Transcription profiling of human colon Caco-2 cells treated with hydroxytyrosol (HTy) and hydroxytyrosyl ethyl ether (HTy-Et)

The anticarcinogenic activity of hydroxytyrosyl ethyl ether (HTy-Et) compared to its precursor hydroxytyrosol (HTy) has been studied in human Caco-2 colon adenocarcinoma cells. Changes in global gene expression in Caco-2 cells exposed to HTy and HTy-Et for 24 h were evaluated using Affymetrix array. Microarray analysis showed that after exposure to HTy and HTy-Et, 451 and 977 genes respectively were differentially expressed compared with untreated cells (P < 0.005; FDR=0). Results show that HTy and its lipophilic ether derivative alter genes related with cancer prevention, which includes inducing cell cycle arrest, promoting apoptosis and enhancing xenobiotic metabolism. Caco-2 cells were treated with 10 μM of HTy and HTy-Et for 24 h, and total RNA from 3 biological replicates of each treatment together with the control cells, were isolated using a QIAGEN® RNeasy Mini Kit according to the manufacturer’s instructions (Qiagen). RNA samples of each of the replicates were processed using Affymetrix Human HG-U133 Plus 2.0 microarrays (Affymetrix).