The bisphosphonate zoledronic acid decreases tumor growth in bone in mice with defective osteoclasts

• Published in: Bone (New York, N.Y.) Vol. 44; no. 5; pp. 908 - 916
• Main Authors: Hirbe, Angela C, Roelofs, Anke J, Floyd, Desiree H, Deng, Hongju, Becker, Stephanie N, Lanigan, Lisa G, Apicelli, Anthony J, Xu, Zhiqiang, Prior, Julie L, Eagleton, Mark C, Piwnica-Worms, David, Rogers, Michael J, Weilbaecher, Katherine
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.05.2009; Elsevier
• Subjects: Animals; Biological and medical sciences; Biphosphonate; Bone Neoplasms - drug therapy; Bone Neoplasms - pathology; Bones, joints and connective tissue. Antiinflammatory agents; Cell Line, Tumor; Cell Survival - drug effects; Diphosphonates - administration & dosage; Diphosphonates - pharmacology; Enzyme Activation - drug effects; FPP synthase; Fundamental and applied biological sciences. Psychology; Geranyltranstransferase - metabolism; Imidazoles - administration & dosage; Imidazoles - pharmacology; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neoplasm Metastasis - prevention & control; Orthopedics; Osteoclast; Osteoclasts - drug effects; Osteoclasts - pathology; Pharmacology. Drug treatments; Protein Prenylation - drug effects; Risodronate; Src; Tumor; Vertebrates: anatomy and physiology, studies on body, several organs or systems; RANKL; interleukin-1; M-CSF; farnesyl diphosphate; CTX; N-BP; TRAP; phosphate-buffered saline; interleukin-6; receptor activator of NFκB ligand; bone mineral density; FBS; Tumor; insulin-like growth factor; FPP synthase; bone marrow macrophages; PBS; parathyroid hormone; IL-1; IGF-1; Tax+ interferon-gamma null; IL-11; ROI; IL-6; fetal bovine serum; tartrate resistant acid phosphatase; TGN; Risodronate; click-beetle red; GGPP; PTH; Src; transforming growth factor β; FL; FPP; interleukin-11; nitrogen bisphosphonates; CBR; charge-coupled device; geranylgeranyl diphosphate; OC; hour; BMD; TGF-β; WT; C-terminus of collagen I; BMM; CCD; Biphosphonate; h; firefly luciferase; region of interest; osteoclast; wild-type; macrophage colony-stimulating factor; Osteoclast; Antiosteoporotic; Rodentia; Malignant tumor; Bisphosphonates; Vertebrata; Mammalia; Antiosteoclastic agent; Mouse; Animal; Morphology; Zoledronic acid; Bone; Cancer
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2009.01.010

Abstract Bisphosphonates (BPs), bone targeted drugs that disrupt osteoclast function, are routinely used to treat complications of bone metastasis. Studies in preclinical models of cancer have shown that BPs reduce skeletal tumor burden and increase survival. Similarly, we observed in the present study that administration of the Nitrogen-containing BP (N-BP), zoledronic acid (ZA) to osteolytic tumor-bearing Tax+ mice beginning at 6 months of age led to resolution of radiographic skeletal lesions. N-BPs inhibit farnesyl diphosphate (FPP) synthase, thereby inhibiting protein prenylation and causing cellular toxicity. We found that ZA decreased Tax+ tumor and B16 melanoma viability and caused the accumulation of unprenylated Rap1a proteins in vitro. However, it is presently unclear whether N-BPs exert anti-tumor effects in bone independent of inhibition of osteoclast (OC) function in vivo. Therefore, we evaluated the impact of treatment with ZA on B16 melanoma bone tumor burden in irradiated mice transplanted with splenic cells from src-/- mice, which have non-functioning OCs. OC-defective mice treated with ZA demonstrated a significant 88% decrease in tumor growth in bone compared to vehicle-treated OC-defective mice. These data support an osteoclast-independent role for N-BP therapy in bone metastasis.