title: High-molecular-mass or macromolecular alkaline phosphatase in sera of children with solid tumors.
abstract: High-molecular-mass alkaline phosphatase (H-Mr AP) was detected in sera from children with solid tumors without liver metastases. H-Mr AP activities were determined by a liquid chromatographic and an electrophoretic method. In 5 out of 10 cases with solid tumors--Ewing sarcoma (n = 2), neuroblastoma (n = 2), and rhabdoid tumor (n = 1)--H-Mr AP activities ranged from 3.1-40.4 U/L and 3.1-16% of total serum AP activity. In sera of patients with leukemia (n = 18) H-Mr AP was not detectable. After the treatment of the sera with papain and phosphatidylinositol-specific phospholipase C, which release membrane-associated AP from membrane particles, H-Mr AP was no longer detectable. These results indicate that H-Mr AP in the sera of patients with solid tumors may derive from increasing cell shedding of the tumor cells with elevated levels of membrane fragments in serum, which is a well known phenomenon in liver tumors. H-Mr AP was not more detectable in the serum after successful tumor treatment. These data suggest that H-Mr AP was produced by the tumors and that this parameter may be a serological marker for some solid tumors even in the presence of normal total AP serum activity.
authors.affiliation: Children's Hospital University of Cologne, Erlangen-Nürnberg.
authors.forename: E
authors.initials: E
authors.lastname: Schönau
authors.forename: U
authors.initials: U
authors.lastname: Glöckel
authors.forename: H J
authors.initials: HJ
authors.lastname: Beck
authors.forename: K
authors.initials: K
authors.lastname: Kruse
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D001797:Blood Protein Electrophoresis; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007223:Infant; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D009369:Neoplasms / Q000175:diagnosis* / Q000201:enzymology
chemical_list: D014408:Biomarkers, Tumor; D007527:Isoenzymes; D000469:Alkaline Phosphatase