ISOLATION AND IDENTIFICATION OF A HUMAN-SERUM FIBRONECTIN-LIKE PROTEIN ELEVATED DURING MALIGNANT DISEASE

  • 1 January 1979
    • journal article
    • research article
    • Vol. 39  (11) , 4341-4345
Abstract
A human DNA-binding protein, designated MAD-2, has recently been found to be elevated in the serum from patients with malignant diseases. MAD-2 was purified approximately 500-fold from peritoneal and pleural fluids collected from cancer patients. Immunodiffusion studies indicated that MAD-2 is immunochemically identical to human plasma fibronectin. The purified material was resolved by sodium dodecyl sulfate gel electrophoresis into 2 major protein chains with MW in the range of 200,000-210,000 in the presence or absence of disulfide bond-reducing agents. MAD-2 may be a fibronectin fragment which has been generated through proteolysis. A quantitative assay system capable of detecting ng quantities of MAD-2 was developed and used to verify the presence of elevated MAD-2 levels in DNA-binding protein fractions isolated from the serum of individuals with malignant diseases. [The possible usefulness of this protein as a tumor marker is discussed.].