Localization of the B and M polypeptide subunits of creatine kinase in normal and neoplastic human tissues by an immunoperoxidase technic.

Measurements of the BB isoenzyme of creatine kinase in serum may be useful in the diagnosis or monitoring of patients who have some types of cancer, and the distribution of creatine kinase isoenzymes in homogenates of certain sarcomas has been evaluated as an aid in the morphologic diagnosis of these neoplasms. The cellular distribution of the B and M polypeptide subunits of creatine kinase in normal and neoplastic tissues were evaluated by an immunoperoxidase technic to determine whether the BB isoenzyme is present in neoplastic epithelial cells and whether immunoperoxidase stains for these polypeptides are useful in microscopic diagnosis. The results indicated that the B polypeptide is distributed very widely in epithelial cells and that normal and neoplastic ductal epithelia from many tissues contain the BB isoenzyme. Normal and neoplastic acinar epithelia contained varying amounts of the B polypeptide, but usually less than ductal epithelia of the same tissues. Large amounts of the B polypeptide were found in tissue sections from malignant fibrous histiocytomas, and of the M polypeptide in sections from an alveolar rhabdomyosarcoma.