Microarray analysis of survival pathways in human PC-3 prostate cancer cells.

Background: Insulin-like growth factor 1 (IGF-1), transforming growth factor beta 1 (TGF‚1), and interleukin 6 (IL-6), act as survival factors inhibiting chemotherapy-induced apoptosis in PC-3 human prostate cancer cells, in vitro. Materials and Methods: To study the intracellular pathways activated by these survival factors we performed a comparative genomic analysis using oligonucleotide microarray chips. A validation by real time-PCR was also performed for the genes of interest. Results: The expression data derived were analysed using various normalization algorithms. The differentially expressed genes were clustered and their ontological annotations were statistically tested to provide evidence for possible deregulated biological processes on the action of the aforementioned survival factors. Emphasis was given on the regulation and the role of the genes AKR1C1, SDPR and GADD45B in the survival pathways of prostate cancer cells, whose expression was also validated by real time-PCR. Conclusion: The overall analyses reveal an overrepresentation of differentially expressed genes related to cellular processes such as cell cycle regulation, lipid metabolism and steroid biosynthesis.