Toranomon Hospital and Okinaka Memorial Institute for Medical Research

Minato-ku, Japan

Toranomon Hospital and Okinaka Memorial Institute for Medical Research

Minato-ku, Japan
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Takeshita A.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research | Igarashi-migitaka J.,St. Marianna University School of Medicine | Nishiyama K.,Teikyo University | Takahashi H.,Teikyo University | And 2 more authors.
Toxicological Sciences | Year: 2011

Steroid and xenobiotic receptor (SXR) is activated by endogenous and exogenous chemicals including steroids, bile acids, and prescription drugs. SXR is highly expressed in the liver and intestine, where it regulates cytochrome P450 3A4 (CYP3A4), which in turn controls xenobiotic and endogenous steroid hormone metabolism. However, it is unclear whether Food and Drug Administration (FDA)-approved plasticizers exert such activity. In the present study, we evaluated the effects of FDA-approved plasticizers on SXR-mediated transcription in vitro by luciferase reporter, SXR-coactivator interaction, quantitative real-time PCR analysis of CYP3A4 expression, CYP3A4 enzyme activity assays, and SXR knockdown. Rats, treated with gavage and intraperitoneal injection of compounds, were examined for CYP3A1 expression in vivo. We found that four of eight FDA-approved plasticizers increased SXR-mediated transcription. In particular, acetyl tributyl citrate (ATBC), an industrial plasticizer widely used in products such as food wrap, vinyl toys, and pharmaceutical excipients, strongly activated human and rat SXR. ATBC increased CYP3A4 messenger RNA (mRNA) levels and enzyme activity in the human intestinal cells but not in human liver cells. Similarly, CYP3A1 mRNA levels were increased in the intestine but not the liver of ATBC-treated rats. These in vitro and in vivo results suggest that ATBC specifically induces CYP3A in the intestine by activating SXR. We suggest that ATBC-containing products be used cautiously because they may alter metabolism of endogenous steroid hormones and prescription drugs. © The Author 2011. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved.


Takeshita A.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research | Igarashi-Migitaka J.,St. Marianna University School of Medicine | Koibuchi N.,Gunma University | Takeuchi Y.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Journal of Endocrinology | Year: 2013

Adrenocortical carcinoma (ACC) is a rare disease with an extremely poor prognosis. Mitotane alone or in combination with other cytotoxic drugs is a common therapeutic option for ACC. In addition to its adrenolytic function, mitotane has been known for decades to increase the metabolic clearance of glucocorticoids. It was recently shown that the tyrosine kinase inhibitor sunitinib is also rapidly metabolized in patients treated with mitotane, indicating that mitotane engages in clinically relevant drug interactions. Although the precise mechanism of these interactions is not well understood, cytochrome P450 mono-oxygenase 3A4 (CYP3A4) is a key enzyme to inactivate both glucocorticoids and sunitinib. The nuclear receptor steroid and xenobiotic receptor (SXR (NR1I2)) is one of the key transcriptional regulators of CYP3A4 gene expression in the liver and intestine. A variety of xenobiotics bind to SXR and stimulate transcription of xenobiotic-response elements (XREs) located in the CYP3A4 gene promoter. In this study, we evaluated the effects of mitotane on SXR-mediated transcription in vitro by luciferase reporter analysis, SXR-steroid receptor coactivator 1 (SRC1) interactions, quantitative real-time PCR analysis of CYP3A4 expression, SXR knockdown, and CYP3A4 enzyme activity assays using human hepatocyte-derived cells. We found that mitotane activated SXR-mediated transcription of the XREs. Mitotane recruited SRC1 to the ligand-binding domain of SXR. Mitotane increased CYP3A4 mRNA levels, which was attenuated by SXR knockdown. Finally, we showed that mitotane increased CYP3A4 enzyme activity.We conclude that mitotane can induce CYP3A4 gene expression and suggest that mitotane is used cautiously due to its drug-drug interactions. © 2013 Society for Endocrinology.


Akuta N.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research | Suzuki F.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research | Sezaki H.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research | Suzuki Y.,Toranomon Hospital and Okinaka Memorial Institute for Medical Research | And 6 more authors.
Journal of Medical Virology | Year: 2014

Using ultra-deep sequencing technology, the present study was designed to investigate the evolution of simeprevir-resistant variants (amino acid substitutions of aa80, aa155, aa156, and aa168 positions in HCV NS3 region) over time. In Toranomon Hospital, 18 Japanese patients infected with HCV genotype 1b, received triple therapy of simeprevir/PEG-IFN/ribavirin (DRAGON or CONCERT study). Sustained virological response rate was 67%, and that was significantly higher in patients with IL28B rs8099917 TT than in those with non-TT. Six patients, who did not achieve sustained virological response, were tested for resistant variants by ultra-deep sequencing, at the baseline, at the time of re-elevation of viral loads, and at 96 weeks after the completion of treatment. Twelve of 18 resistant variants, detected at re-elevation of viral load, were de novo resistant variants. Ten of 12 de novo resistant variants become undetectable over time, and that five of seven resistant variants, detected at baseline, persisted over time. In one patient, variants of Q80R at baseline (0.3%) increased at 96-week after the cessation of treatment (10.2%), and de novo resistant variants of D168E (0.3%) also increased at 96-week after the cessation of treatment (9.7%). In conclusion, the present study indicates that the emergence of simeprevir-resistant variants after the start of treatment could not be predicted at baseline, and the majority of de novo resistant variants become undetectable over time. Further large-scale prospective studies should be performed to investigate the clinical utility in detecting simeprevir-resistant variants. © 2014 Wiley Periodicals, Inc.


PubMed | Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: Comparative Study | Journal: Oncology | Year: 2015

A randomized controlled trial was conducted to evaluate the efficacy of impedance control of a radiofrequency interstitial thermal ablation system (RITA) used to treat hepatocellular carcinoma (HCC).Fifteen patients with hypervascular HCCs <20 mm in diameter were randomly treated with radiofrequency ablation (RFA) using conventional temperature control (group A) or impedance control methods (group B). RITA needle electrodes were used in all cases. We compared ablation time, extent of lesion ablation, and energy use between the two groups.The median long and short diameters of the axial cross sections of radiofrequency-induced necrotic areas visualized by CT were 32 mm (range, 26-36) and 25 mm (20-31) in group A and 32 mm (28-40) and 31 mm (24-37) in group B, respectively. The short diameter of group B patients was significantly greater than that of group A patients (p = 0.029). The median ablation time was 18.8 min in group A and 13.4 min in group B, thus significantly shorter in group B (p = 0.001). The energy requirement did not differ significantly between the groups.Impedance control of the RITA system resulted in an increased size of the ablation zone and a decreased ablation time.


PubMed | Toranomon Hospital and Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: Journal Article | Journal: Hepatology international | Year: 2016

Relationships between circulating microRNA-122 (miR-122) and histological features of nonalcoholic fatty liver disease (NAFLD) are unclear.The impact of serum miR-122 levels for histological features and hepatocellular carcinoma (HCC) was investigated in 305 Japanese patients with histological proven NAFLD. Twenty-three patients were with HCC at the time of diagnosis of NAFLD, and four patients developed HCC during the follow-up. The cross-sectional or longitudinal evaluations were performed to investigate the impact for HCC.Serum miR-122 levels (calibrated relative to the median levels of patients) partly affected severity of steatosis, ballooning, lobular inflammation, and stage. Multivariate analysis identified HCC and/or histological components of NASH as morphological factors that independently influenced serum miR-122 levels at the diagnosis of NAFLD. There was a strong correlation between serum miR-122 levels and AST, ALT levels. In cross-sectional evaluation, serum miR-122 levels of patients without HCC were significantly higher than those with HCC in patients of stage 3 but not stage 4. In longitudinal evaluation of one patient with follow-up time of 25years, from the diagnosis of NAFLD until HCC, serum miR-122 levels had already tended to decrease before the progression of fibrosis stage.HCC and/or histological components of NASH affected serum miR-122 levels, independently. In longitudinal evaluation of HCC patients, serum miR-122 levels had already tended to decrease before the progression of fibrosis stage. Further prospective studies are needed to investigate the impact of serum miR-122 for histological features and hepatocarcinogenesis of NAFLD.


PubMed | Toranomon Hospital and Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: Journal Article | Journal: BMC gastroenterology | Year: 2016

The association between circulating microRNA-122 (miR-122) and histopathological features of nonalcoholic fatty liver disease (NAFLD) remains unclear.The association of serum miR-122 levels with histopathological features of NAFLD (steatosis, ballooning, lobular inflammation, and stage, as histological components of nonalcoholic steatohepatitis) was examined in serial liver biopsies from 36 hepatocellular carcinoma (HCC)-free Japanese patients with histopathologically-proven NAFLD. The median interval between first and second liver biopsies was 4.6years.In patients who showed improvement of histopathological scores (steatosis, ballooning, and stage), serum miR-122 levels were significantly lower at second biopsy than first biopsy. In patients who showed no improvement, the changes at second biopsy were not different from those at first biopsy. There were significant and strong associations between serum miR-122 ratio (ratio of level at second biopsy to that at first biopsy) and changes in histopathological scores (of steatosis, lobular inflammation, and stage). There were also significant and strong associations between serum miR-122 ratio and changes in other clinical parameters, including aspartate aminotransferase and alanine aminotransferase.Longitudinal examination of serial liver biopsies showed the association of serum miR-122 with histopathological features of HCC-free NAFLD patients.


PubMed | Toranomon Hospital and Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: Journal Article | Journal: Journal of medical virology | Year: 2016

Alanine aminotransferase (ALT) elevations were the most frequent adverse events during all-oral combinations with daclatasvir and asunaprevir for patients with hepatitis C virus (HCV) infection, but the underline mechanisms are unclear. Seventy patients with chronic HCV genotype 1b infection, who were introduced daclatasvir 60mg once daily plus asunaprevir 100mg twice daily for 24 weeks, were measured serum asunaprevir concentrations at the one point or more of 2, 4, and 8 weeks after the start of treatment. In 4 and 8 weeks after the start of treatment, asunaprevir concentrations in patients with albumin levels <3.6g/dl at baseline were significantly higher than those in patients with albumin levels 3.6g/dl. The baseline factors did not affect to ALT severe elevations (300 IU/l). At 2 weeks after the start of treatment, ALT severe elevations with asunaprevir concentrations of 800ng/ml (54.5%) tended to indicate the higher rates than those of <800ng/ml (17.6%). Furthermore, the discontinuation or reduction of asunaprevir improved ALT levels, regardless the significant decrease of serum asunaprevir concentrations. In conclusion, serum albumin levels affected to serum asunaprevir concentrations, and serum asunaprevir concentrations might partly affect to ALT severe elevations. Further large-scale prospective studies are needed to investigate the impact of the discontinuation or reduction of asunaprevir to help in the design of more effective therapeutic regimens.


PubMed | Toranomon Hospital and Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: | Journal: Journal of medical virology | Year: 2017

There is little information on retreatment efficacy and predictors of the combination of ledipasvir and sofosbuvir (ledipasvir/sofosbuvir) for patients who fail to respond to NS5A inhibitors. NS5A resistance variants are known to persist for long periods after such treatment. Here, we evaluated 54 patients with chronic HCV genotype 1b infection, free of decompensated cirrhosis and hepatocellular carcinoma, for sustained virological response after 12 weeks (SVR12) of once-daily treatment with 90mg ledipasvir and 400mg sofosbuvir. Intention-to-treat analysis showed SVR12 of 70%. Using ultra-deep sequencing, non-responder to ledipasvir/sofosbuvir showed no change in the rates of detection of NS5A and NS5B resistant-variants at re-elevation of viral loads, relative to baseline. According to response to prior treatment, SVR12 rates were 18, 69, 94, and 100% in non response, viral breakthrough, relapse, and discontinuation due to adverse events, respectively. SVR12 rates in non response were significantly lower than those of the others. Multivariate analysis identified response to previous treatment (failure except for non response) and FIB4 index (<3.25) as significant determinants of SVR12. The SVR12 rates were significantly lower in patients with FIB4 index of 3.25 and had not responded to prior treatment, relative to others. The specificity, and positive- and negative-predictive values were high for prediction of poor response based on the combination of two predictors. In conclusion, our study indicated that ledipasvir/sofosbuvir is a potentially useful salvage treatment for patients who fail prior NS5A inhibitors-based therapy. Response to prior treatment was an important predictor of retreatment efficacy. This article is protected by copyright. All rights reserved.


PubMed | Toranomon Hospital and Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: Journal Article | Journal: Gut and liver | Year: 2016

It is important to determine the noninvasive parameters of histological features in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the value of genetic variations as surrogate markers of histological features.The parameters that affected the histological features of NAFLD were investigated in 211 Japanese patients with biopsy-proven NAFLD. The relationships between genetic variations in PNPLA3 rs738409 or TM6SF2 rs58542926 and histological features were analyzed. Furthermore, the impact of genetic variations that affected the pathological criteria for the diagnosis of nonalcoholic steatohepatitis (NASH) (Matteoni classification and NAFLD activity score) was evaluated.The fibrosis stage of PNPLA3 GG was significantly more progressive than that of CG by multiple comparisons. Multivariate analysis identified PNPLA3 genotypes as predictors of fibrosis of stage 2 or more, but the impact tended to decrease at stage 3 or greater. There were no significant differences among the histological features of the three genotypes of TM6SF2. PNPLA3 genotypes partly affected the definition of NASH by the NAFLD activity score, but TM6SF2 genotypes did not affect the definition of NASH.In Japanese patients with biopsy-proven NAFLD, PNPLA3 genotypes may partly affect histological features, including stage of fibrosis, but the TM6SF2 genotype does not affect histological features.


PubMed | Toranomon Hospital and Okinaka Memorial Institute for Medical Research
Type: Journal Article | Journal: Journal of medical virology | Year: 2015

The present study was designed to assess the evolution of simeprevir-resistant variants (amino acid substitutions of aa80, aa155, aa156, and aa168 positions in HCV NS3 region) over time in virological non-responders (patients with positive HCV-RNA during and at end of treatment). The study enrolled 136 patients infected with HCV genotype 1b who received 12-week simeprevir-PEG-IFN-ribavirin therapy, and data of 87 patients were available for analysis. Twelve patients (14%) were considered virological non-responders, including 9 (75%) who showed absolute no-response (HCV RNA: 3.0 log IU/ml at 12 weeks after start of therapy). Multivariate analysis of these patients identified lack of response to prior treatment, use of low ribavirin dose, and old age as independent and significant determinants of virological non-response. Using ultra-deep sequencing, de novo variants of D168 were detected in all of 9 absolute non-responders. The majority of these variants emerged within 5 weeks of triple therapy. In comparison, de novo variants of Q80 were detected in only 3 of 9 absolute non-responders and emerged at 6-12 weeks. Variants of Q80 detected at baseline increased during the course of treatment in 5 of 9 absolute non-responders, while no such increase was noted in variants of R155 and/or A156 detected at baseline during the 12-week course. De novo variants of R155 and/or A156 were not detected in this study. The results demonstrated the emergence of simeprevir-resistant variants during the early stage of triple therapy.

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