Figure 2: DR protects mice from DEN-induced HCC.

(a) Representative macroscopic images and HE-stained liver sections of mice from different groups at 32 weeks of age [scale bar, 1 cm, 100 μm (100×), 20 μm (400×)]. (b) Tumor incidence in DEN and DEN+DR group, statistical analysis was conducted using the fisher exact test (n = 13). (c) Numbers of macroscopically detectable nodules on the liver surface of mice in each group (n = 12 to 13), *P < 0.001. (d,e) The maximal diameters and accumulated diameters of tumors per mouse were shown (n = 13), *P < 0.001. The diameters of nodules in each mouse were assessed by either vernier caliper for macorscopic nodules at liver surface or calibrated software for inner nodules by histological observation. (f) Percentage of mice with foci, hyperplasia, HCA and HCC, comparison between DEN and DEN+DR group was performed with the Mann-Whitney U tests (n = 13), *P < 0.01. Two 4-mm H&E-stained sections per liver were scored, the pathologic grade for each mouse was predicated by the most aggressive tumor in the fields. (g) Detection of hepatocytes with DNA damage by γH2AX immunostaining (Scale bar, 50 μm). (h) Quantification of γH2AX immunostaining, data from five 200× fields per liver were shown as the mean ± SEM (n = 3), *P < 0.05. (i) Representive electron microscopic images of the livers. Samples from DEN and DEN+DR groups were collected from macroscopic nodules at liver surface (n = 3), and the photographs were selected from more than ten coincident fields and shown at their indicated magnifications [(Scale bar, 2 μm (1, 3, 4), 5 μm (2), 1 μm (5, 6, 7, 8)].