in AML1/ETO AML cells: activation of apoptosis and phagocytosis through induction of annexin A1

The chimeric fusion protein AML1-ETO, created by the t(8;21) translocation, recruits histone deacetylase (HDAC) to AML1-dependent promoters, resulting in transcriptional repression of the target genes. We analyzed the transcriptional changes in t(8;21) Kasumi-1 AML cells in response to the HDAC inhibitors, depsipeptide (FK228) and suberoylanilide hydroxamic acid (SAHA), which induced marked growth inhibition and apoptosis. Using cDNA array, annexin A1 (ANXA1) was identified as one of the FK228-induced genes. Induction of ANXA1 mRNA was associated with histone acetylation in ANXA1 promoter and reversal of the HDAC-dependent suppression of C/EBPα by AML1-ETO with direct recruitment of C/EBPα to ANXA1 promoter. This led to increase in the N-terminal cleaved isoform of ANXA1 protein and accumulation of ANXA1 on cell membrane. Neutralization with anti-ANXA1 antibody or gene silencing with ANXA1 siRNA inhibited FK228-induced apoptosis, suggesting that the upregulation of endogenous ANXA1 promotes cell death. FK228-induced ANXA1 expression was associated with massive increase in cell attachment and engulfment of Kasumi-1 cells by human THP-1-derived macrophages, which was completely abrogated with ANXA1 knockdown via siRNA transfection or ANXA1 neutralization. These findings identify a novel mechanism of action of HDAC inhibitors, which induce the expression and externalization of ANXA1 in leukemic cells, which in turn mediates the phagocytic clearance of apoptotic cells by macrophages.

PML-RARα and AML1–ETO translocations are rarely associated with methylation of the RARβ2 promoter

The acute promyelocytic leukemia-specific PML–RARα fusion protein is a dominant-negative transcriptional repressor of retinoic acid receptor (RAR) target genes, which recruits HDAC and corepressor proteins and inhibits coactivators. Another oncogenic transcription factor, AML1–ETO, was proposed to cause an HDAC-dependent repression of RAR target genes. The RAR target RARβ2 gene has been reported to be frequently silenced by hypermethylation in many types of cancer cells. We examined the methylation status of the RARβ2 and asked if demethylation could reverse ATRA resistance in ATRA-resistant PML–RARα and AML1–ETO-positive cells. PML–RARα positive NB4 and its ATRA-resistant subvariant MR2 and AML1–ETO expressing Kasumi-1 cells had heterozygous methylation of RARβ2. Although DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine partially reversed RARβ2 CpG methylation in these cells, it did not significantly enhance ATRA-induced RARβ2 mRNA expression and induction of maturation. However, the histone acetylase inhibitor SAHA combined with ATRA significantly reactivated RARβ2 mRNA both in NB4 and MR2 cells with degradation of PML–RARα, which was associated with maturation. In contrast, SAHA did not affect AML1–ETO levels and failed to induce RARβ2 expression and maturation in Kasumi-1 cells. In primary AML samples, RARβ2 expression was uniformly low; however, no specific correlation was observed between the methylation of the RARβ2 gene and expression of the fusion proteins, PML–RARα, and AML1–ETO. These results demonstrate that oncogenic PML–RARα and AML1–ETO translocations are rarely associated with RARβ2 promoter methylation in primary AML samples.

Seasonal variation in liver function tests: a time-series analysis of outpatient data

Background Long-term physiological variations, such as seasonal variations, affect the screening efficiency at medical checkups. This study examined the seasonal variation in liver function tests using recently described data-mining methods. Methods The ‘latent reference values’ of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase (γGT), cholinesterase (ChE) and total bilirubin (T-Bil) were extracted from a seven-year database of outpatients (aged 20–79 yr; comprising approximately 1,270,000 test results). After calculating the monthly means for each variable, the time-series data were separated into trend and seasonal components using a local regression model (Loess method). Then, a cosine function model (cosinor method) was applied to the seasonal component to determine the periodicity and fluctuation range. A two-year outpatient database (215,000 results) from another hospital was also analysed to confirm the reproducibility of these methods. Results The serum levels of test results tended to increase in the winter. The increase in AST and ALT was about 6% in men and women, and was greater than that in ChE, ALP (in men and women) and γGT (in men). In contrast, T-Bil increased by 3.6% (men) and 5.0% (women) in the summer. The total protein and albumin concentrations did not change significantly. AST and ALT showed similar seasonal variation in both institutions in the comparative analysis. Conclusions The liver function tests were observed to show seasonal variations. These seasonal variations should therefore be taken into consideration when establishing either reference intervals or cut-off values, which are especially important regarding aminotransferases.

Association between antimicrobial consumption and clinical isolates of methicillin-resistant Staphylococcus aureus: a 14-year study

The objective of this study was to determine the relationship between clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and antimicrobial consumption in hospitalized patients over a 14-year period. The study was retrospectively conducted between January 1995 and December 2008 at Juntendo University Hospital, Tokyo, Japan, a 1,020-bed tertiary-care teaching hospital. The incidence of MRSA isolates was examined using clinical specimens presented to the microbiology laboratory in the hospital. Antimicrobial consumption through intravenous injection was calculated in terms of the number of defined daily doses per 100 bed-days. The correlation between the incidence of MRSA isolates and antimicrobial consumption was determined employing a multiple stepwise regression analysis. A total of 109,946 bacterial isolates were consecutively collected over the 14-year period, and, of these, 13,872 (64% of S. aureus strains excluding coagulase-negative staphylococci) were MRSA strains. The longitudinal observation showed that the number and rate of MRSA isolates marginally decreased. The rate of MRSA isolates among S. aureus strains in 1995 was 68.5%, whereas that in 2008 was 53.8%. Consumption of cephalosporins decreased. Among carbapenems, the rate of imipenem (IPM) consumption decreased, whereas that of meropenem increased. A multiple stepwise regression analysis revealed that the antimicrobial consumption of cefmetazole, cefotiam, and IPM was positively correlated with the incidence of MRSA isolates. The use of β-lactam antimicrobials may contribute to the development of MRSA strains.

Mean postprandial triglyceride concentration is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes.

BACKGROUND Postprandial hypertriglyceridemia is a risk factor for atherosclerotic disease. However, the postprandial triglyceride (PTG) concentration fluctuates markedly and is poorly reproducible. The aim of this study was to determine whether the mean PTG (mean-PTG) concentration is a risk factor for carotid atherosclerosis in patients with type 2 diabetes. METHODS We measured the fasting and postprandial lipid concentrations, and the maximum intima-media thickness (max IMT) of carotid arteries by ultrasound in 115 diabetic patients. A carotid plaque was defined as max IMT of >1.0mm. The mean-PTG concentration was calculated from several PTG concentrations measured on different days during a 1-year follow-up period. RESULTS PTG concentrations showed marked intra-individual variability, and ranged from 0.29 to 6.03 mmol/l. Patients with carotid plaques had higher mean-PTG concentrations than those without carotid plaques (1.51 ± 0.57 vs. 1.29 ± 0.47 mmol/l, p=0.025). Neither fasting triglycerides nor one-point PTG concentrations differed between the two groups. Multivariate stepwise logistic regression analysis revealed that the mean-PTG concentration was significantly associated with carotid plaques [OR 1.20 (95% CI, 1.05-1.37), p=0.009], even after adjusting for traditional risk factors including HDL-cholesterol, LDL-cholesterol, age, hypertension, and duration of diabetes. CONCLUSIONS The mean-PTG concentration is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes.

The use of CellaVision competency software for external quality assessment and continuing professional development

Aims Quality assessment of blood cell morphological testing, such as white blood cell (WBC) differential and its interpretation, is one of the most important and difficult assignments in haematology laboratories. A monthly survey was performed to assess the possible role of the proficiency testing program produced by CellaVision competency software (CCS) in external quality assessment (EQA) of the clinical laboratories of affiliated university hospitals and the effective utilisation of this program in continuing professional development (CPD). Methods Four monthly proficiency surveys were conducted in collaboration with four clinical laboratories affiliated with the teaching hospitals of Juntendo University of Medicine in Japan. Results EQA results by the CCS proficiency testing program revealed a difference of performance levels of WBC differential and morphological interpretation and a discrepancy in the WBC differential criteria among laboratories. With regard to the utilisation of this proficiency program as a tool for CPD, this program successfully improved the performance of the low-scoring laboratories and less experienced individuals. Conclusions The CCS proficiency testing program was useful for the quality assessment of laboratory performance, for education, and for the storage and distribution of cell images to be utilised for further standardisation and education.

Low adiponectin state is associated with metabolic abnormalities in obese children, particularly depending on apolipoprotein E phenotype

Background Adiponectin links obesity with insulin resistance, which causes various metabolic abnormalities including dyslipidaemia. Apolipoprotein E (apoE) phenotypes also affect lipoprotein profiles. We aimed to determine whether low adiponectin concentrations are associated with insulin resistance and downstream metabolic abnormalities in obese children. Methods We measured fasting concentrations of lipids, apoE, glucose, insulin and adiponectin, as well as anthropometric parameters, in 191 obese children aged 6–15 years. ApoE phenotypes were determined by isoelectric focusing. Boys (n = 79) and girls (n = 39) with apoE3/3 were classified into tertiles according to their adiponectin concentrations. Metabolic parameters, were compared among these three groups in boys and girls separately. Results The low adiponectin groups had higher median homeostasis model assessment of insulin resistance (HOMA-IR) than the middle and high adiponectin groups in both boys [5.3 (low) versus 3.1 (middle; P < 0.05) and 3.5 (high; P < 0.05)] and girls [5.0 (low) versus 4.4 (middle) and 3.0 (high; P < 0.05)]. However, only boys who were in the low adiponectin group exhibited significantly higher concentrations of blood pressure, triglycerides, LDL-cholesterol, and remnant-like particle-cholesterol, and lower concentrations of HDL-cholesterol compared with the middle or high adiponectin groups. Conclusion Low adiponectin concentration is associated with insulin resistance in obese children. Furthermore, decreased adiponectin with E3/3 exhibited more prominent downstream metabolic abnormalities in obese boys than in obese girls.

Small cell carcinoma of the uterine cervix metastasizing to the bone marrow: A case report

We report a case of small cell carcinoma (SmCC) of the uterine cervix that metastasized to the bone marrow. A 60‐year‐old woman with stage IIB SmCC of the cervix was treated with three courses of neoadjuvant chemotherapy followed by radical hysterectomy. Because of the presence of a large residual tumor, the patient underwent postoperative adjuvant chemotherapy. Two months after the last course of chemotherapy, severe pancytopenia developed, and erythroblastic cells were found in the peripheral blood. The hematological disorder was shown to be secondary to bone marrow metastasis, and no other metastases were found. The patient died of the disease 8 months after the initial diagnosis. This case suggests that SmCC of the cervix can metastasize to bone marrow, that such metastasis can occur in isolation and lead to severe pancytopenia, influencing the clinical course of the disease.

Identification of Bcl-2/IgH fusion sequences using real-time PCR and chip-based microcapillary electrophoresis

Abstract Background: The determination of polymerase chain reaction (PCR) amplification product sizes of the Bcl-2/IgH fusion gene from follicular lymphoma (FL) provides evidence of clonal identity. Methods: The present study describes detection of Bcl-2/IgH fusion gene clonality utilizing a small, simple microcapillary electrophoretic chip combined with a real-time PCR method. Results: The microcapillary electrophoretic chip system effectively detects size differences among the Bcl-2/IgH fusion gene amplification products of FL from patient samples; something that is not possible using traditional gel electrophoresis. We also describe the potential of this system to utilize formalin-fixed, paraffin-embedded tissue samples sectioned on charged slides. Conclusions: The simple detection of Bcl-2/IgH fusion gene clonality using a microcapillary electrophoretic chip provides reliable information for monitoring minimal residual disease of FL, and can be an effective tool for use in clinical laboratories.