Assessment of a novel nanoparticle hyperthermia therapy in a murine model of osteosarcoma.

Abstract

To evaluate the effects of nanoparticle hyperthermia therapy on monocyte function and tumor-derived factors associated with macrophage polarization in a murine osteosarcoma model. Experimental study. Female C3H mice. Peripheral blood monocyte cell surface phenotype, monocyte chemotaxis, tumor messenger RNA expression, and survival were compared among osteosarcoma (OS)-bearing mice treated with nanoparticle hyperthermia therapy, OS-bearing mice with osteomyelitis, OS-bearing mice, vehicle control mice, and normal control mice. OS-bearing mice with osteomyelitis had a higher proportion of "nonclassical" monocytes (Ly6Clo ) compared with all other experimental groups. There were alterations in monocyte expression of multiple chemokine receptors among experimental groups including CXCR2, CCR2, and CXCR4. Monocytes from OS-bearing mice treated with hyperthermia therapy exhibited greater chemotaxis compared with monocytes from OS-bearing mice with osteomyelitis. OS likely induced alterations in monocyte phenotype and function. Nanoparticle hyperthermia therapy increased in vitro monocyte chemotaxis. Enhancing monocyte/macrophage function in dogs with OS may enhance antitumor immunity.