No potential conflicts of interest were disclosed.
Thermotherapy using magnetic cationic liposomes powerfully suppresses prostate cancer bone metastasis in a novel rat model†
Article first published online: 17 JAN 2013
Copyright © 2013 Wiley Periodicals, Inc.
Volume 73, Issue 9, pages 913–922, June 2013
How to Cite
Kobayashi, D., Kawai, N., Sato, S., Naiki, T., Yamada, K., Yasui, T., Tozawa, K., Kobayashi, T., Takahashi, S. and Kohri, K. (2013), Thermotherapy using magnetic cationic liposomes powerfully suppresses prostate cancer bone metastasis in a novel rat model. Prostate, 73: 913–922. doi: 10.1002/pros.22637
- Issue published online: 25 MAY 2013
- Article first published online: 17 JAN 2013
- Manuscript Accepted: 7 DEC 2012
- Manuscript Received: 11 OCT 2012
- Ministry of Education, Culture, Sports, Science and Technology of Japan. Grant Numbers: 21592055, 21790390
- Nagoya City University
- Ichihara International Scholarship Foundation
- Aichi Cancer Research Foundation
- magnetic cationic liposomes;
- bone metastasis;
- cell death;
- combination therapy;
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.
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.
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.
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. Prostate 73: 913–922, 2013. © 2013 Wiley Periodicals, Inc.