The histochemical behaviour, electrophoretic mobility and distribution in cell fractions of acid phosphatase isozymes in prostatic cancer and benign prostate hyperplasia.

Acid phosphatase isozymes were investigated in cancerous prostatic tissue (4 cases) and benign prostatic hyperplasia (6 cases). Electron-microscopic histochemical examination of cancer tissue revealed irregular acid beta-glycerophosphatase staining in various cell organelles, including the plasma membrane, which was not seen in non-malignant tissue. Cancerous tissue homogenates also contained isozymic acid phosphatase species with high electrophoretic mobility, which was not detectable in benign tissue unless treated with detergent. Fractionation by differential centrifugation confirmed that much of the acid phosphatase activity in cancer tissue was extra-lysosomal. The detection of these isozyme properties may provide an opportunity, by means of tissue investigations, to define tumour stages earlier than on the basis of increased levels of serum acid phosphatase activity indicative of stage IV (D) prostatic cancer.