Isogenic HCT116 p53+/+ and p53-/- cell lines show differential sensitivity towards 11a.
(A) IC50 values of 11a in p53+/+ and p53-/- HCT116 cell lines. The cells were seeded in quadruplicate in the 384-well plates and treated with the indicated concentrations of 11a for 7 days. The growth inhibition was determined by CellTiter Glo luminescent cell viability assay. (B) IC50 values of 11a were examined in the MTT cell viability assays after 72 hours incubation with 11a. (C) The two cell lines were treated with 0, 1, 10, 100 or 1000 nM 11a for 24 hours and subjected to Western blot using anti-PARP antibody to detect PARP cleavage. Hsp90 was used as a loading control. (D) The cells were treated with indicated concentrations of 11a in the presence or absence of 2 mM 3-aminobenzamide (3-AB) for 72 hours and then subjected to MTT assays. (E) After 24 hours treatment with 1 µM 11a, cells were collected and stained with Annexin V/PI and subjected to flow cytometry. 1 µM staurosporine (STS) served as a positive control for apoptosis. The statistical significance were shown as **p<0.01, ***p<0.001 compared with DMSO control. (F) The two cells were transfected with 1 µg GFP or PNR for 24 hours followed by treatment with DMSO or 1 µM 11a for another 24 hours. Western blot was performed to examine the PARP cleavage.