FIGURE 5. Induction of phosphatase-dead PTEN by doxycycline does not alter kinetics of double strand DNA damage repair.

U251-C124S cells were exposed to doxycycline (+Dox) or vehicle (−Dox) for 24 h, followed by irradiation with 4 Gy. At the indicated times after radiation, replicate groups of cells were fixed and stained for γ-H2AX and then counterstained with DAPI to visualize nuclei. The number of γ-H2AX foci was counted for each cell and the average number of foci/cell recorded. A minimum of 300 cells in each treatment group were counted. Representative cells fixed at the indicated times and stained for γ-H2AX are shown in panel A; the quantification of the average number of γ-H2AX foci/cell for each treatment group is shown in panel B. Error bars indicate S.E. γ-H2AX foci noted within micronuclei were not counted.