PTTG1 and Drug-Induced Senescence Figure 1. HCT116 PTTG12/2 cells are more sensitive to doxorubicin (Dox). a) HCT116 WT and PTTG12/2 cells expressing an empty vector (WT+EV and PTTG12/2 +EV), and PTTG1 re-introduced PTTG12/2 (PTTG12/2 +PTTG1) cells were plated in 96-well plates and DNA synthesis assessed at different time points (time 0 represents 0 hours after cell plating); b) HCT116 WT and PTTG12/2 cells expressing an empty vector (WT+EV and PTTG12/2 +EV), and PTTG1 re-introduced PTTG12/2 (PTTG12/2 +PTTG1) cells were plated in 96-well plates for 24 hours and treated with control vehicle (C) or different doxorubicin doses for another 48 hours. DNA synthesis was assessed by measuring BrdU incorporation; c) HCT116 WT and PTTG12/2 cells were plated for 24 hours and treated with control vehicle (C) or doxorubicin (0.02 uM) for another 48 hours, fixed, stained for b-gal PLoS ONE | www.plosone.org 3 August 2011 | Volume 6 | Issue 8 | e23754