Fig. 4
Treatment of mice with NMH maintains genomic integrity. Expression of mutated Kras in hematopoietic cells was induced in a–c double transgenic mice (LSL-KrasG12D × Mx1-Cre; M-KrasG12D) and d triple transgenic mice (Nox2−/−, LSL-KrasG12D, and Mx1-Cre; Nox2−/− M-KrasG12D) by pIpC injections. Mice were treated with NMH (250 μg/mouse; red) or NaCl (CON; blue) i.p. thrice weekly for 5 weeks. For M-KrasG12D mice, peripheral blood samples collected after 3 and 5 weeks (w3, w5) were analyzed for a intracellular ROS levels in CD11b+ cells by use of DCFDA staining (n = 5–7), b oxidized DNA by measurement of 8-OHdG expression in myeloid cells (n = 7–8), and c double-stranded DNA breaks reflected by the expression of gamma-H2AX in myeloid cells (n = 7–8 for each week and each group). In a–c, the stainings for DCFDA, 8-OHdG, and gamma-H2AX were normalized against staining of myeloid cells in blood of KrasWT mice. The increases in staining levels between w3–w5 were analyzed by Student's paired t test, whereas differences between control and NMH-treated samples were analyzed by Student's t test. d For Nox2−/− M-KrasG12D mice, peripheral blood samples were collected 5 weeks after pIpC and analyzed for intracellular ROS levels in CD11b+ cells by use of DCFDA (n = 5 for controls, n = 4 for NMH-treated mice). Peripheral blood collected 5 weeks after pIpC from M-KrasG12D mice (n = 5) was analyzed in parallel, and the stainings were normalized against DCFDA staining of myeloid cells in blood of Nox2−/−KrasWT mice. Statistics by Student's t test. *p < 0.05, **p < 0.01, ***p < 0.001
