Published papers

We describe an autopsy case of a patient with pandemic influenza (A/H1N1pdm) virus infection in Japan, who developed rapidly progressive viral pneumonia exhibiting diffuse alveolar damage. A 41-year-old female visited our hospital with a fever of 38.7 degrees C. She was a public health nurse with no underlying disease and had had contact with a group of elementary school students who had been infected with the influenza (A/H1N1pdm) virus I week earlier. She was prescribed oseltamivir and returned to the hotel where she was staying alone. The next day, she was found dead in her hotel room. At autopsy, both lungs were voluminous and microscopic examination revealed acute-stage, severe diffuse alveolar damage with remarkable mononuclear cell infiltration and hyaline membrane formation in the lungs. CD8-positive T lymphocytes were dominantly observed. Immunohistochemically, influenza A viral protein was confirmed in the damaged type 11 pneumocytes and also in the infiltrated macrophages. Real-time RT-PCR analysis of both pre- and post-mortem pharyngeal swabs confirmed a novel influenza (A/H1N1pdm) virus infection. This is the second autopsy case of influenza (A/H1N1pdm) virus infection in Japan, and the findings indicated that the patient died due to an exceptionally rapid progression of viral pneumonia. This case indicates that patients with influenza (A/H1N1pdm) virus infection should be carefully monitor for acute respiratory distress syndrome.

Ionizing irradiation is an effective treatment for malignant glioma (MG); however, a higher rate of recurrence with more aggressive phenotypes is a vital issue. Although epithelial-mesenchymal transition (EMT) is involved in irradiation-induced cancer progression, the role for such phenotypic transition in MG remains unknown. To investigate the mechanism of irradiation-dependent tumor progression in MG, we performed immunohistochemistry (IHC) and qRT-PCR using primary and recurrent MG specimens, MG cell lines, and primary culture cells of MG. siRNA technique was used for MG cell lines. In 22 cases of clinically recurrent MG, the expression of the mesenchymal markers vimentin and CD44 was found to be increased by IHC. In paired identical MG of 7 patients, the expression of collagen, MMPs, and YKL-40 were also elevated in the recurrent MGs, suggesting the The Cancer Genome Atlas-based mesenchymal subtype. Among EMT regulators, sustained elevation of Snail was observed in MG cells at 21 days after irradiation. Cells exhibited an upregulation of migration, invasion, numbers of focal adhesion, and MMP-2 production, and all of these mesenchymal features were abrogated by Snail knockdown. Intriguingly, phosphorylation of ERK1/2 and GSK-3 were increased after irradiation in a Snail-dependent manner, and TGF- was elevated in both fibroblasts and macrophages but not in MG cells after irradiation. It was noteworthy that irradiated cells also expressed stemness features such as SOX2 expression and tumor-forming potential in vivo. We here propose a novel concept of glial-mesenchymal transition after irradiation in which the sustained Snail expression plays an essential role.

Occult nodal metastases increase the risk of cancer recurrence, demoting prognosis and quality of life of patients. While targeted drug delivery by using systemically administered nanocarriers can potentially control metastatic disease, lymph node metastases have been mainly dealt by locally injecting nanocarriers, which may not always be applicable. Herein, we demonstrated that sub-50 nm polymeric micelles incorporating platinum anticancer drugs could target lymph node metastases in a syngeneic melanoma model after systemic injection, even after removing the primary tumors, limiting the growth of the metastases. By comparing these micelles with clinically used doxorubicin-loaded liposomes (Doxil) having 80 nm, as well as a 70 nm version of the micelles, we found that the targeting efficiency of the nanocarriers against lymph node metastases was associated with their size-regulated abilities to extravasate from the blood vasculature in metastases and to penetrate within the metastatic mass. These findings indicate the potential of sub-50 nm polymeric micelles for developing effective conservative treatments against lymph node metastasis capable of reducing relapse and improving survival.

Background: Several reports have shown that the overexpression of the MET proto-oncogene, receptor tyrosine kinase (MET), was more frequently observed in clear cell carcinoma (CCC) than in non-CCC. We evaluated the antitumor activity of cabozantinib, that targets MET. Materials and Methods: A gene expression analysis of tumors from human ovarian cancers was carried out by transcriptome sequencing. An in vitro 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay (MTT assay) and in vivo experiments were performed to determine the activity of cabozantinib. Results: The MET levels were higher in tumors with CCC than high-grade serous carcinoma (2.2-fold). Cabozantinib inhibited cell viability and phosphorylation of AKT and MAPK under the treatment of hepatocyte growth factor in RMG-I CCC cells. The tumors removed from mice given cabozantinib of 10 mg/kg weighed 70% less than control on day 15, and the immunohistochemical reactivity of phosphorylated MET was reduced compared with control mice. Conclusion: Cabozantinib contributes to tumor reduction, and phosphorylated MET represents an attractive target of CCC.

A 49-year-old man presented with gradually progressive aphasia one month after being diagnosed with acquired immunodeficiency syndrome (AIDS). Brain magnetic resonance imaging showed multiple brain lesions with punctate and linear enhancement. A polymerase chain reaction detected Epstein-Barr virus (EBV) in the patient's cerebrospinal fluid. A diagnosis of isolated central nervous system lymphomatoid granulomatosis (CNS-LYG) was made based on the brain biopsy findings. The complete remission of CNS-LYG was achieved by anti-retroviral therapy (ART) alone. In the present case, the development of AIDS-associated CNS-LYG was considered to have been initiated by the reactivation of EBV in the CNS under immunosuppressive conditions. The patient's condition improved with the reconstitution of the patient's immune system.

Clinical diagnosis of progressive supranuclear palsy (PSP) is sometimes difficult because various phenotypes have been identified. Here, we report a mutation in the bassoon (BSN) gene in a family with PSP-like syndrome. Their clinical features resembled not only those of PSP patients but also those of individuals with multiple system atrophy and Alzheimer's disease. The neuropathological findings showed a novel three + four repeat tauopathy with pallido-luysio-nigral degeneration and hippocampal sclerosis. Whole-exome analysis of this family identified a novel missense mutation in BSN. Within the pedigree, the detected BSN mutation was found only in affected individuals. Further genetic analyses were conducted in probands from four other pedigrees with PSP-like syndrome and in 41 sporadic cases. Three missense mutations in BSN that are very rarely listed in databases of healthy subjects were found in four sporadic cases. Western blot analysis of tau following the overexpression of wild-type or mutated BSN revealed the possibility that wild-type BSN reduced tau accumulation, while mutated BSN lost this function. An association between BSN and neurological diseases has not been previously reported. Our results revealed that the neurodegenerative disorder associated with the original proband's pedigree is a novel tauopathy, differing from known dementia and parkinsonism syndromes, including PSP.

Desmoplasia is a hallmark of pancreatic cancer and consists of fibrotic cells and secreted extracellular matrix (ECM) components. Various in vitro three-dimensional (3D) models of desmoplasia have been reported, but little is known about the relevant thickness of the engineered fibrotic tissue. We thus measured the thickness of fibrotic tissue in human pancreatic cancer, as defined by the distance from the blood vessel wall to tumor cells. We then generated a 3D fibrosis model with a thickness reaching the clinically observed range using pancreatic stellate cells (PSCs), the main cellular constituent of pancreatic cancer desmoplasia. Using this model, we found that Collagen fiber deposition was increased and Fibronectin fibril orientation drastically remodeled by PSCs, but not normal fibroblasts, in a manner dependent on Transforming Growth Factor (TGF)-β/Rho-Associated Kinase (ROCK) signaling and Matrix Metalloproteinase (MMP) activity. Finally, by targeting Secreted Protein, Acidic and Rich in Cysteine (SPARC) by siRNA, we found that SPARC expression in PSCs was necessary for ECM remodeling. Taken together, we developed a 3D fibrosis model of pancreatic cancer with a clinically relevant thickness and observed aberrant SPARC-dependent ECM remodeling in cancer-derived PSCs.

BACKGROUND: Unstable atherosclerotic carotid plaques cause cerebral thromboemboli and ischemic events. However, this instability has not been pathologically quantified, so we sought to quantify it in patients undergoing carotid endarterectomy (CEA).Methods and Results:Carotid plaques were collected during CEA from 67 symptomatic and 15 asymptomatic patients between May 2015 and August 2016. The specimens were stained with hematoxylin-eosin and elastica-Masson. Immunohistochemistry was performed using an endothelial-specific antibody to CD31, CD34 and PDGFRβ. The histopathological characteristics of the plaques were studied. By multiple-variable logistic regression analysis, plaque instability correlated with the presence of plaque rupture [odds ratio (OR), 9.75; P=0.013], minimum fibrous cap thickness (OR per 10 μm 0.70; P=0.025), presence of microcalcifications in the fibrous cap (OR 7.82; P=0.022) and intraplaque microvessels (OR 1.91; P=0.043). Receiver-operating characteristics analyses showed that these factors combined into a single score diagnosed symptomatic carotid plaques in patients with carotid artery stenosis with a high level of accuracy (area under the curve 0.92; 95% confidence interval 0.85-0.99 vs. asymptomatic). CONCLUSIONS: This analysis of carotid plaque instability strongly suggested that the diagnostic scoring of carotid plaque instability improves the understanding and treatment of carotid artery disease in patients undergoing CEA.

BACKGROUND & AIMS: Intraductal papillary mucinous neoplasms (IPMNs) are regarded as precursors of pancreatic ductal adenocarcinomas (PDAs), but little is known about the mechanism of progression. This makes it challenging to assess cancer risk in patients with IPMNs. We investigated associations of IPMNs with concurrent PDAs by genetic and histologic analyses. METHODS: We obtained 30 pancreatic tissues with concurrent PDAs and IPMNs, and 168 lesions, including incipient foci, were mapped, microdissected, and analyzed for mutations in 18 pancreatic cancer-associated genes and expression of tumor suppressors. RESULTS: We determined the clonal relatedness of lesions, based on driver mutations shared by PDAs and concurrent IPMNs, and classified the lesions into 3 subtypes. Twelve PDAs contained driver mutations shared by all concurrent IPMNs, which we called the sequential subtype. This subset was characterized by less diversity in incipient foci with frequent GNAS mutations. Eleven PDAs contained some driver mutations that were shared with concurrent IPMNs, which we called the branch-off subtype. In this subtype, PDAs and IPMNs had identical KRAS mutations but different GNAS mutations, although the lesions were adjacent. Whole-exome sequencing and methylation analysis of these lesions indicated clonal origin with later divergence. Ten PDAs had driver mutations not found in concurrent IPMNs, called the de novo subtype. Expression profiles of TP53 and SMAD4 increased our ability to differentiate these subtypes compared with sequencing data alone. The branch-off and de novo subtypes had substantial heterogeneity among early clones, such as differences in KRAS mutations. Patients with PDAs of the branch-off subtype had a longer times of disease-free survival than patients with PDAs of the de novo or the sequential subtypes. CONCLUSIONS: Detailed histologic and genetic analysis of PDAs and concurrent IPMNs identified 3 different pathways by which IPMNs progress to PDAs-we call these the sequential, branch-off, and de novo subtypes. Subtypes might be associated with clinical and pathologic features and be used to select surveillance programs for patients with IPMNs.

The publication of the 2016 World Health Organization Classification of Tumors of the Central Nervous System (2016 WHO CNS) represented a major change in the classification of brain tumors. However, many pathologists in Japan cannot diagnose astrocytic or oligodendroglial tumors according to the 2016 WHO CNS due to financial or technical problems. Therefore, the Japan Society of Brain Tumor Pathology established a committee for molecular diagnosis to facilitate the integrated diagnosis of astrocytic and oligodendroglial tumors in Japan. We created three levels of diagnoses: Level 1 was defined as simple histopathological diagnosis using hematoxylin and eosin staining and routine cell lineage-based immunostaining. Level 2 was defined as immunohistochemical diagnosis using immunohistochemical examinations using R132H mutation-specific IDH1, ATRX, and/or p53 antibodies. Level 3 was defined as molecular diagnosis, such as diagnosis based on 1p/19q status or the mutation status of the IDH1 and IDH2 genes. In principle, astrocytic and oligodendroglial tumors should be diagnosed based on the 2016 WHO CNS and/or cIMPACT-NOW criteria; however, the findings obtained through our diagnostic flowchart can be added to the histological diagnosis in parentheses. This classification system would be helpful for pathologists with limited resources.

The human polyomavirus JC (JCV) encodes an agnoprotein that consists of 71 amino acid residues, with a molecular weight of approximately 8 kDa, from the late protein coding region. The agnoprotein of JCV shares 50% to 60% homology with those of simian virus 40 (SV40) and BK virus (BKV), and the carboxyl-terminal region of JCV agnoprotein is relatively unique. By using specific antibody to the carboxyl-terminal region of JCV agnoprotein, the authors have demonstrated that JCV agnoprotein expressed in the JCV-infected cells, where it localized predominantly in the perinuclear region of the cytoplasm, and colocalizes with the cellular cytoskeletal protein, tubulin. The results suggest that JCV agnoprotein may play a role in the stability of microtubules and the preservation of JCV infected cells via an interaction with tubulin.

Purpose: The aim of the current study was to evaluate the relationship between FDG-PET and dynamic CT in lung tumors. Method: Forty consecutive patients with pulmonary tumors underwent whole-body FDG-PET and contrast-enhanced dynamic CT. The size of tumors was 2.6 +/- 0.2 cm (mean +/- SD) at the largest diameter. The standardized uptake value (SUV) of FDG-PET, peak attenuation (A(PA)), and relative flow (RF) of dynamic CT were evaluated. All patients underwent surgery. and tissue samples were available to be studied. The intratumoral microvessel densities (MVDs) were counted and compared with the radiologic parameters. The duration between radiologic examinations and surgery was within 2 weeks in all patients. Results: The mean SUV, A(PA), and RF of lung cancers were significantly higher than those of benign lesions (p < 0.05). The mean A(PA) and RF of lung cancers correlated with mean SUV (A(PA) : r = 0.665, p < 0.0001: RF: r = 0.848, p < 0.05) and mean MVD (A(PA): r = 0.801, p < 0.0001; RF: r = 0.723, p < 0.05). The mean SUV of lung cancers correlated with the mean MVD (r = 0.612, p < 0.001). No correlation was found between the mean A(PA), RF, SUV, and MVD in benign tumors. Conclusion: The A(PA) and RF of dynamic CT correlated with the SUV of FDG-PET imaging in lung cancer. The A(PA) and RF of dynamic CT as an index of blood pooling may be related to increased glucose metabolism in lung cancer.

Background: We aimed to investigate whether MIR31 is an oncogene in human endometrial cancer and identify the target molecules associated with the malignant phenotype.Methods: We investigated the growth potentials of MIR31-overexpressing HEC-50B cells in vitro and in vivo. In order to identify the target molecule of MIR31, a luciferase reporter assay was performed, and the corresponding downstream signaling pathway was examined using immunohistochemistry of human endometrial cancer tissues. We also investigated the MIR31 expression in 34 patients according to the postoperative risk of recurrence.Results: The overexpression of MIR31 significantly promoted anchorage-independent growth in vitro and significantly increased the tumor forming potential in vivo. MIR31 significantly suppressed the luciferase activity of mRNA combined with the LATS2 3'-UTR and consequently promoted the translocation of YAP1, a key molecule in the Hippo pathway, into the nucleus. Meanwhile, the nuclear localization of YAP1 increased the transcription of CCND1. Furthermore, the expression levels of MIR31 were significantly increased (10.7-fold) in the patients (n = 27) with a high risk of recurrence compared to that observed in the low-risk patients (n = 7), and this higher expression correlated with a poor survival.Conclusions: MIR31 functions as an oncogene in endometrial cancer by repressing the Hippo pathway. MIR31 is a potential new molecular marker for predicting the risk of recurrence and prognosis of endometrial cancer.

Crk is a signaling adaptor protein which is mostly composed of SH2 and SH3 domains. and has been shown to play a pivotal role in cell proliferation. differentiation, and migration. Because Crk was originally isolated as an avian sarcoma virus CT10 encoding oncoprotein v-Crk. we examined a potential role for c-Crk in the carcinogenesis of human cancers. First, to analyze gene mutations of c-Crk, we isolated a human bacterial artificial chromosome clone containing Crk genome and exon/intron structures, However, polymerase chain reaction-single strand conformation polymorphism methods failed to show any genomic mutations in the Crk exon which could be related to carcinogenesis. Second, immunohistochemical analysis of c-Crk-II demonstrated that the levels of c-Crk-II were significantly elevated in most of the tumors, particularly in the colon and lung cancers. Furthermore, immunoblot analysis using human lung cancer cell lines revealed that the expression levels of c-Crk-II were correlated to growth rates of L cells. The elevated expression levels of c-Crk-II might be related to the development of human cancers. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

The signaling adaptor protein Crk has been shown to play an important role in various human cancers. However, its regulatory machinery is not clear. Here, we demonstrated that Crk induced EMT in A549 human lung adenocarcinoma cells through differential regulation of Rac1/Snail and RhoA/Slug, leading to decreased expression of E-cadherin and increased N-cadherin, fibronectin, and MMP2 expression. Cancer cells with mesenchymal features produced TGF-beta and also increased the levels of TGF-beta receptor. TGF-beta increased the endogenous levels of Crk and also augmented Crk-dependent expression of Snail and Slug, and conversely TGF-beta receptor inhibitor suppressed the levels of Snail and Slug. Overexpression of Crk was observed at the invasive front of human lung cancer tissues and was significantly associated with poor prognosis. Thus, TGF-beta and Crk collaborate to form a positive feedback loop to facilitate EMT, which may lead to the malignancy of human cancers possibly being affected by their microenvironment.

The influenza A virus non-structural protein 1 (NS1) is a multifunctional virulence factor consisting of an RNA binding domain and several Src-homology (SH) 2 and SH3 binding motifs, which promotes virus replication in the host cell and helps to evade antiviral immunity. NS1 modulates general host cell physiology in association with various cellular molecules including NS1-binding protein (NS1-BP) and signaling adapter protein CRK-like (CRKL), while the physiological role of NS1-BP during influenza A virus infection especially in association with NS1 remains unclear. In this study, we analyzed the intracellular association of NS1-BP, NS1 and CRKL to elucidate the physiological roles of these molecules in the host cell. In HEK293T cells, enforced expression of NS1 of A/Beijing (H1N1) and A/Indonesia (H5N1) significantly induced excessive phosphorylation of ERR and elevated cell viability, while the over-expression of NS1-BP and the abrogation of CRKL using siRNA abolished such survival effect of NS1. The pull-down assay using GST-fusion CRKL revealed the formation of intracellular complexes of NS1-BP, NS1 and CRKL. In addition, we identified that the N-terminus SH3 domain of CRKL was essential for binding to NS1-BP using GST-fusion CRKL-truncate mutants. This is the first report to elucidate the novel function of NS1-BP collaborating with viral protein NS1 in modulation of host cell physiology. In addition, an alternative role of adaptor protein CRKL in association with NS1 and NS1-BP during influenza A virus infection is demonstrated. (C) 2013 Elsevier Inc. All rights reserved.

Small-cell lung cancer (SCLC) accounts for nearly 15% of lung cancer cases and exhibits aggressive clinical behavior characterized by rapid growth and metastatic spread to multiple organs. About 70% of patients with SCLC present with extensive disease and distant metastases at diagnosis. HSP90 is a 90-kDa molecular chaperone whose association is required for the stability and function of its numerous "client proteins." Here, we assessed the therapeutic potential of the HSP90 inhibitor 17-DMAG in SCLC. Notably, 17-DMAG hindered the viability of human SCLC cell lines-regardless of their chemosensitivity-via the decreased expression of client proteins, including the proto-oncogene c-Raf (also known as RAF1). In an in vivo imaging model of SCLC multiple-organ metastasis with the human SCLC cell line SBC-5, treatment with 17-DMAG remarkably inhibited the formation of metastatic sites in the liver, but was ineffective in hindering the progression of bone lesions. The latter was likely the result of activation of osteoclasts. IGF-1, which is supposed to be rich in bone environment, preserved c-Raf expression and maintained viability of SBC-5 cells treated with 17-DMAG. Furthermore, the combined use of a bisphosphonate with 17-DMAG significantly attenuated the progression of metastases in both the liver and the bone. These findings suggest that therapeutic effects of HSP90 inhibitors may be organ-specific and should be carefully monitored in SCLC clinical trials.

Although several studies have suggested that aneurysmal wall inflammation and laminar thrombus are associated with the rupture of saccular aneurysms, the mechanisms leading to the rupture remain obscure. We performed full exposure of aneurysms before clip application and attempted to keep the fibrin cap on the rupture point. Using these specimens in a nearly original state before surgery, we conducted a pathological analysis and studied the differences between ruptured and unruptured aneurysms to clarify the mechanism of aneurysmal wall degeneration. This study included ruptured (n=28) and unruptured (n=12) saccular aneurysms resected after clipping. All of the ruptured aneurysms were obtained within 24 h of onset. Immunostainings for markers of inflammatory cells (CD68) and classical histological staining techniques were performed. Clinical variables and pathological findings from ruptured and unruptured aneurysms were compared. Patients with ruptured or unruptured aneurysms did not differ by age, gender, size, location, and risk factors, such as hypertension, smoking, and hyperlipidemia. The absence or fragmentation of the internal elastica lamina, the myointimal hyperplasia, and the thinning of the aneurysmal wall were generally observed in both aneurysms. The existence of subintimal fibrin deposition, organized laminar thrombus, intramural hemorrhage, neovascularization, and monocyte infiltration are more frequently observed in ruptured aneurysms. Multivariate logistic regression analysis showed that ruptured aneurysm was associated with presence of subintimal fibrin deposition and monocyte infiltration. These findings suggest that subintimal fibrin deposition and chronic inflammation have a strong impact on degeneration of the aneurysmal wall leading to their rupture, and this finding may be caused by endothelial dysfunction.