Membrane-Associated Ubiquitin Ligase RING Finger Protein 152 Orchestrates Melanogenesis via Tyrosinase Ubiquitination

Lysosomal degradation of tyrosinase, a pivotal enzyme in melanin synthesis, negatively impacts melanogenesis in melanocytes. Nevertheless, the precise molecular mechanisms by which lysosomes target tyrosinase have remained elusive. Here, we identify RING (Really Interesting New Gene) finger protein 152 (RNF152) as a membrane-associated ubiquitin ligase specifically targeting tyrosinase for the first time, utilizing AlphaScreen technology. We observed that modulating RNF152 levels in B16 cells, either via overexpression or siRNA knockdown, resulted in decreased or increased levels of both tyrosinase and melanin, respectively. Notably, RNF152 and tyrosinase co-localized at the trans-Golgi network (TGN). However, upon treatment with lysosomal inhibitors, both proteins appeared in the lysosomes, indicating that tyrosinase undergoes RNF152-mediated lysosomal degradation. Through ubiquitination assays, we found the indispensable roles of both the RING and transmembrane (TM) domains of RNF152 in facilitating tyrosinase ubiquitination. In summary, our findings underscore RNF152 as a tyrosinase-specific ubiquitin ligase essential for regulating melanogenesis in melanocytes.

[Neuronal intranuclear inclusion disease in a patient who exhibited abnormal behavior]

A 63-year-old woman with no medical history of note developed acute-onset abnormal behavior persisting for one week. Mild disturbance of consciousness was noted on physical examination. Her blood and spinal fluid test results were normal. On brain MRI, diffusion-weighted image showed a high-intensity signal in U-fiber areas of the bilateral frontal lobes, and fluid-attenuated inversion recovery showed white matter lesions. We suspected neuronal intranuclear inclusion disease (NIID) based on brain MRI findings; therefore, we performed a skin biopsy and genetic test. Pathological findings of the skin biopsy revealed the presence of anti-p62-positive intranuclear inclusion bodies in fibroblasts and adipocytes. The genetic test showed GGC repeat expansion of NOTCH2NLC, but no mutation of FMR1. Thus, we diagnosed her with NIID. The acute-onset abnormal behavior was improved by levetiracetam. The present case indicates that patients with a high-intensity area in the corticomedullary junction should undergo a skin biopsy, even though they may present with non-specific symptoms such as acute-onset abnormal behavior.

[Eosinophilic granulomatosis with polyangiitis presenting with Guillain-Barré syndrome-like acute course. A case report]

A 57-years-old man with a history of bronchial asthma and pansinusitis developed acute progressive muscle weakness and sensory disturbance of the distal limbs after upper respiratory infection. On day 15 after onset of sensory disturbance and muscle weakness, the patient admitted to our hospital. A neurological examination revealed asymmetry weakness of both proximal and distal muscles, "glove and stocking type" hypoesthesia, and paresthesia without obvious pain. Blood tests and a nerve conduction study demonstrated eosinophilia and elevation of MPO-ANCA, axonal multiple mononeuropathy, respectively. The cerebrospinal fluid was normal. Eosinophilic granulomatosis with polyangiitis (EGPA) or Guillain-Barré syndrome (GBS) were suspected. So intravenous immunoglobulin therapy (IVIg) and high dose methylprednisolone pulse therapy (HDMP) followed by oral prednisolone were started. However, neurological symptoms did not improve. Sural nerve biopsy on day 31 revealed varying myelinating fiber loss at every nerve bundle and perivascular lymphocytic infiltration. The results did not fulfill the pathologic criteria for EGPA, but supported the changes of vasculitis. Cyclophosphamide (CPA) pulse therapy was administered for the additional therapy. Neurological symptoms did not improve and worsened again after decreasing oral prednisolone; therefore, combined therapy with IVIg, HDMP, and CPA was administered. Neurological symptoms then diminished gradually and the MPO-ANCA level and number of eosinophils normalized. This case suggests the importance of early nerve biopsy to obtain pathological findings supportive of EGPA diagnosis to allow introduction of aggressive immunosuppressive therapy such as CPA in a case with acute progressive motor-sensory neuropathy due to EGPA mimicking GBS.

Oxytocin Influences Male Sexual Activity via Non-synaptic Axonal Release in the Spinal Cord

Oxytocinergic neurons in the paraventricular nucleus of the hypothalamus that project to extrahypothalamic brain areas and the lumbar spinal cord play an important role in the control of erectile function and male sexual behavior in mammals. The gastrin-releasing peptide (GRP) system in the lumbosacral spinal cord is an important component of the neural circuits that control penile reflexes in rats, circuits that are commonly referred to as the "spinal ejaculation generator (SEG)." We have examined the functional interaction between the SEG neurons and the hypothalamo-spinal oxytocin system in rats. Here, we show that SEG/GRP neurons express oxytocin receptors and are activated by oxytocin during male sexual behavior. Intrathecal injection of oxytocin receptor antagonist not only attenuates ejaculation but also affects pre-ejaculatory behavior during normal sexual activity. Electron microscopy of potassium-stimulated acute slices of the lumbar cord showed that oxytocin-neurophysin-immunoreactivity was detected in large numbers of neurosecretory dense-cored vesicles, many of which are located close to the plasmalemma of axonal varicosities in which no electron-lucent microvesicles or synaptic membrane thickenings were visible. These results suggested that, in rats, release of oxytocin in the lumbar spinal cord is not limited to conventional synapses but occurs by exocytosis of the dense-cored vesicles from axonal varicosities and acts by diffusion-a localized volume transmission-to reach oxytocin receptors on GRP neurons and facilitate male sexual function.

Analysis of White Matter Damage in Patients with Multiple Sclerosis via a Novel In Vivo MR Method for Measuring Myelin, Axons, and G-Ratio

BACKGROUND AND PURPOSE

Myelin and axon volume fractions can now be estimated via MR imaging in vivo, as can the g-ratio, which equals the ratio of the inner to the outer diameter of a nerve fiber. The purpose of this study was to evaluate WM damage in patients with MS via this novel MR imaging technique.

MATERIALS AND METHODS

Twenty patients with relapsing-remitting MS with a combined total of 149 chronic plaques were analyzed. Myelin volume fraction was calculated based on simultaneous tissue relaxometry. Intracellular and CSF compartment volume fractions were quantified via neurite orientation dispersion and density imaging. Axon volume fraction and g-ratio were calculated by combining these measurements. Myelin and axon volume fractions and g-ratio were measured in plaques, periplaque WM, and normal-appearing WM.

RESULTS

All metrics differed significantly across the 3 groups (P < .001, except P = .027 for g-ratio between periplaque WM and normal-appearing WM). Those in plaques differed most from those in normal-appearing WM. The percentage changes in plaque and periplaque WM metrics relative to normal-appearing WM were significantly larger in absolute value for myelin volume fraction than for axon volume fraction and g-ratio (P < .001, except P = .033 in periplaque WM relative to normal-appearing WM for comparison between myelin and axon volume fraction).

CONCLUSIONS

In this in vivo MR imaging study, the myelin of WM was more damaged than axons in plaques and periplaque WM of patients with MS. Myelin and axon volume fractions and g-ratio may potentially be useful for evaluating WM damage in patients with MS.

Pulmonary AL amyloidosis in a patient with primary Sjögren syndrome

Abstract The condition of a 29-year-old woman with primary Sjögren syndrome (SS) was complicated by amyloid light chains- (AL-) type amyloidosis in the paranasal sinus. She had not complained of respiratory symptoms, but her chest computed tomography (CT) scan revealed bilateral multiple nodular shadows. Lung biopsy specimens using video-associated thoracoscopy showed amyloidoma in a subpleural nodular lesion and amyloid deposits in the interstitial parenchymal walls and pulmonary vessels. Pulmonary AL amyloidosis, presumably related to a chronic inflammatory lymphoproliferative process in SS, has rarely been reported.

Successful treatment of reactive hemophagocytic syndrome by plasmapheresis and high-dose γ-globulin in a patient with systemic lupus erythematosus

Abstract A 31-year-old woman who had been administered corticosteroid and immunosuppressive agents for systemic lupus erythematosus (SLE) without flare-up was diagnosed as having reactive hemophagocytic syndrome (HPS) with severe disseminated intravascular coagulation. The causative underlying disease was uncertain, but it was not the SLE itself. Her fulminant HPS with increased serum ferritin and inflammatory cytokines (sIL-2R, TNF-α, IL-6, and IFN-γ) was successfully treated with plasmapheresis and high-dose γ-globulin therapy.

Drosophila apc regulates delamination of invasive epithelial clusters

Border Cells in the Drosophila ovaries are a useful genetic model for understanding the molecular events underlying epithelial cell motility. During stage 9 of egg chamber development they detach from neighboring stretched cells and migrate between the nurse cells to reach the oocyte. RNAi screening allowed us to identify the dapc1 gene as being critical in this process. Clonal and live analysis showed a requirement of dapc1 in both outer border cells and contacting stretched cells for delamination. This mutant phenotype was rescued by dapc1 or dapc2 expression. Loss of dapc1 function was associated with an abnormal lasting accumulation of β-catenin/Armadillo and E-cadherin at the boundary between migrating border and stretched cells. Moreover, β-catenin/armadillo or E-cadherin downregulation rescued the dapc1 loss of function phenotype. Altogether these results indicate that Drosophila Apc1 is required for dynamic remodeling of β-catenin/Armadillo and E-cadherin adhesive complexes between outer border cells and stretched cells regulating proper delamination and invasion of migrating epithelial clusters.

Induction of pole cells in sterilized Drosophila embryos by injection of subcellular fraction from eggs

A subcellular fraction isolated from a homogenate of young Drosophila embryos was shown to be capable of inducing pole cells when injected into UV-sterilized Drosophila embryos. Most of the pole cell-inducing activity was recovered from the precipitate after centrifugation at 27,000 x g. The activity remained in this precipitate (called F-3 fraction hereafter) even after membranous structures were removed from it through centrifugation on a sucrose density gradient. Dialysis, lyophilization, and heating at 80 degrees C for 10 min did not inactivate the F-3 fraction. The pole cells, which were produced when the F-3 fraction was injected at the posterior pole of UV-sterilized embryos, did not develop into germ cells. Furthermore, the F-3 fraction was unable to induce pole cells when injected into the anterior region of the egg. These results can be explained by assuming that (i) pole cell formation and germ cell determination are controlled by different factors, (ii) pole cell formation requires at least two factors, which are normally localized in the posterior-pole cytoplasm, one of which is sensitive and one resistant to the UV dosage we used, and (iii) the subcellular fraction we obtained contains the UV-sensitive factor but not the UV-resistant factor.

Bortezomib-resistant myeloma cell lines: a role for mutated PSMB5 in preventing the accumulation of unfolded proteins and fatal ER stress

Bortezomib is an effective agent for treating multiple myeloma (MM). To investigate the underlying mechanisms associated with acquired resistance to this agent, we established two bortezomib-resistant MM cell lines, KMS-11/BTZ and OPM-2/BTZ, the 50% inhibitory concentration values of which were respectively 24.7- and 16.6-fold higher than their parental cell lines. No activation of caspase and BH3-only proteins such as Noxa was noted in bortezomib-resistant cells after exposure to the drug. The accumulation of polyubiquitinated proteins was reduced in bortezomib-resistant cells compared with the parental cells, associated with avoidance of catastrophic ER stress as assessed by downregulation of CHOP expression. These resistant MM cells have a unique point mutation, G322A, in the gene encoding the proteasome beta5 subunit (PSMB5), likely resulting in conformational changes to the bortezomib-binding pocket of this subunit. KMS-11 parental cells transfected to express mutated PSMB5 also showed reduced bortezomib-induced apoptosis compared with those expressing wild-type PSMB5 or the parental cells. Expression of mutated PSMB5 was associated with the prevention of the accumulation of unfolded proteins. Thus, a fraction of MM cells may acquire bortezomib resistance by suppressing apoptotic signals through the inhibition of unfolded protein accumulation and subsequent excessive ER stress by a mutation of the PSMB5 gene.

Correlation of hENT1 expression with response and survival in non-small cell lung cancer patients treated with gemcitabine-containing chemotherapy

e22032

Background: The most active gemcitabine uptake has been found via the human equilibrative nucleoside transporter 1 (hENT1). This study was to explore the prognostic impact of the hENT1 on response and survival in Non-small lung cancer (NSCLC) patients treated with gemcitabine-containing chemotherapy. Methods: We developed polyclonal antibody for hENT1. Then we stained hENT1 expression by immunohistochemical analysis in 24 biopsy samples of NSCLC which was formaline-fixed, paraffin- embedded tissues. We were treated with gemcitabine alone or gemcitabine-containing chemotherapy until third-line regimen. Results: They comprised 16 males and 8 females with a median age of 63 years (range 45–82 years). Seventeen patients had adenocarcinomas, six had squamous-cell carcinomas, and one had a large-cell carcinoma. All patients were treated with gemcitabine- containing chemotherapy, with 9, 12, and 3 patients receiving this as a first-, second-, and third-line therapy, respectively. The hENT1-positive staining in NSCLC samples was significantly associated with response to gemcitabine-containing chemotherapy (Fisher's exact test, P<0.05). Responses to gemcitabine-containing chemotherapy were evident in none of the seven patients with no hENT1 expression. Further 3 years survival differed by hENT1 staining: 714 days for hENT1-positive, 316 days for hENT1-negative (HR 2.86; 95%CI 1.13–15.16, P<0.05). Conclusions: While there are some determinants for gemcitabine sensitivity, hENT1 expression may be a predictive maker for the response and survival to gemcitabine-containing chemotherapy in NSCLC.

No significant financial relationships to disclose.

Disproportionate representation of KRAS gene mutation in atypical adenomatous hyperplasia, but even distribution of EGFR gene mutation from preinvasive to invasive adenocarcinomas

In the resected lung, additional small lesions are occasionally found incidentally, and include the full spectrum of preinvasive to invasive lesions under the current putative schema of the sequential development of lung cancer. In this study, we examined EGFR and KRAS gene mutations in 119 synchronous pulmonary lesions, including 40 precursor lesions (atypical adenomatous hyperplasia, AAH), 26 carcinomas in situ (non-mucinous bronchioloalveolar carcinoma, BAC), 14 minimally invasive adenocarcinomas, 34 overt invasive adenocarcinomas, and five of other subtypes of cancer. Although the mutually exclusive nature of KRAS and EGFR gene mutations was maintained even in preinvasive lesions, the incidences of the lesions along the putative progression schema were quite different. The KRAS gene was mutated in 33% of AAH, 12% of carcinomas in situ, 8% of minimally invasive adenocarcinomas and 0% of well-differentiated adenocarcinomas, whereas the frequencies of EGFR mutation did not fluctuate greatly, at 25%, 51%, 36%, 86% and 67%, respectively. These results are consistent with the findings of a published gene-targeted mouse model; the mice expressing oncogenic KRAS developed AAH but not invasive adenocarcinoma, whereas a spectrum of preinvasive to invasive adenocarcinomas was observed in the mice expressing mutant EGFR. Taking these factors together, it is suggested that AAH could develop by either KRAS or EGFR gene mutation, but AAH harbouring a KRAS gene mutation might not progress further to an invasive cancer.

Proteome analyses of the growth inhibitory effects of NCH-51, a novel histone deacetylase inhibitor, on lymphoid malignant cells

Recent reports showing successful inhibition of cancer and leukemia cell growth using histone deacetylase inhibitor (HDACi) compounds have highlighted the potential use of HDACi as anti-cancer agents. However, high incidence of toxicity and low stability in vivo were observed with hydroxamic acid-based HDACi such as suberoylanilide hydroxamic acid (SAHA), thus limiting its clinical applicability. In this study, we found that a novel non-hydroxamate HDACi NCH-51 could inhibit the cell growth of a variety of lymphoid malignant cells through apoptosis induction, more effectively than SAHA. Activation of caspase-3, -8 and -9, but not -7 was detected after the treatment with NCH-51. Gene expression profiles showed that NCH-51 and SAHA similarly upregulated p21 and downregulated anti-apoptotic molecules including survivin, bcl-w and c-FLIP. Proteome analysis using two-dimensional electrophoresis revealed that NCH-51 upregulated anti-oxidant molecules including peroxiredoxin 1 and 2 and glutathione S-transferase at the protein level. Interestingly, NCH-51 induced reactive oxygen species (ROS) after 8 h whereas SAHA continuously declined ROS. Pretreatment with an antioxidant, N-acetyl-L-cysteine, abolished the cytotoxicity of NCH-51. These findings suggest that NCH-51 exhibits cytotoxicity by sustaining ROS at the higher level greater than SAHA. This study indicates the therapeutic efficacy of NCH-51 and novel insights for anti-HDAC therapy.

POU2AF1, an amplification target at 11q23, promotes growth of multiple myeloma cells by directly regulating expression of a B-cell maturation factor, TNFRSF17

Multiple myeloma (MM), a progressive hematological neoplasm, is thought to result from multiple genetic events affecting the terminal plasma cell. However, genetic aberrations related to MM are seldom reported. Using our in-house array-based comparative genomic hybridization system to locate candidate target genes with following their expression analysis, we identified POU2AF1 at 11q23.1 as a probable amplification target in MM cell lines. POU2AF1 is a B-cell-specific transcriptional co-activator, which interacts with octamer-binding transcription factors Oct-1 and Oct-2, and augments their function. Downregulation of POU2AF1 expression by specific small-interfering RNA (siRNA) inhibited MM cell growth, whereas ectopic expression of POU2AF1 promoted growth of MM cells. Among putative transcriptional targets for POU2AF1, B-cell maturation factor, TNFRSF17, enhanced its transcription by POU2AF1, and POU2AF1 directly bound to an octamer site within the 5' region of TNFRSF17. Expression level of TNFRSF17 was closely correlated with that of POU2AF1 in cell lines and primary samples of MM, and decreasing TNFRSF17 expression by means of TNFRSF17 siRNA inhibited MM cell growth. Taken together, our results suggest that POU2AF1, when activated by amplification or other mechanisms, may contribute to progression of MM by accelerating growth of MM cells through direct transactivation of one of its target genes, TNFRSF17.

Ribosomal P protein P0 as a candidate for the target antigen of anti-endothelial cell antibodies in mixed connective tissue disease

OBJECTIVE

To evaluate the presence of anti-endothelial cell antibodies (AECA) in patients with mixed connective tissue disease (MCTD) compared to those with systemic sclerosis (SSc) and to determine the candidates for the endothelial auto-antigen that reacts with AECA in patients with MCTD using a molecular cloning strategy.

METHODS

AECA were measured by a cellular enzyme-linked immunosorbent assay (ELISA) using fixed human umbilical vein endothelial cells (HUVEC) in 47 MCTD patients, 68 SSc patients, and 52 normal controls. A HUVEC cDNA expression library was immunoscreened with pooled sera from 6 patients with high AECA levels determined by cellular ELISA to explore the endothelial autoantigens in MCTD. An ELISA assay for anti-ribosomal protein P0 antibodies was used to assess the correlation with AECA levels.

RESULTS

The candidate target proteins recognized by AECA in MCTD included: (i) ribosomal protein P0; (ii) a putative oncogene derived from dek mRNA; (iii) SS-B/La protein; (iv) U1 RNA-associated 70K protein; and (v) DNA-binding protein B. A significant correlation between the levels of AECA and anti-ribosomal protein P0 antibodies was demon-strated in MCTD, but not in systemic sclerosis. The sera containing high levels of AECA from patients with MCTD frequently cross-reacted with ribosomal protein P0. On the other hand, sera without AECA activity from patients with MCTD never reacted with ribosomal protein P0.

CONCLUSION

AECA were more frequently seen in patients with MCTD than in patients with SSc. Ribosomal protein P0 may be one of the major target antigens of AECA in patients with MCTD.

Coronary artery disease investigated using 99mTc-tetrofosmin myocardial SPECT

BACKGROUND

Coronary artery disease can be diagnosed from stress and delayed images of myocardial single photon emission computed tomography (SPECT) using technetium-99 m-tetrofosmin (TcTF). However, the negative predictive value of stress SPECT images after a single injection of a low tracer dose remains unknown. Thus, the present study investigates whether normal stress SPECT results predict event-free survival.

MATERIALS AND METHODS

We screened 302 consecutive patients who were randomly assigned to two groups for myocardial ischaemia using either stress SPECT with a low dose of TcTF (296 MBq, TcTF group, n = 150) or stress together with rest SPECT using thallium(201) chloride (TlCl, 111 MBq; TlCl group, n = 152) as the tracer. A total of 80 patients with abnormal SPECT findings were excluded and the remaining 222 with normal results (age, 66.5 +/- 0.7 years; TcTF/TlCl, 112/110) were enrolled in the present study and followed up for 401 +/- 9 days, with the endpoint being ischaemic cardiac events.

RESULTS

The incidence of cardiac events did not differ between the two groups (0.9% and 0.0% in TcTF and TlCl groups, respectively). The cost and duration of TcTF and TlCl SPECT examinations were about 425 and 603 Euros and 50 and 280 min, respectively.

CONCLUSIONS

The negative predictive values of stress SPECT using a low dose of TcTF and of combined stress and rest SPECT using TlCl did not differ and both were clinically acceptable. Thus, stress SPECT using low dose TcTF is useful in screening patients for myocardial ischaemia.

Brain natriuretic peptide detects cardiac abnormalities in mass screening

BACKGROUND

Plasma brain natriuretic peptide (BNP) is elevated in asymptomatic patients with various cardiac abnormalities. We tested the hypothesis that measuring BNP is useful for detecting asymptomatic patients with cardiac abnormalities who are not identified by conventional health check-up programmes.

MATERIALS AND METHODS

From 2001 to 2002, 6189 subjects (women 34.0%; mean age 56.6 years) underwent multiphasic health check-ups in our hospital, of which 4818 without cardiac abnormalities as revealed by the health check-up were enrolled in the present study. Their plasma concentrations of BNP were measured.

RESULTS

Plasma concentrations of BNP were higher than the normal reference upper limit of our hospital (21.3 pg mL(-1)) in 925 of the 4818 subjects. Echocardiography was performed in 471 subjects who were randomly selected from the 925 subjects with elevated BNP. Abnormal findings were detected in 174 subjects, comprising valvular heart disease in 83, systolic dysfunction in 10, diastolic dysfunction in 54, left ventricular hypertrophy in 41, left ventricular enlargement in 11, left atrial enlargement in 13 and paroxysmal atrial fibrillation in 3.

CONCLUSIONS

Since BNP measurement identifies additional subjects with cardiac abnormalities, it is useful for detecting asymptomatic cardiac abnormalities among apparently healthy subjects, and is suitable for use in high-quality mass screening.

Clinicopathological features of pyothorax-associated lymphoma; a retrospective survey involving 98 patients

To investigate clinicopathological features of pyothorax-associated lymphoma (PAL), we examined medical records of 98 patients (88 males and 10 females) with PAL at a median age of 70 years (range 51-86). Seventy-nine patients had a history of artificial pneumothorax. Median interval between diagnosis and artificial pneumothorax was 43 years (range 19-64). At diagnosis, performance status (PS) was 0-1 (n=56) and 2-4 (n=42). Clinical stages were I (n=42), II (n=26), III (n=8) and IV (n=22). Pathological diagnosis comprised diffuse large-B-cell (n=78) and peripheral T-cell lymphoma (n=1). Seventeen were treated supportively. The other 81 received aggressive treatments; chemotherapy (n=52), radiotherapy (n=7), surgery (n=4) and combination (n=18). Five-year overall survival (OS) was 0.35 (95% confidence interval, 24% to 45%). Causes of deaths were PAL (n=39), respiratory failure (n=13) and others (n=12). Multivariate analysis identified prognostic factors for OS; lactate dehydrogenase levels [hazard ratio (HR)=2.36; P=0.013], sex (female versus male) (HR=0.15; P=0.01), PS (2-4 versus 0-1) (HR=2.20; P=0.02), clinical stages (III/IV versus I/II) (HR=1.95; P=0.037) and chemotherapy (HR=0.31; P=0.01). Most patients with PAL are elderly and have comorbidities, while some of them achieve durable remission with appropriate treatments. These findings prompt us to establish an optimal treatment strategy on the basis of risk stratification of individual patients.

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

Induction of cell death in adult T-cell leukemia cells by a novel IkappaB kinase inhibitor

NF-kappaB is constitutively activated in adult T-cell leukemia (ATL) and is considered responsible for cell growth and prevention of cell death. In this study, we demonstrate that NF-kappaB is constitutively activated in various HTLV-1-infected T-cell lines and ATL-derived cell lines irrespectively of Tax expression as evidenced by the phosphorylation of IkappaBalpha and p65 subunit of NF-kappaB, activation of NF-kappaB DNA binding, and upregulation of various target genes including bcl-xL, bcl-2, XIAP, c-IAP1, survivin, cyclinD1, ICAM-1 and VCAM-1. The effects of a novel IkappaB kinase (IKK) inhibitor, 2-amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-piperidin-4-yl nicotinonitrile (ACHP), were examined on cell growth of these cell lines and fresh ATL leukemic cells. We found that ACHP could inhibit the phosphorylation of IkappaBalpha and p65, as well as NF-kappaB DNA-binding, associated with downregulation of the NF-kappaB target genes and induce cell growth arrest and apoptosis in these cells. When Tax-active and Tax-inactive cell lines were compared, ACHP could preferentially inhibit cell growth of Tax-active cells. Moreover, ACHP exhibited strong apoptosis-inducing activity in fresh ATL cells. These findings indicate that ACHP and its derivatives are effective in inducing ATL cell death and thus feasible candidates for the treatment of ATL.

Systematic review and meta-analysis: importance of CagA status for successful eradication of Helicobacter pylori infection

BACKGROUND

Some, but not all studies have provided evidence that the CagA status of Helicobacter pylori strains is a predictive factor for the outcome of eradication therapy.

AIM

To clarify the association between CagA status and eradication outcome.

METHODS

We included studies reporting the numbers of successful and failed cases in H. pylori-eradication therapy according to the CagA status. Fourteen studies (1529 patients) were included of 325 articles identified in the search. The pooled risk ratio for H. pylori-eradication failure in CagA-negative relative to CagA-positive strains and the pooled risk difference in eradication success between the two groups were used as summary statistics. Meta-regression was used for examining the source of heterogeneity.

RESULTS

The summary risk ratio for eradication failure in CagA-negative relative to CagA-positive was 2.0 (95% CI: 1.6-2.4, P < 0.001), corresponding with the summary risk difference for eradication success between the groups of 11% (95% CI: 3-19%, P = 0.011). Meta-regression analysis demonstrated that usage of polymerase chain reaction examination for CagA status and a high proportion of non-ulcer dyspepsia patients were factors for heterogeneity among studies.

CONCLUSIONS

Our meta-analysis confirmed the importance of the presence of CagA as a predictor for successful eradication of H. pylori.

Systematic in vivo RNAi analysis of putative components of the Drosophila cell death machinery

Despite the identification of numerous key players of the cell death machinery, little is known about their physiological role. Using RNA interference (RNAi) in vivo, we have studied the requirement of all Drosophila caspases and caspase-adaptors in different paradigms of apoptosis. Of the seven caspases, Dronc, drICE, Strica and Decay are rate limiting for apoptosis. Surprisingly, Hid-mediated apoptosis requires a broader range of caspases than apoptosis initiated by loss of the caspase inhibitor DIAP1, suggesting that Hid causes apoptosis not only by antagonizing DIAP1 but also by activating DIAP1-independent caspase cascades. While Hid killing requires Strica, Decay, Dronc/Dark and drICE, apoptosis triggered by DIAP1 depletion merely relied upon Dronc/Dark and drICE. Furthermore, we found that overexpression of DIAP2 can rescue diap1-RNAi-mediated apoptosis, suggesting that DIAP2 regulates caspases directly. Consistently, we show that DIAP2 binds active drICE. Since DIAP2 associates with Hid, we propose a model whereby Hid co-ordinately targets both DIAP1 and DIAP2 to unleash drICE.

Population pharmacokinetics of intravenous busulfan in patients undergoing hematopoietic stem cell transplantation

A population pharmacokinetic analysis was performed in 30 patients who received an intravenous busulfan and cyclophosphamide regimen before hematopoietic stem cell transplantation. Each patient received 0.8 mg/kg as a 2 h infusion every 6 h for 16 doses. A total of 690 concentration measurements were analyzed using the nonlinear mixed effect model (NONMEM) program. A one-compartment model with an additive error model as an intraindividual variability including an interoccasion variability (IOV) in clearance (CL) was sufficient to describe the concentration-time profile of busulfan. Actual body weight (ABW) was found to be the determinant for CL and the volume of distribution (V) according to NONMEM analysis. In this limited study, the age (range 7-53 years old; median, 30 years old) had no significant effect on busulfan pharmacokinetics. For a patient weighting 60 kg, the typical CL and V were estimated to be 8.87 l/h and 33.8 l, respectively. The interindividual variability of CL and V were 13.6 and 6.3%, respectively. The IOV (6.6%) in CL was estimated to be less than the intraindividual variability. These results indicate high interpatient and intrapatient consistency of busulfan pharmacokinetics after intravenous administration, which may eliminate the requirement for pharmacokinetic monitoring.

Quantification of red blood cell fragmentation by the automated hematology analyzer XE-2100 in patients with living donor liver transplantation

The fragmented red cell (FRC) is a useful index for diagnosing and determining the severity of thrombotic thrombocytopenic purpura (TTP), thrombotic microangiopathy (TMA) and other similar conditions, as it is found in peripheral blood in patients with these diseases. The FRC expression rate has conventionally been determined by manual methods using smear samples. However, it is difficult to attain accurate quantification by such methods as they are time consuming and prone to a great margin of error. With cases of living donor liver transplantation, the current study examined the possibility of using a multi-parameter automated hematology analyzer, the XE-2100 (Sysmex Corporation) for FRC quantification. While there was a notable correlation between the manual and automated measurements, the manual measurement resulted in higher values. This suggested remarkable variations in judgment by individuals. The FRC values had a significant correlation with the reticulocyte count, red blood cell distribution width (RDW), fibrin/fibrinogen degradation products (P-FDP) and lactate dehydrogenase (LDH) among the test parameters, and this finding was consistent with the clinical progression in patients. The automated method can offer precise measurements in a short time without inter-observer differences, meeting the requirement for standardization. The determination of FRC count (%) by the XE-2100 that enables early diagnoses and monitoring of TTP or TMA will be useful in the clinical field.

Altered regulation of c-jun and its involvement in anchorage-independent growth of human lung cancers

The c-jun oncogene is frequently overexpressed in non-small-cell lung cancers (NSCLC), but its functional involvement in lung cancer development has not been clearly elucidated. In this study, we found that among the immediate-early serum responsible genes, exemplified by c-jun, c-fos and c-myc, induction of c-jun in a human bronchial epithelial cell line, BEAS-2B, was dependent on anchorage, in contrast to clear induction of c-fos and c-myc under both anchorage-dependent and -independent conditions. In fact, forced expression of c-jun in BEAS-2B cells significantly increased cell viability and colony formation in soft agar. Furthermore, we also found that such anchorage-dependent regulation of c-jun was lost in a significant fraction of human lung cancer cell lines. Interestingly, suppressed anchorage-independent but not anchorage-dependent growth was noted by constitutive expression of a dominant-negative c-jun mutant in a lung cancer cell line showing dysregulated and sustained c-jun expression in the absence of anchorage. These findings suggest that dysregulated c-jun expression may be involved in the acquisition of anchorage independence in the process of human lung carcinogenesis.

Antimyeloma effects of a novel synthetic retinoid Am80 (Tamibarotene) through inhibition of angiogenesis

In multiple myeloma (MM), the interaction between myeloma cells and bone marrow microenvironment has an important role in the pathogenesis of MM. We first examined the inducing effect of myeloma cells on migration of human umbilical vein vascular endothelial cells (HUVECs). Five myeloma cell lines produced varying amounts of VEGF, and migration of HUVECs was induced by coculture with myeloma cells. We next examined the inhibitory effect of a novel synthetic retinoid Am80 (Tamibarotene) on both myeloma cells and HUVECs. Am80 is specific for the retinoic-acid receptor-alpha/beta, and has therapeutic effects in all-trans retinoic acid resistant acute promyelocytic leukemia. Am80 slightly inhibited the growth of both myeloma cells and HUVECs, and remarkably inhibited the growth of HUVECs stimulated by VEGF. Am80 showed little growth inhibition of bone marrow stromal cells (BMSCs), but it markedly inhibited migration of HUVECs by cocultured myeloma cells. Am80 inhibited VEGF-induced phosphorylation of VEGF receptor. In addition, VEGF-induced formation of tube-like structures in vitro and neovascularization in mouse corneas were significantly inhibited by Am80. These findings clearly demonstrate that Am80 is a potential inhibitor of angiogenesis caused by the interaction between vascular endothelial cells and myeloma cells, and might be a useful therapeutic agent against MM.

Multiple myeloma oncogene 1 (MUM1)/interferon regulatory factor 4 (IRF4) upregulates monokine induced by interferon-γ (MIG) gene expression in B-cell malignancy

MUM1 (multiple myeloma oncogene 1)/IRF4 (interferon regulatory factor 4) is a transcription factor that is activated as a result of t(6;14)(p25;q32) in multiple myeloma. MUM1 expression is seen in various B-cell lymphomas and predicts an unfavorable outcome in some lymphoma subtypes. To elucidate its role in B-cell malignancies, we prepared MUM1-expressing Ba/F3 cells, which proliferated until higher cellular density than the parental cells, and performed cDNA microarray analysis to identify genes whose expression is regulated by MUM1. We found that the expression of four genes including FK506-binding protein 3 (FKBP3), the monokine induced by interferon-gamma(MIG), Fas apoptotic inhibitory molecule (Faim) and Zinc-finger protein 94 was altered in the MUM1-expressing cells. We then focused on MIG since its expression was immediately upregulated by MUM1. In reporter assays, MUM1 activated the MIG promoter in cooperation with PU.1, and the interaction between MUM1 and the MIG promoter sequence was confirmed. The expression of MIG was correlated with that of MUM1 in B-CLL cell lines, and treatment with neutralizing antibodies against MIG and its receptor, CXCR3, slightly inhibited the proliferation of two MUM1-expressing lines. These results suggest that MUM1 plays roles in the progression of B-cell lymphoma/leukemia by regulating the expression of various genes including MIG. Leukemia (2005) 19, 1471-1478. doi:10.1038/sj.leu.2403833; published online 16 June 2005.

Nonspecific interstitial pneumonia pattern as pulmonary involvement of rheumatoid arthritis

The pathologic patterns of lung involvement were evaluated in 16 patients with rheumatoid arthritis (RA). They consisted of six females and ten males, with a median age of 67.5 years and diagnosed according to the American Rheumatism Association revised criteria. High-resolution computed tomography (HRCT) of the lungs was performed in all patients, and honeycomb formation was apparent in seven. Histopathologically, seven patients were diagnosed with usual interstitial pneumonia (UIP) pattern, seven with nonspecific interstitial pneumonia/fibrosis (NSIP) pattern, and two with UIP/NSIP hybrid pattern. There were no apparent honeycomb formations on HRCT in patients diagnosed with NSIP pattern. In conclusion, the present study demonstrates that NSIP pattern is also a significant histologic classification of interstitial pneumonia associated with RA.

GAFChromic film dosimetry with a flatbed color scanner for Leksell Gamma Knife therapy

GAFChromic films MD-55-2 have recently been established widely in industrial, scientific, and medical applications as radiation dosimeters. We applied these films to the dosimetry for Leksell Gamma Knife therapy. We used a flatbed image scanner to take digital images of irradiated MD-55-2, and the data were converted to Red, Green and Blue pixel values. The absorbed dose, as derived from the response curve of the Red pixel value, was consistent with the Leksell Gamma Plan dose planning system, for exposures using collimator sizes, 4 mm, 8 mm, and 14 mm. However, the maximum dose in the exposure of the 18 mm collimator was measured to be about 5% smaller than Gamma Plan due to the density effect of the compound material in the head phantom.