title: Monocytes, Macrophages, and Osteoclasts in Osteosarcoma.
abstract: Macrophages appear to have a fundamental role in the pathogenesis of osteosarcoma. These highly diverse plastic cells are subdivided into classical or inflammatory macrophages known as M1 and alternative macrophages, which decrease inflammation and are reparative, called M2. Although primary and metastatic osteosarcomas are infiltrated with M2 macrophages, targeting the M1 macrophages with the immune adjuvant muramyl tripeptide phosphatidyl ethanolamine (MTP-PE) has been the greatest recent therapeutic advance in osteosarcoma. This discrepancy between the presence of M2 and activation of M1 macrophages is intriguing and is likely explained either by the plasticity of M1 and M2 macrophages or nonclassical patrolling monocytes (PMos). To date, MTP-PE has been approved in combination with chemotherapy for nonmetastatic osteosarcoma, but its use in metastatic tumors has not been investigated. In this review, we focus on macrophages, monocytes, and osteoclasts, their role in osteosarcoma, and the potential for targeting these cells in this disease.
authors.affiliation: 1 Trinity College Dublin , Dublin, Ireland .|2 Department of Medical Oncology, St. James Hospital , Dublin, Ireland .
authors.forename: Fergal C
authors.initials: FC
authors.lastname: Kelleher
authors.affiliation: 2 Department of Medical Oncology, St. James Hospital , Dublin, Ireland .|3 Whangarei Base Hospital , Whangarei, New Zealand .
authors.forename: Hazel
authors.initials: H
authors.lastname: O'Sullivan
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D006801:Humans; D008264:Macrophages / Q000502:physiology*; D058990:Molecular Targeted Therapy / Q000379:methods; D009000:Monocytes / Q000502:physiology*; D010010:Osteoclasts / Q000502:physiology*; D012516:Osteosarcoma / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents
keywords: chemokine; dendritic cells; macrophages; osteosarcoma