title: Thermotherapy using magnetic cationic liposomes powerfully suppresses prostate cancer bone metastasis in a novel rat model.
abstract: BACKGROUND
  Bone metastasis is a serious problem for individuals with prostate cancer, and the effects of the anticancer drug docetaxel (DTX) are insufficient. We therefore examined the therapeutic potential of magnetic cationic liposomes (MCL) in a novel rat model that allows the evaluation of tumor immunity. The effects of MCL thermotherapy were compared with those of DTX as a conventional therapy for the treatment of bone metastatic prostate cancer.
  
  
  METHODS
  Prostate tumor tissues were transplanted into the femurs of model rats divided into four groups: control, MCL, DTX, and MCL + DTX. Tumors were injected with MCL, and alternating magnetic field (AMF) irradiation was performed three times a week. Tumor proliferation and bone destruction were evaluated by proliferating cell nuclear antigen positivity, computed tomography, and CD68-positive cell number, while tumor immunity was evaluated by heat shock protein (HSP) 70 expression and CD8-positive lymphocyte number.
  
  
  RESULTS
  We successfully established a novel femur metastasis model of prostate cancer, and demonstrated that tumor proliferation and bone destruction in the MCL and MCL + DTX groups were significantly suppressed compared with control and DTX groups. MCL thermotherapy concurrently induced necrosis and apoptosis. The expression of HSP70 in the MCL and MCL + DTX groups was also significantly increased, and tumor immunity was enhanced through the induction of CD8-positive lymphocytes.
  
  
  CONCLUSIONS
  MCL thermotherapy was clearly more effective than DTX in treating bone metastatic prostate cancer. A combination of MCL thermotherapy and DTX therefore deserves consideration as a novel treatment for this disease.
authors: Department of Nephro-Urology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan.
authors: Daichi
authors: D
authors: Kobayashi
authors: Noriyasu
authors: N
authors: Kawai
authors: Shinya
authors: S
authors: Sato
authors: Taku
authors: T
authors: Naiki
authors: Kenji
authors: K
authors: Yamada
authors: Takahiro
authors: T
authors: Yasui
authors: Keiichi
authors: K
authors: Tozawa
authors: Takeshi
authors: T
authors: Kobayashi
authors: Satoru
authors: S
authors: Takahashi
authors: Kenjiro
authors: K
authors: Kohri
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000556:secondary* / Q000628:therapy*; D002412:Cations / Q000008:administration & dosage; D003102:Colloids / Q000008:administration & dosage*; D004195:Disease Models, Animal; D000077143:Docetaxel; D052203:Ferrosoferric Oxide / Q000008:administration & dosage*; D006979:Hyperthermia, Induced / Q000379:methods*; D008081:Liposomes / Q000008:administration & dosage; D008280:Magnetics; D008297:Male; D011471:Prostatic Neoplasms / Q000473:pathology / Q000628:therapy*; D011897:Random Allocation; D051381:Rats; D011916:Rats, Inbred F344; D043823:Taxoids / Q000494:pharmacology
chemical_list: D002412:Cations; D003102:Colloids; D008081:Liposomes; D043823:Taxoids; D000077143:Docetaxel; D052203:Ferrosoferric Oxide