You have accessJournal of UrologyProstate Cancer: Basic Research III1 Apr 2015MP55-04 THERMOTHERAPY WITH MAGNETIC CATIONIC LIPOSOMES POWERFULLY SUPPRESSES PROSTATE CANCER BONE METASTASIS IN A NOVEL RAT MODEL Daichi Kobayashi, Noriyasu Kawai, Keitaro Iida, Toshiki Etani, Taku Naiki, Ryosuke Ando, Keiichi Tozawa, Tohru Mogami, and Kenjiro Kohri Daichi KobayashiDaichi Kobayashi More articles by this author , Noriyasu KawaiNoriyasu Kawai More articles by this author , Keitaro IidaKeitaro Iida More articles by this author , Toshiki EtaniToshiki Etani More articles by this author , Taku NaikiTaku Naiki More articles by this author , Ryosuke AndoRyosuke Ando More articles by this author , Keiichi TozawaKeiichi Tozawa More articles by this author , Tohru MogamiTohru Mogami More articles by this author , and Kenjiro KohriKenjiro Kohri More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2047AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Bone metastasis is a serious problem for prostate cancer patients, and the anticancer drug docetaxel (DTX) does not effectively treat this condition. Therefore, new therapies are urgently required. At the American Urological Association annual meetings in 2007, 2008, and 2010, we reported the therapeutic effects of our magnetite nanoparticles conjugated with cationic liposomes (MCLs). Here, we examined the therapeutic potential of MCLs for bone metastasis from prostate cancer compared to conventional DTX therapy in a novel rat model that allows tumor immunity evaluation. METHODS Prostate tumor tissues were transplanted into the femurs of 4 groups of model rats: control, MCL, DTX, and MCL + DTX. Tumors were injected with MCLs, and alternating magnetic field (AMF) irradiation was performed thrice a week. We poured 200 μl MCLs (33 mg/ml) into the tumor center just before each AMF exposure from 4 directions. DTX (10 mg/kg) was administered transcaudally. Tumor proliferation and bone destruction were evaluated by examining proliferating cell nuclear antigen positivity, computed tomography images, and CD68-positive cell numbers. Tumor immunity was evaluated by assessing interleukin-2 (IL-2), interferon-gamma (IFN-γ), and heat shock protein (HSP) 70 expression and determination of the CD8-positive lymphocyte number. RESULTS We successfully established a novel femur metastasis model of prostate cancer. This model allows long-term evaluation of bones and immune function. Tumor proliferation and bone destruction were significantly lower in the MCL and MCL + DTX groups than in the control and DTX groups. MCL thermotherapy concurrently induced necrosis and apoptosis. IL-2, IFN-γ, and HSP70 expression in the MCL and MCL + DTX groups also significantly increased, and tumor immunity was enhanced through CD8-positive lymphocyte induction. CONCLUSIONS MCL thermotherapy selectively heats MCL-injected tumor tissues, inducing necrotic and apoptotic cancer cell death, tumor immunity, and suppression of bone destruction. MCL thermotherapy was clearly more effective than DTX in treating bone metastatic prostate cancer. Therefore, combined MCL thermotherapy and DTX deserves consideration as a novel treatment for this disease. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e674 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daichi Kobayashi More articles by this author Noriyasu Kawai More articles by this author Keitaro Iida More articles by this author Toshiki Etani More articles by this author Taku Naiki More articles by this author Ryosuke Ando More articles by this author Keiichi Tozawa More articles by this author Tohru Mogami More articles by this author Kenjiro Kohri More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...
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