Ultrastructural characterization of macrophage-like mononuclear leukocytes in human astrocytic tumors.
The aim of this study was to describe the ultrastructural features of macrophage-like mononuclear leukocytes associated with human astrocytic tumors. Tumoral biopsies of 10 patients with a pathological diagnosis of astrocytic tumor by means of transmission electron microscopy were examined. The macrophage-like mononuclear leukocyte shows ultrastructural characteristics related with the physiologic phenotype of the alternatively activated macrophage (M2), localized principally around of tumoral vasculature and tumor milieu; classically activated macrophages (M1) in surrounding necrosis areas were observed. The presence of these two ultrastructural kinds of macrophage-like mononuclear leukocytes into different areas of the tumor denotes that cellular response of TAMs is dependent of microenvironment stimuli in different parts of a tumor. The process of transvascular emigration of monocyte/macrophage-like mononuclear leukocytes into tumor is presented. The preponderance of alternatively activated macrophage-like mononuclear leukocytes suggests disequilibrium between pro-tumoral leukocytes and anti-tumoral leukocytes. Therefore, macrophage polarization toward anti-tumoral macrophage-like mononuclear leukocytes would be a potential target for therapeutic manipulation in human astrocytic tumors.
Arismendi-Morillo
Gabriel
G
Biological Researches Institute, Faculty of Medicine, University of Zulia, Maracaibo, Venezuela. gabrielarismendi@gmail.com
Castellano-Ramírez
Alan
A
Medina
Zulamita
Z
D001254:Astrocytoma / Q000098:blood supply / Q000648:ultrastructure*; D001706:Biopsy; D001932:Brain Neoplasms / Q000098:blood supply / Q000648:ultrastructure*; D002465:Cell Movement; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000648:ultrastructure*; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D009336:Necrosis