RESUMEN
Predominant type of serum prostate specific antigen (PSA) is a complexed-form which is bound to alpha-1-antichymotrypsin (ACT). Major fraction of serum ACF is derived from the liver and ACT has recently been demonstrated to be produced by PSA-producing prostatic epithelium as well. However, the feature and significance of prostate-derived ACT remain ill-defined. We herein immunohistochemically studied prostatic tissues in 40 patients with prostate cancer and 20 patients with benign prostatic hyperplasia (BPH) using antibody to ACT, cytokeratin AE3 and chromogranin A. In normal portion of prostate, secretory epithelia of central zone and peripheral zone, and basa1 cells and neuroendocrine cells of peripheral zone showed positive staining for ACT. Benign hyperplastic prostatic gland did not stain for ACT. On the study of prostate cancer tissues, relatively increased staining for ACT were found in solid and infiltrative type of cancer cells and high grade cancer cells. High intensity staining for ACT were observed in normal prostatic tissues adjacent to invasive cancer cells. In conclusions, basal cells as well as secretory epithelia of the normal prostate gland may be the source of serum ACT production by prostate cancer may be closely related with its malignant and invasive potential.