Genomic profiling of the selected list of test substances (hepatotoxins)in human cultures.

"The overall goal of this study is to identify biomarkers of drug-induced chronic liver toxicity (steatosis and cholestasis) by means of genomics technology. In a first step, we have evaluated the suitability of primary human hepatocytes as in vitro model to identify gene expression changes relevant to chronic liver toxicity. In particular, we have measured gene expression changes in primary human hepatocytes upon incubation in monolayer culture for five periods of time: 1h, 14 h, 24 h, 48 h and 72 h.In a second step, we have searched for steatosis- or cholestasis-associated gene products by measuring gene expression changes induced by an overload of human liver HepG2 cells with either fatty acids (FFAA) or taurocholate respectively. In particular, we have measured gene expression changes upon treatment with two concentrations of FFAA (1 mM and 2 mM) and one of taurocholate (5 mM) at two time points (14 h and 24 h). In a third step towards the identification of relevant steatosis biomarkers, we have measured gene expression changes by treatment of HepG2 cells with the drugs Tetracycline (100 uM), Valproate (125 uM) and Amiodarone (12.5 uM) for a period of 24 h"