Isoferritin Composition of Tissues and Serum in Human Cancers

A highly sensitive technique for isoferritin detection using 125l-labeled monospecific anti-human liver ferritin antibody for the identification of isoferritins after the analysis of small quantities of ferritin by isoelectric focusing in polyacrylamide gels was applied to the study of renal, pancreatic, and colonic carcinomas. In all tumors studied, the isoferritin composition differed from that of the corresponding normal tissue; major isoferritins with pl more basic than those of the normal tissues were consistently detected. Composition of purified ferritin from metastases closely resembled the isoferritin composition of the primary tumors. Examination of the serum isoferritin profiles of four patients with cancers did not reveal the presence of any tumor-specific changes in isoferritins. It is suggested that the abnormality in tissue ferritins in the three human cancers studied is the synthesis of major isoferritins in the more basic range, rather than the appearance of tumor-specific isoferritins in the more acidic range