Figure 2.
UGT1A silencing lowers the antiproliferative activity of actinomycin D and etoposide in both HT29 and LS180 cells. Cells were pretreated with UGT1A siRNA1 or nonspecific siRNA for 24 hours and then exposed to gradient concentrations of actinomycin D or etoposide for 36 hours. (A) Cell proliferation was measured by MTT assay in actinomycin- or etoposide-treated LS180 and HT29 cells. The proliferation rate of cells is expressed as Relative Absorbance (mitochondrial dehydrogenase activity) with non-specific siRNA is expressed as 1. (B) Annexin V fluorescein isothiocyanate/propidium iodide staining of HT29 cells was examined by a flow cytometer. Results are presented as mean ± standard deviation of at least four independent experiments (*P < .05, **P < .01, ***P < .001).