Figure 2
From: Suppression of BRCA1 sensitizes cells to proteasome inhibitors
Bortezomib does not induce γH2AX nuclear foci. HeLa cells with or without treatment with 10 nM bortezomib for 8 h were stained for BRCA1 and γH2AX (a) or BRCA1 and 53BP1 nuclear foci (b). Treatment with 5 Gy ionizing radiation was used as a positive control. Note that bortezomib-treated cells do not show increased number of foci. (c and d) Quantification of the experiment exemplified in (a) and (b), respectively, showing the percentage of foci-positive nuclei. Five view fields containing 73–103 nuclei in total were quantified for each sample. Nuclei were considered positive if they contained over three nuclear foci. Error bars show S.E.M. Each treatment was performed in triplicates. (e) Treatment with bortezomib for 20 h does not induce γH2AX nuclear foci even in BRCA1-depleted HeLa cells (siBRCA1). Arrows show perinuclear γH2AX likely indicating induction of apoptosis in BRCA1-depleted cells treated with bortezomib. Arrowheads mark γH2AX-positive nuclear foci. Scale bars=10 μm
