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.

CONCLUSION:

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: Daichi Kobayashi, Noriyasu Kawai, Shinya Sato, Taku Naiki, Kenji Yamada, Takahiro Yasui, Keiichi Tozawa, Takeshi Kobayashi, Satoru Takahashi, Kenjiro Kohri
• Journal: The Prostate (Prostate) Vol. 73 Issue 9 Pg. 913-22 (Jun 2013) ISSN: 1097-0045 [Electronic] United States
• PMID: 23334935 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Wiley Periodicals, Inc.

Chemical References

• Cations
• Colloids
• Liposomes
• Taxoids
• Docetaxel
• Ferrosoferric Oxide

Topics

• Animals
• Bone Neoplasms (secondary, therapy)
• Cations (administration & dosage)
• Colloids (administration & dosage)
• Disease Models, Animal
• Docetaxel
• Ferrosoferric Oxide (administration & dosage)
• Hyperthermia, Induced (methods)
• Liposomes (administration & dosage)
• Magnetics
• Male
• Prostatic Neoplasms (pathology, therapy)
• Random Allocation
• Rats
• Rats, Inbred F344
• Taxoids (pharmacology)