title: ADP-ribosylation of serum proteins: evaluation as a potential tumor marker.
abstract: Serum samples from cancer patients revealed elevated levels of in vitro ADP-ribosylation through non-enzymic binding of ADP-ribose to free acceptor sites on serum proteins. Low concentrations of serum ADP-ribose caused by high NAD glycohydrolase activity together with elevated rates of ADP-ribose transport into erythrocytes appeared to account for under-saturation of the acceptor sites on serum proteins. ADP-ribosylation of serum proteins was assessed as an indicator of cancer disease, and an attempt was made to determine the correlation of ADP-ribosylation levels with carcinoembryonic antigen (CEA) values. Based on positive test results for all tumor patients and negative test results for all healthy controls, sensitivity and specificity of ADP-ribosylation as a tumor indicator were estimated as 67% and 95%, respectively. A close correlation appeared to exist with CEA (r = 0.67; P < 0.001). Similarly, the changes in the levels of ADP-ribosylation correlated with the changes in the levels of CEA during the clinical course (r = 0.58; P < 0.05).
authors.affiliation: Department of Biophysics, I.U. Istanbul Faculty of Medicine, Capa-Istanbul, Turkey.
authors.forename: I U
authors.initials: IU
authors.lastname: Albeniz
authors.forename: R
authors.initials: R
authors.lastname: Nurten
authors.forename: E
authors.initials: E
authors.lastname: Bermek
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009243:NAD / Q000378:metabolism; D009369:Neoplasms / Q000097:blood / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D001798:Blood Proteins; D002272:Carcinoembryonic Antigen; D009243:NAD; D000246:Adenosine Diphosphate Ribose