Regulation of multidrug resistance protein 2 (MRP2, ABCC2) expression by statins: Involvement of SREBP-mediated gene regulation

Multidrug resistance protein 2 (MRP2, ABCC2) is localized to the apical membrane of hepatocytes and played an important role in the biliary excretion of a broad range of endogenous and xenobiotic compounds and drugs, such as pravastatin. However, the effects of statins on MRP2 in the liver and the precise mechanisms of their actions have been obscure. The goal of this study was to determine the regulatory molecular mechanism for statin-induced MRP2 expression in hepatocytes. In vitro and in vivo studies suggested that pitavastatin increased MRP2 expression. Pitavastatin promoted liver X receptor (LXR) alpha/beta translocation from the cytosol to nuclei, resulting in LXR activation. Deletion and mutational analysis suggested that the potential sterol regulatory element (SRE) played a major role in the observed modulation of MRP2 expression by pitavastatin. Furthermore pitavastatin increased the protein-DNA complex, and when SRE was mutated, stimulation of the protein-DNA complex by pitavastatin was decreased. It was demonstrated that pitavastatin upregulated MRP2 expression by an SREBP regulatory pathway in hepatocytes and that the actions of statins may lead to improve the biliary excretion of MRP2 substrates. (C) 2013 Elsevier B.V. All rights reserved

Effects of N-Substituents on the Functional Activities of Naltrindole Derivatives for the δ Opioid Receptor: Synthesis and Evaluation of Sulfonamide Derivatives

We have recently reported that N-alkyl and N-acyl naltrindole (NTI) derivatives showed activities for the δ opioid receptor (DOR) ranging widely from full inverse agonists to full agonists. We newly designed sulfonamide-type NTI derivatives in order to investigate the effects of the N-substituent on the functional activities because the side chain and S=O part in the sulfonamide moiety located in spatially different positions compared with those in the alkylamine and amide moieties. Among the tested compounds, cyclopropylsulfonamide 9f (SYK-839) was the most potent full inverse agonist for the DOR, whereas phenethylsulfonamide 9e (SYK-901) showed full DOR agonist activity with moderate potency. These NTI derivatives are expected to be useful compounds for investigation of the molecular mechanism inducing these functional activities

Early prediction of lenvatinib treatment efficacy by using 18F-FDG PET/CT in patients with unresectable or advanced thyroid carcinoma that is refractory to radioiodine treatment : a protocol for a non-randomized single-arm multicenter observational study

Introduction: Lenvatinib, an oral molecular targeted drug, is used to treat patients with unresectable or advanced thyroid carcinoma that is refractory to radioiodine treatment. Effective methods for evaluating molecular targeted drugs are a critical unmet need owing to their expensive costs and unique adverse events. The aim of this study is to determine whether 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT at 1 week after commencing lenvatinib can predict treatment outcomes. Design and methods: This study is planned as a non-randomised single-arm multicentre study; patients with pathologically confirmed differentiated thyroid carcinoma (DTC) with lesions that are refractory to radioiodine treatment are eligible. The main exclusion criteria are medullary or anaplastic carcinoma, prior treatment with chemotherapy, poor general condition and thromboembolism-requiring treatment. Patients to be included in the study will be treated with lenvatinib and undergo FDG-PET/CT examination twice: before and 1 week after the initiation of treatment. Contrast-enhanced CT, the gold standard for evaluation, will be performed at least 4 weeks after the initiation of treatment. The primary objective is to evaluate the ability of the lesion maximum standard uptake value for FDG PET/CT performed 1 week after the initiation of treatment to predict outcomes compared with the response evaluation obtained via contrast-enhanced CT performed at least 4 weeks after the initiation of treatment. Ethics and dissemination: This study is conducted in accordance with the Declaration of Helsinki and has received ethical approval from the institutional review board of the Hokkaido University Hospital (approval number: 015-402). The results of this study will be disseminated through a presentation at a conference and the publication of the data in a peer-reviewed journal. The study will be implemented and reported in line with the SPIRIT statement. Trial registration number: UMIN000022592