Creatine phosphokinase isoenzymes in human prostatic tissues: a comparison between benign hyperplasia and...

The objective of this study was to determine the distribution of creatine phosphokinase (CPK) into its three isoenzymes, MM, MB, and BB, in human prostatic tissue, in patients with benign hyperplasia (BPH) and adenocarcinoma. Specimens were obtained from 23 patients with adenocarcinoma of the prostate and 25 patients with benign hyperplasia. We also had the opportunity to analyze the CPK content in two normal prostates, the first from a 16 1/2-year-old boy and the second from a 9 1/2-year-old child. Our results showed prostate tissue to contain almost exclusively the BB isoenzyme with traces of the MB and MM dimers in both cancer and BPH as well as the specimen of normal prostate from the 16 1/2-year-old boy. As for the 9 1/2-year-old child, we found the following distribution: 39% MM, 21% MB, and 40% BB dimer. A comparison of the CPK-BB content in benign hyperplasia and adenocarcinoma revealed no significant difference between the two groups. Furthermore, we tried to correlate prostatic tissue CPK-BB levels with another possible tumor marker of the prostate, prostatic acid phosphatase (PAP) measured in the cytosol. No correlation was found between these two markers. We also studied the relationship of CPK-BB and PAP content in prostatic tissue to nuclear and cytosolic androgen receptor content in human prostatic tissue. We found some correlation between CPK-BB and androgen cytosolic receptors as well as between PAP content and androgen cytosolic receptors in patients with benign hyperplasia. No such correlation was found in the group with adenocarcinoma. In conclusion, this study does not show that the measurement of CPK-BB in the prostatic tissue could be used as an index of tissue malignancy.