Figure 5.

Cells lacking CDK9 exhibit increase sensitivity to genotoxic agents. (A) MCF7 shSCR, shCDK9 and shCDK9–2 were subjected to long-term clonogenic assay after irradiation (1, 2, 3 or 4 Gy). Cells were fixed and stained with crystal violet and colonies were quantified. (B) Cells were also subjected to viability assay after treatment with ionizing radiation in the presence or not of PARP inhibitor, olaparib (50 nM). Viability quantification were determined by the absorbance of crystal violet at 590 nm. Data are presented as means ± SD of triplicates. *** = p<0.001 and ** = p<0.01