ALPHA(1)-ANTICHYMOTRYPSIN PRODUCTION IN PSA-PRODUCING CELLS IS COMMONIN PROSTATE-CANCER BUT RARE IN BENIGN PROSTATIC HYPERPLASIA

Objective. To investigate the distribution and production of alpha1-an tichymotrypsin (ACT) and prostate-specific antigen (PSA) in benign hyp erplastic and malignant prostatic tissue, respectively. Methods. Using monoclonal anti-ACT and anti-PSA IgGs for immunocytochemistry and alk aline phosphatase conjugated 30-mer oligodeoxynucleotide probes for no nradioactive in situ hybridization, tissue specimens were studied from 1 5 patients with benign prostatic hyperplasia after transurethral re section of the prostate (TURP) and from 9 patients with bladder cancer who underwent cystoprostatectomy. Cancer specimens were from 23 TURP patients and from ultrasound guided core biopsies in 1 4 patients. Pro state tumors were graded according to the Gleason system. Results. We found no or only occasional small foci of immunostaining for ACT, and no ACT transcripts in the PSA-producing epithelium in areas with benig n nodular hyperplasia. By contrast, a high proportion of cells express ed both ACT and PSA in prostate cancers with low Gleason score, as det ected by immunocytochemistry and in situ hybridization. Poorly differe ntiated tumor cells manifested greater variation in immunostaining for both ACT and PSA. As compared to tumors of low Gleason score, high-sc ore tumors less frequently manifested immunostaining for ACT than for PSA, and less frequently generated hybridization signals for both PSA and ACT transcripts. Conclusions. A significantly higher proportion of serum PSA has been reported to be complexed to ACT in patients with p rostate cancer than in patients with benign prostatic hyperplasia. The presently reported lack of ACT production in PSA-containing BPH nodul es may contribute to this by making conditions less optimal for comple x formation between PSA and ACT. As opposed to this, production of bot h ACT and PSA in prostate cancers may enhance the complex formation be tween PSA and ACT.