Fig. 7.

HR proficiency is associated with replication stress suppression and cell viability. a Western blot showing RAD51 knockdown in BRCA2 ^∆Ex3-4/– cells stably expressing BRCA2 WT or BRCA2 SE. NT, non targeting siRNA. b HR analysis. Cells expressing RAD51 siRNAs were infected with I-SceI-expressing lentivirus and the percent GFP+ cells was analyzed by an unpaired two-tailed t-test. n ≥ 3. c Cells expressing RAD51 siRNAs were analyzed for fork protection in the presence of HU. Median CldU/IdU tract length ratios are indicated in the graph (red bars). Graphs represent the pooled results of >300 fibers per genotype from at least three independent experiments, analyzed by a two-tailed Mann–Whitney test. d Cells expressing RAD51 siRNAs were released for 22 h from serum starvation to increase mitotic cells, incubated with EdU 1 h, and then analyzed for mitotic DNA synthesis. Early mitotic cells, defined as being in prophase, prometaphase, or metaphase, were analyzed for EdU foci that co-localize with FANCD2 foci pairs. The percent early mitotic cells containing EdU foci were analyzed by an unpaired two-tailed t-test. n = 3. e HU-induced 53BP1 nuclear body formation analysis, as in Fig. 4d, using cells expressing RAD51 siRNAs. Statistical analysis was by an unpaired two-tailed t-test. n ≥ 4. f RAD51 depletion in BRCA2 ^∆Ex3-4/– cells stably expressing BRCA2 WT or BRCA2 SE leads to a reduction in clonogenic survival. g HU-induced 53BP1 nuclear body formation analysis, as in Fig. 4d, using cells transfected with RAD51 siRNAs. Statistical analysis was by an unpaired two-tailed t-test. n = 4. Error bars s.d. ns, not significant; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001