Oncodevelopmental Enzymes of the Dunning Rat Prostatic Adenocarcinoma

In this paper, data are presented which demonstrate that adenylate kinase and creatine kinase are oncodevelopmental enzymes in the rat prostate. The Dunning tumor (dorsal rat prostate) was used as a model system; four sublines of the tumor (R3327-H, R3327-AT, MAT Lu, and MAT LyLu) were studied. The tumor lines were maintained as solid tumors in syngeneic rats (Copenhagen) and as monolayers in tissue culture. The appearance of adenylate kinase with malignant transformation of the dorsal prostate was demonstrated. The disappearance of the CK-M subunit of creatine kinase and decreasing levels of creatine kinase were demonstrated with increasing anaplasia. The lactate dehydrogenase (LDH) concentration increased with increasing anaplasia, and the LDH isoenzyme pattern shifted to a more glycolytic pattern (LDH-4, LDH-5). The malignant isoenzyme pattern was reversible with the use of a differentiating agent (dimethyl sulfoxide). Prostates from neonatal rats and castrated adult male rats exhibited patterns of creatine kinase and adenylate kinase similar to those of the undifferentiated tumor. The oncofetal isoenzyme pattern of the castrated rat prostate was reversible with physiological levels of exogenous testosterone.