Comparison of gene expression profiles of HT29 cells treated with Instant Caffeinated Coffee or Caffeic Acid versus control

A summary of the work associated to these microarrays is the following: Background: Phenolic compounds present in coffee are antioxidants in vitro that might protect against cardiovascular disease and certain types of cancer in humans. Objective: Our aim was to identify differentially expressed genes upon incubation of HT-29 human colon cancer cells with instant caffeinated coffee (ICC) or caffeic acid (CA) using microarrays. Results: In HT-29 cells incubated with ICC, 77 genes were overexpressed whereas 162 were underexpressed. Upon incubation with CA, 12 genes were overexpressed whereas 33 were underexpressed. A list of five overexpressed genes and eleven underexpressed genes were found in common between the two conditions and was use to construct a biological association network. In the generated network, STAT5B and ATF-2 appeared as highly interconnected nodes. STAT5B overexpression was confirmed at the mRNA and protein levels. For ATF-2, the changes in mRNA levels were confirmed for both ICC and CA, whereas the decrease in protein levels was only observed in CA-treated cells. The levels of cyclin D1, a target gene for both STAT5B and ATF-2 transcription factors, decreased dramatically in breast cancer cells treated with CA or ICC. Conclusions: Coffee polyphenols are able to affect gene expression in cancer cells through the modulation of STA5B and ATF-2 transcription factors. The aim of our study was to evaluate, by using whole genome microarrays, the effects of one cup of coffee, either regular caffeinated coffee or a coffee polyphenol, such as caffeic acid, on HT-29 gene expression, Three experimental approaches were conducted to assess the effects of coffee on HT29 cells. I) Incubation with non cytotoxic concentrations of ICC (7 µg/mL) for 24h. (Group ICC); II) Incubation with non cytotoxic concentrations of CA (1.68 µg/mL) for 24h. (Group CA); III) non treatment of HT-29 to refered as a control (Group CNT). Triplicate samples were hybridized for each experimental condition (9 samples in total). The samples provided were analyzed using the specific software GeneSpring GX.