Preliminary Studies for the Binding of 125I –Anti CA 15-3 Antibody to the CA 15-3 in Human Breast Tumor Homogenate

Abstract

This study include the level of CA15-3 was determined in sera of (32) premenopausal malignant breast tumors patients, (15) postmenopausal malignant breast tumors patients, and (40) benign breast tumors patients matched with one group of (10) healthy women as control group by Immunoradiometric Assay (IRMA). The data obtained demonstrated highly significant increase (P<0.0001) in patients with malignant breast tumors, whereas slightly increase (P<0.05) in patients with benign breast tumors when matched with normal women. A modified Imunoradiometric Assay (IRMA) was used for determination of cytosolic carbohydrate antigen 15-3, using 125I-anti CA15-3 antibody and found to be suitable for the assessment of those antigens in benign and malignant breast tumors. The data revealed an increment of CA15-3 in the cytosolic fraction in comparison to the nuclear fraction.The binding of 125I –anti CA 15-3 antibodies with CA 15-3 was studied in three groups: benign breast tumor (Fibroadenoma), pre-and post- menopausal malignant breast tumors (IDC). The optimum conditions measured for the binding of three groups were included :CA 15-3 concentration in tissue homogenate , 125I -anti CA 15-3 antibody concentrations, temperature, time of the incubation, and optimum pH of the binding. The use of different halides and different divalent salts was shown to different effect on the binding between CA 15-3 and 125I –anti CA 15-3 antibody