title: Presence and activity of alkaline phosphatase in two human osteosarcoma cell lines.
abstract: The presence and activity of alkaline phosphatase in SAOS-2 and TE-85 human osteosarcoma cells grown in culture were examined at the ultrastructural level. A monoclonal antibody raised against purified human bone osteosarcoma alkaline phosphatase was used to localize the enzyme in cultures of the osteosarcoma cells. Similar cultures were analyzed for alkaline phosphatase activity using an enzyme cytochemical method with cerium as the capture agent. Alkaline phosphatase was immunolocalized at the light microscopic level in an osteogenic sarcoma and ultrastructurally on the SAOS-2 cell membrane and the enclosing membrane of extracellular vesicular structures close to the cells. In contrast, the TE-85 cells were characterized by the absence of all but a few traces of immunolabeling at the cell surface. Enzyme cytochemical studies revealed strong alkaline phosphatase activity on the outer surface of the SAOS-2 cell membrane. Much lower enzyme activity was observed in the TE-85 cells. The results support biochemical data from previous studies and confirm that SAOS-2 cells have a significantly greater concentration of alkaline phosphatase at the plasma membrane.
authors.affiliation: Department of Pathology and Oncology, University of Kansas Medical Center, Kansas City 66103.
authors.forename: J C
authors.initials: JC
authors.lastname: Randall
authors.forename: D C
authors.initials: DC
authors.lastname: Morris
authors.forename: S
authors.initials: S
authors.lastname: Zeiger
authors.forename: K
authors.initials: K
authors.lastname: Masuhara
authors.forename: T
authors.initials: T
authors.lastname: Tsuda
authors.forename: H C
authors.initials: HC
authors.lastname: Anderson
mesh_terms: D015100:3,3'-Diaminobenzidine; D000469:Alkaline Phosphatase / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002563:Cerium; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D012516:Osteosarcoma / Q000201:enzymology*; D010710:Phosphates; D014407:Tumor Cells, Cultured
chemical_list: D010710:Phosphates; D015100:3,3'-Diaminobenzidine; D002563:Cerium; D000469:Alkaline Phosphatase; C048083:cerium phosphate