The production of creatine kinase isozyme BB in sera of a patient with prostatic carcinoma and in tumor homogenates

A CK(BB) fraction was observed in sera of a patient with prostatic carcinoma. The fraction accounted for 59% of the total enzyme activity. A metastatic tumor of a prostatic carcinoma was observed to contain solely the CK(BB) isozyme. An embryonal testicular carcinoma was observed to have a higher percentage of the CK(BB) fraction when compared to the adjacent tumor free testicular tissue in a third patient. These studies suggested that in certain carcinomas there are tissue isozyme modifications at the molecular level. The isozymic modification was suggested as a reversion towards an embryonic pattern as the adult molecular form tended to disappear while the fetal form increased. This too suggests that the isozymes of CK may be a useful model in elucidating the mechanism through which this transition occurs. The high percentage of CK(BB) in the sera of the patient with metastasis was discussed. The origin could not be determined, but either a primary tumor or a metastatic tumor by their enzyme modifications could account for this increased fraction in sera.