Figure 5: Nonhomologous end joining (NHEJ) and homologous recombination (HR) transcriptional, protein, and functional repair responses to 25 μM VP16 with passage. qPCR evaluation of (a) NHEJ and (b) HR associated mRNA expression following exposure of MSCs to VP16 for 24 hours followed by 0 or 48 hours of recovery in fresh medium. Fold changes are indicated relative to untreated controls. (c) Western analysis of Rad51 and XRCC3 after VP16 exposure with passage. “Untr” indicates untreated cells. “0,” “6,” or “48” indicates recovery time (in hours) following 24 hours of exposure to 25uM VP16. (d) NHEJ and HR plasmid reporter assays for Passage 6, 9, and 12 MSCs exposed to VP16 or medium only control for 24 hours. (e) Western analysis of Rad51 in untreated MSCs with passage. # indicates significant change relative to untreated control; represents significant change relative to indicated group, One-Way ANOVA with Holm-Sidak Post Hoc test; -value < 0.05.