Zoledronic acid enhances tumor growth and metastatic spread in a mouse model of jaw osteosarcoma

Investigation of the therapeutic effect of zoledronic acid (ZA) in a preclinical model of jaw osteosarcoma (JO).

The effect of 100 μg/kg ZA administered twice a week was assessed in a xenogenic mouse model of JO. The clinical (tumor growth, development of lung metastasis), radiological (bone microarchitecture by micro-CT analysis), and molecular and immunohistochemical (TRAP, RANK/RANKL, VEGF, and CD146) parameters were investigated.

Animals receiving ZA exhibited an increased tumor volume compared with nontreated animals (71.3 ± 14.3 mm³ vs. 51.9 ± 19.9 mm³ at D14, respectively; p = 0.06) as well as increased numbers of lung metastases (mean 4.88 ± 4.45 vs. 0.50 ± 1.07 metastases, respectively; p = 0.02). ZA protected mandibular bone against tumor osteolysis (mean bone volume of 12.81 ± 0.53 mm³ in the ZA group vs. 11.55 ± 1.18 mm³ in the control group; p = 0.01). ZA induced a nonsignificant decrease in mRNA expression of the osteoclastic marker TRAP and an increase in RANK/RANKL bone remodeling markers.

The use of bisphosphonates in the therapeutic strategy for JO should be further explored, as should the role of bone resorption in the pathophysiology of the disease.