Figure 4. RelA deficiency compromises OIS.

(A) Ratio of SA-β-Gal–positive mPanIN cells to the total number of mPanIN cells in low-grade mPanIN (LG mPanIN) in Kras (6 mice) and Kras RelA (5 mice) was counted per ×200 optical field (high-power field, HPF). Mean ± SD; n ≥ 50; ***P < 0.0001 by Mann-Whitney test; n, number of HPFs. (B) Detection of senescence in pancreatic cryosections from Kras and Kras RelA mice using SA-β-Gal as a marker. Scale bars: 20 μm. Representative images are shown. (C) Real-time PCR expression analysis of indicated genes in pancreatic lysates from Kras (n = 3) and Kras RelA (n = 3) mice. Error bars are shown as SD. Results are the average of 3 independent experiments and are presented as mean ± SD; *P < 0.05, **P < 0.005 by unpaired t test; n, number of mice. (D) Pancreatic extracts were collected from Kras and Kras RelA genotypes and analyzed by immunoblot analysis using antibodies against DCR2, p53, p16, or p19. β-Actin served as loading control. (E) Immunohistological analysis for DCR2, p53, p21, or p19 in Kras (n = 3) and Kras RelA (n = 3) pancreata. Scale bars: 20 μm. Insets denote single-positive cells. Representative images are shown. Quantification of DCR2, p53, p21, and p19 positivity in PanIN cells shown at the bottom. Results are presented as mean ± SD; *P < 0.05, **P < 0.005, ***P < 0.0005 by unpaired t test; n, number of mice. (F) SASP gene set enrichment analysis of pancreatic RNA from Kras (n = 2) and Kras RelA (n = 2) mice. n, number of mice.