THP-1 cell study: RA and TNF Treatments; RA time course

The study consisted of two experiments. The hypothesis tested was that RA and tumor necrosis factor (TNF)-alpha would independently and synergistically regulate the expression of genes in THP-1 human myeloid cells, and that RA alone would be a significant modulator, as tested in a kinetic experiment. Experiment 1 included 21 arrays from 4 groups of THP-1 cells. Biological replicates (n) equalled 6, 5, 5, and 5 samples/arrays, each representing an independent well of cultured cells: control (0.1% ethanol only); 20 nM RA for 16 h, followed by re-treatment after 24 h for a total time of 40 h; TNFalpha, 5 ng/ml for 24 h; RA, 20 nM for 16 h followed by treatment with RA and TNFalpha for 24 h, respectively. All cells were harvested at the 40 h time point. Experiment 2 was an RA time course study, without TNFalpha, which included 17 arrays from THP-1 cells treated with RA, 20 nM, at time 0 and cells were harvested at times of 0 (ethanol control), 2 hr, 6 hr, and 16 hr. After 16 hr, RA was added again to the remaining 2 wells, which were harvested at 40 h. The number of biological replicates was n=8, 2, 2, 3, and 2, respectively.