This study examines the effects of novel antineoplastic agents(isochalcones) on human metastatic prostate cancer cell lines by screening cells for their relative antiproliferative effects, measuring the protein expression levels of specific oncogenes by Western blotting, and evaluating an array of genes ( 5184) to determine possible mechanisms of action of these novel isochalcones. The array data were supported by real-time polymerase chain reaction (PCR) techniques. The antineoplastic agents were screened in human metastatic prostate cancer cell lines (LNCaP, DU145, PC-3, and MDA-PCa-2b) and non-cancerous prostate epithelial cell line PZ-HPV-7 in concentrations ranging from nanomolar to millimolar. The alamar blue exclusion dye assay, a redox indicator, was used to evaluate cell proliferation when compared to the untreated control. DJ52 demonstrated a growth inhibitory effect on LNCaP, PC-3, and DU145 cell lines at the micromolar concentration (p<0.05). Based on these data, 1 x 106 cells were treated, protein isolated, and expression levels of epidermal growth factor (EGF) and omithine decarboxylase (ODC) were measured and compared to theuntreated controls. These data indicated a dose-dependent decrease of expression of EGF and ODC, therefore, suggesting that other key oncogenes may also have a decrease in expression when treated with these novel antineoplastic agents. Therefore, gene arrays were used to identify possible families of genes and/or specific pathways that may be responsible for the antiproliferative effects noted. It was determined that the key families of genes significantly induced by these agents (Pathways 4®) were proapoptotic and cell cycle regulators. ABI 7700 Prism was used to perform quantitative RT-PCR via the AB Sequence Detector® software.