Abstract:

Objective   To analyze the differential expression of tumor suppressor PDLIM4 gene in nonneoplastic RWPE1 cells and prostate cancer (PC) cell lines and different drug-resistant cell lines.  Methods   Different cell lines including RWPE1, carcinoma cell lines (PC-3, DU145, and LNCaP), multidrug-resistant cells (PC-3/Doc, K562/A02, H460/Doc) were used to identify PDLIM4 expression by quantitative PCR (qPCR), Western blotting, and immunofluorescence (IF) assays.  The expressions and activities of DNA methyltransferases (DNMTs) were also tested in PC-3 and PC-3/Doc cells by Western blotting and enzyme activity assays. Results   PDLIM4 was overexpressed in RWPE1 cells, not expressed in DU145 or LNCaP cells, slightly detected in PC-3 cells but predominantly evidenced in its multidrug resistant PC-3/Doc cells, and this kind of high expression of PDLIM4 in drug-resistant cell lines is tissuespecific. Enzyme activity assays demonstrated that the activity of DNMTs were significantly reduced in PC-3/Doc compared to PC-3 cells, even though the expression levels of DNMTs were similar in both cell lines.  Conclusion   The expressions of PDLIM4 were dramatically reduced in PC cell lines, while this tissue-specific up-regulation of PDLIM4 in PC-3/Doc might result from the decreased enzyme activity of DNMTs when compared to PC-3 cells.

Key words: Gene，  PDLIM4; 5-Aza-2’-deoxycytidine; Docetaxel; Prostate cancer