Dose- and time-dependent changes in expression of selected genes upon exposure to 17-AAG. After the ARPE-19 cells were treated with either 3 μM 17-AAG for 16, 24 or 48 h, or 2, 5, or 10 μM 17-AAG for 24 h, total RNA from each sample was extracted and reverse transcribed into cDNA. Changes in the expression of proteins were verified by real-time quantitative PCR. The dose (A) and time (B) -dependent changes were both evaluated as mean ± SD. The changes in selected genes are consistent with the results of proteomics. Another three unidentified proteins, Hsp70, Hsp90α and Hsp90β, were all upregulated by 17-AAG treatment, but their upregulation declined in a time and dose-dependent manner.