IMMUNOLOGICAL CHARACTERIZATION AND ACTIVITY OF TRANSGLUTAMINASES IN HUMAN NORMAL AND MALIGNANT PROSTATE AND IN PROSTATE-CANCER CELL-LINES

Using biochemical assays, we compared enzyme activities with the immun oreactivity of antibodies against rat seminal transglutaminase (TGase) , human erythrocyte TGase and guinea pig liver TGase in human normal p rostate, primary prostatic carcinomas and prostatic carcinoma cell lin es. Glandular cells of the epithelium were only exceptionally positive with the antibody against (rat) secretory TGase. Using the antibodies against tissue-type TGase, most immunoreactive cells were found in th e basal cell layer of prostatic epithelium as well as in stroma (fibro blasts, endothelial cells), whereas immunoreactive glandular cells wer e sparse. In the case of benign prostatic hyperplasia, few, irregularl y distributed secretory cells along with a small number of stromal cel ls were also immunoreactive with the tissue-type TGase antibody. In de differentiated carcinomas, immunoreactive cells were nearly completely absent. Of the prostate cancer cell lines, the LNCaP line showed neit her TGase enzyme activity nor immunoreactivity, whereas the PC-3 cell line displayed significant enzyme activity and immunoreactivity. No ho rmone-dependent changes in either enzyme activity or immunoreactivity were recorded after in vitro treatment of the respective cell lines wi th estrogens, androgens and antiandrogens. As there is no correlation between androgen deprivation and TGase expression in nonmalignant and malignant human prostatic epithelial cells, TGase activity more likely indicates cellular lesions and consecutive repair mechanisms.