Identification of potential diagnostic markers of prostate cancer and prostatic intraepithelial neoplasia using cDNA microarray

The identification of novel genes or groups of genes expressed in prostate cancer may allow earlier diagnosis or more accurate staging of the disease. We describe the assembly and use of a 1877-member microarray representing cDNA clones from a range of prostate cancer stages and grades, precursor le sions and normal tissue. Using labelled cDNA from tumour samples obtained f rom TURF or radical prostatectomy, analysis of expression patterns identifi ed many up-regulated transcripts. Cell lines were found to over-express few er genes than diseased tissue samples. 17 known genes were found to over-ex press more than 4-fold in 4 or more cancers out of 15 cancers. Only 2 genes were over-expressed in 6 out of 15 cancers or more, whilst no genes were c onsistently found to be over-expressed in all cancer samples. Novel prostat e cancer associations for several well characterized genes or full length c DNAs were identified, including PLRP1, JM27, human UbcM2, dynein light inte rmediate chain 2 and human homologue of rat sec61. Novel associations with high-grade PIN include: breast carcinoma fatty acid synthase and cDNA DKFZp 434B0335, We shortlist and discuss the most significant over-expressed gene s in prostate cancer and PIN, and highlight expression differences between malignant and benign samples. (C) 2001 Cancer Research Campaign.