Language：English   Publishing type：Research paper (scientific journal)  

Pancreatic cancer is notorious for its dismal prognosis. The enhanced permeability and retention (EPR) effect theory posits that nanomedicines (therapeutics in the size range of approximately 10-200 nm) selectively accumulate in tumors. Nanomedicine has thus been suggested to be the "magic bullet"-both effective and safe-to treat pancreatic cancer. However, the densely fibrotic tumor microenvironment of pancreatic cancer impedes nanomedicine delivery. The EPR effect is thus insufficient to achieve a significant therapeutic effect. Intratumoral fibrosis is chiefly driven by aberrantly activated fibroblasts and the extracellular matrix (ECM) components secreted. Fibroblast and ECM abnormalities offer various potential targets for therapeutic intervention. In this review, we detail the diverse strategies being tested to overcome the fibrotic barriers to nanomedicine in pancreatic cancer. Strategies that target the fibrotic tissue/process are discussed first, which are followed by strategies to optimize nanomedicine design. We provide an overview of how a deeper understanding, increasingly at single-cell resolution, of fibroblast biology is revealing the complex role of the fibrotic stroma in pancreatic cancer pathogenesis and consider the therapeutic implications. Finally, we discuss critical gaps in our understanding and how we might better formulate strategies to successfully overcome the fibrotic barriers in pancreatic cancer.

DOI： 10.3390/cancers15030724

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Authorship：Lead author   Language：Japanese   Publisher：日本DDS学会  

Enhanced permeability and retention(EPR)効果により血管からがん組織内へと漏出したナノDDSは、多くの場合、間質障壁により妨げられ、腫瘍細胞へと到達することができない。間質障壁は、がん細胞と種々の「正常」な細胞の相互作用を通じて形成・維持される。こうした相互作用の場を「がん微小環境」という。がん微小環境中の線維化組織、すなわち主として異常な形質を獲得した線維芽細胞およびこれらの細胞により産生され過剰沈着している細胞外基質により構成される組織は、とりわけナノDDSの送達効率の重要な規定要因として知られる。本稿では、がん微小環境における線維化について概説した後、より効率的なナノDDS送達を実現するうえでの示唆について考察する。(著者抄録)

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Authorship：Lead author   Language：Japanese   Publisher：日本DDS学会  

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Objectives: Appropriate antibiotic prescriptions for outpatients with acute respiratory tract infections (ARTIs) are urgently needed in Japan. However, the empirical proof of this need is under-documented. Therefore, we aimed to determine antibiotic prescription rates, and the proportions of antibiotic classes prescribed for Japanese patients with ARTIs. Methods: We analysed health insurance claims data over 2013–2015 among Japanese patients aged <75 years and determined the following indicators: 1) visit rates for patients with ARTIs and antibiotic prescription rates per 1000 person-years, and 2) proportion of visits by antibiotic-prescribed patients with ARTIs. We defined broad-spectrum antibiotics using the WHO Anatomical Therapeutic Chemical classification 4 level codes. Results: Among 8.65 million visits due to ARTIs at 6859 hospitals and 62,024 physicians’ offices, the visit rate and antibiotic prescription rate per 1000 person-years were 990.6 (99% confidence interval [CI], 989.4–991.7) and 532.4 (99% CI, 531.6–533.3), respectively. The visit rates for patients aged 0–17, 18–59, and 60–74 years were 2410.0 (99% CI, 2407.2–2412.9), 683.6 (99% CI, 682.7–684.6), and 682.1 (99% CI, 678.2–686.0), and antibiotic prescription rates were 1093.3 (99% CI, 1091.4–1095.2), 434.1 (99% CI, 433.4–434.9), and 353.4 (99% CI, 350.7–356.1), respectively. The overall proportion of antibiotic prescriptions for ARTI visits was 52.7% and 91.3% of the antibiotics prescribed were broad-spectrum. Conclusions: Both the visit rates and antibiotic prescription rates for ARTIs were high in this Japanese cohort. The proportion of antibiotic prescriptions exceeded that recommended in the clinical guidelines. Thus, there might be a scope for reducing the current antibiotic prescription rate in Japan.

DOI： 10.1016/j.jiac.2020.02.001

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In pulmonary arterial hypertension (PAH), excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) causes vascular medial thickening. Medial thickening is a histopathological hallmark of pulmonary vascular remodeling, the central disease process driving PAH progression. Pulmonary vascular remodeling causes stenosis and/or obstruction of small pulmonary arteries. This leads to increased pulmonary vascular resistance, elevated pulmonary arterial pressure, and ultimately right heart failure. To improve the survival of PAH patients, which remains at approximately 60% at 3 years after diagnosis, the development of novel PAH-targeted drugs is desired. To this end, a detailed understanding of the mechanisms underlying excessive PASMC proliferation and the medial thickening that ensues is necessary. However, a lack of in vitro models that recapitulate medial thickening impedes our deeper understanding of the pathogenetic mechanisms involved. In the present study, we applied 3-dimensional (3D) cell culture technology to develop a novel in vitro model of the pulmonary artery medial layer using human PAH patient-derived PASMCs. The addition of platelet-derived growth factor (PDGF)-BB, a mitogen known to promote excessive PASMC proliferation in PAH, resulted in increased thickness of the 3D-PAH media tissues. Conversely, administration of the PDGF receptor inhibitor imatinib or other clinical PAH drugs inhibited this medial thickening-inducing effect of PDGF-BB. Altogether, by using 3D cell culture technology, we report the generation of an in vitro model of medial thickening in PAH, which had hitherto not been successfully modeled in vitro. This model is potentially useful for assessing the ability of candidate PAH drugs to suppress medial thickening.

DOI： 10.3389/fbioe.2020.00482

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Stabilisation of fragile oligonucleotides, typically small interfering RNA (siRNA), is one of the most critical issues for oligonucleotide therapeutics. Many previous studies encapsulated oligonucleotides into ~100-nm nanoparticles. However, such nanoparticles inevitably accumulate in liver and spleen. Further, some intractable cancers, e.g., tumours in pancreas and brain, have inherent barrier characteristics preventing the penetration of such nanoparticles into tumour microenvironments. Herein, we report an alternative approach to cancer-targeted oligonucleotide delivery using a Y-shaped block catiomer (YBC) with precisely regulated chain length. Notably, the number of positive charges in YBC is adjusted to match that of negative charges in each oligonucleotide strand (i.e., 20). The YBC rendezvouses with a single oligonucleotide in the bloodstream to generate a dynamic ion-pair, termed unit polyion complex (uPIC). Owing to both significant longevity in the bloodstream and appreciably small size (~18 nm), the uPIC efficiently delivers oligonucleotides into pancreatic tumour and brain tumour models, exerting significant antitumour activity.

DOI： 10.1038/s41467-019-09856-w

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Background: Oral anticoagulants use has increased rapidly, internationally. Here we look at risks and benefits, based on Japanese data, of therapy with low risk non-valvular atrial fibrillation patients. Objectives: Using a health insurance claims data set we assessed: (i) oral anticoagulants usage in Japan, and (ii) efficacy and safety of dabigatran compared with warfarin, in Japanese patients with non-valvular atrial fibrillation, aged 18-74 years. Methods: We identified 4380 non-valvular atrial fibrillation patients treated with anticoagulants between 1 January 2005, and 28 February 2014, and estimated the adjusted hazard ratio for stroke or systemic embolism, and any hemorrhagic event (Cox proportional hazards regression model with stabilized inverse probability treatment weighting). Results: The data included 101 989 anticoagulant prescriptions for 4380 patients, of which direct oral anticoagulants increased to 40.0% of the total by the end of the study. After applying exclusion criteria, 1536 new non-valvular atrial fibrillation patients were identified, including 1071 treated with warfarin and 465 with dabigatran. Mean ages were 56.11 ± 9.70 years for warfarin, and 55.80 ± 9.65 years for dabigatran. The adjusted hazard ratio (95% confidence interval), comparing dabigatran with warfarin, was 0.48 (0.25-0.91) for stroke or systemic embolism, and 0.91 (0.60-1.39) for any hemorrhage including intracranial and gastrointestinal. Conclusions: Number of patients prescribed direct oral anticoagulants steadily increased, and incidence of all-cause bleeding related to dabigatran was similar to warfarin, in our study population of younger non-valvular atrial fibrillation patients. Dabigatran, compared with warfarin, generally reduced risk of all-cause stroke and systemic embolism.

DOI： 10.1093/fampra/cmz016

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Background: In this age of antimicrobial resistance, unnecessary use of antibiotics to treat non-bacterial acute respiratory tract infections (ARTIs) and inappropriate use of antibiotics in treating bacterial ARTIs are public health concerns. Purpose: Our aim is to identify the pattern of oral antibiotic prescriptions for outpatients with ARTIs in Japan. Methods: We analysed health insurance claims data of patients (aged ≤74 years) from 2013 to 2015, to determine the pattern of antibiotic prescriptions for outpatient ARTIs and calculated the proportion of each antibiotic. Results: Data on 4.6 million antibiotic prescriptions among 1559394 outpatients with ARTIs were analysed. The most commonly prescribed classes of antibiotics included cephalosporins (41.9%), macrolides (32.8%) and fluoroquinolones (14.7%). The proportion of first-, second- and third-generation cephalosporins was 1.0%, 1.7% and 97.3%, respectively. Fluoroquinolones accounted for a quarter of the prescriptions for ARTIs in patients aged >20 years. In contrast, penicillins accounted for just 8.0% of the total number of antibiotic prescriptions for ARTIs. Conclusions: According to clinical guidelines, penicillins are first-line antibiotics against ARTIs. However, third-generation cephalosporins, macrolides and fluoroquinolones are more frequently prescribed in Japan. Although we could not assess the extent to which appropriate antibiotics are selected, our results support the necessity of improving antibiotic choices in the treatment of ARTIs.

DOI： 10.1093/fampra/cmy094

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Authorship：Lead author   Language：Japanese   Publisher：(株)アークメディア  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

The survival rate of pancreatic ductal adenocarcinoma is still the lowest among all types of cancers, primarily as a consequence of an important desmoplastic reaction. Although the presence of thick stromal tissues in pancreatic tumors has been reported, in vivo animal studies do not enable a clear understanding of the crosstalk between cancer cells and fibroblasts. Accordingly, this paper reports the design and characterization of an in vitro pancreatic cancer–stromal 3D-tissue model, which enhances the understanding of the interactions between cancer cells and fibroblasts and their influence on the secretion of extracellular matrix (ECM). 3D-tissue models comprising fibroblasts and pancreatic cancer cells (MiaPaCa-2 cell line) or colon cancer cells (HT29 cell line, used as a control) show decreased molecular permeability with increased cancer cell ratios. The 3D-MiaPaCa-2 tissues display an increase in the secretion of collagen as a function of the cancer cell ratio, whereas 3D-HT29 tissues do not show a significant difference. Notably, the secretion of ECM proteins from single fibroblasts in 3D-tissue models containing 90% MiaPaCa-2 cells is ten times higher than that under 10% cancer cell conditions. In vitro pancreatic cancer 3D-tissues will be a valuable tool to obtain information on the interactions between cancer and stromal cells.

DOI： 10.1002/adhm.201700057

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Cancer Science  

Angiogenesis is a multi-step process that culminates in vascular maturation whereby nascent vessels stabilize to become functional, and mural cells play an essential role in this process. Recent studies have shown that mural cells in tumors also promote and maintain vascular integrity, with wide-reaching clinical implications including the regulation of tumor growth, metastases, and drug delivery. Various regulatory signaling pathways have been hitherto implicated, but whether regulation of Fas-dependent apoptotic mechanisms is involved has not yet been fully investigated. We first compared endothelial FAS staining in human pancreatic ductal adenocarcinomas and colon carcinomas and show that the latter, characterized by lower mural cell coverage of tumor vasculature, demonstrated higher expression of FAS than the former. Next, in an in vitro coculture system of MS-1 and 10T1/2 cells as endothelial and mural cells respectively, we show that mural cells decreased endothelial Fas expression. Then, in an in vivo model in which C26 colon carcinoma cells were inoculated together with MS-1 cells alone or with the further addition of 10T1/2 cells, we demonstrate that mural cells prevented hemorrhage. Finally, knockdown of endothelial Fas sufficiently recapitulated the protection against hemorrhage seen with the addition of mural cells. These results together suggest that regulation of endothelial Fas signaling is involved in the promotion of vascular integrity by mural cells in tumors.

DOI： 10.1111/cas.13216

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Pancreatic cancer is notorious for its poor prognosis. The histopathologic characteristic of pancreatic ductal adenocarcinoma (PDAC), which is the most common type of pancreatic cancer, is fibrosis within tumor tissue. Although fibrosis within tumor tissue is thought to impede drug therapy by interfering with the intratumoral accumulation of anti-tumor drugs, this hypothesis has yet to be proven directly in preclinical models. Here, we evaluated the effect of enhanced fibrosis on intratumoral accumulation of macromolecular drugs by increasing fibrosis in a murine tumor model of subcutaneously xenografted BxPC-3, a human PDAC cell line. When fibroblast growth factor-2 (FGF-2) was co-administered upon BxPC-3 inoculation, stromal fibrotic area was increased and was characterized by augmented murine collagen accumulation compared to inoculation of BxPC-3 alone, which correlated with increased monocyte/macrophage contents in the tumor tissues. We further discovered that the intratumoral accumulation of intravenously administrated fluorescein isothiocyanate-dextran of 2,000,000 Da (2 MDa) was significantly reduced in the FGF-2 co-administered tumors despite unaltered hyaluronan accumulation and pericyte coverage of the tumor neovasculature and increased lymphangiogenesis. Finally, we found that FGF-2 co-administered tumors are more refractory to macromolecular drug therapy using nab-paclitaxel (Abraxane). The model established and analyzed in this study, characterized by increased fibrotic component, provides a preclinical animal model suited to predict the intratumoral accumulation of macromolecular drugs and to evaluate the efficacy of drugs targeting the tumor stroma.

DOI： 10.1016/j.jconrel.2016.04.007

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

Some psychiatric diseases in children and young adults are thought to originate from adverse exposures during foetal life, including hypoxia and hypoxia/reoxygenation. The mechanism is not understood. Several authors have emphasised that the placenta is likely to play an important role as the key interface between mother and foetus. Here we have explored whether a first trimester human placenta or model barrier of primary human cytotrophoblasts might secrete factors, in response to hypoxia or hypoxia/reoxygenation, that could damage neurones. We find that the secretions in conditioned media caused an increase of [Ca ] and mitochondrial free radicals and a decrease of dendritic lengths, branching complexity, spine density and synaptic activity in dissociated neurones from embryonic rat cerebral cortex. There was altered staining of glutamate and GABA receptors. We identify glutamate as an active factor within the conditioned media and demonstrate a specific release of glutamate from the placenta/cytotrophoblast barriers invitro after hypoxia or hypoxia/reoxygenation. Injection of conditioned media into developing brains of P4 rats reduced the numerical density of parvalbumin-containing neurones in cortex, hippocampus and reticular nucleus, reduced immunostaining of glutamate receptors and altered cellular turnover. These results show that the placenta is able to release factors, in response to altered oxygen, that can damage developing neurones under experimental conditions. © 2014 Elsevier Inc. 2+ i

DOI： 10.1016/j.expneurol.2014.05.003

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Event date： 2020.8

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Event date： 2020.3

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Event date： 2020

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Event date： 2019.9

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Event date： 2019

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Event date： 2018

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