Figure 3.

Veliparib modifies the SASP in irradiated B16SIY tumor cells. (a) Kinetics of IFN-β, CCL5, and CXCL11 expression in B16SIY tumor cells treated with veliparib+IR correlated with the expression of the senescence marker p21. At day 7, once cells had entered senescence, gene expression of p21 (^†P = 0.016), IFN-β (*P = 0.011), CCL5 (^‡P = 0.037), and CXCL11 (§P = 0.012) was significantly upregulated compared to 24 hours after IR. (b,c) Elevated expression of IFN-β (*P = 0.005) and chemokines such as CXCL11 (*P = 0.006) and decreased expression of IL-6 (P = 0.010) were observed in B16SIY tumor cells treated by veliparib+IR compared to IR alone. (d) Expression of cytokines in large senescent B16SIY cells versus small non-senescent cells sorted at day 7 following veliparib+IR treatment. A significant increase in IFN-β (*P = 0.015) was observed. IFN, interferon; IL, interleukin; IR, ionizing radiation; SASP, senescence-associated secretory phenotype.