Detection of PSP94 and its specific binding sites in the prostate adenocarcinoma cell line LNCaP

Purpose: To evaluate the expression of prostate secretory protein of 94 amino acids (PSP94) and PSP94 binding proteins in the LNCaP cell line. Materials and Methods: The reverse-transcription polymerase chain reaction (RT-PCR) and Southern blot hybridization were employed to assay the expression of PSP94. Immunoprecipitation with specific polyclonal antibodies was used to detect PSP94 secreted by the LNCaP cells. The binding proteins were assayed by equilibrium binding assays. Results: PSP94 was expressed and secreted in the LNCaP cells. As well as, LNCaP cells expressed surface membrane proteins capable of binding PSP94 in a specific and saturable manner. Exposure of LNCaP cells to exogenous PSP94 resulted in the up-regulation of PSP94 binding sites, indicating functional interactions for PSP94 and its receptor in this cell line. Conclusion: The expression of PSP94 and its receptors may bet partially regulated by an autocrine pathway in the LNCaP cell line.