The biosynthesis of prostate-specific antigen in non prostatic cell lines

The biosynthesis of prostate specific antigen (PSA) was studied in human epidermoid carcinoma, (KB) cells and in normal human embryonic lung (WI-38)cells. The prostate carcinoma cell line, PC-35F12 was used as a control. PSA specific antibodies were used to precipitate the immunologically reactive peptides from cell extracts and conditioned media. The immunoprecipitates were analyzed by electrophoresis followed by fluorgraphy. Human PSA is initially synthesized as 32-kDa secretory glycopeptide containing one N-linked oligosaccharide and then processed to a 34-kDa secretory glycoprotein in KB cells. PSA is also expressed in normal human embryonic lung cells, WI-38. These results confirm that PSA expression is not prostate specific, but is also found in some nonprostatic cells. From these results, we conclude that PSA may play an important physiologic role in several tissues.