Profiling of differential expression of messenger RNA in normal, benign, and metastatic prostate cell lines

To understand the phenotypic changes associated with prostate cancer development and metastasis, we investigated differential gene expression in primary and established prostate cell lines used as models. We have used a differential display of messenger RNA (DDRT-PCR) technique using 168 primer combinations and total RNA from BPH-1, LNCaP, and PC3 cells to identify filter-based cDNA microarrays containing 18,376 nonredundant clones of genes and expressed sequence tags (EST) using mRNA from PrEC and MDAPCa2a cells to identify genes that are differentially expressed in normal, benign, and cancerous prostate cell lines. Twenty-five cDNA with a significant difference in expression of 76 candidate cDNA, as identified by DDRT-PCR and confirmed by slot-blot analysis, were selected for sequence analysis. Of these, 14 cDNA were further confirmed by Northern blot analysis. Analysis of the cDNA microarray data showed that a variety of genes/EST were up- or down-regulated in the metastatic prostate tumor cells and a majority of these genes encode cytoskeletal proteins and proteins with regulatory function. Expression profile of two EST was confirmed by reverse transcription polymerase chain reaction. We also have identified a number of genes exhibiting differential expression in prostate cancer cells, which were not known earlier to be involved in prostate cancer. This report provides a comparative analysis of differential gene expression between normal prostatic epithelial cells and prostate cancer cells, and a foundation to facilitate in-depth studies on the mechanism of prostate cancer development and metastasis.