E-cadherin expression and PSA secretion in human prostate epithelial cells

Prostate-specific antigen (PSA) is the most widely used marker for the diag nosis of prostate cancer and is an independent predictor of prostatic capsu lar invasion. A number of studies have identified E-cadherin, a cell adhesi on protein, as a potential invasion suppressor which is decreased in prosta te adenocarcinoma. Our goal in the present study was to evaluate E-cadherin expression in primary cultures and determine the relationship between E-ca dherin expression and PSA secretion in both primary cultures and the prosta te tumor cell line, LNCaP. Immunohistochemical studies and Western blot ana lysis confirmed greater expression of E-cadherin in normal epithelial cells than tumor-derived prostate cells. This is the first report that the incub ation of normal prostate epithelial cells with E-cadherin antibody increase s the amount of PSA detected in the media of normal cells as well as in LNC aP. Since E-cadherin may function as an invasion suppressor, an understandi ng of the decreased expression of this adhesion factor and the impact on PS A secretion may aid in understanding epithelial tumorigenesis.