Abstract A99: Evaluation of the effects of naproxen in human colon polyp cells using gene expression and pathway analysis

Cultures of human colon polyp cells were treated with naproxen to determine its potential efficacy as a chemopreventive agent for colon cancer. The exposures and naproxen concentration used were selected to be similar to the anticipated exposures that would be used in a clinical trial. We treated the human precancerous colon polyp cell line, VACO-235, with naproxen at a clinically achievable concentration of 1 µg/mL. The exposure was continuous over 96 hr with treatment media replenishment every 24 hr. This treatment allowed the naproxen induced changes in the cultures to reach a steady state prior to the assessing gene expression levels. For the gene expression analysis, five separate cultures were used to generate five arrays for the control and treated cultures. Gene expression was assessed using Human gene 1.0 ST arrays from Affymetrix (Santa Clara, CA). The quality of the data from each array was assessed using the manufacturer9s software and no outliers were found. Gene expression was assessed using JMP Genomics 4.1 (Cary, NC). The relative gene expression in naproxen treated cultures was compared to the matched controls. Pathway analysis was done using Ariadne Genomics, Pathway Studio 7.1 (Rockville, MD). The data were evaluated using pathway analysis to identify pathway specific changes that were relevant to regulation of growth, metabolism, cell cycle regulation, and cancer. Of the forty-one functional classes and cellular processes associated with the notch pathway, thirty-two showed reduced gene expression or function. In the growth factor receptor pathway associated with AP-1, CREB/CREBBP/ELK-SRF/Myc signaling, thirty-eight of forty-five genes, transcription factors, or functional classes were reduced in expression. Naproxen showed inhibition of genes related to transcription of oncogenes including Ras, Fos, Myc, Jun, Vav1, ELK1, ELK4, multiple map kinases, and TGFBR1 signaling. The data suggest that 96 hr continuous exposure to naproxen at a relevant human serum level was sufficient to reduce the expression of genes in pathways that relate to cancer and growth in the Human colon polyp cells. Supported by NCI contract #N01-CN-43300. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A99.